///////////////////////////////////////////////////////////////////////////
// Name:        src/generic/grid.cpp
// Purpose:     wxGrid and related classes
// Author:      Michael Bedward (based on code by Julian Smart, Robin Dunn)
// Modified by: Robin Dunn, Vadim Zeitlin, Santiago Palacios
// Created:     1/08/1999
// Copyright:   (c) Michael Bedward (mbedward@ozemail.com.au)
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

/*
    TODO:

    - Make Begin/EndBatch() the same as the generic Freeze/Thaw()
    - Review the column reordering code, it's a mess.
 */

// For compilers that support precompilation, includes "wx/wx.h".
#include "wx/wxprec.h"


#if wxUSE_GRID

#include "wx/grid.h"

#ifndef WX_PRECOMP
    #include "wx/utils.h"
    #include "wx/dcclient.h"
    #include "wx/settings.h"
    #include "wx/log.h"
    #include "wx/textctrl.h"
    #include "wx/checkbox.h"
    #include "wx/combobox.h"
    #include "wx/valtext.h"
    #include "wx/intl.h"
    #include "wx/math.h"
    #include "wx/listbox.h"
#endif

#include "wx/dcbuffer.h"
#include "wx/dcgraph.h"
#include "wx/graphics.h"
#include "wx/textfile.h"
#include "wx/spinctrl.h"
#include "wx/tokenzr.h"
#include "wx/renderer.h"
#include "wx/headerctrl.h"
#include "wx/scopeguard.h"

#if wxUSE_CLIPBOARD
    #include "wx/clipbrd.h"
#endif // wxUSE_CLIPBOARD

#include "wx/generic/gridsel.h"
#include "wx/generic/gridctrl.h"
#include "wx/generic/grideditors.h"
#include "wx/generic/private/grid.h"

const char wxGridNameStr[] = "grid";

// Required for wxIs... functions
#include <ctype.h>

// ----------------------------------------------------------------------------
// globals
// ----------------------------------------------------------------------------

namespace
{

//#define DEBUG_ATTR_CACHE
#ifdef DEBUG_ATTR_CACHE
    static size_t gs_nAttrCacheHits = 0;
    static size_t gs_nAttrCacheMisses = 0;
#endif

// this struct simply combines together the default header renderers
//
// as the renderers ctors are trivial, there is no problem with making them
// globals
struct DefaultHeaderRenderers
{
    wxGridColumnHeaderRendererDefault colRenderer;
    wxGridRowHeaderRendererDefault rowRenderer;
    wxGridCornerHeaderRendererDefault cornerRenderer;
} gs_defaultHeaderRenderers;

} // anonymous namespace

// ----------------------------------------------------------------------------
// constants
// ----------------------------------------------------------------------------

wxGridCellCoords wxGridNoCellCoords( -1, -1 );
wxGridBlockCoords wxGridNoBlockCoords( -1, -1, -1, -1 );
wxRect wxGridNoCellRect( -1, -1, -1, -1 );

namespace
{

// scroll line size
const size_t GRID_SCROLL_LINE_X = 15;
const size_t GRID_SCROLL_LINE_Y = GRID_SCROLL_LINE_X;

// the minimal distance in pixels the mouse needs to move to start a drag
// operation
const int DRAG_SENSITIVITY = 3;

// the space between the cell edge and the checkbox mark
const int GRID_CELL_CHECKBOX_MARGIN = 2;

// the margin between a cell vertical line and a cell text
const int GRID_TEXT_MARGIN = 1;

} // anonymous namespace

// ----------------------------------------------------------------------------
// events
// ----------------------------------------------------------------------------

wxDEFINE_EVENT( wxEVT_GRID_CELL_LEFT_CLICK, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_CELL_RIGHT_CLICK, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_CELL_LEFT_DCLICK, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_CELL_RIGHT_DCLICK, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_CELL_BEGIN_DRAG, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_LABEL_LEFT_CLICK, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_LABEL_RIGHT_CLICK, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_LABEL_LEFT_DCLICK, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_LABEL_RIGHT_DCLICK, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_ROW_SIZE, wxGridSizeEvent );
wxDEFINE_EVENT( wxEVT_GRID_ROW_AUTO_SIZE, wxGridSizeEvent );
wxDEFINE_EVENT( wxEVT_GRID_COL_SIZE, wxGridSizeEvent );
wxDEFINE_EVENT( wxEVT_GRID_COL_AUTO_SIZE, wxGridSizeEvent );
wxDEFINE_EVENT( wxEVT_GRID_ROW_LABEL_SIZE, wxGridSizeEvent);
wxDEFINE_EVENT( wxEVT_GRID_COL_LABEL_SIZE, wxGridSizeEvent);
wxDEFINE_EVENT( wxEVT_GRID_ROW_MOVE, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_COL_MOVE, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_COL_SORT, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_RANGE_SELECTING, wxGridRangeSelectEvent );
wxDEFINE_EVENT( wxEVT_GRID_RANGE_SELECTED, wxGridRangeSelectEvent );
wxDEFINE_EVENT( wxEVT_GRID_CELL_CHANGING, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_CELL_CHANGED, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_SELECT_CELL, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_EDITOR_SHOWN, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_EDITOR_HIDDEN, wxGridEvent );
wxDEFINE_EVENT( wxEVT_GRID_EDITOR_CREATED, wxGridEditorCreatedEvent );
wxDEFINE_EVENT( wxEVT_GRID_TABBING, wxGridEvent );

// ============================================================================
// implementation
// ============================================================================

namespace
{

// Helper function for consistent cell span determination based on cell size.
wxGrid::CellSpan GetCellSpan(int numRows, int numCols)
{
    if ( numRows == 1 && numCols == 1 )
        return wxGrid::CellSpan_None; // just a normal cell

    if ( numRows < 0 || numCols < 0 )
        return wxGrid::CellSpan_Inside; // covered by a multi-span cell

    // this cell spans multiple cells to its right/bottom
    return wxGrid::CellSpan_Main;
}

} // anonymous namespace

wxIMPLEMENT_ABSTRACT_CLASS(wxGridCellEditorEvtHandler, wxEvtHandler);

wxBEGIN_EVENT_TABLE( wxGridCellEditorEvtHandler, wxEvtHandler )
    EVT_KILL_FOCUS( wxGridCellEditorEvtHandler::OnKillFocus )
    EVT_KEY_DOWN( wxGridCellEditorEvtHandler::OnKeyDown )
    EVT_CHAR( wxGridCellEditorEvtHandler::OnChar )
wxEND_EVENT_TABLE()

wxBEGIN_EVENT_TABLE(wxGridHeaderCtrl, wxHeaderCtrl)
    EVT_HEADER_CLICK(wxID_ANY, wxGridHeaderCtrl::OnClick)
    EVT_HEADER_DCLICK(wxID_ANY, wxGridHeaderCtrl::OnDoubleClick)
    EVT_HEADER_RIGHT_CLICK(wxID_ANY, wxGridHeaderCtrl::OnRightClick)

    EVT_HEADER_BEGIN_RESIZE(wxID_ANY, wxGridHeaderCtrl::OnBeginResize)
    EVT_HEADER_RESIZING(wxID_ANY, wxGridHeaderCtrl::OnResizing)
    EVT_HEADER_END_RESIZE(wxID_ANY, wxGridHeaderCtrl::OnEndResize)

    EVT_HEADER_BEGIN_REORDER(wxID_ANY, wxGridHeaderCtrl::OnBeginReorder)
    EVT_HEADER_END_REORDER(wxID_ANY, wxGridHeaderCtrl::OnEndReorder)
wxEND_EVENT_TABLE()

wxGridOperations& wxGridRowOperations::Dual() const
{
    static wxGridColumnOperations s_colOper;

    return s_colOper;
}

wxGridOperations& wxGridColumnOperations::Dual() const
{
    static wxGridRowOperations s_rowOper;

    return s_rowOper;
}

int wxGridRowOperations::GetNumberOfLines(const wxGrid *grid, wxGridWindow *gridWindow) const
{
    if ( !gridWindow )
        return grid->GetNumberRows();

    if ( gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenRow )
        return grid->GetNumberFrozenRows();

    return grid->GetNumberRows() - grid->GetNumberFrozenRows();
}

int wxGridColumnOperations::GetNumberOfLines(const wxGrid *grid, wxGridWindow *gridWindow) const
{
    if ( !gridWindow )
        return grid->GetNumberCols();

    if ( gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenCol )
        return grid->GetNumberFrozenCols();

    return grid->GetNumberCols() - grid->GetNumberFrozenCols();
}

int wxGridRowOperations::GetFirstLine(const wxGrid *grid, wxGridWindow *gridWindow) const
{
    if ( !gridWindow || gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenRow )
        return 0;

    return grid->GetNumberFrozenRows();
}

int wxGridColumnOperations::GetFirstLine(const wxGrid *grid, wxGridWindow *gridWindow) const
{
    if ( !gridWindow || gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenCol )
        return 0;

    return grid->GetNumberFrozenCols();
}

void wxGridOperations::PrepareDCForLabels(wxGrid *grid, wxDC &dc) const
{
    // The grid can be scrolled in both directions and so grid->DoPrepareDC
    // could offset the device context in both directions.
    // For row and col labels, we want only one direction and so
    // we reset the other direction to the original, unscrolled value.
    wxPoint dcOriginBefore = dc.GetDeviceOrigin();
    grid->DoPrepareDC(dc);
    wxPoint dcOrigin = dc.GetDeviceOrigin();

    if ( GetOrientation() == wxVERTICAL )
        dcOrigin.x = dcOriginBefore.x;
    else if ( GetOrientation() == wxHORIZONTAL )
        dcOrigin.y = dcOriginBefore.y;

    dc.SetDeviceOrigin(dcOrigin.x, dcOrigin.y);
}

// ----------------------------------------------------------------------------
// wxGridCellWorker is an (almost) empty common base class for
// wxGridCellRenderer and wxGridCellEditor managing ref counting
// ----------------------------------------------------------------------------

wxGridCellWorker::wxGridCellWorker(const wxGridCellWorker& other)
    : wxRefCounter()
{
    CopyClientDataContainer(other);
}

void wxGridCellWorker::SetParameters(const wxString& WXUNUSED(params))
{
    // nothing to do
}

wxGridCellWorker::~wxGridCellWorker()
{
}

// ----------------------------------------------------------------------------
// wxGridCellRenderer
// ----------------------------------------------------------------------------

wxSize
wxGridCellRenderer::GetPreferredSize(wxGrid& WXUNUSED(grid),
                                     wxGridCellAttr& WXUNUSED(attr),
                                     wxReadOnlyDC& WXUNUSED(dc),
                                     int WXUNUSED(row), int WXUNUSED(col))
{
    wxFAIL_MSG("Must be overridden if GetBestSize() isn't.");
    return wxSize();
}

wxSize wxGridCellRenderer::GetBestSize(wxGrid& grid,
                                       wxGridCellAttr& attr,
                                       wxDC& dc,
                                       int row, int col)
{
    return GetPreferredSize(grid, attr, dc, row, col);
}

int wxGridCellRenderer::GetBestHeight(wxGrid& grid,
                                      wxGridCellAttr& attr,
                                      wxDC& dc,
                                      int row, int col,
                                      int WXUNUSED(width))
{
    return GetBestSize(grid, attr, dc, row, col).GetHeight();
}

int wxGridCellRenderer::GetBestWidth(wxGrid& grid,
                                     wxGridCellAttr& attr,
                                     wxDC& dc,
                                     int row, int col,
                                     int WXUNUSED(height))
{
    return GetBestSize(grid, attr, dc, row, col).GetWidth();
}

wxSize wxGridCellRenderer::GetMaxBestSize(wxGrid& grid,
                                          wxGridCellAttr& attr,
                                          wxDC& dc)
{
    return GetMaxSize(grid, attr, dc);
}

// ----------------------------------------------------------------------------
// wxGridHeaderLabelsRenderer and related classes
// ----------------------------------------------------------------------------

void wxGridHeaderLabelsRenderer::DrawLabel(const wxGrid& grid,
                                         wxDC& dc,
                                         const wxString& value,
                                         const wxRect& rect,
                                         int horizAlign,
                                         int vertAlign,
                                         int textOrientation) const
{
    dc.SetBackgroundMode(wxBRUSHSTYLE_TRANSPARENT);
    dc.SetFont(grid.GetLabelFont());

    // Draw text in a different colour and with a shadow when the control
    // is disabled.
    //
    // Note that the colours used here are consistent with wxGenericStaticText
    // rather than our own wxGridCellStringRenderer::SetTextColoursAndFont()
    // because this results in a better disabled appearance for the default
    // bold font used for the labels.
    wxColour colText;
    if ( !grid.IsEnabled() )
    {
        colText = wxSystemSettings::GetColour(wxSYS_COLOUR_BTNHIGHLIGHT);
        dc.SetTextForeground(colText);

        wxRect rectShadow = rect;
        rectShadow.Offset(1, 1);
        grid.DrawTextRectangle(dc, value, rectShadow,
                               horizAlign, vertAlign, textOrientation);

        colText = wxSystemSettings::GetColour(wxSYS_COLOUR_BTNSHADOW);
    }
    else
    {
        colText = grid.GetLabelTextColour();
    }

    dc.SetTextForeground(colText);

    grid.DrawTextRectangle(dc, value, rect, horizAlign, vertAlign, textOrientation);
}

void wxGridHeaderLabelsRenderer::DrawHighlighted(const wxGrid& WXUNUSED(grid),
                                                 wxDC& WXUNUSED(dc),
                                                 wxRect& WXUNUSED(rect),
                                                 int WXUNUSED(rowOrCol),
                                                 int WXUNUSED(flags)) const
{
}

namespace wxPrivate
{
int GridRowLabelDrawBorderCommonDefault(const wxGrid& grid,
                                        wxDC& dc,
                                        wxRect& rect,
                                        const wxColour& colOne,
                                        const wxColour& colTwo)
{
    dc.SetPen(wxPen(colOne));
    dc.DrawLine(rect.GetRight(), rect.GetTop(),
                rect.GetRight(), rect.GetBottom());

    dc.DrawLine(rect.GetLeft(), rect.GetBottom(),
                rect.GetRight() + 1, rect.GetBottom());

    // Only draw the external borders when the containing control doesn't have
    // any border, otherwise they would compound with the outer border which
    // looks bad.
    int ofs = 0;
    if ( grid.GetBorder() == wxBORDER_NONE )
    {
        dc.DrawLine(rect.GetLeft(), rect.GetTop(),
                    rect.GetLeft(), rect.GetBottom());

        ofs = 1;
    }

    dc.SetPen(wxPen(colTwo));
    dc.DrawLine(rect.GetLeft() + ofs, rect.GetTop(),
                rect.GetLeft() + ofs, rect.GetBottom());
    dc.DrawLine(rect.GetLeft() + ofs, rect.GetTop(),
                rect.GetRight(), rect.GetTop());

    return ofs;
}

int GridColLabelDrawBorderCommonDefault(const wxGrid& grid,
                                        wxDC& dc,
                                        wxRect& rect,
                                        const wxColour& colOne,
                                        const wxColour& colTwo)
{
    dc.SetPen(wxPen(colOne));
    dc.DrawLine(rect.GetRight(), rect.GetTop(),
                rect.GetRight(), rect.GetBottom());
    dc.DrawLine(rect.GetLeft(), rect.GetBottom(),
                rect.GetRight() + 1, rect.GetBottom());

    // As above, don't draw the outer border if the control has its own one.
    int ofs = 0;
    if ( grid.GetBorder() == wxBORDER_NONE )
    {
        dc.DrawLine(rect.GetLeft(), rect.GetTop(),
                    rect.GetRight(), rect.GetTop());

        ofs = 1;
    }

    dc.SetPen(wxPen(colTwo));
    dc.DrawLine(rect.GetLeft(), rect.GetTop() + ofs,
                rect.GetLeft(), rect.GetBottom());
    dc.DrawLine(rect.GetLeft(), rect.GetTop() + ofs,
                rect.GetRight(), rect.GetTop() + ofs);

    return ofs;
}
} // wxPrivate namespace

void wxGridRowHeaderRendererDefault::DrawBorder(const wxGrid& grid,
                                                wxDC& dc,
                                                wxRect& rect) const
{
    int ofs = wxPrivate::GridRowLabelDrawBorderCommonDefault(
                grid, dc, rect,
                wxSystemSettings::GetColour(wxSYS_COLOUR_3DSHADOW),
                wxSystemSettings::GetColour(wxSYS_COLOUR_3DLIGHT));

    rect.Deflate(1 + ofs);
}

void wxGridRowHeaderRendererDefault::DrawHighlighted(const wxGrid& grid,
                                                     wxDC& dc,
                                                     wxRect& rect,
                                                     int row,
                                                     int flags) const
{
    const wxColour colBg = grid.GetSelectionBackground();

    dc.SetPen(*wxTRANSPARENT_PEN);
    dc.SetBrush(wxBrush(colBg.ChangeLightness(130)));
    dc.DrawRectangle(rect);

    int ofs;
    if ( !(flags & wxGridRowHeaderRendererDefault::Draw_Pressed) ) {
        ofs = wxPrivate::GridRowLabelDrawBorderCommonDefault(
            grid, dc, rect, colBg, colBg.ChangeLightness(170));

        if ( !grid.IsRowLabelHighlighted(row - 1) )
        {
            dc.SetPen(wxPen(colBg));
            dc.DrawLine(rect.GetLeft() + ofs - 1, rect.GetTop() - 1,
                rect.GetRight(), rect.GetTop() - 1);
        }
    }
    else
    {
        // swap colors for a 'pressed' look
        ofs = wxPrivate::GridRowLabelDrawBorderCommonDefault(
            grid, dc, rect, colBg.ChangeLightness(170), colBg);
    }

    rect.Deflate(1 + ofs);
}

void wxGridColumnHeaderRendererDefault::DrawBorder(const wxGrid& grid,
                                                   wxDC& dc,
                                                   wxRect& rect) const
{
    int ofs = wxPrivate::GridColLabelDrawBorderCommonDefault(
                grid, dc, rect,
                wxSystemSettings::GetColour(wxSYS_COLOUR_3DSHADOW),
                wxSystemSettings::GetColour(wxSYS_COLOUR_3DLIGHT));

    rect.Deflate(1 + ofs);
}

void wxGridColumnHeaderRendererDefault::DrawHighlighted(const wxGrid& grid,
                                                        wxDC& dc,
                                                        wxRect& rect,
                                                        int col,
                                                        int flags) const
{
    const wxColour colBg = grid.GetSelectionBackground();

    dc.SetPen(*wxTRANSPARENT_PEN);
    dc.SetBrush(wxBrush(colBg.ChangeLightness(130)));
    dc.DrawRectangle(rect);

    int ofs;
    if ( !(flags & wxGridRowHeaderRendererDefault::Draw_Pressed) ) {
        ofs = wxPrivate::GridColLabelDrawBorderCommonDefault(
            grid, dc, rect, colBg, colBg.ChangeLightness(170));

        if ( !grid.IsColLabelHighlighted(col - 1) )
        {
            dc.SetPen(wxPen(colBg));
            dc.DrawLine(rect.GetLeft() - 1, rect.GetTop() + ofs - 1,
                rect.GetLeft() - 1, rect.GetBottom());
        }
    }
    else
    {
        // swap colors for a 'pressed' look
        ofs = wxPrivate::GridColLabelDrawBorderCommonDefault(
            grid, dc, rect, colBg.ChangeLightness(170), colBg);
    }

    rect.Deflate(1 + ofs);
}

void wxGridCornerHeaderRendererDefault::DrawBorder(const wxGrid& grid,
                                                   wxDC& dc,
                                                   wxRect& rect) const
{
    dc.SetPen(wxPen(wxSystemSettings::GetColour(wxSYS_COLOUR_3DSHADOW)));
    dc.DrawLine(rect.GetRight() - 1, rect.GetBottom() - 1,
                rect.GetRight() - 1, rect.GetTop());
    dc.DrawLine(rect.GetRight() - 1, rect.GetBottom() - 1,
                rect.GetLeft(), rect.GetBottom() - 1);

    // As above, don't draw either of outer border if there is already a border
    // around the entire window.
    int ofs = 0;
    if ( grid.GetBorder() == wxBORDER_NONE )
    {
        dc.DrawLine(rect.GetLeft(), rect.GetTop(),
                    rect.GetRight(), rect.GetTop());
        dc.DrawLine(rect.GetLeft(), rect.GetTop(),
                    rect.GetLeft(), rect.GetBottom());

        ofs = 1;
    }

    dc.SetPen(wxPen(wxSystemSettings::GetColour(wxSYS_COLOUR_3DLIGHT)));
    dc.DrawLine(rect.GetLeft() + 1, rect.GetTop() + ofs,
                rect.GetRight() - 1, rect.GetTop() + ofs);
    dc.DrawLine(rect.GetLeft() + ofs, rect.GetTop() + ofs,
                rect.GetLeft() + ofs, rect.GetBottom() - 1);

    rect.Deflate(1 + ofs);
}

// ----------------------------------------------------------------------------
// wxGridCellAttr
// ----------------------------------------------------------------------------

void wxGridCellAttr::Init(wxGridCellAttr *attrDefault)
{
    m_isReadOnly = Unset;

    m_renderer = nullptr;
    m_editor = nullptr;

    m_attrkind = wxGridCellAttr::Cell;

    m_sizeRows = m_sizeCols = 1;

    SetDefAttr(attrDefault);
}

wxGridCellAttr *wxGridCellAttr::Clone() const
{
    wxGridCellAttr *attr = new wxGridCellAttr(m_defGridAttr);

    if ( HasTextColour() )
        attr->SetTextColour(GetTextColour());
    if ( HasBackgroundColour() )
        attr->SetBackgroundColour(GetBackgroundColour());
    if ( HasFont() )
        attr->SetFont(GetFont());
    if ( HasAlignment() )
        attr->SetAlignment(m_hAlign, m_vAlign);

    attr->SetSize( m_sizeRows, m_sizeCols );

    if ( m_renderer )
    {
        attr->SetRenderer(m_renderer);
        m_renderer->IncRef();
    }
    if ( m_editor )
    {
        attr->SetEditor(m_editor);
        m_editor->IncRef();
    }

    attr->CopyClientDataContainer(*this);

    if ( IsReadOnly() )
        attr->SetReadOnly();

    attr->m_fitMode = m_fitMode;
    attr->SetKind( m_attrkind );

    return attr;
}

void wxGridCellAttr::MergeWith(wxGridCellAttr *mergefrom)
{
    if ( !HasTextColour() && mergefrom->HasTextColour() )
        SetTextColour(mergefrom->GetTextColour());
    if ( !HasBackgroundColour() && mergefrom->HasBackgroundColour() )
        SetBackgroundColour(mergefrom->GetBackgroundColour());
    if ( !HasFont() && mergefrom->HasFont() )
        SetFont(mergefrom->GetFont());
    if ( !HasAlignment() && mergefrom->HasAlignment() )
    {
        int hAlign, vAlign;
        mergefrom->GetAlignment( &hAlign, &vAlign);
        SetAlignment(hAlign, vAlign);
    }
    if ( !HasSize() && mergefrom->HasSize() )
        mergefrom->GetSize( &m_sizeRows, &m_sizeCols );

    // Directly access member functions as GetRender/Editor don't just return
    // m_renderer/m_editor
    //
    // Maybe add support for merge of Render and Editor?
    if (!HasRenderer() && mergefrom->HasRenderer() )
    {
        m_renderer = mergefrom->m_renderer;
        m_renderer->IncRef();
    }
    if ( !HasEditor() && mergefrom->HasEditor() )
    {
        m_editor =  mergefrom->m_editor;
        m_editor->IncRef();
    }
    if ( !HasClientDataContainer() && mergefrom->HasClientDataContainer() )
    {
        CopyClientDataContainer(*mergefrom);
    }
    if ( !HasReadWriteMode() && mergefrom->HasReadWriteMode() )
        SetReadOnly(mergefrom->IsReadOnly());

    if (!HasOverflowMode() && mergefrom->HasOverflowMode() )
        SetOverflow(mergefrom->GetOverflow());

    SetDefAttr(mergefrom->m_defGridAttr);
}

void wxGridCellAttr::SetSize(int num_rows, int num_cols)
{
    // The size of a cell is normally 1,1

    // If this cell is larger (2,2) then this is the top left cell
    // the other cells that will be covered (lower right cells) must be
    // set to negative or zero values such that
    // row + num_rows of the covered cell points to the larger cell (this cell)
    // same goes for the col + num_cols.

    // Size of 0,0 is NOT valid, neither is <=0 and any positive value

    wxASSERT_MSG( (!((num_rows > 0) && (num_cols <= 0)) ||
                  !((num_rows <= 0) && (num_cols > 0)) ||
                  !((num_rows == 0) && (num_cols == 0))),
                  wxT("wxGridCellAttr::SetSize only takes two positive values or negative/zero values"));

    m_sizeRows = num_rows;
    m_sizeCols = num_cols;
}

const wxColour& wxGridCellAttr::GetTextColour() const
{
    if (HasTextColour())
    {
        return m_colText;
    }
    else if (m_defGridAttr && m_defGridAttr != this)
    {
        return m_defGridAttr->GetTextColour();
    }
    else
    {
        wxFAIL_MSG(wxT("Missing default cell attribute"));
        return wxNullColour;
    }
}

const wxColour& wxGridCellAttr::GetBackgroundColour() const
{
    if (HasBackgroundColour())
    {
        return m_colBack;
    }
    else if (m_defGridAttr && m_defGridAttr != this)
    {
        return m_defGridAttr->GetBackgroundColour();
    }
    else
    {
        wxFAIL_MSG(wxT("Missing default cell attribute"));
        return wxNullColour;
    }
}

const wxFont& wxGridCellAttr::GetFont() const
{
    if (HasFont())
    {
        return m_font;
    }
    else if (m_defGridAttr && m_defGridAttr != this)
    {
        return m_defGridAttr->GetFont();
    }
    else
    {
        wxFAIL_MSG(wxT("Missing default cell attribute"));
        return wxNullFont;
    }
}

void wxGridCellAttr::GetAlignment(int *hAlign, int *vAlign) const
{
    if (HasAlignment())
    {
        if ( hAlign )
            *hAlign = m_hAlign;
        if ( vAlign )
            *vAlign = m_vAlign;
    }
    else if (m_defGridAttr && m_defGridAttr != this)
    {
        m_defGridAttr->GetAlignment(hAlign, vAlign);
    }
    else
    {
        wxFAIL_MSG(wxT("Missing default cell attribute"));
    }
}

void wxGridCellAttr::GetNonDefaultAlignment(int *hAlign, int *vAlign) const
{
    // The logic here is tricky but necessary to handle all the cases: if we
    // have non-default alignment on input, we should only override it if this
    // attribute specifies a non-default alignment. However if the input
    // alignment is invalid, we need to always initialize it, using the default
    // attribute if necessary.

    // First of all, never dereference null pointer.
    if ( hAlign )
    {
        if ( this != m_defGridAttr && m_hAlign != wxALIGN_INVALID )
        {
            // This attribute has its own alignment, which should always
            // override the input alignment value.
            *hAlign = m_hAlign;
        }
        else if ( *hAlign == wxALIGN_INVALID )
        {
            // No input alignment specified, fill it with the default alignment
            // (note that we know that this attribute itself doesn't have any
            // specific alignment or is the same as the default one anyhow in
            // in this "else" branch, so we don't need to check m_hAlign here).
            *hAlign = m_defGridAttr->m_hAlign;
        }
        //else: Input alignment is valid but ours one isn't, nothing to do.
    }

    // This is exactly the same logic as above.
    if ( vAlign )
    {
        if ( this != m_defGridAttr && m_vAlign != wxALIGN_INVALID )
            *vAlign = m_vAlign;
        else if ( *vAlign == wxALIGN_INVALID )
            *vAlign = m_defGridAttr->m_vAlign;
    }
}

void wxGridCellAttr::GetSize( int *num_rows, int *num_cols ) const
{
    if ( num_rows )
        *num_rows = m_sizeRows;
    if ( num_cols )
        *num_cols = m_sizeCols;
}

wxGridFitMode wxGridCellAttr::GetFitMode() const
{
    if ( m_fitMode.IsSpecified() )
    {
        return m_fitMode;
    }
    else if (m_defGridAttr && m_defGridAttr != this)
    {
        return m_defGridAttr->GetFitMode();
    }
    else
    {
        wxFAIL_MSG(wxT("Missing default cell attribute"));
        return wxGridFitMode();
    }
}

bool wxGridCellAttr::CanOverflow() const
{
    // If overflow is disabled anyhow, we definitely can't overflow.
    if ( !GetOverflow() )
        return false;

    // But if it is enabled, we still don't use it for right-aligned or
    // centered cells because it's not really clear how it should work for
    // them.
    int hAlign = wxALIGN_LEFT;
    GetNonDefaultAlignment(&hAlign, nullptr);

    return hAlign == wxALIGN_LEFT;
}

// GetRenderer and GetEditor use a slightly different decision path about
// which attribute to use.  If a non-default attr object has one then it is
// used, otherwise the default editor or renderer is fetched from the grid and
// used.  It should be the default for the data type of the cell.  If it is
// null (because the table has a type that the grid does not have in its
// registry), then the grid's default editor or renderer is used.

wxGridCellRenderer* wxGridCellAttr::GetRenderer(const wxGrid* grid, int row, int col) const
{
    wxGridCellRenderer *renderer = nullptr;

    if ( m_renderer && this != m_defGridAttr )
    {
        // use the cells renderer if it has one
        renderer = m_renderer;
        renderer->IncRef();
    }
    else // no non-default cell renderer
    {
        // get default renderer for the data type
        if ( grid )
        {
            // GetDefaultRendererForCell() will do IncRef() for us
            renderer = grid->GetDefaultRendererForCell(row, col);
        }

        if ( renderer == nullptr )
        {
            if ( (m_defGridAttr != nullptr) && (m_defGridAttr != this) )
            {
                // if we still don't have one then use the grid default
                // (no need for IncRef() here either)
                renderer = m_defGridAttr->GetRenderer(nullptr, 0, 0);
            }
            else // default grid attr
            {
                // use m_renderer which we had decided not to use initially
                renderer = m_renderer;
                if ( renderer )
                    renderer->IncRef();
            }
        }
    }

    // we're supposed to always find something
    wxASSERT_MSG(renderer, wxT("Missing default cell renderer"));

    return renderer;
}

// same as above, except for s/renderer/editor/g
wxGridCellEditor* wxGridCellAttr::GetEditor(const wxGrid* grid, int row, int col) const
{
    wxGridCellEditor *editor = nullptr;

    if ( m_editor && this != m_defGridAttr )
    {
        // use the cells editor if it has one
        editor = m_editor;
        editor->IncRef();
    }
    else // no non default cell editor
    {
        // get default editor for the data type
        if ( grid )
        {
            // GetDefaultEditorForCell() will do IncRef() for us
            editor = grid->GetDefaultEditorForCell(row, col);
        }

        if ( editor == nullptr )
        {
            if ( (m_defGridAttr != nullptr) && (m_defGridAttr != this) )
            {
                // if we still don't have one then use the grid default
                // (no need for IncRef() here either)
                editor = m_defGridAttr->GetEditor(nullptr, 0, 0);
            }
            else // default grid attr
            {
                // use m_editor which we had decided not to use initially
                editor = m_editor;
                if ( editor )
                    editor->IncRef();
            }
        }
    }

    // we're supposed to always find something
    wxASSERT_MSG(editor, wxT("Missing default cell editor"));

    return editor;
}

// ----------------------------------------------------------------------------
// wxGridCellAttrData
// ----------------------------------------------------------------------------

namespace
{

// Helper functions to convert grid coords to a key for the attr map, and
// vice versa.

wxGridCoordsToAttrMap::key_type CoordsToKey(int row, int col)
{
    // Treat both row and col as unsigned to not cause havoc with (unsupported)
    // negative coords.
    return (static_cast<wxULongLong_t>(row) << 32) + static_cast<wxUint32>(col);
}

void KeyToCoords(wxGridCoordsToAttrMap::key_type key, int *pRow, int *pCol)
{
    *pRow = key >> 32;
    *pCol = key & wxUINT32_MAX;
}

} // anonymous namespace

wxGridCellAttrData::~wxGridCellAttrData()
{
    for ( wxGridCoordsToAttrMap::iterator it = m_attrs.begin();
          it != m_attrs.end();
          ++it )
    {
        it->second->DecRef();
    }

    m_attrs.clear();
}

void wxGridCellAttrData::SetAttr(wxGridCellAttr *attr, int row, int col)
{
    wxGridCoordsToAttrMap::iterator it = FindIndex(row, col);
    if ( it == m_attrs.end() )
    {
        if ( attr )
        {
            // add the attribute
            m_attrs[CoordsToKey(row, col)] = attr;
        }
        //else: nothing to do
    }
    else // we already have an attribute for this cell
    {
        // See note near DecRef() in wxGridRowOrColAttrData::SetAttr for why
        // this also works when old and new attribute are the same.
        it->second->DecRef();

        // Change or remove the attribute.
        if ( attr )
            it->second = attr;
        else
            m_attrs.erase(it);
    }
}

wxGridCellAttr *wxGridCellAttrData::GetAttr(int row, int col) const
{
    wxGridCellAttr *attr = nullptr;

    wxGridCoordsToAttrMap::iterator it = FindIndex(row, col);
    if ( it != m_attrs.end() )
    {
        attr = it->second;
        attr->IncRef();
    }

    return attr;
}

namespace
{

void UpdateCellAttrRowsOrCols(wxGridCoordsToAttrMap& attrs, int editPos,
                              int editRowCount, int editColCount)
{
    wxASSERT( !editRowCount || !editColCount );

    const bool isEditingRows = (editRowCount != 0);
    const int editCount = (isEditingRows ? editRowCount : editColCount);

    // Copy updated attributes to a new map instead of attempting to edit attrs
    // map in-place. This requires more memory but greatly simplifies the code
    // and any attempt with in-place editing would likely also require a lot
    // more attr lookups.
    // The updated copy will contain an attrs map with, if applicable: adjusted
    // coords and cell size, newly inserted attributes (for multicells), and
    // without now deleted attributes.
    wxGridCoordsToAttrMap newAttrs;

    for ( wxGridCoordsToAttrMap::iterator it = attrs.begin();
          it != attrs.end();
          ++it )
    {
        const wxGridCoordsToAttrMap::key_type oldCoords = it->first;
        wxGridCellAttr* cellAttr = it->second;

        int cellRows, cellCols;
        cellAttr->GetSize(&cellRows, &cellCols);

        int cellRow, cellCol;
        KeyToCoords(oldCoords, &cellRow, &cellCol);

        const int cellPos = isEditingRows ? cellRow : cellCol;

        if ( cellPos < editPos )
        {
            // This cell's coords aren't influenced by the editing, however
            // do adjust a multicell's main size, if needed.
            if ( GetCellSpan(cellRows, cellCols) == wxGrid::CellSpan_Main )
            {
                int mainSize = isEditingRows ? cellRows : cellCols;
                if ( cellPos + mainSize > editPos )
                {
                    // Multicell is within affected range:
                    // Adjust its size.

                    if ( editCount >= 0 )
                    {
                        mainSize += editCount;
                    }
                    else
                    {
                        // Reduce multicell size by number of deletions, but
                        // never more than the multicell's size minus one:
                        // cellPos (the main cell) is always less than editPos
                        // at this point, then with the below code a multicell
                        // with size 7 is at most reduced by:
                        // cellPos + 7 - (cellPos + 1) = 7 - 1 = 6.
                        mainSize -= wxMin(-editCount,
                                          cellPos + mainSize - editPos);
                        /*
                        The above was derived from:
                        first_del = edit
                        last_del = min(edit - count - 1, cell + size - 1)
                        size -= (last_del + 1 - first_del)

                        eliminating the 1's:

                        first_del = edit
                        last_del = min(edit - count, cell + size)
                        size -= (last_del - first_del)

                        reducing each by edit:

                        first_del = 0
                        last_del_plus_1 = min(0 - count, cell + size - edit)
                        size -= (last_del_plus_1 - 0)

                        after eliminating the 0's and substitution, leaving:

                        size -= min(-count, cell + size - edit)

                        E.g. with a multicell of size 7 and at 2 positions
                        after the main cell 100 positions are deleted then
                        the size will not (/can't) be reduced by 100 cells
                        but by:

                        cellPos + 7 - editPos =       # editPos = cellPos + 2
                        cellPos + 7 - (cellPos + 2) = # eliminate cellPos
                        7 - 2 =
                        5 cells, making the final size 7 - 5 = 2.
                        */
                    }

                    cellAttr->SetSize(isEditingRows ? mainSize : cellRows,
                                      isEditingRows ? cellCols : mainSize);
                }
            }

            // Set attribute at old/unmodified coords.
            newAttrs[oldCoords] = cellAttr;

            continue;
        }

        if ( editCount < 0 && cellPos < editPos - editCount )
        {
            // This row/col is deleted and the cell doesn't exist any longer:
            // Remove the attribute.
            cellAttr->DecRef();

            continue;
        }

        const wxGridCoordsToAttrMap::key_type newCoords
            = CoordsToKey(cellRow + editRowCount, cellCol + editColCount);

        if ( GetCellSpan(cellRows, cellCols) != wxGrid::CellSpan_Inside )
        {
            // Rows/cols inserted or deleted (and this cell still exists):
            // Adjust cell coords.
            newAttrs[newCoords] = cellAttr;

            // Nothing more to do: cell is not an inside cell of a multicell.
            continue;
        }

        // Handle inside cell's existence, coords, and size.

        const int mainPos = cellPos + (isEditingRows ? cellRows : cellCols);

        if ( editCount < 0
             && mainPos >= editPos && mainPos < editPos - editCount )
        {
            // On a position that still exists after deletion but main cell
            // of multicell is within deletion range so the multicell is gone:
            // Remove the attribute.
            cellAttr->DecRef();

            continue;
        }

        // Rows/cols inserted or deleted (and this inside cell still exists):
        // Adjust (inside) cell coords.
        newAttrs[newCoords] = cellAttr;

        if ( mainPos >= editPos )
        {
            // Nothing more to do: the multicell that this inside cell is part
            // of is moving its main cell as well so offsets to the main cell
            // don't change and there are no edits changing the multicell size.
            continue;
        }

        if ( editCount > 0 && cellPos == editPos )
        {
            // At an (old) position that is newly inserted: this is the only
            // opportunity to add required inside cells that point to
            // the main cell. E.g. with a 2x1 multicell that increases in size
            // there's only one inside cell that will be visited while there
            // can be multiple insertions.
            for ( int i = 0; i < editCount; ++i )
            {
                const int adjustRows = i * isEditingRows,
                          adjustCols = i * !isEditingRows;

                wxGridCellAttr* attr = new wxGridCellAttr;
                attr->SetSize(cellRows - adjustRows, cellCols - adjustCols);

                const int row = cellRow + adjustRows,
                          col = cellCol + adjustCols;
                newAttrs[CoordsToKey(row, col)] = attr;
            }
        }

        // Let this inside cell's size point to the main cell of the multicell.
        cellAttr->SetSize(cellRows - editRowCount, cellCols - editColCount);
    }

    attrs = newAttrs;
}

} // anonymous namespace

void wxGridCellAttrData::UpdateAttrRows( size_t pos, int numRows )
{
    UpdateCellAttrRowsOrCols(m_attrs, static_cast<int>(pos), numRows, 0);
}

void wxGridCellAttrData::UpdateAttrCols( size_t pos, int numCols )
{
    UpdateCellAttrRowsOrCols(m_attrs, static_cast<int>(pos), 0, numCols);
}

wxGridCoordsToAttrMap::iterator
wxGridCellAttrData::FindIndex(int row, int col) const
{
    return m_attrs.find(CoordsToKey(row, col));
}

// ----------------------------------------------------------------------------
// wxGridRowOrColAttrData
// ----------------------------------------------------------------------------

wxGridRowOrColAttrData::~wxGridRowOrColAttrData()
{
    size_t count = m_attrs.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        m_attrs[n]->DecRef();
    }
}

wxGridCellAttr *wxGridRowOrColAttrData::GetAttr(int rowOrCol) const
{
    wxGridCellAttr *attr = nullptr;

    int n = m_rowsOrCols.Index(rowOrCol);
    if ( n != wxNOT_FOUND )
    {
        attr = m_attrs[(size_t)n];
        attr->IncRef();
    }

    return attr;
}

void wxGridRowOrColAttrData::SetAttr(wxGridCellAttr *attr, int rowOrCol)
{
    int i = m_rowsOrCols.Index(rowOrCol);
    if ( i == wxNOT_FOUND )
    {
        if ( attr )
        {
            // store the new attribute, taking its ownership
            m_rowsOrCols.Add(rowOrCol);
            m_attrs.Add(attr);
        }
        // nothing to remove
    }
    else // we have an attribute for this row or column
    {
        size_t n = (size_t)i;

        // notice that this code works correctly even when the old attribute is
        // the same as the new one: as we own of it, we must call DecRef() on
        // it in any case and this won't result in destruction of the new
        // attribute if it's the same as old one because it must have ref count
        // of at least 2 to be passed to us while we keep a reference to it too
        m_attrs[n]->DecRef();

        if ( attr )
        {
            // replace the attribute with the new one
            m_attrs[n] = attr;
        }
        else // remove the attribute
        {
            m_rowsOrCols.RemoveAt(n);
            m_attrs.RemoveAt(n);
        }
    }
}

void wxGridRowOrColAttrData::UpdateAttrRowsOrCols( size_t pos, int numRowsOrCols )
{
    size_t count = m_attrs.GetCount();
    for ( size_t n = 0; n < count; n++ )
    {
        int & rowOrCol = m_rowsOrCols[n];
        if ( (size_t)rowOrCol >= pos )
        {
            if ( numRowsOrCols > 0 )
            {
                // If rows or cols inserted, increment row/col counter where necessary
                rowOrCol += numRowsOrCols;
            }
            else if ( numRowsOrCols < 0)
            {
                // If rows/cols deleted, either decrement row/col counter (if row/col still exists)
                if ((size_t)rowOrCol >= pos - numRowsOrCols)
                    rowOrCol += numRowsOrCols;
                else
                {
                    m_rowsOrCols.RemoveAt(n);
                    m_attrs[n]->DecRef();
                    m_attrs.RemoveAt(n);
                    n--;
                    count--;
                }
            }
        }
    }
}

// ----------------------------------------------------------------------------
// wxGridCellAttrProvider
// ----------------------------------------------------------------------------

wxGridCellAttrProvider::wxGridCellAttrProvider()
{
    m_data = nullptr;
}

wxGridCellAttrProvider::~wxGridCellAttrProvider()
{
    delete m_data;
}

void wxGridCellAttrProvider::InitData()
{
    m_data = new wxGridCellAttrProviderData;
}

wxGridCellAttr *wxGridCellAttrProvider::GetAttr(int row, int col,
                                                wxGridCellAttr::wxAttrKind  kind ) const
{
    wxGridCellAttr *attr = nullptr;
    if ( m_data )
    {
        switch (kind)
        {
            case (wxGridCellAttr::Any):
                // Get cached merge attributes.
                // Currently not used as no cache implemented as not mutable
                // attr = m_data->m_mergeAttr.GetAttr(row, col);
                if (!attr)
                {
                    // Basically implement old version.
                    // Also check merge cache, so we don't have to re-merge every time..
                    wxGridCellAttr *attrcell = m_data->m_cellAttrs.GetAttr(row, col);
                    wxGridCellAttr *attrrow = m_data->m_rowAttrs.GetAttr(row);
                    wxGridCellAttr *attrcol = m_data->m_colAttrs.GetAttr(col);

                    if ((attrcell != attrrow) && (attrrow != attrcol) && (attrcell != attrcol))
                    {
                        // Two or more are non null
                        attr = new wxGridCellAttr;
                        attr->SetKind(wxGridCellAttr::Merged);

                        // Order is important..
                        if (attrcell)
                        {
                            attr->MergeWith(attrcell);
                            attrcell->DecRef();
                        }
                        if (attrcol)
                        {
                            attr->MergeWith(attrcol);
                            attrcol->DecRef();
                        }
                        if (attrrow)
                        {
                            attr->MergeWith(attrrow);
                            attrrow->DecRef();
                        }

                        // store merge attr if cache implemented
                        //attr->IncRef();
                        //m_data->m_mergeAttr.SetAttr(attr, row, col);
                    }
                    else
                    {
                        // one or none is non null return it or null.
                        if (attrrow)
                            attr = attrrow;
                        if (attrcol)
                        {
                            if (attr)
                                attr->DecRef();
                            attr = attrcol;
                        }
                        if (attrcell)
                        {
                            if (attr)
                                attr->DecRef();
                            attr = attrcell;
                        }
                    }
                }
                break;

            case (wxGridCellAttr::Cell):
                attr = m_data->m_cellAttrs.GetAttr(row, col);
                break;

            case (wxGridCellAttr::Col):
                attr = m_data->m_colAttrs.GetAttr(col);
                break;

            case (wxGridCellAttr::Row):
                attr = m_data->m_rowAttrs.GetAttr(row);
                break;

            default:
                // unused as yet...
                // (wxGridCellAttr::Default):
                // (wxGridCellAttr::Merged):
                break;
        }
    }

    return attr;
}

void wxGridCellAttrProvider::SetAttr(wxGridCellAttr *attr,
                                     int row, int col)
{
    if ( !m_data )
        InitData();

    m_data->m_cellAttrs.SetAttr(attr, row, col);
}

void wxGridCellAttrProvider::SetRowAttr(wxGridCellAttr *attr, int row)
{
    if ( !m_data )
        InitData();

    m_data->m_rowAttrs.SetAttr(attr, row);
}

void wxGridCellAttrProvider::SetColAttr(wxGridCellAttr *attr, int col)
{
    if ( !m_data )
        InitData();

    m_data->m_colAttrs.SetAttr(attr, col);
}

void wxGridCellAttrProvider::UpdateAttrRows( size_t pos, int numRows )
{
    if ( m_data )
    {
        m_data->m_cellAttrs.UpdateAttrRows( pos, numRows );

        m_data->m_rowAttrs.UpdateAttrRowsOrCols( pos, numRows );
    }
}

void wxGridCellAttrProvider::UpdateAttrCols( size_t pos, int numCols )
{
    if ( m_data )
    {
        m_data->m_cellAttrs.UpdateAttrCols( pos, numCols );

        m_data->m_colAttrs.UpdateAttrRowsOrCols( pos, numCols );
    }
}

const wxGridColumnHeaderRenderer&
wxGridCellAttrProvider::GetColumnHeaderRenderer(int WXUNUSED(col))
{
    return gs_defaultHeaderRenderers.colRenderer;
}

const wxGridRowHeaderRenderer&
wxGridCellAttrProvider::GetRowHeaderRenderer(int WXUNUSED(row))
{
    return gs_defaultHeaderRenderers.rowRenderer;
}

const wxGridCornerHeaderRenderer& wxGridCellAttrProvider::GetCornerRenderer()
{
    return gs_defaultHeaderRenderers.cornerRenderer;
}

// ----------------------------------------------------------------------------
// wxGridBlockCoords
// ----------------------------------------------------------------------------

wxGridBlockDiffResult
wxGridBlockCoords::Difference(const wxGridBlockCoords& other,
                              int splitOrientation) const
{
    wxGridBlockDiffResult result;

    // Check whether the blocks intersect.
    if (!Intersects(other))
    {
        result.m_parts[0] = *this;
        return result;
    }

    // Split the block in up to 4 new parts, that don't contain the other
    // block, like this (for wxHORIZONTAL):
    // |-----------------------------|
    // |                             |
    // |           part[0]           |
    // |                             |
    // |-----------------------------|
    // | part[2] |  other  | part[3] |
    // |-----------------------------|
    // |                             |
    // |           part[1]           |
    // |                             |
    // |-----------------------------|
    // And for wxVERTICAL:
    // |-----------------------------|
    // |         |         |         |
    // |         | part[2] |         |
    // |         |         |         |
    // |         |---------|         |
    // | part[0] |  other  | part[1] |
    // |         |---------|         |
    // |         |         |         |
    // |         | part[3] |         |
    // |         |         |         |
    // |-----------------------------|

    if ( splitOrientation == wxHORIZONTAL )
    {
        // Part[0].
        if ( m_topRow < other.m_topRow )
            result.m_parts[0] =
                wxGridBlockCoords(m_topRow, m_leftCol,
                                  other.m_topRow - 1, m_rightCol);

        // Part[1].
        if ( m_bottomRow > other.m_bottomRow )
            result.m_parts[1] =
                wxGridBlockCoords(other.m_bottomRow + 1, m_leftCol,
                                  m_bottomRow, m_rightCol);

        const int maxTopRow = wxMax(m_topRow, other.m_topRow);
        const int minBottomRow = wxMin(m_bottomRow, other.m_bottomRow);

        // Part[2].
        if ( m_leftCol < other.m_leftCol )
            result.m_parts[2] =
                wxGridBlockCoords(maxTopRow, m_leftCol,
                                  minBottomRow, other.m_leftCol - 1);

        // Part[3].
        if ( m_rightCol > other.m_rightCol )
            result.m_parts[3] =
                wxGridBlockCoords(maxTopRow, other.m_rightCol + 1,
                                  minBottomRow, m_rightCol);
    }
    else // wxVERTICAL
    {
        // Part[0].
        if ( m_leftCol < other.m_leftCol )
            result.m_parts[0] =
                wxGridBlockCoords(m_topRow, m_leftCol,
                                  m_bottomRow, other.m_leftCol - 1);

        // Part[1].
        if ( m_rightCol > other.m_rightCol )
            result.m_parts[1] =
                wxGridBlockCoords(m_topRow, other.m_rightCol + 1,
                                  m_bottomRow, m_rightCol);

        const int maxLeftCol = wxMax(m_leftCol, other.m_leftCol);
        const int minRightCol = wxMin(m_rightCol, other.m_rightCol);

        // Part[2].
        if ( m_topRow < other.m_topRow )
            result.m_parts[2] =
                wxGridBlockCoords(m_topRow, maxLeftCol,
                                  other.m_topRow - 1, minRightCol);

        // Part[3].
        if ( m_bottomRow > other.m_bottomRow )
            result.m_parts[3] =
                wxGridBlockCoords(other.m_bottomRow + 1, maxLeftCol,
                                  m_bottomRow, minRightCol);
    }

    return result;
}

wxGridBlockDiffResult
wxGridBlockCoords::SymDifference(const wxGridBlockCoords& other) const
{
    wxGridBlockDiffResult result;

    // Check whether the blocks intersect.
    if ( !Intersects(other) )
    {
        result.m_parts[0] = *this;
        result.m_parts[1] = other;
        return result;
    }

    // Possible result blocks:
    // |------------------|
    // |                  |            minUpper->m_topRow
    // |      part[0]     |
    // |                  |            maxUpper->m_topRow - 1
    // |-----------------------------|
    // |         |         |         | maxUpper->m_topRow
    // | part[2] |    x    | part[3] |
    // |         |         |         | minLower->m_bottomRow
    // |-----------------------------|
    //           |                   | minLower->m_bottomRow + 1
    //           |      part[1]      |
    //           |                   | maxLower->m_bottomRow
    //           |-------------------|
    //
    // The x marks the intersection of the blocks, which is not a part
    // of the result.

    // Part[0].
    int maxUpperRow;
    if ( m_topRow != other.m_topRow )
    {
        const bool block1Min = m_topRow < other.m_topRow;
        const wxGridBlockCoords& minUpper = block1Min ? *this : other;
        const wxGridBlockCoords& maxUpper = block1Min ? other : *this;
        maxUpperRow = maxUpper.m_topRow;

        result.m_parts[0] = wxGridBlockCoords(minUpper.m_topRow,
                                           minUpper.m_leftCol,
                                           maxUpper.m_topRow - 1,
                                           minUpper.m_rightCol);
    }
    else
    {
        maxUpperRow = m_topRow;
    }

    // Part[1].
    int minLowerRow;
    if ( m_bottomRow != other.m_bottomRow )
    {
        const bool block1Min = m_bottomRow < other.m_bottomRow;
        const wxGridBlockCoords& minLower = block1Min ? *this : other;
        const wxGridBlockCoords& maxLower = block1Min ? other : *this;
        minLowerRow = minLower.m_bottomRow;

        result.m_parts[1] = wxGridBlockCoords(minLower.m_bottomRow + 1,
                                           maxLower.m_leftCol,
                                           maxLower.m_bottomRow,
                                           maxLower.m_rightCol);
    }
    else
    {
        minLowerRow = m_bottomRow;
    }

    // Part[2].
    if ( m_leftCol != other.m_leftCol )
    {
        result.m_parts[2] = wxGridBlockCoords(maxUpperRow,
                                           wxMin(m_leftCol,
                                                 other.m_leftCol),
                                           minLowerRow,
                                           wxMax(m_leftCol,
                                                 other.m_leftCol) - 1);
    }

    // Part[3].
    if ( m_rightCol != other.m_rightCol )
    {
        result.m_parts[3] = wxGridBlockCoords(maxUpperRow,
                                           wxMin(m_rightCol,
                                                 other.m_rightCol) + 1,
                                           minLowerRow,
                                           wxMax(m_rightCol,
                                                 other.m_rightCol));
    }

    return result;
}

// ----------------------------------------------------------------------------
// wxGridTableBase
// ----------------------------------------------------------------------------

wxIMPLEMENT_ABSTRACT_CLASS(wxGridTableBase, wxObject);

wxGridTableBase::wxGridTableBase()
{
    m_view = nullptr;
    m_attrProvider = nullptr;
}

wxGridTableBase::~wxGridTableBase()
{
    delete m_attrProvider;
}

void wxGridTableBase::SetAttrProvider(wxGridCellAttrProvider *attrProvider)
{
    delete m_attrProvider;
    m_attrProvider = attrProvider;
}

bool wxGridTableBase::CanHaveAttributes()
{
    if ( ! GetAttrProvider() )
    {
        // use the default attr provider by default
        SetAttrProvider(new wxGridCellAttrProvider);
    }

    return true;
}

wxGridCellAttr *wxGridTableBase::GetAttr(int row, int col, wxGridCellAttr::wxAttrKind  kind)
{
    if ( m_attrProvider )
        return m_attrProvider->GetAttr(row, col, kind);
    else
        return nullptr;
}

void wxGridTableBase::SetAttr(wxGridCellAttr* attr, int row, int col)
{
    if ( m_attrProvider )
    {
        if ( attr )
            attr->SetKind(wxGridCellAttr::Cell);
        m_attrProvider->SetAttr(attr, row, col);
    }
    else
    {
        // as we take ownership of the pointer and don't store it, we must
        // free it now
        wxSafeDecRef(attr);
    }
}

void wxGridTableBase::SetRowAttr(wxGridCellAttr *attr, int row)
{
    if ( m_attrProvider )
    {
        if ( attr )
            attr->SetKind(wxGridCellAttr::Row);
        m_attrProvider->SetRowAttr(attr, row);
    }
    else
    {
        // as we take ownership of the pointer and don't store it, we must
        // free it now
        wxSafeDecRef(attr);
    }
}

void wxGridTableBase::SetColAttr(wxGridCellAttr *attr, int col)
{
    if ( m_attrProvider )
    {
        if ( attr )
            attr->SetKind(wxGridCellAttr::Col);
        m_attrProvider->SetColAttr(attr, col);
    }
    else
    {
        // as we take ownership of the pointer and don't store it, we must
        // free it now
        wxSafeDecRef(attr);
    }
}

bool wxGridTableBase::InsertRows( size_t WXUNUSED(pos),
                                  size_t WXUNUSED(numRows) )
{
    wxFAIL_MSG( wxT("Called grid table class function InsertRows\nbut your derived table class does not override this function") );

    return false;
}

bool wxGridTableBase::AppendRows( size_t WXUNUSED(numRows) )
{
    wxFAIL_MSG( wxT("Called grid table class function AppendRows\nbut your derived table class does not override this function"));

    return false;
}

bool wxGridTableBase::DeleteRows( size_t WXUNUSED(pos),
                                  size_t WXUNUSED(numRows) )
{
    wxFAIL_MSG( wxT("Called grid table class function DeleteRows\nbut your derived table class does not override this function"));

    return false;
}

bool wxGridTableBase::InsertCols( size_t WXUNUSED(pos),
                                  size_t WXUNUSED(numCols) )
{
    wxFAIL_MSG( wxT("Called grid table class function InsertCols\nbut your derived table class does not override this function"));

    return false;
}

bool wxGridTableBase::AppendCols( size_t WXUNUSED(numCols) )
{
    wxFAIL_MSG(wxT("Called grid table class function AppendCols\nbut your derived table class does not override this function"));

    return false;
}

bool wxGridTableBase::DeleteCols( size_t WXUNUSED(pos),
                                  size_t WXUNUSED(numCols) )
{
    wxFAIL_MSG( wxT("Called grid table class function DeleteCols\nbut your derived table class does not override this function"));

    return false;
}

wxString wxGridTableBase::GetRowLabelValue( int row )
{
    wxString s;

    // RD: Starting the rows at zero confuses users,
    // no matter how much it makes sense to us geeks.
    s << row + 1;

    return s;
}

wxString wxGridTableBase::GetColLabelValue( int col )
{
    // default col labels are:
    //   cols 0 to 25   : A-Z
    //   cols 26 to 675 : AA-ZZ
    //   etc.

    wxString s;
    unsigned int i, n;
    for ( n = 1; ; n++ )
    {
        s += (wxChar) (wxT('A') + (wxChar)(col % 26));
        col = col / 26 - 1;
        if ( col < 0 )
            break;
    }

    // reverse the string...
    wxString s2;
    for ( i = 0; i < n; i++ )
    {
        s2 += s[n - i - 1];
    }

    return s2;
}

wxString wxGridTableBase::GetCornerLabelValue() const
{
    return wxString();
}

wxString wxGridTableBase::GetTypeName( int WXUNUSED(row), int WXUNUSED(col) )
{
    return wxGRID_VALUE_STRING;
}

bool wxGridTableBase::CanGetValueAs( int WXUNUSED(row), int WXUNUSED(col),
                                     const wxString& typeName )
{
    return typeName == wxGRID_VALUE_STRING;
}

bool wxGridTableBase::CanSetValueAs( int row, int col, const wxString& typeName )
{
    return CanGetValueAs(row, col, typeName);
}

long wxGridTableBase::GetValueAsLong( int WXUNUSED(row), int WXUNUSED(col) )
{
    return 0;
}

double wxGridTableBase::GetValueAsDouble( int WXUNUSED(row), int WXUNUSED(col) )
{
    return 0.0;
}

bool wxGridTableBase::GetValueAsBool( int WXUNUSED(row), int WXUNUSED(col) )
{
    return false;
}

void wxGridTableBase::SetValueAsLong( int WXUNUSED(row), int WXUNUSED(col),
                                      long WXUNUSED(value) )
{
}

void wxGridTableBase::SetValueAsDouble( int WXUNUSED(row), int WXUNUSED(col),
                                        double WXUNUSED(value) )
{
}

void wxGridTableBase::SetValueAsBool( int WXUNUSED(row), int WXUNUSED(col),
                                      bool WXUNUSED(value) )
{
}

void* wxGridTableBase::GetValueAsCustom( int WXUNUSED(row), int WXUNUSED(col),
                                         const wxString& WXUNUSED(typeName) )
{
    return nullptr;
}

void  wxGridTableBase::SetValueAsCustom( int WXUNUSED(row), int WXUNUSED(col),
                                         const wxString& WXUNUSED(typeName),
                                         void* WXUNUSED(value) )
{
}

//////////////////////////////////////////////////////////////////////
//
// Message class for the grid table to send requests and notifications
// to the grid view
//

wxGridTableMessage::wxGridTableMessage()
{
    m_table =  nullptr;
    m_id = -1;
    m_comInt1 = -1;
    m_comInt2 = -1;
}

wxGridTableMessage::wxGridTableMessage( wxGridTableBase *table, int id,
                                        int commandInt1, int commandInt2 )
{
    m_table = table;
    m_id = id;
    m_comInt1 = commandInt1;
    m_comInt2 = commandInt2;
}

//////////////////////////////////////////////////////////////////////
//
// A basic grid table for string data. An object of this class will
// created by wxGrid if you don't specify an alternative table class.
//

wxIMPLEMENT_DYNAMIC_CLASS(wxGridStringTable, wxGridTableBase);

wxGridStringTable::wxGridStringTable()
        : wxGridTableBase()
{
    m_numCols = 0;
}

wxGridStringTable::wxGridStringTable( int numRows, int numCols )
        : wxGridTableBase(),
          m_data(numRows, ColData(numCols))
{
    m_numCols = numCols;
}

wxString wxGridStringTable::GetValue( int row, int col )
{
    wxCHECK_MSG( (row >= 0 && row < GetNumberRows()) &&
                 (col >= 0 && col < GetNumberCols()),
                 wxEmptyString,
                 wxT("invalid row or column index in wxGridStringTable") );

    return m_data[row][col];
}

void wxGridStringTable::SetValue( int row, int col, const wxString& value )
{
    wxCHECK_RET( (row >= 0 && row < GetNumberRows()) &&
                 (col >= 0 && col < GetNumberCols()),
                 wxT("invalid row or column index in wxGridStringTable") );

    m_data[row][col] = value;
}

void wxGridStringTable::Clear()
{
    for ( auto& colData : m_data )
    {
        for ( auto& cell : colData )
            cell.clear();
    }
}

bool wxGridStringTable::InsertRows( size_t pos, size_t numRows )
{
    if ( pos >= m_data.size() )
    {
        return AppendRows( numRows );
    }

    m_data.insert( m_data.begin() + pos, numRows, ColData(m_numCols) );

    if ( GetView() )
    {
        GetView()->ProcessTableMessage( this,
                                wxGRIDTABLE_NOTIFY_ROWS_INSERTED,
                                pos,
                                numRows );
    }

    return true;
}

bool wxGridStringTable::AppendRows( size_t numRows )
{
    m_data.insert( m_data.end(), numRows, ColData(m_numCols) );

    if ( GetView() )
    {
        GetView()->ProcessTableMessage( this,
                                wxGRIDTABLE_NOTIFY_ROWS_APPENDED,
                                numRows );
    }

    return true;
}

bool wxGridStringTable::DeleteRows( size_t pos, size_t numRows )
{
    size_t curNumRows = m_data.size();

    if ( pos >= curNumRows )
    {
        wxFAIL_MSG( wxString::Format
                    (
                        wxT("Called wxGridStringTable::DeleteRows(pos=%lu, N=%lu)\nPos value is invalid for present table with %lu rows"),
                        (unsigned long)pos,
                        (unsigned long)numRows,
                        (unsigned long)curNumRows
                    ) );

        return false;
    }

    if ( numRows > curNumRows - pos )
    {
        numRows = curNumRows - pos;
    }

    if ( numRows >= curNumRows )
    {
        m_data.clear();
    }
    else
    {
        const auto first = m_data.begin() + pos;
        m_data.erase( first, first + numRows );
    }

    if ( GetView() )
    {
        GetView()->ProcessTableMessage( this,
                                wxGRIDTABLE_NOTIFY_ROWS_DELETED,
                                pos,
                                numRows );
    }

    return true;
}

bool wxGridStringTable::InsertCols( size_t pos, size_t numCols )
{
    if ( pos >= static_cast<size_t>(m_numCols) )
    {
        return AppendCols( numCols );
    }

    if ( !m_colLabels.IsEmpty() )
    {
        m_colLabels.Insert( wxEmptyString, pos, numCols );

        for ( size_t i = pos; i < pos + numCols; i++ )
            m_colLabels[i] = wxGridTableBase::GetColLabelValue( i );
    }

    for ( auto& colData: m_data )
    {
        colData.insert( colData.begin() + pos, numCols, {} );
    }

    m_numCols += numCols;

    if ( GetView() )
    {
        GetView()->ProcessTableMessage( this,
                                wxGRIDTABLE_NOTIFY_COLS_INSERTED,
                                pos,
                                numCols );
    }

    return true;
}

bool wxGridStringTable::AppendCols( size_t numCols )
{
    for ( auto& colData: m_data )
    {
        colData.insert( colData.end(), numCols, {} );
    }

    m_numCols += numCols;

    if ( GetView() )
    {
        GetView()->ProcessTableMessage( this,
                                wxGRIDTABLE_NOTIFY_COLS_APPENDED,
                                numCols );
    }

    return true;
}

bool wxGridStringTable::DeleteCols( size_t pos, size_t numCols )
{
    size_t curNumCols = m_numCols;

    if ( pos >= curNumCols )
    {
        wxFAIL_MSG( wxString::Format
                    (
                        wxT("Called wxGridStringTable::DeleteCols(pos=%lu, N=%lu)\nPos value is invalid for present table with %lu cols"),
                        (unsigned long)pos,
                        (unsigned long)numCols,
                        (unsigned long)curNumCols
                    ) );
        return false;
    }

    int colID;
    if ( GetView() )
        colID = GetView()->GetColAt( pos );
    else
        colID = pos;

    if ( numCols > curNumCols - colID )
    {
        numCols = curNumCols - colID;
    }

    if ( !m_colLabels.IsEmpty() )
    {
        // m_colLabels stores just as many elements as it needs, e.g. if only
        // the label of the first column had been set it would have only one
        // element and not numCols, so account for it
        int numRemaining = m_colLabels.size() - colID;
        if (numRemaining > 0)
            m_colLabels.RemoveAt( colID, wxMin(numCols, numRemaining) );
    }

    if ( numCols >= curNumCols )
    {
        for ( auto& colData: m_data )
        {
            colData.clear();
        }

        m_numCols = 0;
    }
    else // something will be left
    {
        for ( auto& colData: m_data )
        {
            const auto first = colData.begin() + colID;
            colData.erase( first, first + numCols );
        }

        m_numCols -= numCols;
    }

    if ( GetView() )
    {
        GetView()->ProcessTableMessage( this,
                                wxGRIDTABLE_NOTIFY_COLS_DELETED,
                                pos,
                                numCols );
    }

    return true;
}

wxString wxGridStringTable::GetRowLabelValue( int row )
{
    if ( row > (int)(m_rowLabels.GetCount()) - 1 )
    {
        // using default label
        //
        return wxGridTableBase::GetRowLabelValue( row );
    }
    else
    {
        return m_rowLabels[row];
    }
}

wxString wxGridStringTable::GetColLabelValue( int col )
{
    if ( col > (int)(m_colLabels.GetCount()) - 1 )
    {
        // using default label
        //
        return wxGridTableBase::GetColLabelValue( col );
    }
    else
    {
        return m_colLabels[col];
    }
}

void wxGridStringTable::SetRowLabelValue( int row, const wxString& value )
{
    if ( row > (int)(m_rowLabels.GetCount()) - 1 )
    {
        int n = m_rowLabels.GetCount();
        int i;

        for ( i = n; i <= row; i++ )
        {
            m_rowLabels.Add( wxGridTableBase::GetRowLabelValue(i) );
        }
    }

    m_rowLabels[row] = value;
}

void wxGridStringTable::SetColLabelValue( int col, const wxString& value )
{
    if ( col > (int)(m_colLabels.GetCount()) - 1 )
    {
        int n = m_colLabels.GetCount();
        int i;

        for ( i = n; i <= col; i++ )
        {
            m_colLabels.Add( wxGridTableBase::GetColLabelValue(i) );
        }
    }

    m_colLabels[col] = value;
}

void wxGridStringTable::SetCornerLabelValue( const wxString& value )
{
    m_cornerLabel = value;
}

wxString wxGridStringTable::GetCornerLabelValue() const
{
    return m_cornerLabel;
}

//////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////

wxBEGIN_EVENT_TABLE(wxGridSubwindow, wxWindow)
    EVT_MOUSE_CAPTURE_LOST(wxGridSubwindow::OnMouseCaptureLost)
wxEND_EVENT_TABLE()

void wxGridSubwindow::OnMouseCaptureLost(wxMouseCaptureLostEvent& WXUNUSED(event))
{
    m_owner->CancelMouseCapture();
}

wxBEGIN_EVENT_TABLE( wxGridRowLabelWindow, wxGridSubwindow )
    EVT_PAINT( wxGridRowLabelWindow::OnPaint )
    EVT_MOUSEWHEEL( wxGridRowLabelWindow::OnMouseWheel )
    EVT_MOUSE_EVENTS( wxGridRowLabelWindow::OnMouseEvent )
wxEND_EVENT_TABLE()

void wxGridRowLabelWindow::OnPaint( wxPaintEvent& WXUNUSED(event) )
{
    wxPaintDC dc(this);

    // NO - don't do this because it will set both the x and y origin
    // coords to match the parent scrolled window and we just want to
    // set the y coord  - MB
    //
    // m_owner->PrepareDC( dc );

    int x, y;
    wxGridWindow *gridWindow = IsFrozen() ? m_owner->m_frozenRowGridWin :
                                            m_owner->m_gridWin;
    m_owner->GetGridWindowOffset(gridWindow, x, y);
    m_owner->CalcGridWindowUnscrolledPosition( x, y, &x, &y, gridWindow );
    wxPoint pt = dc.GetDeviceOrigin();
    dc.SetDeviceOrigin( pt.x, pt.y-y );

    wxArrayInt rows = m_owner->CalcRowLabelsExposed( GetUpdateRegion(), gridWindow);
    m_owner->DrawRowLabels( dc, rows );

    if ( IsFrozen() )
        m_owner->DrawLabelFrozenBorder(dc, this, true);
}

void wxGridRowLabelWindow::OnMouseEvent( wxMouseEvent& event )
{
    m_owner->ProcessRowColLabelMouseEvent( wxGridRowOperations(), event, this );
}

void wxGridRowLabelWindow::OnMouseWheel( wxMouseEvent& event )
{
    if (!m_owner->ProcessWindowEvent( event ))
        event.Skip();
}

//////////////////////////////////////////////////////////////////////

wxBEGIN_EVENT_TABLE( wxGridColLabelWindow, wxGridSubwindow )
    EVT_PAINT( wxGridColLabelWindow::OnPaint )
    EVT_MOUSEWHEEL( wxGridColLabelWindow::OnMouseWheel )
    EVT_MOUSE_EVENTS( wxGridColLabelWindow::OnMouseEvent )
wxEND_EVENT_TABLE()

void wxGridColLabelWindow::OnPaint( wxPaintEvent& WXUNUSED(event) )
{
    wxPaintDC dc(this);

    // NO - don't do this because it will set both the x and y origin
    // coords to match the parent scrolled window and we just want to
    // set the x coord  - MB
    //
    // m_owner->PrepareDC( dc );

    // Column indices become invalid when the grid is empty, so avoid doing
    // anything at all in this case.
    if ( m_owner->GetNumberCols() == 0 )
        return;

    int x, y;
    wxGridWindow *gridWindow = IsFrozen() ? m_owner->m_frozenColGridWin :
                                            m_owner->m_gridWin;
    m_owner->GetGridWindowOffset(gridWindow, x, y);
    m_owner->CalcGridWindowUnscrolledPosition( x, y, &x, &y, gridWindow );
    wxPoint pt = dc.GetDeviceOrigin();
    dc.SetDeviceOrigin( pt.x-x, pt.y );

    wxArrayInt cols = m_owner->CalcColLabelsExposed( GetUpdateRegion(), gridWindow );
    m_owner->DrawColLabels( dc, cols );

    if ( IsFrozen() )
        m_owner->DrawLabelFrozenBorder(dc, this, false);
}

void wxGridColLabelWindow::OnMouseEvent( wxMouseEvent& event )
{
    m_owner->ProcessRowColLabelMouseEvent( wxGridColumnOperations(), event, this );
}

void wxGridColLabelWindow::OnMouseWheel( wxMouseEvent& event )
{
    if (!m_owner->ProcessWindowEvent( event ))
        event.Skip();
}

//////////////////////////////////////////////////////////////////////

wxBEGIN_EVENT_TABLE( wxGridCornerLabelWindow, wxGridSubwindow )
    EVT_MOUSEWHEEL( wxGridCornerLabelWindow::OnMouseWheel )
    EVT_MOUSE_EVENTS( wxGridCornerLabelWindow::OnMouseEvent )
    EVT_PAINT( wxGridCornerLabelWindow::OnPaint )
wxEND_EVENT_TABLE()

void wxGridCornerLabelWindow::OnPaint( wxPaintEvent& WXUNUSED(event) )
{
    wxPaintDC dc(this);

    m_owner->DrawCornerLabel(dc);
}

void wxGridCornerLabelWindow::OnMouseEvent( wxMouseEvent& event )
{
    m_owner->ProcessCornerLabelMouseEvent( event );
}

void wxGridCornerLabelWindow::OnMouseWheel( wxMouseEvent& event )
{
    if (!m_owner->ProcessWindowEvent(event))
        event.Skip();
}

//////////////////////////////////////////////////////////////////////

wxBEGIN_EVENT_TABLE( wxGridWindow, wxGridSubwindow )
    EVT_PAINT( wxGridWindow::OnPaint )
    EVT_MOUSEWHEEL( wxGridWindow::OnMouseWheel )
    EVT_MOUSE_EVENTS( wxGridWindow::OnMouseEvent )
    EVT_KEY_DOWN( wxGridWindow::OnKeyDown )
    EVT_KEY_UP( wxGridWindow::OnKeyUp )
    EVT_CHAR( wxGridWindow::OnChar )
    EVT_SET_FOCUS( wxGridWindow::OnFocus )
    EVT_KILL_FOCUS( wxGridWindow::OnFocus )
wxEND_EVENT_TABLE()

void wxGridWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
{
    wxAutoBufferedPaintDC dc( this );
    m_owner->PrepareDCFor( dc, this );
    wxRegion reg = GetUpdateRegion();

    wxGridCellCoordsVector dirtyCells = m_owner->CalcCellsExposed( reg , this );
    m_owner->DrawGridCellArea( dc, dirtyCells );

    m_owner->DrawGridSpace( dc, this );

    m_owner->DrawAllGridWindowLines( dc, reg, this );

    m_owner->DrawOverlaySelection( dc, this );

    if ( m_type != wxGridWindow::wxGridWindowNormal )
        m_owner->DrawFrozenBorder( dc, this );

    m_owner->DrawHighlight( dc, dirtyCells );
}

void wxGrid::Render( wxDC& dc,
                     const wxPoint& position,
                     const wxSize& size,
                     const wxGridCellCoords& topLeft,
                     const wxGridCellCoords& bottomRight,
                     int style )
{
    wxCHECK_RET( bottomRight.GetCol() < GetNumberCols(),
                 "Invalid right column" );
    wxCHECK_RET( bottomRight.GetRow() < GetNumberRows(),
                 "Invalid bottom row" );

    // store user settings and reset later

    // Don't show row/col highlight of the current cell when rendering
    const auto currentCellCoords = m_currentCellCoords;
    m_currentCellCoords = wxGridNoCellCoords;
    wxON_BLOCK_EXIT_SET(m_currentCellCoords, currentCellCoords);

    // remove grid selection, don't paint selection colour
    // unless we have wxGRID_DRAW_SELECTION
    wxGridSelection* selectionOrig = nullptr;
    if ( m_selection && !( style & wxGRID_DRAW_SELECTION ) )
    {
        // remove the selection temporarily, it will be restored below
        selectionOrig = m_selection;
        m_selection = nullptr;
    }

    // store user device origin
    wxCoord userOriginX, userOriginY;
    dc.GetDeviceOrigin( &userOriginX, &userOriginY );

    // store user scale
    double scaleUserX, scaleUserY;
    dc.GetUserScale( &scaleUserX, &scaleUserY );

    // set defaults if necessary
    wxGridCellCoords leftTop( topLeft ), rightBottom( bottomRight );
    if ( leftTop.GetCol() < 0 )
        leftTop.SetCol(0);
    if ( leftTop.GetRow() < 0 )
        leftTop.SetRow(0);
    if ( rightBottom.GetCol() < 0 )
        rightBottom.SetCol(GetNumberCols() - 1);
    if ( rightBottom.GetRow() < 0 )
        rightBottom.SetRow(GetNumberRows() - 1);

    // get grid offset, size and cell parameters
    wxPoint pointOffSet;
    wxSize sizeGrid;
    wxGridCellCoordsArray renderCells;
    wxArrayInt arrayCols;
    wxArrayInt arrayRows;

    GetRenderSizes( leftTop, rightBottom,
                    pointOffSet, sizeGrid,
                    renderCells,
                    arrayCols, arrayRows );

    // add headers/labels to dimensions
    if ( style & wxGRID_DRAW_ROWS_HEADER )
        sizeGrid.x += GetRowLabelSize();
    if ( style & wxGRID_DRAW_COLS_HEADER )
        sizeGrid.y += GetColLabelSize();

    // get render start position in logical units
    wxPoint positionRender = GetRenderPosition( dc, position );

    wxCoord originX = dc.LogicalToDeviceX( positionRender.x );
    wxCoord originY = dc.LogicalToDeviceY( positionRender.y );

    dc.SetDeviceOrigin( originX, originY );

    SetRenderScale( dc, positionRender, size, sizeGrid );

    // draw row headers at specified origin
    if ( GetRowLabelSize() > 0 && ( style & wxGRID_DRAW_ROWS_HEADER ) )
    {
        if ( style & wxGRID_DRAW_COLS_HEADER )
        {
            DrawCornerLabel( dc ); // do only if both col and row labels drawn
            originY += dc.LogicalToDeviceYRel( GetColLabelSize() );
        }

        originY -= dc.LogicalToDeviceYRel( pointOffSet.y );
        dc.SetDeviceOrigin( originX, originY );

        DrawRowLabels( dc, arrayRows );

        // reset for columns
        if ( style & wxGRID_DRAW_COLS_HEADER )
            originY -= dc.LogicalToDeviceYRel( GetColLabelSize() );

        originY += dc.LogicalToDeviceYRel( pointOffSet.y );
        // X offset so we don't overwrite row labels
        originX += dc.LogicalToDeviceXRel( GetRowLabelSize() );
    }

    // subtract col offset where startcol > 0
    originX -= dc.LogicalToDeviceXRel( pointOffSet.x );
    // no y offset for col labels, they are at the Y origin

    // draw column labels
    if ( style & wxGRID_DRAW_COLS_HEADER )
    {
        dc.SetDeviceOrigin( originX, originY );
        DrawColLabels( dc, arrayCols );
        // don't overwrite the labels, increment originY
        originY += dc.LogicalToDeviceYRel( GetColLabelSize() );
    }

    // set device origin to draw grid cells and lines
    originY -= dc.LogicalToDeviceYRel( pointOffSet.y );
    dc.SetDeviceOrigin( originX, originY );

    // draw cell area background
    dc.SetBrush( GetDefaultCellBackgroundColour() );
    dc.SetPen( *wxTRANSPARENT_PEN );
    // subtract headers from grid area dimensions
    wxSize sizeCells( sizeGrid );
    if ( style & wxGRID_DRAW_ROWS_HEADER )
        sizeCells.x -= GetRowLabelSize();
    if ( style & wxGRID_DRAW_COLS_HEADER )
        sizeCells.y -= GetColLabelSize();

    dc.DrawRectangle( pointOffSet, sizeCells );

    // draw cells
    {
        wxDCClipper clipper( dc, wxRect(pointOffSet, sizeCells) );
        DrawGridCellArea( dc, renderCells );
    }

    // draw grid lines
    if ( style & wxGRID_DRAW_CELL_LINES )
    {
        wxRegion regionClip( pointOffSet.x, pointOffSet.y,
                             sizeCells.x, sizeCells.y );

        DrawRangeGridLines(dc, regionClip, renderCells[0], renderCells.Last());
    }

    // draw render rectangle bounding lines
    DoRenderBox( dc, style,
                 pointOffSet, sizeCells,
                 leftTop, rightBottom );

    // draw selection overlay if any
    const wxRect renderExtent = wxRect(pointOffSet, sizeGrid);

    if ( UsesOverlaySelection() )
    {
        InvalidateOverlaySelection();

        // We only need the grid window at offset (0, 0) to pass to DrawOverlaySelection() below.

        wxGridWindow* gridWin;

        if ( m_frozenCornerGridWin )
            gridWin = m_frozenCornerGridWin;
        else if ( m_frozenColGridWin )
            gridWin = m_frozenColGridWin;
        else if ( m_frozenRowGridWin )
            gridWin = m_frozenRowGridWin;
        else
            gridWin = m_gridWin;

        DrawOverlaySelection( dc, gridWin, renderExtent );

        InvalidateOverlaySelection();
    }

    // draw frozen row/col borders if any
    if ( m_frozenColGridWin )
    {
        wxRect clip = renderExtent;
        clip.y -= GetColLabelSize();
        wxDCClipper clipper( dc, clip );
        DrawFrozenBorder( dc, m_frozenColGridWin, renderExtent );
    }

    if ( m_frozenRowGridWin )
    {
        wxRect clip = renderExtent;
        clip.x -= GetRowLabelSize();
        wxDCClipper clipper( dc, clip );
        DrawFrozenBorder( dc, m_frozenRowGridWin, renderExtent );
    }

    // restore user setings
    dc.SetDeviceOrigin( userOriginX, userOriginY );
    dc.SetUserScale( scaleUserX, scaleUserY );

    if ( selectionOrig )
    {
        m_selection = selectionOrig;
    }
}

void
wxGrid::SetRenderScale(wxDC& dc,
                       const wxPoint& pos, const wxSize& size,
                       const wxSize& sizeGrid )
{
    double scaleX, scaleY;
    wxSize sizeTemp;

    if ( size.GetWidth() != wxDefaultSize.GetWidth() ) // size.x was specified
        sizeTemp.SetWidth( size.GetWidth() );
    else
        sizeTemp.SetWidth( dc.DeviceToLogicalXRel( dc.GetSize().GetWidth() )
                           - pos.x );

    if ( size.GetHeight() != wxDefaultSize.GetHeight() ) // size.y was specified
        sizeTemp.SetHeight( size.GetHeight() );
    else
        sizeTemp.SetHeight( dc.DeviceToLogicalYRel( dc.GetSize().GetHeight() )
                            - pos.y );

    scaleX = (double)( (double) sizeTemp.GetWidth() / (double) sizeGrid.GetWidth() );
    scaleY = (double)( (double) sizeTemp.GetHeight() / (double) sizeGrid.GetHeight() );

    dc.SetUserScale( wxMin( scaleX, scaleY), wxMin( scaleX, scaleY ) );
}

// get grid rendered size, origin offset and fill cell arrays
void wxGrid::GetRenderSizes( const wxGridCellCoords& topLeft,
                             const wxGridCellCoords& bottomRight,
                             wxPoint& pointOffSet, wxSize& sizeGrid,
                             wxGridCellCoordsVector& renderCells,
                             wxArrayInt& arrayCols, wxArrayInt& arrayRows ) const
{
    pointOffSet.x = 0;
    pointOffSet.y = 0;
    sizeGrid.SetWidth( 0 );
    sizeGrid.SetHeight( 0 );

    int col, row;

    wxGridSizesInfo sizeinfo = GetColSizes();
    for ( col = 0; col <= bottomRight.GetCol(); col++ )
    {
        if ( col < topLeft.GetCol() )
        {
            pointOffSet.x += sizeinfo.GetSize( col );
        }
        else
        {
            for ( row = topLeft.GetRow(); row <= bottomRight.GetRow(); row++ )
            {
                renderCells.emplace_back( row, col );
                arrayRows.Add( row ); // column labels rendered in DrawColLabels
            }
            arrayCols.Add( col ); // row labels rendered in DrawRowLabels
            sizeGrid.x += sizeinfo.GetSize( col );
        }
    }

    sizeinfo = GetRowSizes();
    for ( row = 0; row <= bottomRight.GetRow(); row++ )
    {
        if ( row < topLeft.GetRow() )
            pointOffSet.y += sizeinfo.GetSize( row );
        else
            sizeGrid.y += sizeinfo.GetSize( row );
    }
}

// get render start position
// if position not specified use dc draw extents MaxX and MaxY
wxPoint wxGrid::GetRenderPosition( wxDC& dc, const wxPoint& position )
{
    wxPoint positionRender( position );

    if ( !positionRender.IsFullySpecified() )
    {
        if ( positionRender.x == wxDefaultPosition.x )
            positionRender.x = dc.MaxX();

        if ( positionRender.y == wxDefaultPosition.y )
            positionRender.y = dc.MaxY();
    }

    return positionRender;
}

// draw render rectangle bounding lines
// useful where there is multi cell row or col clipping and no cell border
void wxGrid::DoRenderBox( wxDC& dc, const int& style,
                          const wxPoint& pointOffSet,
                          const wxSize& sizeCells,
                          const wxGridCellCoords& topLeft,
                          const wxGridCellCoords& bottomRight )
{
    if ( !( style & wxGRID_DRAW_BOX_RECT ) )
        return;

    int bottom = pointOffSet.y + sizeCells.GetY(),
        right = pointOffSet.x + sizeCells.GetX() - 1;

    // horiz top line if we are not drawing column header/labels
    if ( !( style & wxGRID_DRAW_COLS_HEADER ) )
    {
        int left = pointOffSet.x;
        left += ( style & wxGRID_DRAW_COLS_HEADER )
                     ? - GetRowLabelSize() : 0;
        dc.SetPen( GetRowGridLinePen( topLeft.GetRow() ) );
        dc.DrawLine( left,
                     pointOffSet.y,
                     right,
                     pointOffSet.y );
    }

    // horiz bottom line
    dc.SetPen( GetRowGridLinePen( bottomRight.GetRow() ) );
    dc.DrawLine( pointOffSet.x, bottom - 1, right, bottom - 1 );

    // left vertical line if we are not drawing row header/labels
    if ( !( style & wxGRID_DRAW_ROWS_HEADER ) )
    {
        int top = pointOffSet.y;
        top += ( style & wxGRID_DRAW_COLS_HEADER )
                     ? - GetColLabelSize() : 0;
        dc.SetPen( GetColGridLinePen( topLeft.GetCol() ) );
        dc.DrawLine( pointOffSet.x -1,
                     top,
                     pointOffSet.x - 1,
                     bottom - 1 );
    }

    // right vertical line
    dc.SetPen( GetColGridLinePen( bottomRight.GetCol() ) );
    dc.DrawLine( right, pointOffSet.y, right, bottom - 1 );
}

void wxGridWindow::ScrollWindow( int dx, int dy, const wxRect *rect )
{
    m_owner->ScrollWindow(dx, dy, rect);
}

void wxGrid::ScrollWindow( int dx, int dy, const wxRect *rect )
{
    if ( UsesOverlaySelection() && IsSelection() )
    {
        wxRect r; // dummy renderExtent
        wxRect oldSel = m_selection->GetSelectionShape(r).GetBoundingBox();
        if ( !oldSel.IsEmpty() )
        {
            // Refresh the previous selection shape before invalidating it,
            // because otherwise some areas might not be updated while
            // drag-selecting the grid.
            RefreshRect(&oldSel);
        }

        m_selection->InvalidateSelectionShape();
    }

    // We must explicitly call wxWindow version to avoid infinite recursion as
    // wxGridWindow::ScrollWindow() calls this method back.
    m_gridWin->wxWindow::ScrollWindow( dx, dy, rect );

    if ( m_frozenColGridWin )
        m_frozenColGridWin->wxWindow::ScrollWindow( 0, dy, rect );
    if ( m_frozenRowGridWin )
        m_frozenRowGridWin->wxWindow::ScrollWindow( dx, 0, rect );

    m_rowLabelWin->ScrollWindow( 0, dy, rect );
    m_colLabelWin->ScrollWindow( dx, 0, rect );
}

void wxGridWindow::OnMouseEvent( wxMouseEvent& event )
{
    if (event.ButtonDown(wxMOUSE_BTN_LEFT) && FindFocus() != this)
        SetFocus();

    m_owner->ProcessGridCellMouseEvent( event, this );
}

void wxGridWindow::OnMouseWheel( wxMouseEvent& event )
{
    if (!m_owner->ProcessWindowEvent( event ))
        event.Skip();
}

// This seems to be required for wxX11/wxGTK otherwise the mouse
// cursor must be in the cell edit control to get key events
//
void wxGridWindow::OnKeyDown( wxKeyEvent& event )
{
    if ( !m_owner->ProcessWindowEvent( event ) )
        event.Skip();
}

void wxGridWindow::OnKeyUp( wxKeyEvent& event )
{
    if ( !m_owner->ProcessWindowEvent( event ) )
        event.Skip();
}

void wxGridWindow::OnChar( wxKeyEvent& event )
{
    if ( !m_owner->ProcessWindowEvent( event ) )
        event.Skip();
}

void wxGridWindow::OnFocus(wxFocusEvent& event)
{
    // and if we have any selection, it has to be repainted, because it
    // uses different colour when the grid is not focused:
    if ( m_owner->IsSelection() )
    {
        Refresh();
    }
    else
    {
        // NB: Note that this code is in "else" branch only because the other
        //     branch refreshes everything and so there's no point in calling
        //     Refresh() again, *not* because it should only be done if
        //     !IsSelection(). If the above code is ever optimized to refresh
        //     only selected area, this needs to be moved out of the "else"
        //     branch so that it's always executed.

        // current cell cursor {dis,re}appears on focus change:
        const wxGridCellCoords cursorCoords(m_owner->GetGridCursorRow(),
                                            m_owner->GetGridCursorCol());
        const wxRect cursor =
            m_owner->BlockToDeviceRect(cursorCoords, cursorCoords, this);
        if (cursor != wxGridNoCellRect)
            Refresh(true, &cursor);
    }

    if ( !m_owner->ProcessWindowEvent( event ) )
        event.Skip();
}

// Unlike XToCol() and YToRow() these macros always return a valid column/row,
// so their results don't need to be checked, while the results of the public
// functions always must be.
#define internalXToCol(x, gridWindowPtr) XToCol(x, true, gridWindowPtr)
#define internalYToRow(y, gridWindowPtr) YToRow(y, true, gridWindowPtr)

/////////////////////////////////////////////////////////////////////

wxBEGIN_EVENT_TABLE( wxGrid, wxScrolledCanvas )
    EVT_SIZE( wxGrid::OnSize )
    EVT_DPI_CHANGED( wxGrid::OnDPIChanged )
    EVT_KEY_DOWN( wxGrid::OnKeyDown )
    EVT_CHAR ( wxGrid::OnChar )
wxEND_EVENT_TABLE()

bool wxGrid::Create(wxWindow *parent, wxWindowID id,
                          const wxPoint& pos, const wxSize& size,
                          long style, const wxString& name)
{
    if (!wxScrolledCanvas::Create(parent, id, pos, size,
                                  style | wxWANTS_CHARS, name))
        return false;

    Create();
    SetInitialSize(size);
    CalcDimensions();

    return true;
}

wxGrid::~wxGrid()
{
    if ( m_winCapture )
        m_winCapture->ReleaseMouse();

    // Ensure that the editor control is destroyed before the grid is,
    // otherwise we crash later when the editor tries to do something with the
    // half destroyed grid
    HideCellEditControl();

    // Must do this or ~wxScrollHelper will pop the wrong event handler
    SetTargetWindow(this);
    ClearAttrCache();
    wxSafeDecRef(m_defaultCellAttr);

#ifdef DEBUG_ATTR_CACHE
    size_t total = gs_nAttrCacheHits + gs_nAttrCacheMisses;
    wxPrintf(wxT("wxGrid attribute cache statistics: "
                "total: %u, hits: %u (%u%%)\n"),
             total, gs_nAttrCacheHits,
             total ? (gs_nAttrCacheHits*100) / total : 0);
#endif

    // if we own the table, just delete it, otherwise at least don't leave it
    // with dangling view pointer
    if ( m_ownTable )
        delete m_table;
    else if ( m_table && m_table->GetView() == this )
        m_table->SetView(nullptr);

    delete m_typeRegistry;
    delete m_selection;

    delete m_setFixedRows;
    delete m_setFixedCols;

#if wxUSE_ACCESSIBILITY
    SetAccessible(nullptr);
    wxAccessible::NotifyEvent(wxACC_EVENT_OBJECT_DESTROY, this, wxOBJID_CLIENT, wxACC_SELF);
#endif // wxUSE_ACCESSIBILITY
}

//
// ----- internal init and update functions
//

// NOTE: If using the default visual attributes works everywhere then this can
// be removed as well as the #else cases below.
#define _USE_VISATTR 0

void wxGrid::Create()
{
    // create the type registry
    m_typeRegistry = new wxGridTypeRegistry;

    m_cellEditCtrlEnabled = false;

    m_defaultCellAttr = new wxGridCellAttr();

    // Set default cell attributes
    m_defaultCellAttr->SetDefAttr(m_defaultCellAttr);
    m_defaultCellAttr->SetKind(wxGridCellAttr::Default);
    m_defaultCellAttr->SetFont(GetFont());
    m_defaultCellAttr->SetAlignment(wxALIGN_LEFT, wxALIGN_TOP);
    m_defaultCellAttr->SetRenderer(new wxGridCellStringRenderer);
    m_defaultCellAttr->SetEditor(new wxGridCellTextEditor);
    m_defaultCellAttr->SetFitMode(wxGridFitMode::Overflow());

#if _USE_VISATTR
    wxVisualAttributes gva = wxListBox::GetClassDefaultAttributes();
    wxVisualAttributes lva = wxPanel::GetClassDefaultAttributes();

    m_defaultCellAttr->SetTextColour(gva.colFg);
    m_defaultCellAttr->SetBackgroundColour(gva.colBg);

#else
    m_defaultCellAttr->SetTextColour(
        wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT));
    m_defaultCellAttr->SetBackgroundColour(
        wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOW));
#endif

    m_numRows = 0;
    m_numCols = 0;
    m_numFrozenRows = 0;
    m_numFrozenCols = 0;
    m_currentCellCoords = wxGridNoCellCoords;

    // subwindow components that make up the wxGrid
    m_rowLabelWin = new wxGridRowLabelWindow(this);
    CreateColumnWindow();
    m_cornerLabelWin = new wxGridCornerLabelWindow(this);
    m_gridWin = new wxGridWindow(this, wxGridWindow::wxGridWindowNormal);

    SetTargetWindow( m_gridWin );

#if _USE_VISATTR
    wxColour gfg = gva.colFg;
    wxColour gbg = gva.colBg;
    wxColour lfg = lva.colFg;
    wxColour lbg = lva.colBg;
#else
    wxColour gfg = wxSystemSettings::GetColour( wxSYS_COLOUR_WINDOWTEXT );
    wxColour gbg = wxSystemSettings::GetColour( wxSYS_COLOUR_WINDOW );
    wxColour lfg = wxSystemSettings::GetColour( wxSYS_COLOUR_WINDOWTEXT );
    wxColour lbg = wxSystemSettings::GetColour( wxSYS_COLOUR_BTNFACE );
#endif

    m_cornerLabelWin->SetOwnForegroundColour(lfg);
    m_cornerLabelWin->SetOwnBackgroundColour(lbg);
    m_rowLabelWin->SetOwnForegroundColour(lfg);
    m_rowLabelWin->SetOwnBackgroundColour(lbg);
    m_colLabelWin->SetOwnForegroundColour(lfg);
    m_colLabelWin->SetOwnBackgroundColour(lbg);

    m_gridWin->SetOwnForegroundColour(gfg);
    m_gridWin->SetOwnBackgroundColour(gbg);

    m_labelBackgroundColour = m_rowLabelWin->GetBackgroundColour();
    m_labelTextColour = m_rowLabelWin->GetForegroundColour();

    InitPixelFields();

#if wxUSE_ACCESSIBILITY
    wxAccessible::NotifyEvent(wxACC_EVENT_OBJECT_CREATE, this, wxOBJID_CLIENT, wxACC_SELF);
#endif // wxUSE_ACCESSIBILITY
}

void wxGrid::InitPixelFields()
{
    m_defaultRowHeight = m_gridWin->GetCharHeight();
#if defined(__WXGTK__) || defined(__WXQT__)  // see also text ctrl sizing in ShowCellEditControl()
    m_defaultRowHeight += 8;
#else
    m_defaultRowHeight += 4;
#endif

    // Scroll by row height to avoid showing partial rows when all heights are
    // the same.
    m_yScrollPixelsPerLine = m_defaultRowHeight;

    // Don't change the value when called from OnDPIChanged() later if the
    // corresponding label window is hidden, these values should remain zeroes
    // then.
    if ( m_rowLabelWin->IsShown() )
        m_rowLabelWidth  = FromDIP(WXGRID_DEFAULT_ROW_LABEL_WIDTH);
    if ( m_colLabelWin->IsShown() )
        m_colLabelHeight = FromDIP(WXGRID_DEFAULT_COL_LABEL_HEIGHT);
    m_rowLabelMinWidth = 0;
    m_colLabelMinHeight = 0;

    m_defaultColWidth = FromDIP(WXGRID_DEFAULT_COL_WIDTH);

    m_minAcceptableColWidth  = FromDIP(WXGRID_MIN_COL_WIDTH);
    m_minAcceptableRowHeight = FromDIP(WXGRID_MIN_ROW_HEIGHT);
}

void wxGrid::CreateColumnWindow()
{
    if ( m_useNativeHeader )
    {
        m_colLabelWin = new wxGridHeaderCtrl(this);
        m_colLabelHeight = m_colLabelWin->GetBestSize().y;
    }
    else // draw labels ourselves
    {
        m_colLabelWin = new wxGridColLabelWindow(this);
        m_colLabelHeight = FromDIP(WXGRID_DEFAULT_COL_LABEL_HEIGHT);
    }
}

bool wxGrid::CreateGrid( int numRows, int numCols,
                         wxGridSelectionModes selmode )
{
    wxCHECK_MSG( !m_created,
                 false,
                 wxT("wxGrid::CreateGrid or wxGrid::SetTable called more than once") );

    return SetTable(new wxGridStringTable(numRows, numCols), true, selmode);
}

void wxGrid::SetSelectionMode(wxGridSelectionModes selmode)
{
    wxCHECK_RET( m_created,
                 wxT("Called wxGrid::SetSelectionMode() before calling CreateGrid()") );

    m_selection->SetSelectionMode( selmode );
}

wxGrid::wxGridSelectionModes wxGrid::GetSelectionMode() const
{
    wxCHECK_MSG( m_created, wxGridSelectCells,
                 wxT("Called wxGrid::GetSelectionMode() before calling CreateGrid()") );

    return m_selection->GetSelectionMode();
}

bool
wxGrid::SetTable(wxGridTableBase *table,
                 bool takeOwnership,
                 wxGrid::wxGridSelectionModes selmode )
{
    if ( m_created )
    {
        // stop all processing
        m_created = false;

        if (m_table)
        {
            // We can't leave the in-place control editing the data of the
            // table alive, as it would try to use the table object that we
            // don't have any more later otherwise, so hide it manually.
            //
            // Notice that we can't call DisableCellEditControl() from here
            // which would try to save the current editor value into the table
            // which might be half-deleted by now, so we have to manually mark
            // the edit control as being disabled.
            HideCellEditControl();
            m_cellEditCtrlEnabled = false;

            // Don't hold on to attributes cached from the old table
            ClearAttrCache();

            m_table->SetView(nullptr);
            if( m_ownTable )
                delete m_table;
            m_table = nullptr;
        }

        wxDELETE(m_selection);

        m_ownTable = false;
        m_numRows = 0;
        m_numCols = 0;
        m_numFrozenRows = 0;
        m_numFrozenCols = 0;

        // kill row and column size arrays
        m_colWidths.Empty();
        m_colRights.Empty();
        m_rowHeights.Empty();
        m_rowBottoms.Empty();
    }

    if (table)
    {
        m_numRows = table->GetNumberRows();
        m_numCols = table->GetNumberCols();

        m_table = table;
        m_table->SetView( this );
        m_ownTable = takeOwnership;

        // Notice that this must be called after setting m_table as it uses it
        // indirectly, via wxGrid::GetColLabelValue().
        if ( m_useNativeHeader )
            SetNativeHeaderColCount();

        m_selection = new wxGridSelection( this, selmode );
        CalcDimensions();

        m_created = true;
    }

    InvalidateBestSize();

    // If we already have a valid current cell, ensure that it is in valid
    // range for the new table with a possibly different number of rows/columns
    // but don't do anything if the current cell is invalid, setting the table
    // shouldn't automatically select the cell at (0, 0).
    if ( m_currentCellCoords != wxGridNoCellCoords )
        UpdateCurrentCellOnRedim();

    return m_created;
}

void wxGrid::AssignTable(wxGridTableBase *table, wxGridSelectionModes selmode)
{
    wxCHECK_RET( table, wxS("Table pointer must be valid") );
    wxCHECK_RET( !m_created, wxS("wxGrid already has a table") );

    SetTable(table, true /* take ownership */, selmode);
}

void wxGrid::Init()
{
    m_created = false;

    m_cornerLabelWin = nullptr;
    m_rowLabelWin = nullptr;
    m_rowFrozenLabelWin = nullptr;
    m_colLabelWin = nullptr;
    m_colFrozenLabelWin = nullptr;
    m_gridWin = nullptr;
    m_frozenColGridWin = nullptr;
    m_frozenRowGridWin = nullptr;
    m_frozenCornerGridWin = nullptr;

    m_table = nullptr;
    m_ownTable = false;

    m_selection = nullptr;
    m_defaultCellAttr = nullptr;
    m_typeRegistry = nullptr;

    m_setFixedRows =
    m_setFixedCols = nullptr;

    // init attr cache
    m_attrCache.row = -1;
    m_attrCache.col = -1;
    m_attrCache.attr = nullptr;

    m_labelFont = GetFont();
    m_labelFont.SetWeight( wxFONTWEIGHT_BOLD );

    m_rowLabelHorizAlign = wxALIGN_CENTRE;
    m_rowLabelVertAlign  = wxALIGN_CENTRE;

    m_colLabelHorizAlign = wxALIGN_CENTRE;
    m_colLabelVertAlign  = wxALIGN_CENTRE;
    m_colLabelTextOrientation = wxHORIZONTAL;

    m_cornerLabelHorizAlign = wxALIGN_CENTRE;
    m_cornerLabelVertAlign = wxALIGN_CENTRE;
    m_cornerLabelTextOrientation = wxHORIZONTAL;

    // All these fields require a valid window, so are initialized in Create().
    m_rowLabelWidth  =
    m_colLabelHeight = 0;

    m_defaultColWidth  =
    m_defaultRowHeight = 0;

    m_minAcceptableColWidth  =
    m_minAcceptableRowHeight = 0;

    m_gridLineColour = wxSystemSettings::GetColour(wxSYS_COLOUR_GRIDLINES);
    m_gridLinesEnabled = true;
    m_gridLinesClipHorz =
    m_gridLinesClipVert = true;
    m_cellHighlightColour = wxSystemSettings::GetColour(wxSYS_COLOUR_WINDOWTEXT);
    m_cellHighlightPenWidth = 2;
    m_cellHighlightROPenWidth = 1;
    m_gridFrozenBorderColour = wxSystemSettings::SelectLightDark(*wxBLACK, *wxWHITE);
    m_gridFrozenBorderPenWidth = 2;

    m_canDragRowMove = false;
    m_canDragColMove = false;
    m_canHideColumns = true;

    m_canDragRowLabelSize = false;
    m_canDragColLabelSize = false;

    m_cursorMode = WXGRID_CURSOR_SELECT_CELL;
    m_winCapture = nullptr;
    m_canDragRowSize = true;
    m_canDragColSize = true;
    m_canDragGridSize = true;
    m_canDragCell = false;
    m_dragMoveRowOrCol = -1;
    m_dragLastPos  = -1;
    m_dragLastColour  = nullptr;
    m_dragRowOrCol = -1;
    m_dragRowOrColOldSize = -1;
    m_dragLabel = false;
    m_isDragging = false;
    m_cancelledDragging = false;
    m_startDragPos = wxDefaultPosition;
    m_lastMousePos = wxDefaultPosition;

    m_sortCol = wxNOT_FOUND;
    m_sortIsAscending = true;

    m_useNativeHeader =
    m_nativeColumnLabels = false;

    m_waitForSlowClick = false;

    m_rowResizeCursor = wxCursor( wxCURSOR_SIZENS );
    m_colResizeCursor = wxCursor( wxCURSOR_SIZEWE );

    m_currentCellCoords = wxGridNoCellCoords;

    m_selectionBackground = wxSystemSettings::GetColour(wxSYS_COLOUR_HIGHLIGHT);
    m_selectionForeground = wxSystemSettings::GetColour(wxSYS_COLOUR_HIGHLIGHTTEXT);

    m_editable = true;  // default for whole grid

    m_batchCount = 0;

    m_extraWidth =
    m_extraHeight = 0;

    // we can't call SetScrollRate() as the window isn't created yet but OTOH
    // we don't need to call it either as the scroll position is (0, 0) right
    // now anyhow, so just set the parameters directly
    m_xScrollPixelsPerLine = GRID_SCROLL_LINE_X;
    m_yScrollPixelsPerLine = GRID_SCROLL_LINE_Y;

    m_tabBehaviour = Tab_Stop;
}

// ----------------------------------------------------------------------------
// the idea is to call these functions only when necessary because they create
// quite big arrays which eat memory mostly unnecessary - in particular, if
// default widths/heights are used for all rows/columns, we may not use these
// arrays at all
//
// with some extra code, it should be possible to only store the widths/heights
// different from default ones (resulting in space savings for huge grids) but
// this is not done currently
// ----------------------------------------------------------------------------

void wxGrid::InitRowHeights()
{
    m_rowHeights.Empty();
    m_rowBottoms.Empty();

    m_rowHeights.Alloc( m_numRows );
    m_rowBottoms.Alloc( m_numRows );

    m_rowHeights.Add( m_defaultRowHeight, m_numRows );

    for ( int i = 0; i < m_numRows; i++ )
    {
        int rowBottom = ( GetRowPos( i ) + 1 ) * m_defaultRowHeight;
        m_rowBottoms.Add( rowBottom );
    }
}

void wxGrid::InitColWidths()
{
    m_colWidths.Empty();
    m_colRights.Empty();

    m_colWidths.Alloc( m_numCols );
    m_colRights.Alloc( m_numCols );

    m_colWidths.Add( m_defaultColWidth, m_numCols );

    for ( int i = 0; i < m_numCols; i++ )
    {
        int colRight = ( GetColPos( i ) + 1 ) * m_defaultColWidth;
        m_colRights.Add( colRight );
    }
}

int wxGrid::GetColWidth(int col) const
{
    if ( m_colWidths.IsEmpty() )
        return m_defaultColWidth;

    // a negative width indicates a hidden column
    return m_colWidths[col] > 0 ? m_colWidths[col] : 0;
}

int wxGrid::GetColLeft(int col) const
{
    if ( m_colRights.IsEmpty() )
        return GetColPos( col ) * m_defaultColWidth;

    return m_colRights[col] - GetColWidth(col);
}

int wxGrid::GetColRight(int col) const
{
    return m_colRights.IsEmpty() ? (GetColPos( col ) + 1) * m_defaultColWidth
                                 : m_colRights[col];
}

int wxGrid::GetRowHeight(int row) const
{
    // no custom heights / hidden rows
    if ( m_rowHeights.IsEmpty() )
        return m_defaultRowHeight;

    // a negative height indicates a hidden row
    return m_rowHeights[row] > 0 ? m_rowHeights[row] : 0;
}

int wxGrid::GetRowTop(int row) const
{
    if ( m_rowBottoms.IsEmpty() )
        return GetRowPos( row ) * m_defaultRowHeight;

    return m_rowBottoms[row] - GetRowHeight(row);
}

int wxGrid::GetRowBottom(int row) const
{
    return m_rowBottoms.IsEmpty() ? (GetRowPos( row ) + 1) * m_defaultRowHeight
                                  : m_rowBottoms[row];
}

void wxGrid::CalcDimensions()
{
    // Wait until the window is thawed if it's currently frozen.
    if ( GetBatchCount() )
        return;

    // if our OnSize() hadn't been called (it would if we have scrollbars), we
    // still must reposition the children
    CalcWindowSizes();

    // compute the size of the scrollable area
    int w = m_numCols > 0 ? GetColRight(GetColAt(m_numCols - 1)) : 0;
    int h = m_numRows > 0 ? GetRowBottom(GetRowAt(m_numRows - 1)) : 0;

    w += m_extraWidth;
    h += m_extraHeight;

    // take into account editor if shown
    if ( IsCellEditControlShown() )
    {
        const wxRect rect = GetCurrentCellEditorPtr()->GetWindow()->GetRect();
        if ( rect.GetRight() > w )
            w = rect.GetRight();
        if ( rect.GetBottom() > h )
            h = rect.GetBottom();
    }

    wxPoint offset = GetGridWindowOffset(m_gridWin);
    w -= offset.x;
    h -= offset.y;

    // preserve (more or less) the previous position
    int x, y;
    GetViewStart( &x, &y );

    // ensure the position is valid for the new scroll ranges
    if ( x >= w )
        x = wxMax( w - 1, 0 );
    if ( y >= h )
        y = wxMax( h - 1, 0 );

    // update the virtual size and refresh the scrollbars to reflect it
    m_gridWin->SetVirtualSize(w, h);
    Scroll(x, y);
    AdjustScrollbars();
}

wxSize wxGrid::GetSizeAvailableForScrollTarget(const wxSize& size)
{
    wxPoint offset = GetGridWindowOffset(m_gridWin);
    wxSize sizeGridWin(size);
    sizeGridWin.x -= m_rowLabelWidth + offset.x;
    sizeGridWin.y -= m_colLabelHeight + offset.y;

    return sizeGridWin;
}

void wxGrid::CalcWindowSizes()
{
    // escape if the window is has not been fully created yet

    if ( m_cornerLabelWin == nullptr )
        return;

    int cw, ch;
    GetClientSize( &cw, &ch );

    // frozen rows and cols windows size
    int fgw = 0, fgh = 0;

    for ( int i = 0; i < m_numFrozenRows; i++ )
        fgh += GetRowHeight(i);

    for ( int i = 0; i < m_numFrozenCols; i++ )
        fgw += GetColWidth(i);

    // the grid may be too small to have enough space for the labels yet, don't
    // size the windows to negative sizes in this case
    int gw = cw - m_rowLabelWidth - fgw;
    int gh = ch - m_colLabelHeight - fgh;
    if (gw < 0)
        gw = 0;
    if (gh < 0)
        gh = 0;

    if ( m_cornerLabelWin && m_cornerLabelWin->IsShown() )
        m_cornerLabelWin->SetSize( 0, 0, m_rowLabelWidth, m_colLabelHeight );

    if ( m_colFrozenLabelWin && m_colFrozenLabelWin->IsShown() )
        m_colFrozenLabelWin->SetSize( m_rowLabelWidth, 0, fgw, m_colLabelHeight);

    if ( m_colLabelWin && m_colLabelWin->IsShown() )
        m_colLabelWin->SetSize( m_rowLabelWidth + fgw, 0, gw, m_colLabelHeight );

    if ( m_rowFrozenLabelWin && m_rowFrozenLabelWin->IsShown() )
        m_rowFrozenLabelWin->SetSize ( 0, m_colLabelHeight, m_rowLabelWidth, fgh);

    if ( m_rowLabelWin && m_rowLabelWin->IsShown() )
        m_rowLabelWin->SetSize( 0, m_colLabelHeight + fgh, m_rowLabelWidth, gh );

    if ( m_frozenCornerGridWin && m_frozenCornerGridWin->IsShown() )
        m_frozenCornerGridWin->SetSize( m_rowLabelWidth, m_colLabelHeight, fgw, fgh );

    if ( m_frozenColGridWin && m_frozenColGridWin->IsShown() )
        m_frozenColGridWin->SetSize( m_rowLabelWidth, m_colLabelHeight + fgh, fgw, gh);

    if ( m_frozenRowGridWin && m_frozenRowGridWin->IsShown() )
        m_frozenRowGridWin->SetSize( m_rowLabelWidth + fgw, m_colLabelHeight, gw, fgh);

    if ( m_gridWin && m_gridWin->IsShown() )
        m_gridWin->SetSize( m_rowLabelWidth + fgw, m_colLabelHeight + fgh, gw, gh );
}

// this is called when the grid table sends a message
// to indicate that it has been redimensioned
//
bool wxGrid::Redimension( const wxGridTableMessage& msg )
{
    int i;
    int labelArea = 0;

    // Clear the attribute cache as the attribute might refer to a different
    // cell than stored in the cache after adding/removing rows/columns.
    ClearAttrCache();

    // By the same reasoning, the editor should be dismissed if columns are
    // added or removed. And for consistency, it should IMHO always be
    // removed, not only if the cell "underneath" it actually changes.
    // For now, I intentionally do not save the editor's content as the
    // cell it might want to save that stuff to might no longer exist.
    HideCellEditControl();

    switch ( msg.GetId() )
    {
        case wxGRIDTABLE_NOTIFY_ROWS_INSERTED:
        {
            int pos = msg.GetCommandInt();
            wxCHECK_MSG( pos >= 0 && pos <= m_numRows, false,
                         "Invalid row insertion position" );

            int numRows = msg.GetCommandInt2();
            wxCHECK_MSG( numRows >= 0, false,
                         "Invalid number of rows inserted" );

            m_numRows += numRows;

            if ( !m_rowAt.IsEmpty() )
            {
                //Shift the row IDs
                for ( i = 0; i < m_numRows - numRows; i++ )
                {
                    if ( m_rowAt[i] >= pos )
                        m_rowAt[i] += numRows;
                }

                m_rowAt.Insert( pos, pos, numRows );

                //Set the new rows' positions
                for ( i = pos + 1; i < pos + numRows; i++ )
                {
                    m_rowAt[i] = i;
                }
            }


            if ( !m_rowHeights.IsEmpty() )
            {
                m_rowHeights.Insert( m_defaultRowHeight, pos, numRows );
                m_rowBottoms.Insert( 0, pos, numRows );

                int bottom = 0;
                if ( pos > 0 )
                    bottom = m_rowBottoms[GetRowAt( pos - 1 )];

                int rowPos;
                for ( rowPos = pos; rowPos < m_numRows; rowPos++ )
                {
                    i = GetRowAt( rowPos );

                    bottom += GetRowHeight(i);
                    m_rowBottoms[i] = bottom;
                }
            }

            UpdateCurrentCellOnRedim();

            if ( m_selection )
                m_selection->UpdateRows( pos, numRows );
            wxGridCellAttrProvider * attrProvider = m_table->GetAttrProvider();
            if (attrProvider)
                attrProvider->UpdateAttrRows( pos, numRows );

            CalcDimensions();
        }
        labelArea = wxGA_RowLabels;
        break;

        case wxGRIDTABLE_NOTIFY_ROWS_APPENDED:
        {
            int numRows = msg.GetCommandInt();
            wxCHECK_MSG( numRows >= 0, false,
                         "Invalid number of rows appended" );

            wxASSERT_MSG( msg.GetCommandInt2() == -1, "Ignored when appending" );

            int oldNumRows = m_numRows;
            m_numRows += numRows;

            if ( !m_rowAt.IsEmpty() )
            {
                m_rowAt.Add( 0, numRows );

                //Set the new rows' positions
                for ( i = oldNumRows; i < m_numRows; i++ )
                {
                    m_rowAt[i] = i;
                }
            }

            if ( !m_rowHeights.IsEmpty() )
            {
                m_rowHeights.Add( m_defaultRowHeight, numRows );
                m_rowBottoms.Add( 0, numRows );

                int bottom = 0;
                if ( oldNumRows > 0 )
                    bottom = m_rowBottoms[oldNumRows - 1];

                int rowPos;
                for ( rowPos = oldNumRows; rowPos < m_numRows; rowPos++ )
                {
                    i = GetRowAt( rowPos );

                    bottom += GetRowHeight(i);
                    m_rowBottoms[i] = bottom;
                }
            }

            UpdateCurrentCellOnRedim();

            CalcDimensions();
        }
        labelArea = wxGA_RowLabels;
        break;

        case wxGRIDTABLE_NOTIFY_ROWS_DELETED:
        {
            int pos = msg.GetCommandInt();
            wxCHECK_MSG( pos >= 0 && pos <= m_numRows, false,
                         "Invalid row deletion position" );

            int numRows = msg.GetCommandInt2();
            wxCHECK_MSG( numRows >= 0 && pos + numRows <= m_numRows, false,
                         "Wrong number of rows being deleted" );

            m_numRows -= numRows;

            if ( !m_rowAt.IsEmpty() )
            {
                int rowID = GetRowAt( pos );

                m_rowAt.RemoveAt( pos, numRows );

                //Shift the row IDs
                int rowPos;
                for ( rowPos = 0; rowPos < m_numRows; rowPos++ )
                {
                    if ( m_rowAt[rowPos] > rowID )
                        m_rowAt[rowPos] -= numRows;
                }
            }

            if ( !m_rowHeights.IsEmpty() )
            {
                m_rowHeights.RemoveAt( pos, numRows );
                m_rowBottoms.RemoveAt( pos, numRows );

                int h = 0;
                int rowPos;
                for ( rowPos = 0; rowPos < m_numRows; rowPos++ )
                {
                    i = GetRowAt( rowPos );

                    h += GetRowHeight(i);
                    m_rowBottoms[i] = h;
                }
            }

            UpdateCurrentCellOnRedim();

            if ( m_selection )
                m_selection->UpdateRows( pos, -numRows );
            wxGridCellAttrProvider * attrProvider = m_table->GetAttrProvider();
            if (attrProvider)
            {
                attrProvider->UpdateAttrRows( pos, -numRows );

// ifdef'd out following patch from Paul Gammans
#if 0
                // No need to touch column attributes, unless we
                // removed _all_ rows, in this case, we remove
                // all column attributes.
                // I hate to do this here, but the
                // needed data is not available inside UpdateAttrRows.
                if ( !GetNumberRows() )
                    attrProvider->UpdateAttrCols( 0, -GetNumberCols() );
#endif
            }

            CalcDimensions();
        }
        labelArea = wxGA_RowLabels;
        break;

        case wxGRIDTABLE_NOTIFY_COLS_INSERTED:
        {
            int pos = msg.GetCommandInt();
            wxCHECK_MSG( pos >= 0 && pos <= m_numCols, false,
                         "Invalid column insertion position" );

            int numCols = msg.GetCommandInt2();
            wxCHECK_MSG( numCols >= 0, false,
                         "Invalid number of columns inserted" );

            m_numCols += numCols;

            if ( !m_colAt.IsEmpty() )
            {
                //Shift the column IDs
                for ( i = 0; i < m_numCols - numCols; i++ )
                {
                    if ( m_colAt[i] >= pos )
                        m_colAt[i] += numCols;
                }

                m_colAt.Insert( pos, pos, numCols );

                //Set the new columns' positions
                for ( i = pos + 1; i < pos + numCols; i++ )
                {
                    m_colAt[i] = i;
                }
            }

            if ( !m_colWidths.IsEmpty() )
            {
                m_colWidths.Insert( m_defaultColWidth, pos, numCols );
                m_colRights.Insert( 0, pos, numCols );

                int right = 0;
                if ( pos > 0 )
                    right = m_colRights[GetColAt( pos - 1 )];

                int colPos;
                for ( colPos = pos; colPos < m_numCols; colPos++ )
                {
                    i = GetColAt( colPos );

                    right += GetColWidth(i);
                    m_colRights[i] = right;
                }
            }

            // See comment for wxGRIDTABLE_NOTIFY_COLS_APPENDED case explaining
            // why this has to be done here and not before.
            if ( m_useNativeHeader )
                GetGridColHeader()->SetColumnCount(m_numCols);

            UpdateCurrentCellOnRedim();

            if ( m_selection )
                m_selection->UpdateCols( pos, numCols );
            wxGridCellAttrProvider * attrProvider = m_table->GetAttrProvider();
            if (attrProvider)
                attrProvider->UpdateAttrCols( pos, numCols );

            CalcDimensions();
        }
        labelArea = wxGA_ColLabels;
        break;

        case wxGRIDTABLE_NOTIFY_COLS_APPENDED:
        {
            int numCols = msg.GetCommandInt();
            wxCHECK_MSG( numCols >= 0, false,
                         "Invalid number of columns appended" );

            wxASSERT_MSG( msg.GetCommandInt2() == -1, "Ignored when appending" );

            int oldNumCols = m_numCols;
            m_numCols += numCols;

            if ( !m_colAt.IsEmpty() )
            {
                m_colAt.Add( 0, numCols );

                //Set the new columns' positions
                for ( i = oldNumCols; i < m_numCols; i++ )
                {
                    m_colAt[i] = i;
                }
            }

            if ( !m_colWidths.IsEmpty() )
            {
                m_colWidths.Add( m_defaultColWidth, numCols );
                m_colRights.Add( 0, numCols );

                int right = 0;
                if ( oldNumCols > 0 )
                    right = m_colRights[GetColAt( oldNumCols - 1 )];

                int colPos;
                for ( colPos = oldNumCols; colPos < m_numCols; colPos++ )
                {
                    i = GetColAt( colPos );

                    right += GetColWidth(i);
                    m_colRights[i] = right;
                }
            }

            // Notice that this must be called after updating m_colWidths above
            // as the native grid control will check whether the new columns
            // are shown which results in accessing m_colWidths array.
            if ( m_useNativeHeader )
                GetGridColHeader()->SetColumnCount(m_numCols);

            UpdateCurrentCellOnRedim();

            CalcDimensions();
        }
        labelArea = wxGA_ColLabels;
        break;

        case wxGRIDTABLE_NOTIFY_COLS_DELETED:
        {
            int pos = msg.GetCommandInt();
            wxCHECK_MSG( pos >= 0 && pos <= m_numCols, false,
                         "Invalid column deletion position" );

            int numCols = msg.GetCommandInt2();
            wxCHECK_MSG( numCols >= 0 && pos + numCols <= m_numCols, false,
                         "Wrong number of columns being deleted" );

            m_numCols -= numCols;

            if ( !m_colAt.IsEmpty() )
            {
                int colID = GetColAt( pos );

                m_colAt.RemoveAt( pos, numCols );

                //Shift the column IDs
                int colPos;
                for ( colPos = 0; colPos < m_numCols; colPos++ )
                {
                    if ( m_colAt[colPos] > colID )
                        m_colAt[colPos] -= numCols;
                }
            }

            if ( !m_colWidths.IsEmpty() )
            {
                m_colWidths.RemoveAt( pos, numCols );
                m_colRights.RemoveAt( pos, numCols );

                int w = 0;
                int colPos;
                for ( colPos = 0; colPos < m_numCols; colPos++ )
                {
                    i = GetColAt( colPos );

                    w += GetColWidth(i);
                    m_colRights[i] = w;
                }
            }

            // See comment for wxGRIDTABLE_NOTIFY_COLS_APPENDED case explaining
            // why this has to be done here and not before.
            if ( m_useNativeHeader )
                GetGridColHeader()->SetColumnCount(m_numCols);

            UpdateCurrentCellOnRedim();

            if ( m_selection )
                m_selection->UpdateCols( pos, -numCols );
            wxGridCellAttrProvider * attrProvider = m_table->GetAttrProvider();
            if (attrProvider)
            {
                attrProvider->UpdateAttrCols( pos, -numCols );

// ifdef'd out following patch from Paul Gammans
#if 0
                // No need to touch row attributes, unless we
                // removed _all_ columns, in this case, we remove
                // all row attributes.
                // I hate to do this here, but the
                // needed data is not available inside UpdateAttrCols.
                if ( !GetNumberCols() )
                    attrProvider->UpdateAttrRows( 0, -GetNumberRows() );
#endif
            }

            CalcDimensions();
        }
        labelArea = wxGA_ColLabels;
        break;
    }

    InvalidateBestSize();

    if ( labelArea && ShouldRefresh() )
    {
        RefreshArea(labelArea | wxGA_Cells);
    }

    return labelArea;
}

wxArrayInt wxGrid::CalcRowLabelsExposed( const wxRegion& reg, wxGridWindow *gridWindow ) const
{
    wxRect r;

    wxArrayInt  rowlabels;

    int top, bottom;
    for ( wxRegionIterator iter( reg ); iter; ++iter )
    {
        r = iter.GetRect();
        r.Offset(GetGridWindowOffset(gridWindow));

        // logical bounds of update region
        //
        CalcGridWindowUnscrolledPosition( 0, r.GetTop(), nullptr, &top, gridWindow );
        CalcGridWindowUnscrolledPosition( 0, r.GetBottom(), nullptr, &bottom, gridWindow );

        // find the row labels within these bounds
        const int rowFirst = internalYToRow(top, gridWindow);
        if ( rowFirst == wxNOT_FOUND )
            continue;

        for ( int rowPos = GetRowPos(rowFirst); rowPos < m_numRows; rowPos++ )
        {
            int row;
            row = GetRowAt( rowPos );

            if ( GetRowBottom(row) < top )
                continue;

            if ( GetRowTop(row) > bottom )
                break;

            rowlabels.Add( row );
        }
    }

    return rowlabels;
}

wxArrayInt wxGrid::CalcColLabelsExposed( const wxRegion& reg, wxGridWindow *gridWindow ) const
{
    wxRect r;

    wxArrayInt colLabels;

    int left, right;
    for ( wxRegionIterator iter( reg ); iter; ++iter )
    {
        r = iter.GetRect();
        r.Offset( GetGridWindowOffset(gridWindow) );

        // logical bounds of update region
        //
        CalcGridWindowUnscrolledPosition( r.GetLeft(), 0, &left, nullptr, gridWindow );
        CalcGridWindowUnscrolledPosition( r.GetRight(), 0, &right, nullptr, gridWindow );

        // find the cells within these bounds
        //
        const int colFirst = internalXToCol(left, gridWindow);
        if ( colFirst == wxNOT_FOUND )
           continue;

        for ( int colPos = GetColPos(colFirst); colPos < m_numCols; colPos++ )
        {
            int col;
            col = GetColAt( colPos );

            if ( GetColRight(col) < left )
                continue;

            if ( GetColLeft(col) > right )
                break;

            colLabels.Add( col );
        }
    }

    return colLabels;
}

wxGridCellCoordsArray wxGrid::CalcCellsExposed( const wxRegion& reg,
                                                wxGridWindow *gridWindow) const
{
    wxRect r;

    wxGridCellCoordsArray  cellsExposed;

    int left, top, right, bottom;
    for ( wxRegionIterator iter(reg); iter; ++iter )
    {
        r = iter.GetRect();
        r.Offset(GetGridWindowOffset(gridWindow));

        // Skip 0-height cells, they're invisible anyhow, don't waste time
        // getting their rectangles and so on.
        if ( !r.GetHeight() )
            continue;

        // logical bounds of update region
        //
        CalcGridWindowUnscrolledPosition( r.GetLeft(), r.GetTop(), &left, &top, gridWindow );
        CalcGridWindowUnscrolledPosition( r.GetRight(), r.GetBottom(), &right, &bottom, gridWindow );

        // find the cells within these bounds
        //
        const int rowFirst = internalYToRow(top, gridWindow);
        if ( rowFirst == wxNOT_FOUND )
            continue;

        wxArrayInt cols;
        for ( int rowPos = GetRowPos(rowFirst); rowPos < m_numRows; rowPos++ )
        {
            const int row = GetRowAt( rowPos );

            if ( GetRowBottom(row) <= top )
                continue;

            if ( GetRowTop(row) > bottom )
                break;

            // add all dirty cells in this row: notice that the columns which
            // are dirty don't depend on the row so we compute them only once
            // for the first dirty row and then reuse for all the next ones
            if ( cols.empty() )
            {
                // do determine the dirty columns
                for ( int pos = XToPos(left, gridWindow); pos <= XToPos(right, gridWindow); pos++ )
                    cols.push_back(GetColAt(pos));

                // if there are no dirty columns at all, nothing to do
                if ( cols.empty() )
                    break;
            }

            const size_t count = cols.size();
            for ( size_t n = 0; n < count; n++ )
                cellsExposed.Add(wxGridCellCoords(row, cols[n]));
        }
    }

    return cellsExposed;
}

void wxGrid::PrepareDCFor(wxDC &dc, wxGridWindow *gridWindow)
{
    wxScrolledCanvas::PrepareDC( dc );

    wxPoint dcOrigin = dc.GetDeviceOrigin() - GetGridWindowOffset(gridWindow);

    if ( gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenCol )
        dcOrigin.x = 0;
    if ( gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenRow )
        dcOrigin.y = 0;

    dc.SetDeviceOrigin(dcOrigin.x, dcOrigin.y);
}

void wxGrid::CheckDoDragScroll(wxGridSubwindow *eventGridWindow, wxGridSubwindow *gridWindow,
                               wxPoint posEvent, int direction)
{
    // helper for Process{Row|Col}LabelMouseEvent, ProcessGridCellMouseEvent:
    //  scroll when at the edges or outside the window w. respect to direction
    // eventGridWindow: the window that received the mouse event
    // gridWindow: the same or the corresponding non-frozen window

    if ( !m_isDragging )
    {
        // drag is just starting
        m_lastMousePos = posEvent;
        return;
    }

    int w, h;
    eventGridWindow->GetSize(&w, &h);
    // ViewStart is scroll position in scroll units
    wxPoint scrollPos = GetViewStart();
    wxPoint newScrollPos = wxPoint(wxDefaultCoord, wxDefaultCoord);

    if ( direction & wxHORIZONTAL )
    {
        // check x direction
        if ( eventGridWindow->IsFrozen() && posEvent.x < w )
        {
            // in the frozen window, moving left?
            if ( scrollPos.x > 0 && posEvent.x < m_lastMousePos.x )
                newScrollPos.x = scrollPos.x - 1;
        }
        else if ( eventGridWindow->IsFrozen() && posEvent.x >= w )
        {
            // frozen window was left, add the width of the non-frozen window
            w += gridWindow->GetSize().x;
        }

        if ( posEvent.x < 0 && scrollPos.x > 0 )
            newScrollPos.x = scrollPos.x - 1;
        else if ( posEvent.x >= w )
            newScrollPos.x = scrollPos.x + 1;
    }

    if ( direction & wxVERTICAL )
    {
        // check y direction
        if ( eventGridWindow->IsFrozen() && posEvent.y < h )
        {
            // in the frozen window, moving upward?
            if ( scrollPos.y && posEvent.y < m_lastMousePos.y )
                newScrollPos.y = scrollPos.y - 1;
        }
        else if ( eventGridWindow->IsFrozen() && posEvent.y >= h )
        {
            // frozen window was left, add the height of the non-frozen window
            h += gridWindow->GetSize().y;
        }

        if ( posEvent.y < 0 && scrollPos.y > 0 )
            newScrollPos.y = scrollPos.y - 1;
        else if ( posEvent.y >= h )
            newScrollPos.y = scrollPos.y + 1;
    }

    if ( newScrollPos.x != wxDefaultCoord || newScrollPos.y != wxDefaultCoord )
        Scroll(newScrollPos);

    m_lastMousePos = posEvent;
}

bool wxGrid::CheckIfDragCancelled(wxMouseEvent *event)
{
    // helper for Process{Row|Col}LabelMouseEvent, ProcessGridCellMouseEvent:
    // block re-triggering m_isDragging
    if ( !m_cancelledDragging )
        return false;

    if ( event->LeftIsDown() )
        return true;

    m_cancelledDragging = false;

    return false;
}

bool wxGrid::CheckIfAtDragSourceLine(const wxGridOperations &oper, int coord)
{
    // check whether coord on the dragged line or at max half of a line away
    // (the sizes of the lines before/after can be 0, if they are hidden)
    int minCoord = oper.GetLineStartPos(this, m_dragMoveRowOrCol);
    int maxCoord = minCoord + oper.GetLineSize(this, m_dragMoveRowOrCol);

    int lineBefore = oper.GetLineBefore(this, m_dragMoveRowOrCol);
    if ( lineBefore == -1 && coord < maxCoord )
        return true;
    if ( lineBefore != -1 )
        minCoord -= oper.GetLineSize(this, lineBefore) / 2;

    int posAfter = oper.GetLinePos(this, m_dragMoveRowOrCol) + 1;
    int lineAfter = posAfter < oper.GetTotalNumberOfLines(this) ?
                        oper.GetLineAt(this, posAfter) : -1;

    if ( lineAfter == -1 && coord >= minCoord )
        return true;
    if ( lineAfter != -1 )
        maxCoord += oper.GetLineSize(this, lineAfter) / 2;

    if ( coord >= minCoord && coord < maxCoord )
        return true;
    return false;
}

void wxGrid::ProcessRowColLabelMouseEvent( const wxGridOperations &oper, wxMouseEvent& event, wxGridSubwindow* labelWin )
{
    const wxGridOperations &dual = oper.Dual();

    wxGridSubwindow *headerWin = (wxGridSubwindow *) oper.GetHeaderWindow(this);
    wxGridWindow *gridWindow = labelWin->IsFrozen() ? oper.GetFrozenGrid(this) :
                                                      m_gridWin;

    // store position, before it's modified in the next step
    const wxPoint posEvent = event.GetPosition();

    event.SetPosition(posEvent + GetGridWindowOffset(gridWindow));

    // for drag, we could be moving from the window sending the event to the other
    if ( labelWin->IsFrozen() &&
        dual.Select( event.GetPosition() ) > dual.Select( labelWin->GetClientSize() ) )
        gridWindow = m_gridWin;

    const wxPoint unscrolledPos = CalcGridWindowUnscrolledPosition(event.GetPosition(), gridWindow);

    // find y or x mouse coordinate for row / col label window
    int coord = dual.Select(unscrolledPos);
    // index into data rows/cols;  wxNOT_FOUND if outside label window
    int line = oper.PosToLine(this, coord, nullptr);

    // wxNOT_FOUND if not near a line edge;  otherwise index into data rows/cols
    int lineEdge = PosToEdgeOfLine(coord, oper);


    // these are always valid, even if the mouse is outside the row/col range:
    // index into displayed rows/cols
    int posAt = PosToLinePos(coord, true /* clip */, oper, nullptr);
    // index into data rows/cols
    int lineAt = oper.GetLineAt(this, posAt);


    int edge = FromDIP(WXGRID_LABEL_EDGE_ZONE);
    // this will be set if we are dragging or could drag a label window edge
    const wxGridOperations* labelEdgeOper = nullptr;
    if ( m_dragLabel && m_cursorMode == oper.GetCursorModeResize() )
    {
        // dragging the edge to the corner label window
        labelEdgeOper = &oper;
    }
    else if ( m_dragLabel && m_cursorMode == dual.GetCursorModeResize() )
    {
        // dragging the right/bottom edge to the grid window
        labelEdgeOper = &dual;
    }
    else if ( oper.CanDragLabelSize(this) && abs(coord) < edge )  // coord < 0 can happen w. captured mouse; probably not relevant here, though
    {
        // near the edge to the corner label window
        labelEdgeOper = &oper;
    }
    else if ( dual.CanDragLabelSize(this) && oper.Select(posEvent) > dual.GetLabelSize(this) - edge )
    {
        // near the right/bottom edge to the grid window
        labelEdgeOper = &dual;
    }


    if ( CheckIfDragCancelled(&event) )
        return;

    if ( event.Dragging() && (m_winCapture == labelWin) )
    {
        // scroll when at the edges or outside the window
        CheckDoDragScroll(labelWin, headerWin, posEvent, oper.GetOrientation());
    }

    if ( event.Dragging() )
    {
        if (!m_isDragging)
        {
            m_isDragging = true;

            if ( m_cursorMode == oper.GetCursorModeMove() && line != -1 )
                DoStartMoveRowOrCol(line);
        }

        if ( event.LeftIsDown() )
        {
            if ( m_cursorMode == oper.GetCursorModeResize() )
            {
                // resizing a row/col
                // or the labels at the edge to the corner label window
                DoGridDragResize(event.GetPosition(), oper, gridWindow);
            }
            else if ( labelEdgeOper && m_cursorMode == labelEdgeOper->GetCursorModeResize() )
            {
                // resizing labels at the edge to the grid window
                DoGridDragResize(posEvent, *labelEdgeOper, nullptr);
            }
            else if ( m_cursorMode == oper.GetCursorModeSelect() && line >=0 )
            {
                // We can't extend the selection from non-selected row / col,
                // which may happen if we Ctrl-clicked it initially.
                // Therefore check m_selection->IsInSelection(m_currentCellCoords)

                if ( m_selection && m_numRows && m_numCols &&
                     m_selection->IsInSelection(m_currentCellCoords) )
                {
                    oper.SelectionExtendCurrentBlock(this, line, event, wxEVT_GRID_RANGE_SELECTING);
                }
            }
            else if ( m_cursorMode == oper.GetCursorModeMove() )
            {
                // determine the y or x position of the drop marker
                int markerPos;
                if ( coord >= oper.GetLineStartPos(this, lineAt) + (oper.GetLineSize(this, lineAt) / 2) )
                    markerPos = oper.GetLineEndPos(this, lineAt);
                else
                    markerPos = oper.GetLineStartPos(this, lineAt);

                const wxColour *markerColour;
                // Moving to the same place? Draw a grey marker.
                if ( CheckIfAtDragSourceLine(oper, coord) )
                    markerColour = wxLIGHT_GREY;
                else
                    markerColour = wxBLUE;

                if ( markerPos != m_dragLastPos || markerColour != m_dragLastColour )
                {
                    wxClientDC dc( headerWin );
                    oper.PrepareDCForLabels(this, dc);

                    int markerLength = oper.Select(headerWin->GetClientSize());

                    // Clean up the last indicator if position has changed
                    if ( m_dragLastPos >= 0 && markerPos != m_dragLastPos )
                    {
                        wxPen pen(headerWin->GetBackgroundColour(), 2);
                        dc.SetPen(pen);
                        oper.DrawParallelLine(dc, 0, markerLength, m_dragLastPos + 1);
                        dc.SetPen(wxNullPen);

                        int lastLine = oper.PosToLine(this, m_dragLastPos, nullptr, false);

                        if ( lastLine != -1 )
                            oper.DrawLineLabel(this, dc, lastLine);
                    }

                    // Draw the marker
                    wxPen pen(*markerColour, 2);
                    dc.SetPen(pen);
                    oper.DrawParallelLine(dc, 0, markerLength, markerPos + 1);
                    dc.SetPen(wxNullPen);

                    m_dragLastPos = markerPos;
                    m_dragLastColour = markerColour;
                }
            }
        }
        return;
    }

    if ( (m_isDragging || m_winCapture == labelWin) && (event.Entering() || event.Leaving()) )
        return;

    // ------------ Entering or leaving the window
    //
    if ( event.Entering() || event.Leaving() )
    {
        ChangeCursorMode(WXGRID_CURSOR_SELECT_CELL, labelWin);
    }

    // ------------ Left button pressed
    //
    else if ( event.LeftDown() )
    {
        if ( lineEdge != wxNOT_FOUND && oper.CanDragLineSize(this, lineEdge) )
        {
            DoStartResizeRowOrCol(lineEdge, oper.GetLineSize(this, lineEdge));
            ChangeCursorMode(oper.GetCursorModeResize(), labelWin);
        }
        else if ( labelEdgeOper )
        {
            DoStartResizeLabel(labelEdgeOper->GetLabelSize(this));
            ChangeCursorMode(labelEdgeOper->GetCursorModeResize(), labelWin);
        }
        else
        {
            // not a request to start resizing
            if ( line >= 0 &&
                 oper.SendEvent( this, wxEVT_GRID_LABEL_LEFT_CLICK, line, event ) == Event_Unhandled )
            {
                if ( oper.CanDragMove(this) )
                {
                    ChangeCursorMode(oper.GetCursorModeMove(), headerWin);
                    m_dragMoveRowOrCol = line;
                    // Show button as pressed
                    wxClientDC dc( headerWin );
                    oper.PrepareDCForLabels(this, dc);
                    oper.DrawLineLabel(this, dc, line);
                }

                // Check if row/col selection is possible and allowed, before doing
                // anything else, including changing the cursor mode to "select
                // row"/"select col".
                if ( m_selection && m_numRows > 0 && m_numCols > 0 &&
                        m_selection->GetSelectionMode() != dual.GetSelectionMode() )
                {
                    bool selectNewLine = false,
                         makeLineCurrent = false;

                    if ( event.ShiftDown() && !event.CmdDown() )
                    {
                        // Continue editing the current selection and don't
                        // move the grid cursor.
                        oper.SelectionExtendCurrentBlock(this, line, event);
                        oper.MakeLineVisible(this, line);
                    }
                    else if ( event.CmdDown() && !event.ShiftDown() )
                    {
                        if ( oper.IsLineInSelection(this, line) )
                        {
                            oper.DeselectLine(this, line);
                            makeLineCurrent = true;
                        }
                        else
                        {
                            makeLineCurrent =
                            selectNewLine = true;
                        }
                    }
                    else
                    {
                        ClearSelection();
                        makeLineCurrent =
                        selectNewLine = true;
                    }

                    if ( selectNewLine )
                        oper.SelectLine(this, line, event);

                    if ( makeLineCurrent )
                        oper.MakeLineCurrent(this, line);

                    if ( !oper.CanDragMove(this) )
                        ChangeCursorMode(oper.GetCursorModeSelect(), labelWin);
                }
            }
        }
    }

    // ------------ Left double click
    //
    else if (event.LeftDClick() )
    {
        if ( lineEdge != wxNOT_FOUND && oper.CanDragLineSize(this, line) )
        {
            // adjust row or column size depending on label text
            oper.HandleLineAutosize(this, lineEdge, event);

            ChangeCursorMode(WXGRID_CURSOR_SELECT_CELL, labelWin);
            m_dragLastPos = -1;
        }
        else // not on line separator or it's not resizable
        {
            ChangeCursorMode(WXGRID_CURSOR_SELECT_CELL, labelWin);  // can be CursorModeMove at label edge
            if ( line >=0 &&
                 oper.SendEvent( this, wxEVT_GRID_LABEL_LEFT_DCLICK, line, event ) == Event_Unhandled )
            {
                // no default action at the moment
            }
        }
    }

    // ------------ Left button released
    //
    else if ( event.LeftUp() )
    {
        if ( m_dragRowOrCol != -1 && m_cursorMode == oper.GetCursorModeResize() )
        {
            DoEndDragResizeRowOrCol(event, gridWindow, oper);
        }
        else if ( m_dragLabel && m_cursorMode == oper.GetCursorModeResize() )
        {
            oper.DoEndLabelResize(this, event, gridWindow);
        }
        else if ( labelEdgeOper && m_cursorMode == labelEdgeOper->GetCursorModeResize() )
        {
            event.SetPosition(posEvent);
            labelEdgeOper->DoEndLabelResize(this, event, nullptr);
        }
        else if ( m_cursorMode == oper.GetCursorModeMove() )
        {
            if ( CheckIfAtDragSourceLine(oper, coord) )
            {
                // the line didn't actually move anywhere, "unpress" the label
                if ( oper.GetOrientation() == wxVERTICAL && line != -1 )
                    DoColHeaderClick(line);
                oper.GetHeaderWindow(this)->Refresh();
            }
            else
            {
                // find the target position: start with current mouse position
                // (posAt and lineAt are always valid indices, not wxNOT_FOUND)
                int posNew = posAt;

                // adjust for the row being dragged itself
                if ( posAt < oper.GetLinePos(this, m_dragMoveRowOrCol) )
                    posNew++;

                // if mouse is on the near part of the target row,
                // insert it before it, not after
                if ( posNew > 0 &&
                     ( coord <= oper.GetLineStartPos(this, lineAt) +
                                oper.GetLineSize(this, lineAt) / 2 ) )
                    posNew--;

                oper.DoEndMove(this, posNew);
            }
        }
        else if ( oper.GetOrientation() == wxHORIZONTAL && line != -1 &&
                  (m_cursorMode == WXGRID_CURSOR_SELECT_CELL ||
                   m_cursorMode == WXGRID_CURSOR_SELECT_COL) )
        {
            DoColHeaderClick(line);
        }
        EndDraggingIfNecessary();
    }

    // ------------ Right button down
    //
    else if ( event.RightDown() )
    {
        if ( line < 0 ||
             oper.SendEvent( this, wxEVT_GRID_LABEL_RIGHT_CLICK, line, event ) == Event_Unhandled )
        {
            // no default action at the moment
            event.Skip();
        }
    }

    // ------------ Right double click
    //
    else if ( event.RightDClick() )
    {
        if ( line < 0 ||
             oper.SendEvent( this, wxEVT_GRID_LABEL_RIGHT_DCLICK, line, event ) == Event_Unhandled )
        {
            // no default action at the moment
            event.Skip();
        }
    }

    // ------------ No buttons down and mouse moving
    //
    else if ( event.Moving() )
    {
        if ( lineEdge != wxNOT_FOUND )
        {
            if ( m_cursorMode == WXGRID_CURSOR_SELECT_CELL )
            {
                if ( oper.CanDragLineSize(this, lineEdge) )
                {
                    ChangeCursorMode(oper.GetCursorModeResize(), labelWin, false);
                }
            }
        }
        else if ( labelEdgeOper )
        {
            if ( m_cursorMode == WXGRID_CURSOR_SELECT_CELL )
            {
                ChangeCursorMode(labelEdgeOper->GetCursorModeResize(), labelWin, false);
            }
        }
        else if ( m_cursorMode != WXGRID_CURSOR_SELECT_CELL )
        {
            ChangeCursorMode(WXGRID_CURSOR_SELECT_CELL, labelWin, false);
        }
    }

    // Don't consume the remaining events (e.g. right up).
    else
    {
        event.Skip();
    }
}

void wxGrid::UpdateCurrentCellOnRedim()
{
    if (m_currentCellCoords == wxGridNoCellCoords)
    {
        // We didn't have any valid selection before, which can only happen
        // if the grid was empty.
        // Check if this is still the case and ensure we do have valid
        // selection if the grid is not empty any more.
        if (m_numCols > 0 && m_numRows > 0)
        {
            SetCurrentCell(0, 0);
        }
    }
    else
    {
        if (m_numCols == 0 || m_numRows == 0)
        {
            // We have to reset the selection, as it must either use validate
            // coordinates otherwise, but there are no valid coordinates for
            // the grid cells any more now that it is empty.
            m_currentCellCoords = wxGridNoCellCoords;
        }
        else
        {
            // Check if the current cell coordinates are still valid.
            wxGridCellCoords updatedCoords = m_currentCellCoords;
            if ( updatedCoords.GetCol() >= m_numCols )
                updatedCoords.SetCol(m_numCols - 1);
            if ( updatedCoords.GetRow() >= m_numRows )
                updatedCoords.SetRow(m_numRows - 1);

            // And change them if they're not.
            if ( updatedCoords != m_currentCellCoords )
            {
                // Prevent SetCurrentCell() from redrawing the previous current
                // cell whose coordinates are invalid now.
                m_currentCellCoords = wxGridNoCellCoords;
                SetCurrentCell(updatedCoords);
            }
        }
    }
}

void wxGrid::UpdateColumnSortingIndicator(int col)
{
    wxCHECK_RET( col != wxNOT_FOUND, "invalid column index" );

    if ( m_useNativeHeader )
        GetGridColHeader()->UpdateColumn(col);
    else if ( m_nativeColumnLabels )
        m_colLabelWin->Refresh();
    //else: sorting indicator display not yet implemented in grid version
}

void wxGrid::SetSortingColumn(int col, bool ascending)
{
    if ( col == m_sortCol )
    {
        // we are already using this column for sorting (or not sorting at all)
        // but we might still change the sorting order, check for it
        if ( m_sortCol != wxNOT_FOUND && ascending != m_sortIsAscending )
        {
            m_sortIsAscending = ascending;

            UpdateColumnSortingIndicator(m_sortCol);
        }
    }
    else // we're changing the column used for sorting
    {
        const int sortColOld = m_sortCol;

        // change it before updating the column as we want GetSortingColumn()
        // to return the correct new value
        m_sortCol = col;

        if ( sortColOld != wxNOT_FOUND )
            UpdateColumnSortingIndicator(sortColOld);

        if ( m_sortCol != wxNOT_FOUND )
        {
            m_sortIsAscending = ascending;
            UpdateColumnSortingIndicator(m_sortCol);
        }
    }
}

void wxGrid::DoColHeaderClick(int col)
{
    // we consider that the grid was resorted if this event is processed and
    // not vetoed
    if ( SendEvent(wxEVT_GRID_COL_SORT, -1, col) == Event_Handled )
    {
        SetSortingColumn(col, IsSortingBy(col) ? !m_sortIsAscending : true);
        Refresh();
    }
}

void wxGrid::DoStartResizeRowOrCol(int col, int size)
{
    // Hide the editor if it's currently shown to avoid any weird interactions
    // with it while dragging the row/column separator.
    AcceptCellEditControlIfShown();

    m_dragRowOrCol = col;
    m_dragRowOrColOldSize = size;
}

void wxGrid::DoStartResizeLabel(int size)
{
    // Hide the editor if it's currently shown to avoid any weird interactions
    // with it while dragging the row/column separator.
    AcceptCellEditControlIfShown();

    m_dragLabel = true;
    m_dragRowOrColOldSize = size;
}

void wxGrid::ProcessCornerLabelMouseEvent( wxMouseEvent& event )
{

    if ( CheckIfDragCancelled(&event) )
        return;

    // if label resize is allowed:
    //  - check the mouse position is at right or bottom edge
    //  - initialize oper to correct operation type
    bool atBottomEdge = false, atRightEdge = false, atLabelEdge = false;
    const wxPoint posEvent = event.GetPosition();
    int edge = FromDIP(WXGRID_LABEL_EDGE_ZONE);
    std::unique_ptr<wxGridOperations> oper;

    if ( m_canDragRowLabelSize && posEvent.x >= m_rowLabelWidth - edge )
        atLabelEdge = atRightEdge = true;
    else if ( m_canDragColLabelSize && posEvent.y >= m_colLabelHeight - edge )
        atLabelEdge = atBottomEdge = true;

    if ( m_cursorMode == WXGRID_CURSOR_RESIZE_ROW ||
        ( atBottomEdge && m_cursorMode == WXGRID_CURSOR_SELECT_CELL ) )
        oper.reset(new wxGridRowOperations());
    else if ( m_cursorMode == WXGRID_CURSOR_RESIZE_COL || atRightEdge )
        oper.reset(new wxGridColumnOperations());

    if ( m_dragLabel && event.Dragging() )
    {
        if ( !m_isDragging )
            m_isDragging = true;

        if ( event.LeftIsDown() )
        {
            if ( oper && m_cursorMode == oper->GetCursorModeResize() )
            {
                DoGridDragResize(event.GetPosition(), *oper, nullptr);
            }
        }
        return;
    }

    if ( (m_isDragging || m_winCapture == m_cornerLabelWin) && (event.Entering() || event.Leaving()) )
        return;

    if ( event.Entering() || event.Leaving() )
    {
        ChangeCursorMode(WXGRID_CURSOR_SELECT_CELL, m_cornerLabelWin);
    }
    else if ( event.LeftDown() )
    {
        if ( atLabelEdge && oper->CanDragLabelSize(this) )
        {
            DoStartResizeLabel(oper->GetLabelSize(this));
            ChangeCursorMode(oper->GetCursorModeResize(), m_cornerLabelWin);
        }
        // indicate corner label by having both row and col args == -1
        else if ( SendEvent(wxEVT_GRID_LABEL_LEFT_CLICK, -1, -1, event) == Event_Unhandled )
        {
            SelectAll();
        }
    }
    else if ( event.LeftUp() && m_isDragging && m_dragLabel )
    {
        if ( m_cursorMode == oper->GetCursorModeResize() )
        {
            oper->DoEndLabelResize(this, event, nullptr);
        }
        EndDraggingIfNecessary();
    }
    else if ( event.LeftDClick() )
    {
        SendEvent( wxEVT_GRID_LABEL_LEFT_DCLICK, -1, -1, event );
    }
    else if ( event.RightDown() )
    {
        if ( SendEvent( wxEVT_GRID_LABEL_RIGHT_CLICK, -1, -1, event ) == Event_Unhandled )
        {
            // no default action at the moment
            event.Skip();
        }
    }
    else if ( event.RightDClick() )
    {
        if ( SendEvent( wxEVT_GRID_LABEL_RIGHT_DCLICK, -1, -1, event ) == Event_Unhandled )
        {
            // no default action at the moment
            event.Skip();
        }
    }
    else if ( event.Moving() )
    {
        if ( atLabelEdge )
            ChangeCursorMode(oper->GetCursorModeResize(), m_cornerLabelWin, false);
        else
            ChangeCursorMode(WXGRID_CURSOR_SELECT_CELL, m_cornerLabelWin, false);
    }
    else
    {
        event.Skip();
    }
}

void wxGrid::HandleRowAutosize(int row, const wxMouseEvent& event)
{
    // adjust row height depending on label text
    //
    // TODO: generate RESIZING event, see #10754
    if ( !SendGridSizeEvent(wxEVT_GRID_ROW_AUTO_SIZE, row, event) )
        AutoSizeRowLabelSize(row);

    SendGridSizeEvent(wxEVT_GRID_ROW_SIZE, row, event);
}

void wxGrid::HandleColumnAutosize(int col, const wxMouseEvent& event)
{
    // adjust column width depending on label text
    //
    // TODO: generate RESIZING event, see #10754
    if ( !SendGridSizeEvent(wxEVT_GRID_COL_AUTO_SIZE, col, event) )
        AutoSizeColLabelSize(col);

    SendGridSizeEvent(wxEVT_GRID_COL_SIZE, col, event);
}

void wxGrid::CancelMouseCapture()
{
    // cancel operation currently in progress, whatever it is
    if ( m_winCapture )
    {
        if ( m_cursorMode == WXGRID_CURSOR_MOVE_COL ||
             m_cursorMode == WXGRID_CURSOR_MOVE_ROW )
            m_winCapture->Refresh();
        DoAfterDraggingEnd();
    }
}

void wxGrid::DoAfterDraggingEnd()
{
    if ( m_isDragging &&
         (m_cursorMode == WXGRID_CURSOR_SELECT_CELL ||
          m_cursorMode == WXGRID_CURSOR_SELECT_ROW ||
          m_cursorMode == WXGRID_CURSOR_SELECT_COL) )
    {
        m_selection->EndSelecting();
    }

    m_isDragging = false;
    m_startDragPos = wxDefaultPosition;
    m_lastMousePos = wxDefaultPosition;
    // from drag moving row/col
    m_dragMoveRowOrCol = -1;
    m_dragLastPos = -1;
    m_dragLastColour = nullptr;

    m_cursorMode = WXGRID_CURSOR_SELECT_CELL;
    m_winCapture->SetCursor( *wxSTANDARD_CURSOR );
    m_winCapture = nullptr;
}

void wxGrid::EndDraggingIfNecessary()
{
    if ( m_winCapture )
    {
        m_winCapture->ReleaseMouse();

        DoAfterDraggingEnd();
    }
}

void wxGrid::ChangeCursorMode(CursorMode mode,
                              wxWindow *win,
                              bool captureMouse)
{
#if wxUSE_LOG_TRACE
    static const wxChar *const cursorModes[] =
    {
        wxT("SELECT_CELL"),
        wxT("RESIZE_ROW"),
        wxT("RESIZE_COL"),
        wxT("SELECT_ROW"),
        wxT("SELECT_COL"),
        wxT("MOVE_ROW"),
        wxT("MOVE_COL"),
    };

    wxLogTrace(wxT("grid"),
               wxT("wxGrid cursor mode (mouse capture for %s): %s -> %s"),
               win == m_colLabelWin ? wxT("colLabelWin")
                                    : win ? wxT("rowLabelWin")
                                          : wxT("gridWin"),
               cursorModes[m_cursorMode], cursorModes[mode]);
#endif // wxUSE_LOG_TRACE

    if ( mode == m_cursorMode &&
         win == m_winCapture &&
         captureMouse == (m_winCapture != nullptr))
        return;

    if ( !win )
    {
        // by default use the grid itself
        win = m_gridWin;
    }

    EndDraggingIfNecessary();

    m_cursorMode = mode;

    switch ( m_cursorMode )
    {
        case WXGRID_CURSOR_RESIZE_ROW:
            win->SetCursor( m_rowResizeCursor );
            break;

        case WXGRID_CURSOR_RESIZE_COL:
            win->SetCursor( m_colResizeCursor );
            break;

        case WXGRID_CURSOR_MOVE_ROW:
        case WXGRID_CURSOR_MOVE_COL:
            win->SetCursor( wxCursor(wxCURSOR_HAND) );
            break;

        case WXGRID_CURSOR_SELECT_CELL:
            // Mouse is captured in ProcessGridCellMouseEvent() in this mode.
            captureMouse = false;
            wxFALLTHROUGH;

        case WXGRID_CURSOR_SELECT_ROW:
        case WXGRID_CURSOR_SELECT_COL:
            win->SetCursor( *wxSTANDARD_CURSOR );
            break;
    }

    if ( captureMouse )
    {
        win->CaptureMouse();
        m_winCapture = win;
    }
}

// ----------------------------------------------------------------------------
// grid mouse event processing
// ----------------------------------------------------------------------------

bool
wxGrid::DoGridCellDrag(wxMouseEvent& event,
                       const wxGridCellCoords& coords,
                       bool isFirstDrag)
{
    if ( coords == wxGridNoCellCoords )
        return false; // we're outside any valid cell

    if ( isFirstDrag )
    {
        // Hide the edit control, so it won't interfere with drag-shrinking.
        AcceptCellEditControlIfShown();

        switch ( event.GetModifiers() )
        {
            case wxMOD_CONTROL:
                // Ctrl-dragging is special, because we could have started it
                // by Ctrl-clicking a previously selected cell, which has the
                // effect of deselecting it and in this case we can't start
                // drag-selection from it because the selection anchor should
                // always be selected itself.
                if ( !m_selection->IsInSelection(m_currentCellCoords) )
                    return false;
                break;

            case wxMOD_NONE:
                if ( CanDragCell() )
                {
                    // if event is handled by user code, no further processing
                    return SendEvent(wxEVT_GRID_CELL_BEGIN_DRAG, coords, event) == Event_Unhandled;
                }
                break;

            //default: In all the other cases, we don't have anything special
            //         to do and we'll just extend the selection below.
        }
    }

    // Note that we don't need to check the modifiers here, it doesn't matter
    // which keys are pressed for the current event, as pressing or releasing
    // Ctrl later can't change the dragging behaviour. Only the initial state
    // of the modifier keys matters.
    if ( m_selection )
    {
        m_selection->ExtendCurrentBlock(m_currentCellCoords,
                                        coords,
                                        event,
                                        wxEVT_GRID_RANGE_SELECTING);
    }

    return true;
}

bool wxGrid::DoGridDragEvent(wxMouseEvent& event,
                             const wxGridCellCoords& coords,
                             bool isFirstDrag,
                             wxGridWindow *gridWindow)
{
    switch ( m_cursorMode )
    {
        case WXGRID_CURSOR_SELECT_CELL:
            return DoGridCellDrag(event, coords, isFirstDrag);

        case WXGRID_CURSOR_RESIZE_ROW:
        case WXGRID_CURSOR_RESIZE_COL:
        {
            const auto oper(DoGetOperationsFromCursorMode());
            if ( m_dragLabel || m_dragRowOrCol != -1 )
                DoGridDragResize(event.GetPosition(), *oper, gridWindow);
        }
        break;

        default:
            event.Skip();
    }

    return true;
}

void
wxGrid::DoGridCellLeftDown(wxMouseEvent& event,
                           const wxGridCellCoords& coords,
                           const wxPoint& pos,
                           wxGridWindow* gridWindow)
{
    if ( SendEvent(wxEVT_GRID_CELL_LEFT_CLICK, coords, event) != Event_Unhandled )
    {
        // event handled by user code, no need to do anything here
        return;
    }


    bool captureMouse = false;
    // Process the mouse down event depending on the current cursor mode. Note
    // that this assumes m_cursorMode was set in the mouse move event hendler.
    switch ( m_cursorMode )
    {
        case WXGRID_CURSOR_RESIZE_ROW:
        case WXGRID_CURSOR_RESIZE_COL:
            {
                const auto oper(DoGetOperationsFromCursorMode());
                int dragRowOrCol = PosToEdgeOfLine(oper->Dual().Select(pos), *oper);

                if ( dragRowOrCol != wxNOT_FOUND )
                {
                    DoStartResizeRowOrCol(dragRowOrCol, oper->GetLineSize(this, dragRowOrCol));
                }
                else
                {
                    DoStartResizeLabel(oper->GetLabelSize(this));
                    captureMouse = true;
                }
            }
            break;

        case WXGRID_CURSOR_SELECT_CELL:
        case WXGRID_CURSOR_SELECT_ROW:
        case WXGRID_CURSOR_SELECT_COL:
            DisableCellEditControl();
            MakeCellVisible(coords);

            if (event.ShiftDown() && !event.CmdDown())
            {
                if (m_selection)
                {
                    m_selection->ExtendCurrentBlock(m_currentCellCoords, coords, event);
                }
            }
            else
            {
                if ( event.CmdDown() && !event.ShiftDown() )
                {
                    if ( m_selection )
                    {
                        if ( !m_selection->IsInSelection(coords) )
                        {
                            // If the cell is not selected, select it.
                            m_selection->SelectBlock(coords.GetRow(), coords.GetCol(),
                                                     coords.GetRow(), coords.GetCol(),
                                                     event);
                        }
                        else
                        {
                            // Otherwise deselect it.
                            m_selection->DeselectBlock(
                                wxGridBlockCoords(coords.GetRow(), coords.GetCol(),
                                                  coords.GetRow(), coords.GetCol()),
                                                  event);
                        }
                    }
                }
                else
                {
                    ClearSelection();

                    if ( m_selection )
                    {
                        // In row or column selection mode just clicking on the cell
                        // should select the row or column containing it: this is more
                        // convenient for the kinds of controls that use such selection
                        // mode and is compatible with 2.8 behaviour (see #12062).
                        switch ( m_selection->GetSelectionMode() )
                        {
                            case wxGridSelectNone:
                            case wxGridSelectCells:
                            case wxGridSelectRowsOrColumns:
                                // nothing to do in these cases
                                break;

                            case wxGridSelectRows:
                                m_selection->SelectRow(coords.GetRow());
                                break;

                            case wxGridSelectColumns:
                                m_selection->SelectCol(coords.GetCol());
                                break;
                        }
                    }

                    m_waitForSlowClick = m_currentCellCoords == coords &&
                                         coords != wxGridNoCellCoords;
                }

                SetCurrentCell(coords);
            }
            break;

        case WXGRID_CURSOR_MOVE_ROW:
        case WXGRID_CURSOR_MOVE_COL:
            // Nothing to do here for this case.
            break;
    }

    if ( captureMouse && m_winCapture != gridWindow )
    {
        // for label resizing, we capture the mouse as the we might be at x or y = 0 and
        // the window could be left before resizing actually starts / dragging is detected
        gridWindow->CaptureMouse();
        m_winCapture = gridWindow;
        m_isDragging = true;  // avoid capturing again in ProcessGridCellMouseEvent
    }
}

void
wxGrid::DoGridCellLeftDClick(wxMouseEvent& event,
                             const wxGridCellCoords& coords,
                             const wxPoint& pos)
{
    if ( XToEdgeOfCol(pos.x) < 0 && YToEdgeOfRow(pos.y) < 0 )
    {
        if ( SendEvent(wxEVT_GRID_CELL_LEFT_DCLICK, coords, event) == Event_Unhandled )
        {
            // we want double click to select a cell and start editing
            // (i.e. to behave in same way as sequence of two slow clicks):
            m_waitForSlowClick = true;
        }
    }
}

// helper to get the wxGridOperations that match the cursor mode
// the returned unique_ptr does not require a delete
std::unique_ptr<wxGridOperations> wxGrid::DoGetOperationsFromCursorMode()
{
    if ( m_cursorMode == WXGRID_CURSOR_RESIZE_ROW )
        return std::unique_ptr<wxGridOperations> (new wxGridRowOperations());
    if ( m_cursorMode == WXGRID_CURSOR_RESIZE_COL )
        return std::unique_ptr<wxGridOperations> (new wxGridColumnOperations());
    return nullptr;
}

void
wxGrid::DoGridCellLeftUp(wxMouseEvent& event,
                         const wxGridCellCoords& coords,
                         wxGridWindow* gridWindow)
{
    if ( m_cursorMode == WXGRID_CURSOR_SELECT_CELL )
    {
        if ( coords == m_currentCellCoords && m_waitForSlowClick && CanEnableCellControl() )
        {
            ClearSelection();

            if ( DoEnableCellEditControl(wxGridActivationSource::From(event)) )
                GetCurrentCellEditorPtr()->StartingClick();

            m_waitForSlowClick = false;
        }
    }
    else if ( m_cursorMode == WXGRID_CURSOR_RESIZE_ROW ||
              m_cursorMode == WXGRID_CURSOR_RESIZE_COL )
    {
        const auto oper(DoGetOperationsFromCursorMode());
        ChangeCursorMode(WXGRID_CURSOR_SELECT_CELL);
        if ( m_dragRowOrCol != -1 )
            DoEndDragResizeRowOrCol(event, gridWindow, *oper);
        else if ( m_dragLabel )
            DoEndDragResizeLabel(event, gridWindow, *oper);
    }

    m_dragLastPos = -1;
}

void
wxGrid::DoGridMouseMoveEvent(wxMouseEvent& WXUNUSED(event),
                             const wxGridCellCoords& coords,
                             const wxPoint& pos,
                             wxGridWindow* gridWindow)
{
    if ( coords.GetRow() < 0 || coords.GetCol() < 0 )
    {
        // out of grid cell area
        ChangeCursorMode(WXGRID_CURSOR_SELECT_CELL);
        return;
    }

    int dragRow = YToEdgeOfRow( pos.y );
    int dragCol = XToEdgeOfCol( pos.x );
    int edge = FromDIP(WXGRID_LABEL_EDGE_ZONE);

    // Dragging on the corner of a cell to resize in both directions is not
    // implemented, so choose to resize the column when the cursor is over the
    // cell corner, as this is a more common operation.
    CursorMode newCursorMode = WXGRID_CURSOR_SELECT_CELL;  // default value

    if ( dragCol >= 0 && CanDragGridColEdges() && CanDragColSize(dragCol) )
        newCursorMode = WXGRID_CURSOR_RESIZE_COL;
    else if ( dragRow >= 0 && CanDragGridRowEdges() && CanDragRowSize(dragRow) )
        newCursorMode = WXGRID_CURSOR_RESIZE_ROW;
    else if ( abs(pos.x) <= edge && CanDragRowLabelSize() )
        newCursorMode = WXGRID_CURSOR_RESIZE_COL;
    else if ( abs(pos.y) <= edge && CanDragColLabelSize() )
        newCursorMode = WXGRID_CURSOR_RESIZE_ROW;

    if ( newCursorMode != m_cursorMode )
        ChangeCursorMode(newCursorMode, gridWindow, false);
}

void wxGrid::ProcessGridCellMouseEvent(wxMouseEvent& event, wxGridWindow *eventGridWindow )
{
    // the window receiving the event might not be the same as the one under
    // the mouse (e.g. in the case of a dragging event started in one window,
    // but continuing over another one)

    if ( CheckIfDragCancelled(&event) )
        return;

    wxGridWindow *gridWindow =
        DevicePosToGridWindow(event.GetPosition() + eventGridWindow->GetPosition());

    if ( !gridWindow )
        gridWindow = eventGridWindow;

    // store position, before it's modified in the next step
    const wxPoint posEvent = event.GetPosition();

    event.SetPosition(posEvent + eventGridWindow->GetPosition() -
                      wxPoint(m_rowLabelWidth, m_colLabelHeight));

    wxPoint pos = CalcGridWindowUnscrolledPosition(event.GetPosition(), gridWindow);

    // coordinates of the cell under mouse
    wxGridCellCoords coords = XYToCell(pos, gridWindow);

    int cell_rows, cell_cols;
    if ( GetCellSize( coords.GetRow(), coords.GetCol(), &cell_rows, &cell_cols )
            == CellSpan_Inside )
    {
        coords.SetRow(coords.GetRow() + cell_rows);
        coords.SetCol(coords.GetCol() + cell_cols);
    }

    // Releasing the left mouse button must be processed in any case, so deal
    // with it first.
    if ( event.LeftUp() )
    {
        // Note that we must call this one first, before resetting the
        // drag-related data, as it relies on m_cursorMode being still set and
        // EndDraggingIfNecessary() resets it.
        DoGridCellLeftUp(event, coords, gridWindow);

        EndDraggingIfNecessary();
        return;
    }

    const bool isDraggingWithLeft = event.Dragging() && event.LeftIsDown();

    if ( isDraggingWithLeft && (m_winCapture == eventGridWindow) )
    {
        // scroll when at the edges or outside the window
        CheckDoDragScroll(eventGridWindow, m_gridWin, posEvent,
                          wxHORIZONTAL | wxVERTICAL);
    }

    // While dragging the mouse, only releasing the left mouse button, which
    // cancels the drag operation, is processed (above) and any other events
    // are just ignored while it's in progress.
    if ( m_isDragging )
    {
        if ( isDraggingWithLeft )
            DoGridDragEvent(event, coords, false /* not first drag */, gridWindow);

        if ( m_winCapture != gridWindow )
        {
            if ( m_winCapture )
                m_winCapture->ReleaseMouse();

            m_winCapture = gridWindow;
            m_winCapture->CaptureMouse();
        }
        return;
    }

    // Now check if we're starting a drag operation (if it had been already
    // started, m_isDragging would be true above).
    if ( isDraggingWithLeft )
    {
        // To avoid accidental drags, don't start doing anything until the
        // mouse has been dragged far enough.
        const wxPoint& pt = event.GetPosition();
        if ( m_startDragPos == wxDefaultPosition )
        {
            m_startDragPos = pt;
            return;
        }

        if ( abs(m_startDragPos.x - pt.x) <= DRAG_SENSITIVITY &&
                abs(m_startDragPos.y - pt.y) <= DRAG_SENSITIVITY )
            return;

        if ( DoGridDragEvent(event, coords, true /* first drag */, gridWindow) )
        {
            wxASSERT_MSG( !m_winCapture, "shouldn't capture the mouse twice" );

            m_winCapture = gridWindow;
            m_winCapture->CaptureMouse();

            m_isDragging = true;
        }

        return;
    }

    // If we're not dragging, cancel any dragging operation which could have
    // been in progress.
    EndDraggingIfNecessary();

    bool handled = false;

    // deal with various button presses
    if ( event.IsButton() )
    {
        if ( coords != wxGridNoCellCoords )
        {
            DisableCellEditControl();

            if ( event.LeftDown() )
            {
                DoGridCellLeftDown(event, coords, pos, gridWindow);
                handled = true;
            }
            else if ( event.LeftDClick() )
            {
                DoGridCellLeftDClick(event, coords, pos);
                handled = true;
            }
            else if ( event.RightDown() )
                handled = SendEvent(wxEVT_GRID_CELL_RIGHT_CLICK, coords, event) != Event_Unhandled;
            else if ( event.RightDClick() )
                handled = SendEvent(wxEVT_GRID_CELL_RIGHT_DCLICK, coords, event) != Event_Unhandled;
        }
    }
    else if ( event.Moving() )
    {
        DoGridMouseMoveEvent(event, coords, pos, gridWindow);
        handled = true;
    }

    if ( !handled )
    {
        event.Skip();
    }
}

void wxGrid::DoGridDragResize(const wxPoint& position,
                              const wxGridOperations& oper,
                              wxGridWindow* gridWindow)
{
    wxCHECK_RET( m_dragRowOrCol != -1 || m_dragLabel,
                 "shouldn't be called when not drag resizing" );

    // Get the logical position from the physical one we're passed.
    wxPoint logicalPos = position;
    if ( gridWindow )
        logicalPos = CalcGridWindowUnscrolledPosition(position, gridWindow);

    // Size of the row/column is determined by the mouse coordinates in the
    // orthogonal direction.
    const int linePos = oper.Dual().Select(logicalPos);

    if ( m_dragLabel )
    {
        // dragging label size, either in row/col label window or corner
        if ( gridWindow )
            oper.SetLabelSize(this, wxMax(linePos + oper.GetLabelSize(this), oper.GetMinimalLabelSize(this)));
        else
            oper.SetLabelSize(this, wxMax(linePos, oper.GetMinimalLabelSize(this)));
    }
    else
    {
        const int lineStart = oper.GetLineStartPos(this, m_dragRowOrCol);
        oper.SetLineSize(this, m_dragRowOrCol,
            wxMax(linePos - lineStart,
                oper.GetMinimalLineSize(this, m_dragRowOrCol)));
        // TODO: generate RESIZING event, see #10754, if the size has changed.
    }
}

wxPoint wxGrid::GetPositionForResizeEvent(int width) const
{
    wxCHECK_MSG( m_dragRowOrCol != -1, wxPoint(),
                 "shouldn't be called when not drag resizing" );

    // Note that we currently always use m_gridWin here as using
    // wxGridHeaderCtrl is incompatible with using frozen rows/columns.
    // This would need to be changed if they're allowed to be used together.
    int x;
    CalcGridWindowScrolledPosition(GetColLeft(m_dragRowOrCol) + width, 0,
                                   &x, nullptr,
                                   m_gridWin);

    return wxPoint(x, 0);
}

void wxGrid::DoEndDragResizeRowOrCol(const wxMouseEvent& event, wxGridWindow* gridWindow, const wxGridOperations& oper)
{
    DoGridDragResize(event.GetPosition(), oper, gridWindow);
    SendGridSizeEvent(oper.GetEventTypeLineSize(), m_dragRowOrCol, event);
    m_dragRowOrCol = -1;
}

void wxGrid::DoEndDragResizeLabel(const wxMouseEvent& event, wxGridWindow* gridWindow,
    const wxGridOperations& oper)
{
    DoGridDragResize(event.GetPosition(), oper, gridWindow);
    SendGridSizeEvent(oper.GetEventTypeLabelSize(), -1, event);
    m_dragLabel = false;
}

void wxGrid::DoHeaderStartDragResizeCol(int col)
{
    DoStartResizeRowOrCol(col, GetColSize(col));
}

void wxGrid::DoHeaderDragResizeCol(int width)
{
    DoGridDragResize(GetPositionForResizeEvent(width),
                     wxGridColumnOperations(),
                     m_gridWin);
}

void wxGrid::DoHeaderEndDragResizeCol(int width)
{
    // We can sometimes be called even when we're not resizing any more,
    // although it's rather difficult to reproduce: one way to do it is to
    // double click the column separator line while pressing Esc at the same
    // time. There seems to be some kind of check for Esc inside the native
    // header control and so an extra "end resizing" message gets generated.
    if ( m_dragRowOrCol == -1 )
        return;

    // Unfortunately we need to create a dummy mouse event here to avoid
    // modifying too much existing code. Note that only position and keyboard
    // state parts of this event object are actually used, so the rest
    // (even including some crucial parts, such as event type) can be left
    // uninitialized.
    wxMouseEvent e;
    e.SetState(wxGetMouseState());
    e.SetPosition(GetPositionForResizeEvent(width));

    DoEndDragResizeRowOrCol(e, m_gridWin, wxGridColumnOperations());
}

void wxGrid::DoStartMoveRowOrCol(int col)
{
    m_dragMoveRowOrCol = col;
}

void wxGrid::DoEndMoveRow(int pos)
{
    wxASSERT_MSG( m_dragMoveRowOrCol != -1, "no matching DoStartMoveRow?" );
    // col is used for the target row
    wxGridEvent gridEvt(GetId(), wxEVT_GRID_ROW_MOVE, this, m_dragMoveRowOrCol, pos);
    if ( DoSendEvent(gridEvt) != Event_Vetoed )
        SetRowPos(m_dragMoveRowOrCol, pos);

    m_dragMoveRowOrCol = -1;
}

void wxGrid::RefreshAfterRowPosChange()
{
    // recalculate the row bottoms as the row positions have changed,
    // unless we calculate them dynamically because all rows heights are the
    // same and it's easy to do
    if ( !m_rowHeights.empty() )
    {
        int rowBottom = 0;
        for ( int rowPos = 0; rowPos < m_numRows; rowPos++ )
        {
            int rowID = GetRowAt( rowPos );

            // Ignore the currently hidden rows.
            const int height = m_rowHeights[rowID];
            if ( height > 0 )
                rowBottom += height;

            m_rowBottoms[rowID] = rowBottom;
        }
    }

    // and make the changes visible
    RefreshArea(wxGA_Cells | wxGA_RowLabels);
}

void wxGrid::SetRowsOrder(const wxArrayInt& order)
{
    m_rowAt = order;

    RefreshAfterRowPosChange();
}

void wxGrid::SetRowPos(int idx, int pos)
{
    // we're going to need m_rowAt now, initialize it if needed
    if ( m_rowAt.empty() )
    {
        m_rowAt.reserve(m_numRows);
        for ( int i = 0; i < m_numRows; i++ )
            m_rowAt.push_back(i);
    }

    // from wxHeaderCtrl::MoveRowInOrderArray:
    int posOld = m_rowAt.Index(idx);
    wxASSERT_MSG( posOld != wxNOT_FOUND, "invalid index" );

    if ( pos != posOld )
    {
        m_rowAt.RemoveAt(posOld);
        m_rowAt.Insert(idx, pos);
    }

    RefreshAfterRowPosChange();
}

int wxGrid::GetRowPos(int idx) const
{
    wxASSERT_MSG( idx >= 0 && idx < m_numRows, "invalid row index" );

    if ( m_rowAt.IsEmpty() )
        return idx;

    int pos = m_rowAt.Index(idx);
    wxASSERT_MSG( pos != wxNOT_FOUND, "invalid row index" );

    return pos;
}

void wxGrid::ResetRowPos()
{
    m_rowAt.clear();

    RefreshAfterRowPosChange();
}

bool wxGrid::EnableDragRowMove( bool enable )
{
    if ( m_canDragRowMove == enable ||
        (enable && m_rowFrozenLabelWin) )
        return false;

    m_canDragRowMove = enable;

    // we use to call ResetRowPos() from here if !enable but this doesn't seem
    // right as it would mean there would be no way to "freeze" the current
    // rows order by disabling moving them after putting them in the desired
    // order, whereas now you can always call ResetRowPos() manually if needed
    return true;
}

void wxGrid::DoEndMoveCol(int pos)
{
    wxASSERT_MSG( m_dragMoveRowOrCol != -1, "no matching DoStartMoveCol?" );
    // row is used for the target col
    wxGridEvent gridEvt(GetId(), wxEVT_GRID_COL_MOVE, this, pos, m_dragMoveRowOrCol);
    if ( DoSendEvent(gridEvt) != Event_Vetoed )
        SetColPos(m_dragMoveRowOrCol, pos);

    m_dragMoveRowOrCol = -1;
}

void wxGrid::RefreshAfterColPosChange()
{
    // recalculate the column rights as the column positions have changed,
    // unless we calculate them dynamically because all columns widths are the
    // same and it's easy to do
    if ( !m_colWidths.empty() )
    {
        int colRight = 0;
        for ( int colPos = 0; colPos < m_numCols; colPos++ )
        {
            int colID = GetColAt( colPos );

            // Ignore the currently hidden columns.
            const int width = m_colWidths[colID];
            if ( width > 0 )
                colRight += width;

            m_colRights[colID] = colRight;
        }
    }

    int areas = wxGA_Cells;

    // and make the changes visible
    if ( m_useNativeHeader )
    {
        SetNativeHeaderColOrder();
    }
    else
    {
        areas |= wxGA_ColLabels;
    }

    RefreshArea(areas);
}

void wxGrid::SetColumnsOrder(const wxArrayInt& order)
{
    m_colAt = order;

    RefreshAfterColPosChange();
}

void wxGrid::SetColPos(int idx, int pos)
{
    // we're going to need m_colAt now, initialize it if needed
    if ( m_colAt.empty() )
    {
        m_colAt.reserve(m_numCols);
        for ( int i = 0; i < m_numCols; i++ )
            m_colAt.push_back(i);
    }

    wxHeaderCtrl::MoveColumnInOrderArray(m_colAt, idx, pos);

    RefreshAfterColPosChange();
}

int wxGrid::GetColPos(int idx) const
{
    wxASSERT_MSG( idx >= 0 && idx < m_numCols, "invalid column index" );

    if ( m_colAt.IsEmpty() )
        return idx;

    int pos = m_colAt.Index(idx);
    wxASSERT_MSG( pos != wxNOT_FOUND, "invalid column index" );

    return pos;
}

void wxGrid::ResetColPos()
{
    m_colAt.clear();

    RefreshAfterColPosChange();
}

bool wxGrid::EnableDragColMove( bool enable )
{
    if ( m_canDragColMove == enable ||
        (enable && m_colFrozenLabelWin) )
        return false;

    if ( m_useNativeHeader )
    {
        wxHeaderCtrl *header = GetGridColHeader();
        long setFlags = header->GetWindowStyleFlag();

        if ( enable )
            header->SetWindowStyleFlag(setFlags | wxHD_ALLOW_REORDER);
        else
            header->SetWindowStyleFlag(setFlags & ~wxHD_ALLOW_REORDER);
    }

    m_canDragColMove = enable;

    // we use to call ResetColPos() from here if !enable but this doesn't seem
    // right as it would mean there would be no way to "freeze" the current
    // columns order by disabling moving them after putting them in the desired
    // order, whereas now you can always call ResetColPos() manually if needed
    return true;
}

bool wxGrid::EnableHidingColumns(bool enable)
{
    if ( m_canHideColumns == enable || !m_useNativeHeader )
        return false;

    GetGridColHeader()->ToggleWindowStyle(wxHD_ALLOW_HIDE);

    m_canHideColumns = enable;

    return true;
}

void wxGrid::InitializeFrozenWindows()
{
    // frozen row windows
    if ( m_numFrozenRows > 0 && !m_frozenRowGridWin )
    {
        m_frozenRowGridWin = new wxGridWindow(this, wxGridWindow::wxGridWindowFrozenRow);
        m_rowFrozenLabelWin = new wxGridRowFrozenLabelWindow(this);

        m_frozenRowGridWin->SetOwnForegroundColour(m_gridWin->GetForegroundColour());
        m_frozenRowGridWin->SetOwnBackgroundColour(m_gridWin->GetBackgroundColour());
        m_rowFrozenLabelWin->SetOwnForegroundColour(m_labelTextColour);
        m_rowFrozenLabelWin->SetOwnBackgroundColour(m_labelBackgroundColour);
    }
    else if ( m_numFrozenRows == 0 && m_frozenRowGridWin )
    {
        delete m_frozenRowGridWin;
        delete m_rowFrozenLabelWin;
        m_frozenRowGridWin = nullptr;
        m_rowFrozenLabelWin = nullptr;
    }

    // frozen column windows
    if ( m_numFrozenCols > 0 && !m_frozenColGridWin )
    {
        m_frozenColGridWin = new wxGridWindow(this, wxGridWindow::wxGridWindowFrozenCol);
        m_colFrozenLabelWin = new wxGridColFrozenLabelWindow(this);

        m_frozenColGridWin->SetOwnForegroundColour(m_gridWin->GetForegroundColour());
        m_frozenColGridWin->SetOwnBackgroundColour(m_gridWin->GetBackgroundColour());
        m_colFrozenLabelWin->SetOwnForegroundColour(m_labelTextColour);
        m_colFrozenLabelWin->SetOwnBackgroundColour(m_labelBackgroundColour);
    }
    else if ( m_numFrozenCols == 0 && m_frozenColGridWin )
    {
        delete m_frozenColGridWin;
        delete m_colFrozenLabelWin;
        m_frozenColGridWin = nullptr;
        m_colFrozenLabelWin = nullptr;
    }

    // frozen corner window
    if ( m_numFrozenRows > 0 && m_numFrozenCols > 0 && !m_frozenCornerGridWin )
    {
        m_frozenCornerGridWin = new wxGridWindow(this, wxGridWindow::wxGridWindowFrozenCorner);

        m_frozenCornerGridWin->SetOwnForegroundColour(m_gridWin->GetForegroundColour());
        m_frozenCornerGridWin->SetOwnBackgroundColour(m_gridWin->GetBackgroundColour());
    }
    else if ((m_numFrozenRows == 0 || m_numFrozenCols == 0) && m_frozenCornerGridWin)
    {
        delete m_frozenCornerGridWin;
        m_frozenCornerGridWin = nullptr;
    }
}

bool wxGrid::FreezeTo(int row, int col)
{
    wxCHECK_MSG( row >= 0 && row <= m_numRows, false,
                 "Invalid number of rows to freeze" );

    wxCHECK_MSG( col >= 0 && col <= m_numCols, false,
                 "Invalid number of columns to freeze" );

    if ( !m_rowAt.empty() || m_canDragRowMove ||
         !m_colAt.empty() || m_canDragColMove || m_useNativeHeader )
        return false;

    // freeze
    if ( row > m_numFrozenRows || col > m_numFrozenCols )
    {
        // check all involved cells for merged ones
        int cell_rows, cell_cols;

        for ( int i = m_numFrozenRows; i < row; i++ )
        {
            for ( int j = 0; j < m_numCols; j++ )
            {
                GetCellSize(GetRowAt(i), GetColAt(j), &cell_rows, &cell_cols );

                if (( cell_rows > 1 ) || ( cell_cols > 1 ))
                    return false;
            }
        }

        for ( int i = m_numFrozenCols; i < col; i++ )
        {
            for ( int j = 0; j < m_numRows; j++ )
            {
                GetCellSize(GetRowAt(j), GetColAt(i), &cell_rows, &cell_cols );

                if (( cell_rows > 1 ) || ( cell_cols > 1 ))
                    return false;
            }
        }
    }

    m_numFrozenRows = row;
    m_numFrozenCols = col;

    HideCellEditControl();

    InitializeFrozenWindows();

    // recompute dimensions
    InvalidateBestSize();

    CalcDimensions();

    if ( ShouldRefresh() )
        Refresh();

    return true;
}

bool wxGrid::IsFrozen() const
{
    return m_numFrozenRows || m_numFrozenCols;
}

void wxGrid::UpdateGridWindows() const
{
    m_gridWin->Update();

    if ( m_frozenCornerGridWin )
        m_frozenCornerGridWin->Update();

    if ( m_frozenRowGridWin )
        m_frozenRowGridWin->Update();

    if ( m_frozenColGridWin )
        m_frozenColGridWin->Update();
}

//
// ------ interaction with data model
//
bool wxGrid::ProcessTableMessage( const wxGridTableMessage& msg )
{
    switch ( msg.GetId() )
    {
        case wxGRIDTABLE_NOTIFY_ROWS_INSERTED:
        case wxGRIDTABLE_NOTIFY_ROWS_APPENDED:
        case wxGRIDTABLE_NOTIFY_ROWS_DELETED:
        case wxGRIDTABLE_NOTIFY_COLS_INSERTED:
        case wxGRIDTABLE_NOTIFY_COLS_APPENDED:
        case wxGRIDTABLE_NOTIFY_COLS_DELETED:
            return Redimension( msg );

        default:
            return false;
    }
}

bool wxGrid::ProcessTableMessage(wxGridTableBase *table, int id,
                                 int comInt1,
                                 int comInt2)
{
    return ProcessTableMessage(wxGridTableMessage(table, id, comInt1, comInt2));
}

// The behaviour of this function depends on the grid table class
// Clear() function. For the default wxGridStringTable class the
// behaviour is to replace all cell contents with wxEmptyString but
// not to change the number of rows or cols.
//
void wxGrid::ClearGrid()
{
    if ( m_table )
    {
        DisableCellEditControl();

        m_table->Clear();
        if ( ShouldRefresh() )
            RefreshArea(wxGA_Cells);
    }
}

bool
wxGrid::DoModifyLines(bool (wxGridTableBase::*funcModify)(size_t, size_t),
                      int pos, int num, bool WXUNUSED(updateLabels) )
{
    wxCHECK_MSG( m_created, false, "must finish creating the grid first" );

    if ( !m_table )
        return false;

    DisableCellEditControl();

    return (m_table->*funcModify)(pos, num);

    // the table will have sent the results of the insert row
    // operation to this view object as a grid table message
}

bool
wxGrid::DoAppendLines(bool (wxGridTableBase::*funcAppend)(size_t),
                      int num, bool WXUNUSED(updateLabels))
{
    wxCHECK_MSG( m_created, false, "must finish creating the grid first" );

    if ( !m_table )
        return false;

    return (m_table->*funcAppend)(num);
}

// ----------------------------------------------------------------------------
// event generation helpers
// ----------------------------------------------------------------------------

bool
wxGrid::SendGridSizeEvent(wxEventType type,
                      int rowOrCol,
                      const wxMouseEvent& mouseEv)
{
   wxGridSizeEvent gridEvt( GetId(),
           type,
           this,
           rowOrCol,
           mouseEv.GetX() + GetRowLabelSize(),
           mouseEv.GetY() + GetColLabelSize(),
           mouseEv);

   return ProcessWindowEvent(gridEvt);
}

wxGrid::EventResult wxGrid::DoSendEvent(wxGridEvent& gridEvt)
{
    const bool claimed = ProcessWindowEvent(gridEvt);

    // A Veto'd event may not be `claimed' so test this first
    if ( !gridEvt.IsAllowed() )
        return Event_Vetoed;

    // Detect the special case in which the event cell was deleted, as this
    // allows to have checks in several functions that generate an event and
    // then proceed doing something by default with the selected cell: this
    // shouldn't be done if the user-defined handler deleted this cell.
    if ( gridEvt.GetRow() >= GetNumberRows() ||
            gridEvt.GetCol() >= GetNumberCols() )
        return Event_CellDeleted;

    return claimed ? Event_Handled : Event_Unhandled;
}

// Generate a grid event based on a mouse event and call DoSendEvent() with it.
wxGrid::EventResult
wxGrid::SendEvent(wxEventType type,
                  int row, int col,
                  const wxMouseEvent& mouseEv)
{

   if ( type == wxEVT_GRID_LABEL_LEFT_CLICK ||
        type == wxEVT_GRID_LABEL_LEFT_DCLICK ||
        type == wxEVT_GRID_LABEL_RIGHT_CLICK ||
        type == wxEVT_GRID_LABEL_RIGHT_DCLICK )
   {
       wxPoint pos = mouseEv.GetPosition();

       if ( mouseEv.GetEventObject() == GetGridRowLabelWindow() )
           pos.y += GetColLabelSize();
       if ( mouseEv.GetEventObject() == GetGridColLabelWindow() )
           pos.x += GetRowLabelSize();

       wxGridEvent gridEvt( GetId(),
               type,
               this,
               row, col,
               pos.x,
               pos.y,
               false,
               mouseEv);

       return DoSendEvent(gridEvt);
   }
   else
   {
       wxGridEvent gridEvt( GetId(),
               type,
               this,
               row, col,
               mouseEv.GetX() + GetRowLabelSize(),
               mouseEv.GetY() + GetColLabelSize(),
               false,
               mouseEv);

       if ( type == wxEVT_GRID_CELL_BEGIN_DRAG )
       {
           // by default the dragging is not supported, the user code must
           // explicitly allow the event for it to take place
           gridEvt.Veto();
       }

       return DoSendEvent(gridEvt);
   }
}

// Generate a grid event of specified type, return value same as above
//
wxGrid::EventResult
wxGrid::SendEvent(wxEventType type, int row, int col, const wxString& s)
{
    wxGridEvent gridEvt( GetId(), type, this, row, col );
    gridEvt.SetString(s);

    return DoSendEvent(gridEvt);
}

void wxGrid::Refresh(bool eraseb, const wxRect* rect)
{
    // Don't do anything if between Begin/EndBatch...
    // EndBatch() will do all this on the last nested one anyway.
    if ( ShouldRefresh() )
    {
        wxScrolledCanvas::Refresh(eraseb, rect);

        // Notice that this function expects the rectangle to be relative
        // to the wxGrid window itself, i.e. the origin (0, 0) at the top
        // left corner of the window. and will correctly refresh the sub-
        // windows for us, including the frozen ones, but only the parts
        // intersecting with rect will be refreshed of course. So if we
        // want to refresh a rectangle in a grid area, we should pass that
        // rectangle shifted by the position of the area in the grid. e.g.:
        // wxRect rect = ... // rect calculated relative to cells area
        // rect.Offset(GetRowLabelSize(), GetColLabelSize());
        // Refresh(true, &rect);
    }
}

void wxGrid::RefreshBlock(const wxGridCellCoords& topLeft,
                          const wxGridCellCoords& bottomRight)
{
    RefreshBlock(topLeft.GetRow(), topLeft.GetCol(),
                 bottomRight.GetRow(), bottomRight.GetCol());
}

void wxGrid::RefreshBlock(int topRow, int leftCol,
                          int bottomRow, int rightCol)
{
    // Note that it is valid to call this function with wxGridNoCellCoords as
    // either or even both arguments, but we can't have a mix of valid and
    // invalid columns/rows for each corner coordinates.
    const bool noTopLeft = topRow == -1 || leftCol == -1;
    const bool noBottomRight = bottomRow == -1 || rightCol == -1;

    if ( noTopLeft )
    {
        // So check that either both or none of the components are valid.
        wxASSERT( topRow == -1 && leftCol == -1 );

        // And specifying bottom right corner when the top left one is not
        // specified doesn't make sense either.
        wxASSERT( noBottomRight );

        return;
    }

    if ( noBottomRight )
    {
        wxASSERT( bottomRow == -1 && rightCol == -1 );

        bottomRow = topRow;
        rightCol = leftCol;
    }


    int row = topRow;
    int col = leftCol;

    // corner grid
    if ( GetRowPos(topRow) < m_numFrozenRows && GetColPos(leftCol) < m_numFrozenCols && m_frozenCornerGridWin )
    {
        row = wxMin(bottomRow, m_numFrozenRows - 1);
        col = wxMin(rightCol, m_numFrozenCols - 1);

        wxRect rect = BlockToDeviceRect(wxGridCellCoords(topRow, leftCol),
                                        wxGridCellCoords(row, col),
                                        m_frozenCornerGridWin);
        m_frozenCornerGridWin->Refresh(false, &rect);
        row++; col++;
    }

    // frozen cols grid
    if ( GetColPos(leftCol) < m_numFrozenCols && GetRowPos(bottomRow) >= m_numFrozenRows && m_frozenColGridWin )
    {
        col = wxMin(rightCol, m_numFrozenCols - 1);

        wxRect rect = BlockToDeviceRect(wxGridCellCoords(row, leftCol),
                                        wxGridCellCoords(bottomRow, col),
                                        m_frozenColGridWin);
        m_frozenColGridWin->Refresh(false, &rect);
        col++;
    }

    // frozen rows grid
    if ( GetRowPos(topRow) < m_numFrozenRows && GetColPos(rightCol) >= m_numFrozenCols && m_frozenRowGridWin )
    {
        row = wxMin(bottomRow, m_numFrozenRows - 1);

        wxRect rect = BlockToDeviceRect(wxGridCellCoords(topRow, col),
                                        wxGridCellCoords(row, rightCol),
                                        m_frozenRowGridWin);
        m_frozenRowGridWin->Refresh(false, &rect);
        row++;
    }

    // main grid
    if ( GetRowPos(bottomRow) >= m_numFrozenRows && GetColPos(rightCol) >= m_numFrozenCols )
    {
        const wxRect rect = BlockToDeviceRect(wxGridCellCoords(row, col),
                                              wxGridCellCoords(bottomRow, rightCol),
                                              m_gridWin);
        if ( !rect.IsEmpty() )
            m_gridWin->Refresh(false, &rect);
    }
}

void wxGrid::RefreshBlock(const wxGridCellCoords& coords)
{
    if ( !ShouldRefresh() )
        return;

    if ( coords != wxGridNoCellCoords )
    {
        const auto gridWindow = CellToGridWindow(coords);

        wxRect rect = CellToRect(coords);
        rect.Inflate(1);
        CalcGridWindowScrolledPosition(rect.x, rect.y, &rect.x, &rect.y, gridWindow);

        RefreshRect(&rect);
    }
}

void wxGrid::RefreshRect(wxRect* rect)
{
    if ( rect )
    {
        // Note that the cells in the first row and first column have y = -1 and x = -1 resp.
        // we must therefore take this into account.
        const bool refreshCells = !rect->IsEmpty();
        const bool refreshColLabels = GetColLabelSize() > 0 && rect->x >= -1 && rect->width > 0;
        const bool refreshRowLabels = GetRowLabelSize() > 0 && rect->y >= -1 && rect->height > 0;

        rect->Offset(GetRowLabelSize(), GetColLabelSize());
        rect->Inflate(3); // +2 to fix refresh problems with wxQt under Kubuntu

        // Refresh the cell(s) area
        if ( refreshCells )
        {
            Refresh(false, rect);
        }

        // Refresh the corresponding col label(s)
        if ( refreshColLabels )
        {
            const wxRect r(rect->x, 0, rect->width, GetColLabelSize() + 2);

            Refresh(false, &r);
        }

        // Refresh the corresponding row label(s)
        if ( refreshRowLabels )
        {
            const wxRect r(0, rect->y, GetRowLabelSize() + 2, rect->height);

            Refresh(false, &r);
        }
    }
    else
    {
        Refresh();
    }
}

void wxGrid::RefreshArea(int areas)
{
    if ( areas == wxGA_All )
    {
        // Normally if we want to refresh the entire grid we call
        // Refresh() instead, but to make this function consistent
        // and correct, just forward to it if the argument is wxGA_All.
        Refresh();
        return;
    }

    // Corner area
    if ( (areas & wxGA_Corner) != 0 )
        m_cornerLabelWin->Refresh();

    int cw, ch;
    GetClientSize(&cw, &ch);

    // Cells area
    if ( (areas & wxGA_Cells) != 0 )
    {
        const wxRect rect(GetRowLabelSize(), GetColLabelSize(), cw, ch);

        Refresh(true, &rect);
    }

    // RowLabels area
    if ( (areas & wxGA_RowLabels) != 0 && GetRowLabelSize() > 0 )
    {
        const wxRect rect(0, GetColLabelSize(), GetRowLabelSize(), ch);

        Refresh(true, &rect);
    }

    // ColLabels area
    if ( (areas & wxGA_ColLabels) != 0 && GetColLabelSize() > 0 )
    {
        const wxRect rect(GetRowLabelSize(), 0, cw, GetColLabelSize());

        Refresh(true, &rect);
    }
}

void wxGrid::OnSize(wxSizeEvent& event)
{
    if (m_targetWindow != this) // check whether initialisation has been done
    {
        // reposition our children windows
        CalcWindowSizes();
        InvalidateOverlaySelection();
        event.Skip();
    }
}

void wxGrid::OnDPIChanged(wxDPIChangedEvent& event)
{
    InitPixelFields();

    // If we have any non-default row sizes, we need to scale them (default
    // ones will be scaled due to the reinitialization of m_defaultRowHeight
    // inside InitPixelFields() above).
    if ( !m_rowHeights.empty() )
    {
        int total = 0;
        for ( unsigned i = 0; i < m_rowHeights.size(); ++i )
        {
            int height = m_rowHeights[i];

            // Note that even hidden rows heights must be scaled to ensure that
            // they appear in the expected size if they are shown again.
            height = event.ScaleY(height);

            m_rowHeights[i] = height;

            // But don't count hidden rows for the total height.
            if ( height > 0 )
                total += height;

            m_rowBottoms[i] = total;
        }
    }

    // Similarly for columns, except that here we need to update the native
    // control even if none of the widths had been changed, as it's not going
    // to do it on its own when redisplayed.
    wxHeaderCtrl* const
        colHeader = m_useNativeHeader ? GetGridColHeader() : nullptr;
    if ( !m_colWidths.empty() )
    {
        int total = 0;
        for ( unsigned i = 0; i < m_colWidths.size(); ++i )
        {
            int width = m_colWidths[i];

            width = event.ScaleX(width);

            m_colWidths[i] = width;

            if ( width > 0 )
                total += width;

            m_colRights[i] = total;

            if ( colHeader )
                colHeader->UpdateColumn(i);
        }
    }
    else if ( colHeader )
    {
        for ( int i = 0; i < m_numCols; ++i )
        {
            colHeader->UpdateColumn(i);
        }
    }

    InvalidateBestSize();

    CalcDimensions();

    event.Skip();
}

void wxGrid::OnKeyDown( wxKeyEvent& event )
{
    // propagate the event up and see if it gets processed
    wxWindow *parent = GetParent();
    wxKeyEvent keyEvt( event );
    keyEvt.SetEventObject( parent );

    if ( !parent->ProcessWindowEvent( keyEvt ) )
    {
        if (GetLayoutDirection() == wxLayout_RightToLeft)
        {
            if (event.GetKeyCode() == WXK_RIGHT)
                event.m_keyCode = WXK_LEFT;
            else if (event.GetKeyCode() == WXK_LEFT)
                event.m_keyCode = WXK_RIGHT;
        }

        // try local handlers
        switch ( event.GetKeyCode() )
        {
            case WXK_UP:
                DoMoveCursorFromKeyboard
                (
                    event,
                    wxGridBackwardOperations(this, wxGridRowOperations())
                );
                break;

            case WXK_DOWN:
                DoMoveCursorFromKeyboard
                (
                    event,
                    wxGridForwardOperations(this, wxGridRowOperations())
                );
                break;

            case WXK_LEFT:
                DoMoveCursorFromKeyboard
                (
                    event,
                    wxGridBackwardOperations(this, wxGridColumnOperations())
                );
                break;

            case WXK_RIGHT:
                DoMoveCursorFromKeyboard
                (
                    event,
                    wxGridForwardOperations(this, wxGridColumnOperations())
                );
                break;

            case WXK_RETURN:
            case WXK_NUMPAD_ENTER:
                if ( event.ControlDown() )
                {
                    event.Skip();  // to let the edit control have the return
                }
                else
                {
                    // We want to accept the changes in the editor when Enter
                    // is pressed in any case, so do it (note that in many
                    // cases this would be done by MoveCursorDown() itself, but
                    // not always, e.g. it wouldn't do it when editing the
                    // cells in the last row or when using Shift-Enter).
                    DisableCellEditControl();

                    MoveCursorDown( event.ShiftDown() );
                }
                break;

            case WXK_ESCAPE:
                if ( m_isDragging && m_winCapture )
                {
                    switch ( m_cursorMode )
                    {
                        case WXGRID_CURSOR_MOVE_COL:
                        case WXGRID_CURSOR_MOVE_ROW:
                            // end row/column moving
                            m_winCapture->Refresh();
                            m_dragLastPos = -1;
                            m_dragLastColour = nullptr;
                            break;

                        case WXGRID_CURSOR_RESIZE_ROW:
                        case WXGRID_CURSOR_RESIZE_COL:
                        {
                            // reset to size from before dragging
                            const auto oper(DoGetOperationsFromCursorMode());
                            if ( m_dragLabel )
                            {
                                oper->SetLabelSize(this, m_dragRowOrColOldSize);
                                m_dragLabel = false;
                            }
                            else
                            {
                                oper->SetLineSize(this, m_dragRowOrCol, m_dragRowOrColOldSize);
                                m_dragRowOrCol = -1;
                            }
                        }
                        break;

                        case WXGRID_CURSOR_SELECT_CELL:
                        case WXGRID_CURSOR_SELECT_ROW:
                        case WXGRID_CURSOR_SELECT_COL:
                            if ( m_selection )
                                m_selection->CancelSelecting();
                            break;
                    }
                    EndDraggingIfNecessary();

                    // ensure that a new drag operation is only started after a LeftUp
                    m_cancelledDragging = true;
                }
                else
                {
                    ClearSelection();
                }
                break;

            case WXK_TAB:
                {
                    // send an event to the grid's parents for custom handling
                    wxGridEvent gridEvt(GetId(), wxEVT_GRID_TABBING, this,
                                        GetGridCursorRow(), GetGridCursorCol(),
                                        -1, -1, false, event);
                    if ( ProcessWindowEvent(gridEvt) )
                    {
                        // the event has been handled so no need for more processing
                        break;
                    }
                }
                DoGridProcessTab( event );
                break;

            case WXK_HOME:
            case WXK_END:
                if ( m_currentCellCoords != wxGridNoCellCoords )
                {
                    const bool goToBeginning = event.GetKeyCode() == WXK_HOME;

                    // Find the first or last visible row if we need to go to it
                    // (without Control, we keep the current row).
                    int row;
                    if ( event.ControlDown() )
                    {
                        if ( goToBeginning )
                        {
                            for ( row = 0; row < m_numRows; ++row )
                            {
                                if ( IsRowShown(row) )
                                    break;
                            }
                        }
                        else
                        {
                            for ( row = m_numRows - 1; row >= 0; --row )
                            {
                                if ( IsRowShown(row) )
                                    break;
                            }
                        }
                    }
                    else
                    {
                        // If we're extending the selection, try to continue in
                        // the same row, which may well be different from the
                        // one in which we started selecting.
                        if ( m_selection && event.ShiftDown() )
                        {
                            row = m_selection->GetExtensionAnchor().GetRow();
                        }
                        else // Just use the current row.
                        {
                            row = m_currentCellCoords.GetRow();
                        }
                    }

                    // Also find the last or first visible column in any case.
                    int col;
                    if ( goToBeginning )
                    {
                        for ( col = 0; col < m_numCols; ++col )
                        {
                            if ( IsColShown(GetColAt(col)) )
                                break;
                        }
                    }
                    else
                    {
                        for ( col = m_numCols - 1; col >= 0; --col )
                        {
                            if ( IsColShown(GetColAt(col)) )
                                break;
                        }
                    }

                    if ( event.ShiftDown() )
                    {
                        if ( m_selection )
                            m_selection->ExtendCurrentBlock(
                                             m_currentCellCoords,
                                             wxGridCellCoords(row, col),
                                             event);
                        MakeCellVisible(row, col);
                    }
                    else
                    {
                        ClearSelection();
                        GoToCell(row, GetColAt(col));
                    }
                }
                break;

            case WXK_PAGEUP:
                DoMoveCursorByPage
                (
                    event,
                    wxGridBackwardOperations(this, wxGridRowOperations())
                );
                break;

            case WXK_PAGEDOWN:
                DoMoveCursorByPage
                (
                    event,
                    wxGridForwardOperations(this, wxGridRowOperations())
                );
                break;

            case WXK_SPACE:
                // Ctrl-Space selects the current column or, if there is a
                // selection, all columns containing the selected cells,
                // Shift-Space -- the current row (or all selection rows) and
                // Ctrl-Shift-Space -- everything.
                {
                    wxGridCellCoords selStart, selEnd;
                    switch ( m_selection ? event.GetModifiers() : wxMOD_NONE )
                    {
                        case wxMOD_CONTROL:
                            selStart.Set(0, m_currentCellCoords.GetCol());
                            selEnd.Set(m_numRows - 1,
                                       m_selection->GetExtensionAnchor().GetCol());
                            break;

                        case wxMOD_SHIFT:
                            selStart.Set(m_currentCellCoords.GetRow(), 0);
                            selEnd.Set(m_selection->GetExtensionAnchor().GetRow(),
                                       m_numCols - 1);
                            break;

                        case wxMOD_CONTROL | wxMOD_SHIFT:
                            selStart.Set(0, 0);
                            selEnd.Set(m_numRows - 1, m_numCols - 1);
                            break;

                        case wxMOD_NONE:
                            if ( !IsEditable() )
                            {
                                MoveCursorRight(false);
                                break;
                            }
                            wxFALLTHROUGH;

                        default:
                            event.Skip();
                    }

                    if ( selStart != wxGridNoCellCoords )
                        m_selection->ExtendCurrentBlock(selStart, selEnd, event);
                }
                break;

#if wxUSE_CLIPBOARD
            case WXK_INSERT:
            case 'C':
                if ( event.GetModifiers() == wxMOD_CONTROL )
                {
                    if ( !CopySelection() )
                    {
                        wxLogWarning(_("Error copying grid to the clipboard. "
                            "Either selected cells were not contiguous or "
                            "no cell was selected."));
                    }
                    break;
                }
                wxFALLTHROUGH;
#endif // wxUSE_CLIPBOARD

            default:
                event.Skip();
                break;
        }
    }
}

void wxGrid::OnChar( wxKeyEvent& event )
{
    // is it possible to edit the current cell at all?
    if ( !IsCellEditControlEnabled() && CanEnableCellControl() )
    {
        // yes, now check whether the cells editor accepts the key
        wxGridCellEditorPtr editor = GetCurrentCellEditorPtr();

        // <F2> is special and will always start editing, for
        // other keys - ask the editor itself
        const bool specialEditKey = event.GetKeyCode() == WXK_F2 &&
                                        !event.HasModifiers();
        if ( specialEditKey || editor->IsAcceptedKey(event) )
        {
            // ensure cell is visble
            MakeCellVisible(m_currentCellCoords);

            if ( DoEnableCellEditControl(wxGridActivationSource::From(event))
                    && !specialEditKey )
                editor->StartingKey(event);
        }
        else
        {
            event.Skip();
        }
    }
    else
    {
        event.Skip();
    }
}

void wxGrid::DoGridProcessTab(wxKeyboardState& kbdState)
{
    const bool isForwardTab = !kbdState.ShiftDown();

    // TAB processing only changes when we are at the borders of the grid, so
    // let's first handle the common behaviour when we are not at the border.
    if ( isForwardTab )
    {
        if ( GetGridCursorCol() < GetNumberCols() - 1 )
        {
            MoveCursorRight( false );
            return;
        }
    }
    else // going back
    {
        if ( GetGridCursorCol() )
        {
            MoveCursorLeft( false );
            return;
        }
    }


    // We only get here if the cursor is at the border of the grid, apply the
    // configured behaviour.
    switch ( m_tabBehaviour )
    {
        case Tab_Stop:
            // Nothing special to do, we remain at the current cell.
            break;

        case Tab_Wrap:
            // Go to the beginning of the next or the end of the previous row.
            if ( isForwardTab )
            {
                if ( GetGridCursorRow() < GetNumberRows() - 1 )
                {
                    GoToCell( GetGridCursorRow() + 1, 0 );
                    return;
                }
            }
            else
            {
                if ( GetGridCursorRow() > 0 )
                {
                    GoToCell( GetGridCursorRow() - 1, GetNumberCols() - 1 );
                    return;
                }
            }
            break;

        case Tab_Leave:
            if ( Navigate( isForwardTab ? wxNavigationKeyEvent::IsForward
                                        : wxNavigationKeyEvent::IsBackward ) )
                return;
            break;
    }

    // If we remain in this cell, stop editing it if we were doing so.
    DisableCellEditControl();
}

bool wxGrid::SetCurrentCell( const wxGridCellCoords& coords )
{
    switch ( SendEvent(wxEVT_GRID_SELECT_CELL, coords) )
    {
        case Event_Vetoed:
        case Event_CellDeleted:
            // We shouldn't do anything if the event was vetoed and can't do
            // anything if the cell doesn't exist any longer.
            return false;

        case Event_Unhandled:
        case Event_Handled:
            // But it doesn't matter here if the event was skipped or not.
            break;
    }

    if ( m_currentCellCoords != wxGridNoCellCoords )
    {
        DisableCellEditControl();

        // Ensure the old highlighted row/col labels are refreshed
        RefreshBlock(m_currentCellCoords);
    }

    m_currentCellCoords = coords;

    RefreshBlock(coords);

#if wxUSE_ACCESSIBILITY
    int numCols = GetNumberCols();
    if ( m_rowLabelWidth )
        numCols++;
    int row = coords.GetRow();
    if ( m_colLabelHeight )
        row++;
    int objectId = numCols*row + coords.GetCol() + 1;
    if ( m_rowLabelWidth )
        objectId++;
    wxAccessible::NotifyEvent(wxACC_EVENT_OBJECT_SELECTIONWITHIN, this, wxOBJID_CLIENT, wxACC_SELF);
    wxAccessible::NotifyEvent(wxACC_EVENT_OBJECT_FOCUS, this, wxOBJID_CLIENT, objectId);
#endif // wxUSE_ACCESSIBILITY

    return true;
}

// Note - this function only draws cells that are in the list of
// exposed cells (usually set from the update region by
// CalcExposedCells)
//
void wxGrid::DrawGridCellArea( wxDC& dc, const wxGridCellCoordsVector& cells )
{
    if ( !m_numRows || !m_numCols )
        return;

    int i, numCells = cells.size();
    wxGridCellCoordsVector redrawCells;

    for ( i = numCells - 1; i >= 0; i-- )
    {
        int row, col, cell_rows, cell_cols;
        row = cells[i].GetRow();
        col = cells[i].GetCol();

        // If this cell is part of a multicell block, find owner for repaint
        if ( GetCellSize( row, col, &cell_rows, &cell_cols ) == CellSpan_Inside )
        {
            wxGridCellCoords cell( row + cell_rows, col + cell_cols );
            bool marked = false;
            for ( int j = 0; j < numCells; j++ )
            {
                if ( cell == cells[j] )
                {
                    marked = true;
                    break;
                }
            }

            if (!marked)
            {
                int count = redrawCells.size();
                for (int j = 0; j < count; j++)
                {
                    if ( cell == redrawCells[j] )
                    {
                        marked = true;
                        break;
                    }
                }

                if (!marked)
                    redrawCells.push_back( cell );
            }

            // don't bother drawing this cell
            continue;
        }

        // If this cell is empty, find cell to left that might want to overflow
        if (m_table && m_table->IsEmptyCell(row, col))
        {
            for ( int l = 0; l < cell_rows; l++ )
            {
                // find a cell in this row to leave already marked for repaint
                int left = col;
                for ( const auto& cell: redrawCells )
                {
                    if ((cell.GetCol() < left) && (cell.GetRow() == row))
                    {
                        left = cell.GetCol();
                    }
                }

                if (left == col)
                    left = 0; // oh well

                for (int j = col - 1; j >= left; j--)
                {
                    if (!m_table->IsEmptyCell(row + l, j))
                    {
                        wxGridCellAttrPtr attr = GetCellAttrPtr(row + l, j);
                        int numRows, numCols;
                        attr->GetSize(&numRows, &numCols);
                        if ( GetCellSpan(numRows, numCols)
                                 == wxGrid::CellSpan_Inside )
                            // As above: don't bother drawing inside cells.
                            continue;

                        if ( attr->CanOverflow() )
                        {
                            wxGridCellCoords cellOver(row + l, j);
                            bool marked = false;

                            for ( const auto& cell: cells )
                            {
                                if ( cellOver == cell )
                                {
                                    marked = true;
                                    break;
                                }
                            }

                            if (!marked)
                            {
                                for ( const auto& cell: redrawCells )
                                {
                                    if ( cellOver == cell )
                                    {
                                        marked = true;
                                        break;
                                    }
                                }
                                if (!marked)
                                    redrawCells.push_back( cellOver );
                            }
                        }
                        break;
                    }
                }
            }
        }

        DrawCell( dc, cells[i] );
    }

    numCells = redrawCells.size();

    for ( i = numCells - 1; i >= 0; i-- )
    {
        DrawCell( dc, redrawCells[i] );
    }
}

void wxGrid::DrawGridSpace( wxDC& dc, wxGridWindow *gridWindow )
{
  int cw, ch;
  gridWindow->GetClientSize( &cw, &ch );

  int right, bottom;
  wxPoint offset = GetGridWindowOffset(gridWindow);
  CalcGridWindowUnscrolledPosition(cw + offset.x, ch + offset.y, &right, &bottom, gridWindow);

  int rightCol = m_numCols > 0 ? GetColRight(GetColAt( m_numCols - 1 )) : 0;
  int bottomRow = m_numRows > 0 ? GetRowBottom(GetRowAt( m_numRows - 1 )) : 0;

  if ( right > rightCol || bottom > bottomRow )
  {
      int left, top;
      CalcGridWindowUnscrolledPosition(offset.x, offset.y, &left, &top, gridWindow);

      dc.SetBrush(GetDefaultCellBackgroundColour());
      dc.SetPen( *wxTRANSPARENT_PEN );

      if ( right > rightCol )
      {
          dc.DrawRectangle( rightCol, top, right - rightCol, ch );
      }

      if ( bottom > bottomRow )
      {
          dc.DrawRectangle( left, bottomRow, cw, bottom - bottomRow );
      }
  }
}

void wxGrid::DrawCell( wxDC& dc, const wxGridCellCoords& coords )
{
    int row = coords.GetRow();
    int col = coords.GetCol();

    if ( GetColWidth(col) <= 0 || GetRowHeight(row) <= 0 )
        return;

    // we draw the cell border ourselves
    wxGridCellAttrPtr attr = GetCellAttrPtr(row, col);

    bool isCurrent = coords == m_currentCellCoords;

    wxRect rect = CellToRect( row, col );

    // if the editor is shown, we should use it and not the renderer
    // Note: However, only if it is really _shown_, i.e. not hidden!
    if ( isCurrent && IsCellEditControlShown() )
    {
        attr->GetEditorPtr(this, row, col)->PaintBackground(dc, rect, *attr);
    }
    else
    {
        // but all the rest is drawn by the cell renderer and hence may be customized
        attr->GetRendererPtr(this, row, col)
            ->Draw(*this, *attr, dc, rect, row, col, IsInSelection(coords));
    }
}

void wxGrid::DrawCellHighlight( wxDC& dc, const wxGridCellAttr *attr )
{
    // don't show highlight when the grid doesn't have focus
    if ( !HasFocus() )
        return;

    int row = m_currentCellCoords.GetRow();
    int col = m_currentCellCoords.GetCol();

    if ( GetColWidth(col) <= 0 || GetRowHeight(row) <= 0 )
        return;

    wxRect rect = CellToRect(row, col);

    // hmmm... what could we do here to show that the cell is disabled?
    // for now, I just draw a thinner border than for the other ones, but
    // it doesn't look really good

    int penWidth = attr->IsReadOnly() ? m_cellHighlightROPenWidth : m_cellHighlightPenWidth;

    if (penWidth > 0)
    {
        // The center of the drawn line is where the position/width/height of
        // the rectangle is actually at (on wxMSW at least), so the
        // size of the rectangle is reduced to compensate for the thickness of
        // the line. If this is too strange on non-wxMSW platforms then
        // please #ifdef this appropriately.
        rect.x += penWidth / 2;
        rect.y += penWidth / 2;
        rect.width -= penWidth - 1;
        rect.height -= penWidth - 1;

        // Now draw the rectangle
        // use the cellHighlightColour if the cell is inside a selection, this
        // will ensure the cell is always visible.
        const auto penCol = (UsesOverlaySelection() || !IsInSelection(row, col))
                          ? m_cellHighlightColour : m_selectionForeground;

        dc.SetPen(wxPen(penCol, penWidth));
        dc.SetBrush(*wxTRANSPARENT_BRUSH);
        dc.DrawRectangle(rect);
    }
}

wxPen wxGrid::GetDefaultGridLinePen()
{
    return wxPen(GetGridLineColour());
}

wxPen wxGrid::GetRowGridLinePen(int WXUNUSED(row))
{
    return GetDefaultGridLinePen();
}

wxPen wxGrid::GetColGridLinePen(int WXUNUSED(col))
{
    return GetDefaultGridLinePen();
}

void wxGrid::DrawCellBorder( wxDC& dc, const wxGridCellCoords& coords )
{
    int row = coords.GetRow();
    int col = coords.GetCol();
    if ( GetColWidth(col) <= 0 || GetRowHeight(row) <= 0 )
        return;


    wxRect rect = CellToRect( row, col );

    // right hand border
    dc.SetPen( GetColGridLinePen(col) );
    dc.DrawLine( rect.x + rect.width, rect.y,
                 rect.x + rect.width, rect.y + rect.height + 1 );

    // bottom border
    dc.SetPen( GetRowGridLinePen(row) );
    dc.DrawLine( rect.x, rect.y + rect.height,
                 rect.x + rect.width, rect.y + rect.height);
}

void wxGrid::DrawHighlight(wxDC& dc, const wxGridCellCoordsVector& cells)
{
    // This if block was previously in wxGrid::OnPaint but that doesn't
    // seem to get called under wxGTK - MB
    //
    if ( m_currentCellCoords == wxGridNoCellCoords &&
         m_numRows && m_numCols )
    {
        m_currentCellCoords.Set(0, 0);
    }

    if ( IsCellEditControlShown() )
    {
        // don't show highlight when the edit control is shown
        return;
    }

    // if the active cell was repainted, repaint its highlight too because it
    // might have been damaged by the grid lines
    for ( auto cell: cells )
    {
        // If we are using attributes, then we may have just exposed another
        // cell in a partially-visible merged cluster of cells. If the "anchor"
        // (upper left) cell of this merged cluster is the cell indicated by
        // m_currentCellCoords, then we need to refresh the cell highlight even
        // though the "anchor" itself is not part of our update segment.
        if ( CanHaveAttributes() )
        {
            int rows = 0,
                cols = 0;
            GetCellSize(cell.GetRow(), cell.GetCol(), &rows, &cols);

            if ( rows < 0 )
                cell.SetRow(cell.GetRow() + rows);

            if ( cols < 0 )
                cell.SetCol(cell.GetCol() + cols);
        }

        if ( cell == m_currentCellCoords )
        {
            wxGridCellAttrPtr attr = GetCellAttrPtr(m_currentCellCoords);
            DrawCellHighlight(dc, attr.get());

            break;
        }
    }
}

void wxGrid::DrawFrozenBorder(wxDC& dc, wxGridWindow *gridWindow, const wxRect& renderExtent)
{
    if ( gridWindow && m_numCols && m_numRows)
    {
        const bool isFrozenCol = gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenCol;
        const bool isFrozenRow = gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenRow;
        int top, bottom, left, right;
        int cw, ch;
        wxPoint gridOffset = GetGridWindowOffset(gridWindow);
        gridWindow->GetClientSize(&cw, &ch);

        int gridFrozenBorderPenWidth = m_gridFrozenBorderPenWidth;

        if ( renderExtent.IsEmpty() )
        {
            CalcGridWindowUnscrolledPosition( gridOffset.x, gridOffset.y, &left, &top, gridWindow );
            CalcGridWindowUnscrolledPosition( cw + gridOffset.x, ch + gridOffset.y, &right, &bottom, gridWindow );
        }
        else
        {
            // We are rendering on external DC. Offset and scroll position are already
            // calculated in wxGrid::Render().

            gridFrozenBorderPenWidth /= 2;

            top    = -GetColLabelSize() + renderExtent.x;
            left   = -GetRowLabelSize() + renderExtent.y;
            bottom = isFrozenRow ? ch - gridFrozenBorderPenWidth
                                 : renderExtent.y + renderExtent.height;
            right  = isFrozenCol ? cw - gridFrozenBorderPenWidth
                                 : renderExtent.x + renderExtent.width;
        }

        if ( isFrozenRow )
        {
            right = wxMin(right, GetColRight(m_numCols - 1));

            dc.SetPen(wxPen(m_gridFrozenBorderColour,
                            gridFrozenBorderPenWidth));
            dc.DrawLine(left, bottom, right, bottom);
        }

        if ( isFrozenCol )
        {
            bottom = wxMin(bottom, GetRowBottom(m_numRows - 1));

            dc.SetPen(wxPen(m_gridFrozenBorderColour,
                            gridFrozenBorderPenWidth));
            dc.DrawLine(right, top, right, bottom);
        }
    }
}

void wxGrid::DrawLabelFrozenBorder(wxDC& dc, wxWindow *window, bool isRow)
{
    if ( window )
    {
        int cw, ch;
        window->GetClientSize(&cw, &ch);

        dc.SetPen(wxPen(m_gridFrozenBorderColour,
                        m_gridFrozenBorderPenWidth));

        if ( isRow )
            dc.DrawLine(0, ch, cw, ch);
        else
            dc.DrawLine(cw, 0, cw, ch);
    }
}

// Used by wxGrid::Render() to draw the grid lines only for the cells in the
// specified range.
void
wxGrid::DrawRangeGridLines(wxDC& dc,
                           const wxRegion& reg,
                           const wxGridCellCoords& topLeft,
                           const wxGridCellCoords& bottomRight)
{
    if ( !m_gridLinesEnabled )
         return;

    int top, left, width, height;
    reg.GetBox( left, top, width, height );

    // create a clipping region
    wxRegion clippedcells( dc.LogicalToDeviceX( left ),
                           dc.LogicalToDeviceY( top ),
                           dc.LogicalToDeviceXRel( width ),
                           dc.LogicalToDeviceYRel( height ) );

    // subtract multi cell span area from clipping region for lines
    wxRect rect;
    for ( int row = topLeft.GetRow(); row <= bottomRight.GetRow(); row++ )
    {
        for ( int col = topLeft.GetCol(); col <= bottomRight.GetCol(); col++ )
        {
            int cell_rows, cell_cols;
            switch ( GetCellSize( row, col, &cell_rows, &cell_cols ) )
            {
                case CellSpan_Main: // multi cell
                    rect = CellToRect( row, col );
                    // cater for scaling
                    // device origin already set in ::Render() for x, y
                    rect.x = dc.LogicalToDeviceX( rect.x );
                    rect.y = dc.LogicalToDeviceY( rect.y );
                    rect.width = dc.LogicalToDeviceXRel( rect.width );
                    rect.height = dc.LogicalToDeviceYRel( rect.height ) - 1;
                    clippedcells.Subtract( rect );
                    break;

                case CellSpan_Inside: // part of multicell
                    rect = CellToRect( row + cell_rows, col + cell_cols );
                    rect.x = dc.LogicalToDeviceX( rect.x );
                    rect.y = dc.LogicalToDeviceY( rect.y );
                    rect.width = dc.LogicalToDeviceXRel( rect.width );
                    rect.height = dc.LogicalToDeviceYRel( rect.height ) - 1;
                    clippedcells.Subtract( rect );
                    break;

                case CellSpan_None:
                    // Nothing special to do.
                    break;
            }
        }
    }

    dc.SetDeviceClippingRegion( clippedcells );

    DoDrawGridLines(dc,
                    top, left, top + height, left + width,
                    topLeft.GetRow(), topLeft.GetCol(),
                    bottomRight.GetRow(), bottomRight.GetCol());

    dc.DestroyClippingRegion();
}

// This is used to redraw all grid lines e.g. when the grid line colour
// has been changed
//
void wxGrid::DrawAllGridWindowLines(wxDC& dc, const wxRegion & WXUNUSED(reg), wxGridWindow *gridWindow)
{
    if ( !m_gridLinesEnabled || !gridWindow )
         return;

    int top, bottom, left, right;

    wxPoint gridOffset = GetGridWindowOffset(gridWindow);

    int cw, ch;
    gridWindow->GetClientSize(&cw, &ch);
    CalcGridWindowUnscrolledPosition( gridOffset.x, gridOffset.y, &left, &top, gridWindow );
    CalcGridWindowUnscrolledPosition( cw + gridOffset.x, ch + gridOffset.y, &right, &bottom, gridWindow );

    // avoid drawing grid lines past the last row and col
    if ( m_gridLinesClipHorz )
    {
        if ( !m_numCols )
            return;

        const int lastColRight = GetColRight(GetColAt(m_numCols - 1));
        if ( right > lastColRight )
            right = lastColRight;
    }

    if ( m_gridLinesClipVert )
    {
        if ( !m_numRows )
            return;

        const int lastRowBottom = GetRowBottom(GetRowAt(m_numRows - 1));
        if ( bottom > lastRowBottom )
            bottom = lastRowBottom;
    }

    // no gridlines inside multicells, clip them out
    int leftCol = GetColPos( internalXToCol(left, gridWindow) );
    int topRow = GetRowPos( internalYToRow(top, gridWindow) );
    int rightCol = GetColPos( internalXToCol(right, gridWindow) );
    int bottomRow = GetRowPos( internalYToRow(bottom, gridWindow) );

    if ( gridWindow == m_gridWin )
    {
        wxRegion clippedcells(0, 0, cw, ch);

        int cell_rows, cell_cols;
        wxRect rect;

        for ( int j = topRow; j <= bottomRow; j++ )
        {
            for ( int colPos = leftCol; colPos <= rightCol; colPos++ )
            {
                int i = GetColAt( colPos );

                switch ( GetCellSize( j, i, &cell_rows, &cell_cols ) )
                {
                    case CellSpan_Main:
                        rect = CellToRect(j,i);
                        rect.Offset(-gridOffset);
                        CalcScrolledPosition( rect.x, rect.y, &rect.x, &rect.y );
                        clippedcells.Subtract(rect);
                        break;

                    case CellSpan_Inside:
                        rect = CellToRect(j + cell_rows, i + cell_cols);
                        rect.Offset(-gridOffset);
                        CalcScrolledPosition( rect.x, rect.y, &rect.x, &rect.y );
                        clippedcells.Subtract(rect);
                        break;

                    case CellSpan_None:
                        // Nothing special to do.
                        break;
                }
            }
        }

        dc.SetDeviceClippingRegion( clippedcells );
    }

    DoDrawGridLines(dc,
                    top, left, bottom, right,
                    topRow, leftCol, m_numRows, m_numCols);

    dc.DestroyClippingRegion();
}

void wxGrid::DrawAllGridLines()
{
    if ( m_gridWin )
    {
        wxClientDC dc(m_gridWin);
        PrepareDCFor(dc, m_gridWin);

        DrawAllGridWindowLines(dc, wxRegion(), m_gridWin);
    }

    if ( m_frozenRowGridWin )
    {
        wxClientDC dc(m_frozenRowGridWin);
        PrepareDCFor(dc, m_frozenRowGridWin);

        DrawAllGridWindowLines(dc, wxRegion(), m_frozenRowGridWin);
    }

    if ( m_frozenColGridWin )
    {
        wxClientDC dc(m_frozenColGridWin);
        PrepareDCFor(dc, m_frozenColGridWin);

        DrawAllGridWindowLines(dc, wxRegion(), m_frozenColGridWin);
    }

    if ( m_frozenCornerGridWin )
    {
        wxClientDC dc(m_frozenCornerGridWin);
        PrepareDCFor(dc, m_frozenCornerGridWin);

        DrawAllGridWindowLines(dc, wxRegion(), m_frozenCornerGridWin);
    }
}

void
wxGrid::DoDrawGridLines(wxDC& dc,
                        int top, int left,
                        int bottom, int right,
                        int topRow, int leftCol,
                        int bottomRow, int rightCol)
{
    // horizontal grid lines
    for ( int rowPos = topRow; rowPos < bottomRow; rowPos++ )
    {
        int i = GetRowAt( rowPos );
        int bot = GetRowBottom(i) - 1;

        if ( bot > bottom )
            break;

        if ( bot >= top )
        {
            dc.SetPen( GetRowGridLinePen(i) );
            dc.DrawLine( left, bot, right, bot );
        }
    }

    // vertical grid lines
    for ( int colPos = leftCol; colPos < rightCol; colPos++ )
    {
        int i = GetColAt( colPos );

        int colRight = GetColRight(i);
#if defined(__WXGTK__)
        if (GetLayoutDirection() != wxLayout_RightToLeft)
#endif
            colRight--;

        if ( colRight > right )
            break;

        if ( colRight >= left )
        {
            dc.SetPen( GetColGridLinePen(i) );
            dc.DrawLine( colRight, top, colRight, bottom );
        }
    }
}

void wxGrid::DrawRowLabels( wxDC& dc, const wxArrayInt& rows)
{
    if ( !m_numRows )
        return;

    const size_t numLabels = rows.GetCount();
    for ( size_t i = 0; i < numLabels; i++ )
    {
        DrawRowLabel( dc, rows[i] );
    }

    if ( m_cursorMode == WXGRID_CURSOR_MOVE_ROW && m_dragLastColour )
    {
        // draw the insertion marker for drag-moving
        wxPen pen(*m_dragLastColour, 2);
        dc.SetPen(pen);
        dc.DrawLine(0, m_dragLastPos + 1, m_rowLabelWidth, m_dragLastPos + 1);
        dc.SetPen(wxNullPen);
    }
}

void wxGrid::DrawRowLabel( wxDC& dc, int row )
{
    if ( GetRowHeight(row) <= 0 || m_rowLabelWidth <= 0 )
        return;

    wxGridCellAttrProvider * const
        attrProvider = m_table ? m_table->GetAttrProvider() : nullptr;

    // notice that an explicit static_cast is needed to avoid a compilation
    // error with VC7.1 which, for some reason, tries to instantiate (abstract)
    // wxGridRowHeaderRenderer class without it
    const wxGridRowHeaderRenderer&
        rend = attrProvider ? attrProvider->GetRowHeaderRenderer(row)
                            : static_cast<const wxGridRowHeaderRenderer&>
                                (gs_defaultHeaderRenderers.rowRenderer);

    wxRect rect(0, GetRowTop(row), m_rowLabelWidth, GetRowHeight(row));

    if ( m_cursorMode == WXGRID_CURSOR_MOVE_ROW )
    {
        // clear the background:
        // when called from ProcessRowColLabelMouseEvent the background is not
        // cleared at this point
        dc.SetPen(*wxTRANSPARENT_PEN);
        dc.SetBrush(m_colLabelWin->GetBackgroundColour());
        dc.DrawRectangle(rect);
    }

    // draw a border if the row is not being drag-moved
    // (in that case it's omitted to have a 'pressed' appearance)
    if (m_cursorMode != WXGRID_CURSOR_MOVE_ROW || row != m_dragMoveRowOrCol)
    {
        IsRowLabelHighlighted(row) ? rend.DrawHighlighted(*this, dc, rect, row)
                                   : rend.DrawBorder(*this, dc, rect);
    }
    else
    {
        // just highlight the current row
        rend.DrawHighlighted(*this, dc, rect, row, true);  // pressed

        rect.Deflate(GetBorder() == wxBORDER_NONE ? 2 : 1);
    }

    int hAlign, vAlign;
    GetRowLabelAlignment(&hAlign, &vAlign);

    rend.DrawLabel(*this, dc, GetRowLabelValue(row),
                   rect, hAlign, vAlign, wxHORIZONTAL);
}

void wxGrid::DrawOverlaySelection(wxDC& paintDC, wxGridWindow *gridWindow, const wxRect& renderExtent)
{
    if ( !UsesOverlaySelection() || !IsSelection() )
        return;

    const auto& selectionShape = m_selection->GetSelectionShape(renderExtent);

    wxRect updateRect = selectionShape.GetBoundingBox();

    if ( updateRect.IsEmpty() )
    {
        return; // nothing to draw
    }

#if wxUSE_GRAPHICS_CONTEXT
    wxGCDC gdc;
    auto renderer = wxGraphicsRenderer::GetDefaultRenderer();
    auto context  = renderer->CreateContext(static_cast<wxPaintDC&>(paintDC));

    gdc.SetBackground(GetBackgroundColour());
    gdc.SetGraphicsContext(context);

    wxDC& dc = gdc;
#else
    wxDC& dc = paintDC;
#endif

    const wxPoint oldOrig = paintDC.GetLogicalOrigin();
    const wxPoint orig    = paintDC.GetDeviceOrigin();
    const wxPoint offset  = GetGridWindowOffset(gridWindow);

    wxRect clipRect;

    if ( renderExtent.IsEmpty() )
    {
        dc.SetLogicalOrigin(orig.x + offset.x, orig.y + offset.y);
        clipRect = gridWindow->GetClientRect();
    }
    else // We are rendering on external DC
    {
        clipRect = renderExtent;
    }

    wxON_BLOCK_EXIT_OBJ2(dc, wxDC::SetLogicalOrigin, oldOrig.x, oldOrig.y);

    clipRect.Offset(offset);

    // Don't draw selection edges on frozen borders.
    if ( offset.x > 0 )
        clipRect.x += 1;
    if ( offset.y > 0 )
        clipRect.y += 1;

    wxDCClipper clip(dc, clipRect);

    const wxColour colBg = GetSelectionBackground();

    dc.SetPen(wxPen(colBg));
    dc.SetBrush(wxColour(colBg.Red(), colBg.Green(), colBg.Blue(), 64));

    const int n = selectionShape.GetSize();

    if ( n == 0 )
    {
        dc.DrawRectangle(updateRect);

        wxLogTrace("gridsel", "[n:0] dc.DrawRectangle()");
    }
    else
    {
        const int* counts = selectionShape.GetCounts();
        const wxPoint* points = selectionShape.GetPoints();

        if ( n == 1 )
        {
            dc.DrawPolygon(counts[0], points);

            wxLogTrace("gridsel", "[n:1] dc.DrawPolygon()");
        }
        else
        {
            dc.DrawPolyPolygon(n, counts, points);

            wxLogTrace("gridsel", "[n:%d] dc.DrawPolyPolygon()", n);
        }
    }
}

void wxGrid::InvalidateOverlaySelection()
{
    if ( UsesOverlaySelection() && IsSelection() )
    {
        m_selection->InvalidateSelectionShape();
    }
}

bool wxGrid::UseNativeColHeader(bool native)
{
    if ( native == m_useNativeHeader )
        return true;

    // Using native control doesn't work if any columns are frozen currently.
    if ( native && m_numFrozenCols )
        return false;

    delete m_colLabelWin;
    m_useNativeHeader = native;

    CreateColumnWindow();

    if ( m_useNativeHeader )
    {
        SetNativeHeaderColCount();

        wxHeaderCtrl* const colHeader = GetGridColHeader();
        colHeader->SetBackgroundColour( GetLabelBackgroundColour() );
        colHeader->SetForegroundColour( GetLabelTextColour() );
        colHeader->SetFont( GetLabelFont() );
    }

    CalcWindowSizes();

    return true;
}

void wxGrid::SetUseNativeColLabels( bool native )
{
    wxASSERT_MSG( !m_useNativeHeader,
                  "doesn't make sense when using native header" );

    m_nativeColumnLabels = native;
    if (native)
    {
        int height = wxRendererNative::Get().GetHeaderButtonHeight( this );
        SetColLabelSize( height );
    }

    RefreshArea(wxGA_Heading);
}

void wxGrid::DrawColLabels( wxDC& dc,const wxArrayInt& cols )
{
    if ( !m_numCols )
        return;

    const size_t numLabels = cols.GetCount();
    for ( size_t i = 0; i < numLabels; i++ )
    {
        DrawColLabel( dc, cols[i] );
    }

    if ( m_cursorMode == WXGRID_CURSOR_MOVE_COL && m_dragLastColour )
    {
        // draw the insertion marker for drag-moving
        wxPen pen(*m_dragLastColour, 2);
        dc.SetPen(pen);
        dc.DrawLine(m_dragLastPos + 1, 0, m_dragLastPos + 1, m_colLabelHeight);
        dc.SetPen(wxNullPen);
    }
}

void wxGrid::DrawCornerLabel(wxDC& dc)
{
    wxRect rect(wxSize(m_rowLabelWidth, m_colLabelHeight));

    wxGridCellAttrProvider * const
        attrProvider = m_table ? m_table->GetAttrProvider() : nullptr;
    const wxGridCornerHeaderRenderer&
        rend = attrProvider ? attrProvider->GetCornerRenderer()
                            : static_cast<wxGridCornerHeaderRenderer&>
                                (gs_defaultHeaderRenderers.cornerRenderer);

    if ( m_nativeColumnLabels )
    {
        rect.Deflate(1);

        wxRendererNative::Get().DrawHeaderButton(m_cornerLabelWin, dc, rect, 0);
    }
    else
    {
        rect.width++;
        rect.height++;

        rend.DrawBorder(*this, dc, rect);
    }

    wxString label = GetCornerLabelValue();
    if( !label.IsEmpty() )
    {
        int hAlign, vAlign;
        GetCornerLabelAlignment(&hAlign, &vAlign);
        const int orient = GetCornerLabelTextOrientation();

        rend.DrawLabel(*this, dc, label, rect, hAlign, vAlign, orient);
    }
}

void wxGrid::DrawColLabel(wxDC& dc, int col)
{
    if ( GetColWidth(col) <= 0 || m_colLabelHeight <= 0 )
        return;

    wxGridCellAttrProvider * const
        attrProvider = m_table ? m_table->GetAttrProvider() : nullptr;
    const wxGridColumnHeaderRenderer&
        rend = attrProvider ? attrProvider->GetColumnHeaderRenderer(col)
                            : static_cast<wxGridColumnHeaderRenderer&>
                                (gs_defaultHeaderRenderers.colRenderer);

    wxRect rect(GetColLeft(col), 0, GetColWidth(col), m_colLabelHeight);

    if ( m_nativeColumnLabels )
    {
        wxRendererNative::Get().DrawHeaderButton
                                (
                                    GetColLabelWindow(),
                                    dc,
                                    rect,
                                    0,
                                    IsSortingBy(col)
                                        ? IsSortOrderAscending()
                                            ? wxHDR_SORT_ICON_UP
                                            : wxHDR_SORT_ICON_DOWN
                                        : wxHDR_SORT_ICON_NONE
                                );
        rect.Deflate(2);
    }
    else
    {

        if ( m_cursorMode == WXGRID_CURSOR_MOVE_COL )
        {
            // clear the background:
            // when called from ProcessRowColLabelMouseEvent the background
            // is not cleared at this point
            wxDCBrushChanger setBrush(dc, m_colLabelWin->GetBackgroundColour());
            wxDCPenChanger setPen(dc, *wxTRANSPARENT_PEN);
            dc.DrawRectangle(rect);
        }

        // draw a border if the column is not being drag-moved
        // (in that case it's omitted to have a 'pressed' appearance)
        if (m_cursorMode != WXGRID_CURSOR_MOVE_COL || col != m_dragMoveRowOrCol)
        {
            IsColLabelHighlighted(col) ? rend.DrawHighlighted(*this, dc, rect, col)
                                       : rend.DrawBorder(*this, dc, rect);
        }
        else
        {
            // just highlight the current column
            rend.DrawHighlighted(*this, dc, rect, col,
                wxGridRowHeaderRendererDefault::Draw_Pressed);
            rect.Deflate(GetBorder() == wxBORDER_NONE ? 2 : 1);
        }
    }

    int hAlign, vAlign;
    GetColLabelAlignment(&hAlign, &vAlign);
    const int orient = GetColLabelTextOrientation();

    rend.DrawLabel(*this, dc, GetColLabelValue(col), rect, hAlign, vAlign, orient);
}

// TODO: these 2 functions should be replaced with wxDC::DrawLabel() to which
//       we just have to add textOrientation support
void wxGrid::DrawTextRectangle( wxDC& dc,
                                const wxString& value,
                                const wxRect& rect,
                                int horizAlign,
                                int vertAlign,
                                int textOrientation ) const
{
    wxArrayString lines;

    StringToLines( value, lines );

    DrawTextRectangle(dc, lines, rect, horizAlign, vertAlign, textOrientation);
}

void wxGrid::DrawTextRectangle(wxDC& dc,
                               const wxArrayString& lines,
                               const wxRect& rect,
                               int horizAlign,
                               int vertAlign,
                               int textOrientation) const
{
    if ( lines.empty() )
        return;

    wxDCClipper clip(dc, rect);

    long textWidth,
         textHeight;

    if ( textOrientation == wxHORIZONTAL )
        GetTextBoxSize( dc, lines, &textWidth, &textHeight );
    else
        GetTextBoxSize( dc, lines, &textHeight, &textWidth );

    int x = 0,
        y = 0;
    switch ( vertAlign )
    {
        case wxALIGN_BOTTOM:
            if ( textOrientation == wxHORIZONTAL )
                y = rect.y + (rect.height - textHeight - GRID_TEXT_MARGIN);
            else
                x = rect.x + (rect.width - textWidth - GRID_TEXT_MARGIN);
            break;

        case wxALIGN_CENTRE:
        case wxALIGN_CENTRE_VERTICAL:
            if ( textOrientation == wxHORIZONTAL )
                y = rect.y + ((rect.height - textHeight) / 2);
            else
                x = rect.x + ((rect.width - textWidth) / 2);
            break;

        case wxALIGN_TOP:
        default:
            if ( textOrientation == wxHORIZONTAL )
                y = rect.y + GRID_TEXT_MARGIN;
            else
                x = rect.x + GRID_TEXT_MARGIN;
            break;
    }

    // Align each line of a multi-line label
    size_t nLines = lines.GetCount();
    for ( size_t l = 0; l < nLines; l++ )
    {
        const wxString& line = lines[l];

        if ( line.empty() )
        {
            *(textOrientation == wxHORIZONTAL ? &y : &x) += dc.GetCharHeight();
            continue;
        }

        wxCoord lineWidth = 0,
             lineHeight = 0;
        dc.GetTextExtent(line, &lineWidth, &lineHeight);

        switch ( horizAlign )
        {
            case wxALIGN_RIGHT:
                if ( textOrientation == wxHORIZONTAL )
                    x = rect.x + (rect.width - lineWidth - GRID_TEXT_MARGIN);
                else
                    y = rect.y + lineWidth + GRID_TEXT_MARGIN;
                break;

            case wxALIGN_CENTRE:
            case wxALIGN_CENTRE_HORIZONTAL:
                if ( textOrientation == wxHORIZONTAL )
                    x = rect.x + ((rect.width - lineWidth) / 2);
                else
                    y = rect.y + rect.height - ((rect.height - lineWidth) / 2);
                break;

            case wxALIGN_LEFT:
            default:
                if ( textOrientation == wxHORIZONTAL )
                    x = rect.x + GRID_TEXT_MARGIN;
                else
                    y = rect.y + rect.height - GRID_TEXT_MARGIN;
                break;
        }

        if ( textOrientation == wxHORIZONTAL )
        {
            dc.DrawText( line, x, y );
            y += lineHeight;
        }
        else
        {
            dc.DrawRotatedText( line, x, y, 90.0 );
            x += lineHeight;
        }
    }
}

void wxGrid::DrawTextRectangle(wxDC& dc,
                               const wxString& text,
                               const wxRect& rect,
                               const wxGridCellAttr& attr,
                               int hAlign,
                               int vAlign) const
{
    attr.GetNonDefaultAlignment(&hAlign, &vAlign);

    // This does nothing if there is no need to ellipsize.
    const wxString& ellipsizedText = wxControl::Ellipsize
                                     (
                                         text,
                                         dc,
                                         attr.GetFitMode().GetEllipsizeMode(),
                                         rect.GetWidth() - 2 * GRID_TEXT_MARGIN,
                                         wxELLIPSIZE_FLAGS_NONE
                                     );

    DrawTextRectangle(dc, ellipsizedText, rect, hAlign, vAlign);
}

// Split multi-line text up into an array of strings.
// Any existing contents of the string array are preserved.
//
// TODO: refactor wxTextFile::Read() and reuse the same code from here
void wxGrid::StringToLines( const wxString& value, wxArrayString& lines ) const
{
    int startPos = 0;
    wxString eol = wxTextFile::GetEOL( wxTextFileType_Unix );
    wxString tVal = wxTextFile::Translate( value, wxTextFileType_Unix );

    while ( startPos < (int)tVal.length() )
    {
        int pos;
        pos = tVal.Mid(startPos).Find( eol );
        if ( pos < 0 )
        {
            break;
        }
        else if ( pos == 0 )
        {
            lines.Add( wxEmptyString );
        }
        else
        {
            lines.Add( tVal.Mid(startPos, pos) );
        }

        startPos += pos + 1;
    }

    if ( startPos < (int)tVal.length() )
    {
        lines.Add( tVal.Mid( startPos ) );
    }
}

void wxGrid::GetTextBoxSize( const wxReadOnlyDC& dc,
                             const wxArrayString& lines,
                             long *width, long *height ) const
{
    wxCoord w = 0;
    wxCoord h = 0;
    wxCoord lineW = 0, lineH = 0;

    size_t i;
    for ( i = 0; i < lines.GetCount(); i++ )
    {
        if ( lines[i].empty() )
        {
            // GetTextExtent() would return 0 for empty lines, but we still
            // need to account for their height.
            h += dc.GetCharHeight();
        }
        else
        {
            dc.GetTextExtent( lines[i], &lineW, &lineH );
            w = wxMax( w, lineW );
            h += lineH;
        }
    }

    *width = w;
    *height = h;
}

//
// ------ Batch processing.
//
void wxGrid::EndBatch()
{
    if ( m_batchCount > 0 )
    {
        m_batchCount--;
        if ( !m_batchCount )
        {
            CalcDimensions();
            InvalidateOverlaySelection();
            Refresh();
        }
    }
}

// Use this, rather than wxWindow::Refresh(), to force an immediate
// repainting of the grid. Has no effect if you are already inside a
// BeginBatch / EndBatch block.
//
void wxGrid::ForceRefresh()
{
    BeginBatch();
    EndBatch();
}

void wxGrid::DoEnable(bool enable)
{
    wxScrolledCanvas::DoEnable(enable);
#if wxUSE_ACCESSIBILITY
    wxAccessible::NotifyEvent(wxACC_EVENT_OBJECT_STATECHANGE, this, wxOBJID_CLIENT, wxACC_SELF);
#endif // wxUSE_ACCESSIBILITY
    Refresh(false /* don't erase background */);
}

//
// ------ Edit control functions
//

void wxGrid::EnableEditing( bool edit )
{
    if ( edit != m_editable )
    {
        if (!edit)
            EnableCellEditControl(edit);
        m_editable = edit;
    }
}

void wxGrid::EnableCellEditControl( bool enable )
{
    if (! m_editable)
        return;

    if ( enable != m_cellEditCtrlEnabled )
    {
        if ( enable )
        {
            // this should be checked by the caller!
            wxCHECK_RET( CanEnableCellControl(), wxT("can't enable editing for this cell!") );

            DoEnableCellEditControl(wxGridActivationSource::FromProgram());
        }
        else
        {
            DoDisableCellEditControl();
        }
    }
}

bool wxGrid::DoEnableCellEditControl(const wxGridActivationSource& actSource)
{
    switch ( SendEvent(wxEVT_GRID_EDITOR_SHOWN) )
    {
        case Event_Vetoed:
        case Event_CellDeleted:
            // We shouldn't do anything if the event was vetoed and can't do
            // anything if the cell doesn't exist any longer.
            return false;

        case Event_Unhandled:
        case Event_Handled:
            // But it doesn't matter here if the event was skipped or not.
            break;
    }

    if ( !DoShowCellEditControl(actSource) )
    {
        // We have to send the HIDDEN event matching the SHOWN one above as the
        // user code may reasonably expect always getting them in pairs, so do
        // it even if the editor hadn't really been shown at all.
        SendEvent(wxEVT_GRID_EDITOR_HIDDEN);

        return false;
    }

    return true;
}

void wxGrid::DoDisableCellEditControl()
{
    SendEvent(wxEVT_GRID_EDITOR_HIDDEN);

    DoAcceptCellEditControl();
}

bool wxGrid::IsCurrentCellReadOnly() const
{
    return const_cast<wxGrid *>(this)->
                GetCellAttrPtr(m_currentCellCoords)->IsReadOnly();
}

bool wxGrid::CanEnableCellControl() const
{
    return m_editable && (m_currentCellCoords != wxGridNoCellCoords) &&
        !IsCurrentCellReadOnly();
}

bool wxGrid::IsCellEditControlShown() const
{
    bool isShown = false;

    if ( m_cellEditCtrlEnabled )
    {
        if ( wxGridCellEditorPtr editor = GetCurrentCellEditorPtr() )
        {
            if ( editor->IsCreated() )
            {
                isShown = editor->GetWindow()->IsShown();
            }
        }
    }

    return isShown;
}

void wxGrid::ShowCellEditControl()
{
    if ( IsCellEditControlEnabled() )
    {
        if ( !IsVisible( m_currentCellCoords, false ) )
        {
            m_cellEditCtrlEnabled = false;
            return;
        }

        DoShowCellEditControl(wxGridActivationSource::FromProgram());
    }
}

bool wxGrid::DoShowCellEditControl(const wxGridActivationSource& actSource)
{
    wxRect rect = CellToRect( m_currentCellCoords );
    int row = m_currentCellCoords.GetRow();
    int col = m_currentCellCoords.GetCol();

    wxGridCellAttrPtr attr = GetCellAttrPtr(row, col);
    wxGridCellEditorPtr editor = attr->GetEditorPtr(this, row, col);

    const wxGridActivationResult&
        res = editor->TryActivate(row, col, this, actSource);
    switch ( res.GetAction() )
    {
        case wxGridActivationResult::Change:
            // This is somewhat similar to what DoSaveEditControlValue() does.
            // but we don't allow vetoing CHANGED event here as this code is
            // new and shouldn't have to support this obsolete usage.
            switch ( SendEvent(wxEVT_GRID_CELL_CHANGING, res.GetNewValue()) )
            {
                case Event_Vetoed:
                case Event_CellDeleted:
                    break;

                case Event_Unhandled:
                case Event_Handled:
                    const wxString& oldval = GetCellValue(m_currentCellCoords);

                    editor->DoActivate(row, col, this);

                    // Show the new cell value.
                    RefreshBlock(m_currentCellCoords);

                    if ( SendEvent(wxEVT_GRID_CELL_CHANGED, oldval) == Event_Vetoed )
                    {
                        wxFAIL_MSG( "Vetoing wxEVT_GRID_CELL_CHANGED is ignored" );
                    }
                    break;
            }
            wxFALLTHROUGH;

        case wxGridActivationResult::Ignore:
            // In any case, don't start editing normally.
            return false;

        case wxGridActivationResult::ShowEditor:
            // Continue normally.
            break;
    }

    // It's not enabled just yet, but will be soon, and we need to set it
    // before generating any events in case their user-defined handlers decide
    // to call EnableCellEditControl() to avoid reentrancy problems.
    m_cellEditCtrlEnabled = true;

    wxGridWindow *gridWindow = CellToGridWindow(row, col);

    // if this is part of a multicell, find owner (topleft)
    int cell_rows, cell_cols;
    if ( GetCellSize( row, col, &cell_rows, &cell_cols ) == CellSpan_Inside )
    {
        row += cell_rows;
        col += cell_cols;
        m_currentCellCoords.SetRow( row );
        m_currentCellCoords.SetCol( col );
    }

    rect.Offset(-GetGridWindowOffset(gridWindow));

    // convert to scrolled coords
    CalcGridWindowScrolledPosition( rect.x, rect.y, &rect.x, &rect.y, gridWindow );

#ifdef __WXQT__
    // Substract 2 pixel in every dimension to fit in the cell area.
    // If not, Qt will draw the control outside the cell.
    // TODO: Check offsets under Qt.
    rect.Deflate(2, 2);
#endif

    if ( !editor->IsCreated() )
    {
        editor->Create(gridWindow, wxID_ANY,
                       new wxGridCellEditorEvtHandler(this, editor.get()));

        // Ensure the editor window has wxWANTS_CHARS flag, so that it
        // gets Tab, Enter and Esc keys, which need to be processed
        // specially by wxGridCellEditorEvtHandler.
        wxWindow* const editorWindow = editor->GetWindow();
        if ( editorWindow )
        {
            editorWindow->SetWindowStyle(editorWindow->GetWindowStyle()
                                            | wxWANTS_CHARS);
        }

        wxGridEditorCreatedEvent evt(GetId(),
                                     wxEVT_GRID_EDITOR_CREATED,
                                     this,
                                     row,
                                     col,
                                     editorWindow);
        ProcessWindowEvent(evt);
    }
    else if ( editor->GetWindow() &&
              editor->GetWindow()->GetParent() != gridWindow )
    {
        editor->GetWindow()->Reparent(gridWindow);
    }

    // resize editor to overflow into righthand cells if allowed
    int maxWidth = rect.width;
    wxString value = GetCellValue(row, col);
    if ( !value.empty() && attr->GetOverflow() )
    {
        int y;
        GetTextExtent(value, &maxWidth, &y, nullptr, nullptr, &attr->GetFont());
        if (maxWidth < rect.width)
            maxWidth = rect.width;
    }

    if ((maxWidth > rect.width) && (col < m_numCols) && m_table)
    {
        GetCellSize( row, col, &cell_rows, &cell_cols );
        // may have changed earlier
        for (int i = col + cell_cols; i < m_numCols; i++)
        {
            int c_rows, c_cols;
            GetCellSize( row, i, &c_rows, &c_cols );

            // looks weird going over a multicell
            if (m_table->IsEmptyCell( row, i ) &&
                    (rect.width < maxWidth) && (c_rows == 1))
            {
                rect.width += GetColWidth( i );
            }
            else
                break;
        }
    }

    editor->SetCellAttr( attr.get() );
    editor->SetSize( rect );

    // Note that the actual rectangle used by the editor could be
    // different from the one we proposed.
    rect = editor->GetWindow()->GetRect();

    // Ensure that the edit control fits into the visible part of the
    // window by shifting it if necessary: we don't want to truncate
    // any part of it by trying to position it too far to the left or
    // top and we definitely don't want to start showing scrollbars by
    // positioning it too far to the right or bottom.
    const wxSize sizeMax = gridWindow->GetClientSize();
    if ( !wxRect(sizeMax).Contains(rect) )
    {
        if ( rect.x < 0 )
            rect.x = 0;
        if ( rect.y < 0 )
            rect.y = 0;
        if ( rect.x > sizeMax.x - rect.width )
            rect.x = sizeMax.x - rect.width;
        if ( rect.y > sizeMax.y - rect.height )
            rect.y = sizeMax.y - rect.height;

        editor->GetWindow()->Move(rect.x, rect.y);
    }

    editor->Show( true, attr.get() );

    // recalc dimensions in case we need to
    // expand the scrolled window to account for editor
    CalcDimensions();

    editor->BeginEdit(row, col, this);
    editor->SetCellAttr(nullptr);

    return true;
}

void wxGrid::HideCellEditControl()
{
    if ( IsCellEditControlEnabled() )
    {
        DoHideCellEditControl();
    }
}

void wxGrid::DoHideCellEditControl()
{
    wxGridCellEditorPtr editor = GetCurrentCellEditorPtr();
    const bool editorHadFocus = editor->GetWindow()->IsDescendant(FindFocus());

    if ( editor->GetWindow()->GetParent() != m_gridWin )
        editor->GetWindow()->Reparent(m_gridWin);

    editor->Show( false );

    wxGridWindow *gridWindow = CellToGridWindow(m_currentCellCoords);
    // return the focus to the grid itself if the editor had it
    //
    // note that we must not do this unconditionally to avoid stealing
    // focus from the window which just received it if we are hiding the
    // editor precisely because we lost focus
    if ( editorHadFocus )
        gridWindow->SetFocus();

    // refresh whole row to the right
    wxRect rect( CellToRect(m_currentCellCoords) );
    rect.Offset( -GetGridWindowOffset(gridWindow) );
    CalcGridWindowScrolledPosition(rect.x, rect.y, &rect.x, &rect.y, gridWindow);
    rect.width = gridWindow->GetClientSize().GetWidth() - rect.x;

#ifdef __WXMAC__
    // ensure that the pixels under the focus ring get refreshed as well
    rect.Inflate(10, 10);
#endif

    gridWindow->Refresh( false, &rect );

    // refresh also the grid to the right
    wxGridWindow *rightGridWindow = nullptr;
    if ( gridWindow->GetType() == wxGridWindow::wxGridWindowFrozenCorner )
        rightGridWindow = m_frozenRowGridWin;
    else if ( gridWindow->GetType() == wxGridWindow::wxGridWindowFrozenCol )
        rightGridWindow = m_gridWin;

    if ( rightGridWindow )
    {
        rect.x = 0;
        rect.width = rightGridWindow->GetClientSize().GetWidth();
        rightGridWindow->Refresh( false, &rect );
    }
}

void wxGrid::AcceptCellEditControlIfShown()
{
    if ( IsCellEditControlShown() )
    {
        DoAcceptCellEditControl();
    }
}

void wxGrid::DoAcceptCellEditControl()
{
    // Reset it first to avoid any problems with recursion via
    // DisableCellEditControl() if it's called from the user-defined event
    // handlers.
    m_cellEditCtrlEnabled = false;

    DoHideCellEditControl();

    DoSaveEditControlValue();
}

void wxGrid::SaveEditControlValue()
{
    if ( IsCellEditControlEnabled() )
    {
        DoSaveEditControlValue();
    }
}

void wxGrid::DoSaveEditControlValue()
{
    int row = m_currentCellCoords.GetRow();
    int col = m_currentCellCoords.GetCol();

    wxString oldval = GetCellValue(m_currentCellCoords);

    wxGridCellEditorPtr editor = GetCurrentCellEditorPtr();

    wxString newval;
    if ( !editor->EndEdit(row, col, this, oldval, &newval) )
        return;

    switch ( SendEvent(wxEVT_GRID_CELL_CHANGING, newval) )
    {
        case Event_Vetoed:
        case Event_CellDeleted:
            break;

        case Event_Unhandled:
        case Event_Handled:
            editor->ApplyEdit(row, col, this);

            // for compatibility reasons dating back to wx 2.8 when this event
            // was called wxEVT_GRID_CELL_CHANGE and wxEVT_GRID_CELL_CHANGING
            // didn't exist we allow vetoing this one too
            if ( SendEvent(wxEVT_GRID_CELL_CHANGED, oldval) == Event_Vetoed )
            {
                // Event has been vetoed, set the data back.
                //
                // Note that we must use row and col here, which are sure to
                // not have been changed, while m_currentCellCoords could have
                // been changed by the event handler.
                SetCellValue(row, col, oldval);
            }
        }
}

//
// ------ Grid location functions
//  Note that all of these functions work with the logical coordinates of
//  grid cells and labels so you will need to convert from device
//  coordinates for mouse events etc.
//

wxGridCellCoords wxGrid::XYToCell(int x, int y, wxGridWindow *gridWindow) const
{
    int row = YToRow(y, false, gridWindow);
    int col = XToCol(x, false, gridWindow);

    return row == -1 || col == -1 ? wxGridNoCellCoords
                                  : wxGridCellCoords(row, col);
}

// compute row or column from some (unscrolled) coordinate value, using either
// m_defaultRowHeight/m_defaultColWidth or binary search on array of
// m_rowBottoms/m_colRights to do it quickly in O(log n) time.
// NOTE: This may not work correctly for reordered columns.
int wxGrid::PosToLinePos(int coord,
                         bool clipToMinMax,
                         const wxGridOperations& oper,
                         wxGridWindow *gridWindow) const
{
    const int numLines = oper.GetNumberOfLines(this, gridWindow);

    if ( coord < 0 )
        return clipToMinMax && numLines > 0 ? 0 : wxNOT_FOUND;

    const int defaultLineSize = oper.GetDefaultLineSize(this);
    wxCHECK_MSG( defaultLineSize, -1, "can't have 0 default line size" );

    int maxPos = coord / defaultLineSize;
    int minPos = oper.GetFirstLine(this, gridWindow);

    // check for the simplest case: if we have no explicit line sizes
    // configured, then we already know the line this position falls in
    const wxArrayInt& lineEnds = oper.GetLineEnds(this);
    if ( lineEnds.empty() )
    {
        if ( maxPos < (numLines + minPos) )
            return maxPos;

        return clipToMinMax ? numLines + minPos - 1 : -1;
    }

    // binary search is quite efficient and we can't really make any assumptions
    // on where to start here since row and columns could be of size 0 if they are
    // hidden. While this could be made more efficient, some profiling will be
    // necessary to determine if it really is a performance bottleneck
    maxPos = numLines + minPos - 1;

    // check if the position is beyond the last column
    const int lineAtMaxPos = oper.GetLineAt(this, maxPos);
    if ( coord >= lineEnds[lineAtMaxPos] )
        return clipToMinMax ? maxPos : wxNOT_FOUND;

    // or before the first one
    const int lineAt0 = oper.GetLineAt(this, minPos);
    if ( coord < oper.GetLineStartPos(this, lineAt0) )
        return clipToMinMax ? minPos : wxNOT_FOUND;
    else if ( coord < lineEnds[lineAt0] )
        return minPos;

    // finally do perform the binary search
    while ( minPos < maxPos )
    {
        wxCHECK_MSG( lineEnds[oper.GetLineAt(this, minPos)] <= coord &&
                        coord < lineEnds[oper.GetLineAt(this, maxPos)],
                     -1,
                     "wxGrid: internal error in PosToLinePos()" );

        if ( coord >= lineEnds[oper.GetLineAt(this, maxPos - 1)] )
            return maxPos;
        else
            maxPos--;

        const int median = minPos + (maxPos - minPos + 1) / 2;
        if ( coord < lineEnds[oper.GetLineAt(this, median)] )
            maxPos = median;
        else
            minPos = median;
    }

    return maxPos;
}

int
wxGrid::PosToLine(int coord,
                  bool clipToMinMax,
                  const wxGridOperations& oper,
                  wxGridWindow *gridWindow) const
{
    int pos = PosToLinePos(coord, clipToMinMax, oper, gridWindow);

    return pos == wxNOT_FOUND ? wxNOT_FOUND : oper.GetLineAt(this, pos);
}

int wxGrid::YToRow(int y, bool clipToMinMax, wxGridWindow *gridWindow) const
{
    return PosToLine(y, clipToMinMax, wxGridRowOperations(), gridWindow);
}

int wxGrid::XToCol(int x, bool clipToMinMax, wxGridWindow *gridWindow) const
{
    return PosToLine(x, clipToMinMax, wxGridColumnOperations(), gridWindow);
}

int wxGrid::YToPos(int y, wxGridWindow *gridWindow) const
{
    return PosToLinePos(y, true /* clip */, wxGridRowOperations(), gridWindow);
}

int wxGrid::XToPos(int x, wxGridWindow *gridWindow) const
{
    return PosToLinePos(x, true /* clip */, wxGridColumnOperations(), gridWindow);
}

// return the row/col number such that the pos is near the edge of, or -1 if
// not near an edge.
//
// notice that position can only possibly be near an edge if the row/column is
// large enough to still allow for an "inner" area that is _not_ near the edge
// (i.e., if the height/width is smaller than WXGRID_LABEL_EDGE_ZONE, pos will
// _never_ be considered to be near the edge).
int wxGrid::PosToEdgeOfLine(int pos, const wxGridOperations& oper) const
{
    // Get the bottom or rightmost line that could match.
    int line = oper.PosToLine(this, pos, nullptr, true);

    if ( line == wxNOT_FOUND )
        return -1;

    const int edge = FromDIP(WXGRID_LABEL_EDGE_ZONE);

    if ( oper.GetLineSize(this, line) > edge )
    {
        // We know that we are in this line, test whether we are close enough
        // to start or end border, respectively.
        if ( abs(oper.GetLineEndPos(this, line) - pos) < edge )
            return line;
        else if ( line > 0 && pos - oper.GetLineStartPos(this, line) < edge )
        {
            // We need to find the previous visible line, so skip all the
            // hidden (of size 0) ones.
            do
            {
                line = oper.GetLineBefore(this, line);
            }
            while ( line >= 0 && oper.GetLineSize(this, line) == 0 );

            // It can possibly be -1 here.
            return line;
        }
    }

    return -1;
}

int wxGrid::YToEdgeOfRow(int y) const
{
    return PosToEdgeOfLine(y, wxGridRowOperations());
}

int wxGrid::XToEdgeOfCol(int x) const
{
    return PosToEdgeOfLine(x, wxGridColumnOperations());
}

wxRect wxGrid::CellToRect( int row, int col ) const
{
    wxRect rect( -1, -1, -1, -1 );

    if ( row >= 0 && row < m_numRows &&
         col >= 0 && col < m_numCols )
    {
        int i, cell_rows, cell_cols;
        rect.width = rect.height = 0;
        if ( GetCellSize( row, col, &cell_rows, &cell_cols ) == CellSpan_Inside )
        {
            row += cell_rows;
            col += cell_cols;
            GetCellSize( row, col, &cell_rows, &cell_cols );
        }

        rect.x = GetColLeft(col);
        rect.y = GetRowTop(row);
        for (i=col; i < col + cell_cols; i++)
            rect.width += GetColWidth(i);
        for (i=row; i < row + cell_rows; i++)
            rect.height += GetRowHeight(i);

        // if grid lines are enabled, then the area of the cell is a bit smaller
        if (m_gridLinesEnabled)
        {
            rect.width -= 1;
            rect.height -= 1;
        }
    }

    return rect;
}

wxGridWindow* wxGrid::CellToGridWindow( int row, int col ) const
{
    // It may happen that we're called during grid creation, when the current
    // cell still has invalid coordinates -- don't return (possibly null)
    // frozen corner window in this case.
    if ( row == -1 && col == -1 )
        return m_gridWin;
    else if ( GetRowPos(row) < m_numFrozenRows && GetColPos(col) < m_numFrozenCols )
        return m_frozenCornerGridWin;
    else if ( GetRowPos(row) < m_numFrozenRows )
        return m_frozenRowGridWin;
    else if ( GetColPos(col) < m_numFrozenCols )
        return m_frozenColGridWin;

    return m_gridWin;
}

void wxGrid::GetGridWindowOffset(const wxGridWindow *gridWindow, int &x, int &y) const
{
    wxPoint pt = GetGridWindowOffset(gridWindow);

    x = pt.x;
    y = pt.y;
}

wxPoint wxGrid::GetGridWindowOffset(const wxGridWindow *gridWindow) const
{
    wxPoint pt(0, 0);

    if ( gridWindow )
    {
        if ( m_frozenRowGridWin &&
           (gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenRow) == 0 )
        {
            pt.y = m_frozenRowGridWin->GetClientSize().y;
        }

        if ( m_frozenColGridWin &&
           (gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenCol) == 0 )
        {
            pt.x = m_frozenColGridWin->GetClientSize().x;
        }
    }

    return pt;
}

wxGridWindow* wxGrid::DevicePosToGridWindow(wxPoint pos) const
{
    return DevicePosToGridWindow(pos.x, pos.y);
}

wxGridWindow* wxGrid::DevicePosToGridWindow(int x, int y) const
{
    if ( m_gridWin->GetRect().Contains(x, y) )
        return m_gridWin;
    else if ( m_frozenCornerGridWin && m_frozenCornerGridWin->GetRect().Contains(x, y) )
        return m_frozenCornerGridWin;
    else if ( m_frozenRowGridWin && m_frozenRowGridWin->GetRect().Contains(x, y) )
        return m_frozenRowGridWin;
    else if ( m_frozenColGridWin && m_frozenColGridWin->GetRect().Contains(x, y) )
        return m_frozenColGridWin;

    return nullptr;
}

void wxGrid::CalcGridWindowUnscrolledPosition(int x, int y, int *xx, int *yy,
                                              const wxGridWindow *gridWindow) const
{
    CalcUnscrolledPosition(x, y, xx, yy);

    if ( gridWindow )
    {
        if ( yy && (gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenRow) )
            *yy = y;
        if ( xx && (gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenCol) )
            *xx = x;
    }
}

wxPoint wxGrid::CalcGridWindowUnscrolledPosition(const wxPoint& pt,
                                                 const wxGridWindow *gridWindow) const
{
    wxPoint pt2;
    CalcGridWindowUnscrolledPosition(pt.x, pt.y, &pt2.x, &pt2.y, gridWindow);
    return pt2;
}

void wxGrid::CalcGridWindowScrolledPosition(int x, int y, int *xx, int *yy,
                                            const wxGridWindow *gridWindow) const
{
    CalcScrolledPosition(x, y, xx, yy);

    if ( gridWindow )
    {
        if ( yy && (gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenRow) )
            *yy = y;
        if ( xx && (gridWindow->GetType() & wxGridWindow::wxGridWindowFrozenCol) )
            *xx = x;
    }
}

wxPoint wxGrid::CalcGridWindowScrolledPosition(const wxPoint& pt,
                                               const wxGridWindow *gridWindow) const
{
    wxPoint pt2;
    CalcGridWindowScrolledPosition(pt.x, pt.y, &pt2.x, &pt2.y, gridWindow);
    return pt2;
}

bool wxGrid::IsVisible( int row, int col, bool wholeCellVisible ) const
{
    // get the cell rectangle in logical coords
    //
    wxRect r( CellToRect( row, col ) );

    wxGridWindow *gridWindow = CellToGridWindow(row, col);
    r.Offset(-GetGridWindowOffset(gridWindow));

    // convert to device coords
    //
    int left, top, right, bottom;
    CalcGridWindowScrolledPosition( r.GetLeft(), r.GetTop(), &left, &top, gridWindow );
    CalcGridWindowScrolledPosition( r.GetRight(), r.GetBottom(), &right, &bottom, gridWindow );

    // check against the client area of the grid window
    int cw, ch;
    gridWindow->GetClientSize( &cw, &ch );

    if ( wholeCellVisible )
    {
        // is the cell wholly visible ?
        return ( left >= 0 && right <= cw &&
                 top >= 0 && bottom <= ch );
    }
    else
    {
        // is the cell partly visible ?
        //
        return ( ((left >= 0 && left < cw) || (right > 0 && right <= cw)) &&
                 ((top >= 0 && top < ch) || (bottom > 0 && bottom <= ch)) );
    }
}

// make the specified cell location visible by doing a minimal amount
// of scrolling
//
void wxGrid::MakeCellVisible( int row, int col )
{
    int xpos = -1, ypos = -1;

    if ( row < -1 || row >= m_numRows ||
         col < -1 || col >= m_numCols )
        return;

    // We don't scroll in the corresponding direction if "pixels per line" is 0.
    const bool processRow = row != -1 && m_yScrollPixelsPerLine != 0;
    const bool processCol = col != -1 && m_xScrollPixelsPerLine != 0;

    // Get the cell rectangle in logical coords.
    wxRect r;
    wxGridWindow *gridWindow;

    if ( processRow && processCol )
    {
        r = CellToRect(row, col);
        gridWindow = CellToGridWindow(row, col);
    }
    else if ( processRow )
    {
        r.SetTop(GetRowTop(row));
        r.SetHeight(GetRowHeight(row));
        gridWindow = row < m_numFrozenRows
                        ? m_frozenRowGridWin
                        : m_gridWin;
    }
    else if ( processCol )
    {
        r.SetLeft(GetColLeft(col));
        r.SetWidth(GetColWidth(col));
        gridWindow = col < m_numFrozenCols
                        ? m_frozenColGridWin
                        : m_gridWin;
    }
    else
    {
        return;
    }

    wxPoint gridOffset = GetGridWindowOffset(gridWindow);

    if ( processRow )
    {
        // Convert to device coords.
        int top, bottom;
        CalcGridWindowScrolledPosition(0, r.GetTop(), nullptr, &top, gridWindow);
        CalcGridWindowScrolledPosition(0, r.GetBottom(), nullptr, &bottom, gridWindow);

        int ch;
        gridWindow->GetClientSize(nullptr, &ch);

        if ( top < gridOffset.y )
        {
            ypos = r.GetTop() - gridOffset.y;
        }
        else if ( bottom > (ch + gridOffset.y) )
        {
            int h = r.GetHeight();

            ypos = r.GetTop() - gridOffset.y;

            int i;
            for ( i = row - 1; i >= 0; i-- )
            {
                int rowHeight = GetRowHeight(i);
                if ( h + rowHeight > ch )
                    break;

                h += rowHeight;
                ypos -= rowHeight;
            }

            // we divide it later by GRID_SCROLL_LINE, make sure that we don't
            // have rounding errors (this is important, because if we do,
            // we might not scroll at all and some cells won't be redrawn)
            //
            // Sometimes GRID_SCROLL_LINE / 2 is not enough,
            // so just add a full scroll unit...
            ypos += m_yScrollPixelsPerLine;
        }
    }

    if ( processCol )
    {
        // Convert to device coords.
        int left, right;
        CalcGridWindowScrolledPosition(r.GetLeft(), 0, &left, nullptr, gridWindow);
        CalcGridWindowScrolledPosition(r.GetRight(), 0, &right, nullptr, gridWindow);

        int cw;
        gridWindow->GetClientSize(&cw, nullptr);

        // special handling for wide cells - show always left part of the cell!
        // Otherwise, e.g. when stepping from row to row, it would jump between
        // left and right part of the cell on every step!
//      if ( left < 0 )
        if ( left < gridOffset.x || (right - left) >= cw )
        {
            xpos = r.GetLeft() - gridOffset.x;
        }
        else if ( right > (cw + gridOffset.x) )
        {
            // position the view so that the cell is on the right
            int x0, y0;
            CalcGridWindowUnscrolledPosition(0, 0, &x0, &y0, gridWindow);
            xpos = x0 + (right - cw);

            // see comment for ypos above
            xpos += m_xScrollPixelsPerLine;
        }
    }

    if ( xpos == -1 && ypos == -1 )
        return;

    if ( xpos != -1 )
        xpos /= m_xScrollPixelsPerLine;
    if ( ypos != -1 )
        ypos /= m_yScrollPixelsPerLine;
    Scroll(xpos, ypos);
    AdjustScrollbars();
}

int wxGrid::GetFirstFullyVisibleRow() const
{
    if ( m_numRows == 0 )
        return -1;

    int row;
    if ( GetNumberFrozenRows() > 0 )
    {
        row = 0;
    }
    else
    {
        int y;
        CalcGridWindowUnscrolledPosition(0, 0,
                                         nullptr, &y,
                                         m_gridWin);

        row = internalYToRow(y, m_gridWin);

        // If the row is not fully visible (if only 2 pixels is hidden
        // the row still looks fully visible).
        if ( GetRowTop(row) + 2 < y )
        {
            // Use the next visible row.
            for ( ;; )
            {
                // But we can't go beyond the last row anyhow.
                if ( row == m_numRows - 1 )
                    break;

                if ( IsRowShown(++row) )
                    break;
            }
        }
    }

    return row;
}

int wxGrid::GetFirstFullyVisibleColumn() const
{
    if ( m_numCols == 0 )
        return -1;

    int col;
    if ( GetNumberFrozenCols() > 0 )
    {
        col = 0;
    }
    else
    {
        int x;
        CalcGridWindowUnscrolledPosition(0, 0,
                                         &x, nullptr,
                                         m_gridWin);

        col = internalXToCol(x, m_gridWin);

        // If the column is not fully visible.
        if ( GetColLeft(col) < x )
        {
            // Use the next visible column.
            for ( ;; )
            {
                if ( col == m_numCols - 1 )
                    break;

                if ( IsColShown(GetColAt(++col)) )
                    break;
            }
        }
    }

    return col;
}

//
// ------ Grid cursor movement functions
//

namespace
{

// Helper function creating dummy wxKeyboardState object corresponding to the
// value of "expandSelection" flag specified to our public MoveCursorXXX().
// This function only exists to avoid breaking compatibility in the public API,
// all internal code should use the real, not dummy, wxKeyboardState.
inline
wxKeyboardState DummyKeyboardState(bool expandSelection)
{
    // Normally "expandSelection" is set depending on whether Shift is pressed
    // or not, but here we reconstruct the keyboard state from this flag.
    return wxKeyboardState(false /* control */, expandSelection /* shift */);
}

} // anonymous namespace

void
wxGrid::DoMoveCursorFromKeyboard(const wxKeyboardState& kbdState,
                                 const wxGridDirectionOperations& diroper)
{
    if ( kbdState.ControlDown() )
        DoMoveCursorByBlock(kbdState, diroper);
    else
        DoMoveCursor(kbdState, diroper);
}

bool
wxGrid::DoMoveCursor(const wxKeyboardState& kbdState,
                     const wxGridDirectionOperations& diroper)
{
    if ( m_currentCellCoords == wxGridNoCellCoords )
        return false;

    // Expand selection if Shift is pressed.
    if ( kbdState.ShiftDown() )
    {
        if ( !m_selection )
            return false;

        wxGridCellCoords coords(m_selection->GetExtensionAnchor());
        if ( !diroper.TryToAdvance(coords) )
            return false;

        if ( m_selection->ExtendCurrentBlock(m_currentCellCoords,
                                             coords,
                                             kbdState) )
        {
            // We want to show a line (a row or a column), not the end of
            // the selection block. And do it only if the selection block
            // was actually changed.
            MakeCellVisible(diroper.MakeWholeLineCoords(coords));
        }
    }
    else // don't expand selection
    {
        ClearSelection();

        wxGridCellCoords coords = m_currentCellCoords;
        if ( !diroper.TryToAdvance(coords) )
            return false;

        GoToCell(coords);
    }

    return true;
}

bool wxGrid::MoveCursorUp(bool expandSelection)
{
    return DoMoveCursor(DummyKeyboardState(expandSelection),
                        wxGridBackwardOperations(this, wxGridRowOperations()));
}

bool wxGrid::MoveCursorDown(bool expandSelection)
{
    return DoMoveCursor(DummyKeyboardState(expandSelection),
                        wxGridForwardOperations(this, wxGridRowOperations()));
}

bool wxGrid::MoveCursorLeft(bool expandSelection)
{
    return DoMoveCursor(DummyKeyboardState(expandSelection),
                        wxGridBackwardOperations(this, wxGridColumnOperations()));
}

bool wxGrid::MoveCursorRight(bool expandSelection)
{
    return DoMoveCursor(DummyKeyboardState(expandSelection),
                        wxGridForwardOperations(this, wxGridColumnOperations()));
}

bool
wxGrid::AdvanceByPage(wxGridCellCoords& coords,
                      const wxGridDirectionOperations& diroper)
{
    if ( diroper.IsAtBoundary(coords) )
        return false;

    const int oldRow = coords.GetRow();
    coords.SetRow(diroper.MoveByPixelDistance(oldRow, m_gridWin->GetClientSize().y));
    if ( coords.GetRow() == oldRow )
        diroper.Advance(coords);

    return true;
}

bool
wxGrid::DoMoveCursorByPage(const wxKeyboardState& kbdState,
                           const wxGridDirectionOperations& diroper)
{
    if ( m_currentCellCoords == wxGridNoCellCoords )
        return false;

    // We don't handle Ctrl-PageUp/Down, it's not really clear what are they
    // supposed to do, so don't do anything for now.
    if ( kbdState.ControlDown() )
        return false;

    if ( kbdState.ShiftDown() )
    {
        if ( !m_selection )
            return false;

        wxGridCellCoords coords = m_selection->GetExtensionAnchor();
        if ( !AdvanceByPage(coords, diroper) )
            return false;

        if ( m_selection->ExtendCurrentBlock(m_currentCellCoords, coords, kbdState) )
            MakeCellVisible(diroper.MakeWholeLineCoords(coords));
    }
    else
    {
        wxGridCellCoords coords(m_currentCellCoords);
        if ( !AdvanceByPage(coords, diroper) )
            return false;

        ClearSelection();
        GoToCell(coords);
    }

    return true;
}

bool wxGrid::MovePageUp()
{
    return DoMoveCursorByPage(DummyKeyboardState(false),
                wxGridBackwardOperations(this, wxGridRowOperations()));
}

bool wxGrid::MovePageDown()
{
    return DoMoveCursorByPage(DummyKeyboardState(false),
                wxGridForwardOperations(this, wxGridRowOperations()));
}

// helper of DoMoveCursorByBlock(): advance the cell coordinates using diroper
// until we find a non-empty cell or reach the grid end
void
wxGrid::AdvanceToNextNonEmpty(wxGridCellCoords& coords,
                              const wxGridDirectionOperations& diroper)
{
    while ( !diroper.IsAtBoundary(coords) )
    {
        diroper.Advance(coords);
        if ( !m_table->IsEmpty(coords) )
            break;
    }
}

bool
wxGrid::AdvanceByBlock(wxGridCellCoords& coords,
                       const wxGridDirectionOperations& diroper)
{
    if ( m_table->IsEmpty(coords) )
    {
        // we are in an empty cell: find the next block of non-empty cells
        AdvanceToNextNonEmpty(coords, diroper);
    }
    else // current cell is not empty
    {
        if ( !diroper.TryToAdvance(coords) )
            return false;

        if ( m_table->IsEmpty(coords) )
        {
            // we started at the end of a block, find the next one
            AdvanceToNextNonEmpty(coords, diroper);
        }
        else // we're in a middle of a block
        {
            // go to the end of it, i.e. find the last cell before the next
            // empty one
            while ( !diroper.IsAtBoundary(coords) )
            {
                wxGridCellCoords coordsNext(coords);
                diroper.Advance(coordsNext);
                if ( m_table->IsEmpty(coordsNext) )
                    break;

                coords = coordsNext;
            }
        }
    }

    return true;
}

bool
wxGrid::DoMoveCursorByBlock(const wxKeyboardState& kbdState,
                            const wxGridDirectionOperations& diroper)
{
    if ( !m_table )
        return false;

    wxGridCellCoords coords(m_currentCellCoords);
    if ( kbdState.ShiftDown() )
    {
        if ( !m_selection )
            return false;

        // Extending selection by block is tricky for several reasons. First of
        // all, we need to combine the coordinates of the current cell and the
        // anchor point of selection to find our starting point.
        //
        // To explain why we need to do this, consider the example of moving by
        // rows (i.e. vertically). In this case, it's the contents of column
        // containing the current cell which should determine the destination
        // of Shift-Ctrl-Up/Down movement, just as it does for Ctrl-Up/Down. In
        // fact, the column containing the selection anchor might not even be
        // visible at all, e.g. if a whole row is selected and that column is
        // the last one, so we definitely don't want to use the contents of
        // this column to determine the destination row.
        //
        // So instead of using the anchor itself here, use only its component
        // component in "our" direction with the current cell component.
        const wxGridCellCoords anchor = m_selection->GetExtensionAnchor();

        // This is a really ugly hack that we use to check if we're moving by
        // rows or columns here, but it's not worth adding a specific method
        // just for this, so just check if MakeWholeLineCoords() fixes the
        // column or the row as -1 to determine the direction we're moving in.
        const bool byRow = diroper.MakeWholeLineCoords(coords).GetCol() == -1;

        if ( byRow )
            coords.SetRow(anchor.GetRow());
        else
            coords.SetCol(anchor.GetCol());

        if ( !AdvanceByBlock(coords, diroper) )
            return false;

        // Second, now that we've found the destination, we need to copy the
        // other component, i.e. the one we didn't modify, from the anchor to
        // do as if we started from the anchor originally.
        //
        // Again, to understand why this is necessary, consider the same
        // example as above: if we didn't do this, we would lose the column of
        // the original anchor completely and end up with a single column
        // selection block even if we had started with the full row selection.
        if ( byRow )
            coords.SetCol(anchor.GetCol());
        else
            coords.SetRow(anchor.GetRow());

        if ( m_selection->ExtendCurrentBlock(m_currentCellCoords,
                                             coords,
                                             kbdState) )
        {
            // We want to show a line (a row or a column), not the end of
            // the selection block. And do it only if the selection block
            // was actually changed.
            MakeCellVisible(diroper.MakeWholeLineCoords(coords));
        }
    }
    else
    {
        if ( !AdvanceByBlock(coords, diroper) )
            return false;

        ClearSelection();
        GoToCell(coords);
    }

    return true;
}

bool wxGrid::MoveCursorUpBlock(bool expandSelection)
{
    return DoMoveCursorByBlock(
                DummyKeyboardState(expandSelection),
                wxGridBackwardOperations(this, wxGridRowOperations())
           );
}

bool wxGrid::MoveCursorDownBlock( bool expandSelection )
{
    return DoMoveCursorByBlock(
                DummyKeyboardState(expandSelection),
                wxGridForwardOperations(this, wxGridRowOperations())
           );
}

bool wxGrid::MoveCursorLeftBlock( bool expandSelection )
{
    return DoMoveCursorByBlock(
                DummyKeyboardState(expandSelection),
                wxGridBackwardOperations(this, wxGridColumnOperations())
           );
}

bool wxGrid::MoveCursorRightBlock( bool expandSelection )
{
    return DoMoveCursorByBlock(
                DummyKeyboardState(expandSelection),
                wxGridForwardOperations(this, wxGridColumnOperations())
           );
}

//
// ------ Label values and formatting
//

void wxGrid::GetRowLabelAlignment( int *horiz, int *vert ) const
{
    if ( horiz )
        *horiz = m_rowLabelHorizAlign;
    if ( vert )
        *vert  = m_rowLabelVertAlign;
}

void wxGrid::GetColLabelAlignment( int *horiz, int *vert ) const
{
    if ( horiz )
        *horiz = m_colLabelHorizAlign;
    if ( vert )
        *vert  = m_colLabelVertAlign;
}

int wxGrid::GetColLabelTextOrientation() const
{
    return m_colLabelTextOrientation;
}

void wxGrid::GetCornerLabelAlignment( int *horiz, int *vert ) const
{
    if ( horiz )
        *horiz = m_cornerLabelHorizAlign;
    if ( vert )
        *vert  = m_cornerLabelVertAlign;
}

int wxGrid::GetCornerLabelTextOrientation() const
{
    return m_cornerLabelTextOrientation;
}

wxString wxGrid::GetRowLabelValue( int row ) const
{
    if ( m_table )
    {
        return m_table->GetRowLabelValue( row );
    }
    else
    {
        wxString s;
        s << row;
        return s;
    }
}

wxString wxGrid::GetColLabelValue( int col ) const
{
    if ( m_table )
    {
        return m_table->GetColLabelValue( col );
    }
    else
    {
        wxString s;
        s << col;
        return s;
    }
}

wxString wxGrid::GetCornerLabelValue() const
{
    if ( m_table )
    {
        return m_table->GetCornerLabelValue();
    }
    else
    {
        return wxString();
    }
}

void wxGrid::SetRowLabelSize( int width )
{
    wxASSERT( width >= 0 || width == wxGRID_AUTOSIZE );

    if ( width == wxGRID_AUTOSIZE )
    {
        width = CalcColOrRowLabelAreaMinSize(wxGRID_ROW);
    }

    if ( width != m_rowLabelWidth )
    {
        if ( width == 0 )
        {
            m_rowLabelWin->Show( false );
            m_cornerLabelWin->Show( false );
        }
        else if ( m_rowLabelWidth == 0 )
        {
            m_rowLabelWin->Show( true );
            if ( m_colLabelHeight > 0 )
                m_cornerLabelWin->Show( true );
        }

        m_rowLabelWidth = width;
        InvalidateBestSize();
        CalcWindowSizes();
        Refresh();
    }
}

void wxGrid::SetColLabelSize( int height )
{
    wxASSERT( height >=0 || height == wxGRID_AUTOSIZE );

    if ( height == wxGRID_AUTOSIZE )
    {
        height = CalcColOrRowLabelAreaMinSize(wxGRID_COLUMN);
    }

    if ( height != m_colLabelHeight )
    {
        if ( height == 0 )
        {
            m_colLabelWin->Show( false );
            m_cornerLabelWin->Show( false );
        }
        else if ( m_colLabelHeight == 0 )
        {
            m_colLabelWin->Show( true );
            if ( m_rowLabelWidth > 0 )
                m_cornerLabelWin->Show( true );
        }

        m_colLabelHeight = height;
        InvalidateBestSize();
        CalcWindowSizes();
        Refresh();
    }
}

void wxGrid::SetRowLabelMinimalSize(int width)
{
    wxCHECK_RET(width >= 0, "invalid min row label width");
    m_rowLabelMinWidth = width;
}


void wxGrid::SetColLabelMinimalSize(int height)
{
    wxCHECK_RET(height >= 0, "invalid min col label height");
    m_colLabelMinHeight = height;
}

void wxGrid::SetLabelBackgroundColour( const wxColour& colour )
{
    if ( m_labelBackgroundColour != colour )
    {
        m_labelBackgroundColour = colour;
        m_rowLabelWin->SetBackgroundColour( colour );
        m_colLabelWin->SetBackgroundColour( colour );
        m_cornerLabelWin->SetBackgroundColour( colour );
        if ( m_rowFrozenLabelWin )
            m_rowFrozenLabelWin->SetBackgroundColour( colour );
        if ( m_colFrozenLabelWin )
            m_colFrozenLabelWin->SetBackgroundColour( colour );

        if ( ShouldRefresh() )
        {
            RefreshArea(wxGA_Labels);
        }
    }
}

void wxGrid::SetLabelTextColour( const wxColour& colour )
{
    if ( m_labelTextColour != colour )
    {
        m_labelTextColour = colour;

        if ( IsUsingNativeHeader() )
            GetGridColHeader()->SetForegroundColour( colour );

        if ( ShouldRefresh() )
        {
            RefreshArea(wxGA_Labels);
        }
    }
}

void wxGrid::SetLabelFont( const wxFont& font )
{
    m_labelFont = font;

    if ( IsUsingNativeHeader() )
        GetGridColHeader()->SetFont( font );

    if ( ShouldRefresh() )
    {
        RefreshArea(wxGA_Labels);
    }
}

void wxGrid::SetRowLabelAlignment( int horiz, int vert )
{
    // allow old (incorrect) defs to be used
    switch ( horiz )
    {
        case wxLEFT:   horiz = wxALIGN_LEFT; break;
        case wxRIGHT:  horiz = wxALIGN_RIGHT; break;
        case wxCENTRE: horiz = wxALIGN_CENTRE; break;
    }

    switch ( vert )
    {
        case wxTOP:    vert = wxALIGN_TOP;    break;
        case wxBOTTOM: vert = wxALIGN_BOTTOM; break;
        case wxCENTRE: vert = wxALIGN_CENTRE; break;
    }

    if ( horiz == wxALIGN_LEFT || horiz == wxALIGN_CENTRE || horiz == wxALIGN_RIGHT )
    {
        m_rowLabelHorizAlign = horiz;
    }

    if ( vert == wxALIGN_TOP || vert == wxALIGN_CENTRE || vert == wxALIGN_BOTTOM )
    {
        m_rowLabelVertAlign = vert;
    }

    if ( ShouldRefresh() )
    {
        RefreshArea(wxGA_RowLabels);
    }
}

void wxGrid::SetColLabelAlignment( int horiz, int vert )
{
    // allow old (incorrect) defs to be used
    switch ( horiz )
    {
        case wxLEFT:   horiz = wxALIGN_LEFT; break;
        case wxRIGHT:  horiz = wxALIGN_RIGHT; break;
        case wxCENTRE: horiz = wxALIGN_CENTRE; break;
    }

    switch ( vert )
    {
        case wxTOP:    vert = wxALIGN_TOP;    break;
        case wxBOTTOM: vert = wxALIGN_BOTTOM; break;
        case wxCENTRE: vert = wxALIGN_CENTRE; break;
    }

    if ( horiz == wxALIGN_LEFT || horiz == wxALIGN_CENTRE || horiz == wxALIGN_RIGHT )
    {
        m_colLabelHorizAlign = horiz;
    }

    if ( vert == wxALIGN_TOP || vert == wxALIGN_CENTRE || vert == wxALIGN_BOTTOM )
    {
        m_colLabelVertAlign = vert;
    }

    if ( ShouldRefresh() )
    {
        RefreshArea(wxGA_ColLabels);
    }
}

void wxGrid::SetCornerLabelAlignment( int horiz, int vert )
{
    // allow old (incorrect) defs to be used
    switch ( horiz )
    {
        case wxLEFT:   horiz = wxALIGN_LEFT; break;
        case wxRIGHT:  horiz = wxALIGN_RIGHT; break;
        case wxCENTRE: horiz = wxALIGN_CENTRE; break;
    }

    switch ( vert )
    {
        case wxTOP:    vert = wxALIGN_TOP;    break;
        case wxBOTTOM: vert = wxALIGN_BOTTOM; break;
        case wxCENTRE: vert = wxALIGN_CENTRE; break;
    }

    if ( horiz == wxALIGN_LEFT || horiz == wxALIGN_CENTRE || horiz == wxALIGN_RIGHT )
    {
        m_cornerLabelHorizAlign = horiz;
    }

    if ( vert == wxALIGN_TOP || vert == wxALIGN_CENTRE || vert == wxALIGN_BOTTOM )
    {
        m_cornerLabelVertAlign = vert;
    }

    if ( ShouldRefresh() )
    {
        m_cornerLabelWin->Refresh();
    }
}

// Note: under MSW, the default column label font must be changed because it
//       does not support vertical printing
//
// Example:
//      pGrid->SetLabelFont(wxFontInfo(9).Family(wxFONTFAMILY_SWISS));
//      pGrid->SetColLabelTextOrientation(wxVERTICAL);
//
void wxGrid::SetColLabelTextOrientation( int textOrientation )
{
    if ( textOrientation == wxHORIZONTAL || textOrientation == wxVERTICAL )
        m_colLabelTextOrientation = textOrientation;

    if ( ShouldRefresh() )
        RefreshArea(wxGA_ColLabels);
}

void wxGrid::SetCornerLabelTextOrientation( int textOrientation )
{
    if ( textOrientation == wxHORIZONTAL || textOrientation == wxVERTICAL )
        m_cornerLabelTextOrientation = textOrientation;

    if ( ShouldRefresh() )
        m_cornerLabelWin->Refresh();
}

void wxGrid::SetRowLabelValue( int row, const wxString& s )
{
    if ( m_table )
    {
        m_table->SetRowLabelValue( row, s );
        if ( ShouldRefresh() )
        {
            wxRect rect = CellToRect( row, 0 );
            if ( rect.height > 0 )
            {
                wxGridWindow* const gridWindow = CellToGridWindow(row, 0);
                CalcGridWindowScrolledPosition(0, rect.y, &rect.x, &rect.y, gridWindow);
                rect.x = 0;
                rect.width = GetRowLabelSize();
                rect.Offset(0, GetColLabelSize());
                Refresh(true, &rect);
            }
        }
    }
}

void wxGrid::SetColLabelValue( int col, const wxString& s )
{
    if ( m_table )
    {
        m_table->SetColLabelValue( col, s );
        if ( ShouldRefresh() )
        {
            if ( m_useNativeHeader )
            {
                GetGridColHeader()->UpdateColumn(col);
            }
            else
            {
                wxRect rect = CellToRect( 0, col );
                if ( rect.width > 0 )
                {
                    wxGridWindow* const gridWindow = CellToGridWindow(0, col);
                    CalcGridWindowScrolledPosition(rect.x, 0, &rect.x, &rect.y, gridWindow);
                    rect.y = 0;
                    rect.height = GetColLabelSize();
                    rect.Offset(GetRowLabelSize(), 0);
                    Refresh(true, &rect);
                }
            }
        }
    }
}

void wxGrid::SetCornerLabelValue( const wxString& s )
{
    if ( m_table )
    {
        m_table->SetCornerLabelValue( s );
        if ( ShouldRefresh() )
        {
            m_cornerLabelWin->Refresh();
        }
    }
}

void wxGrid::SetGridLineColour( const wxColour& colour )
{
    if ( m_gridLineColour != colour )
    {
        m_gridLineColour = colour;

        if ( GridLinesEnabled() )
            RedrawGridLines();
    }
}

void wxGrid::SetCellHighlightColour( const wxColour& colour )
{
    if ( m_cellHighlightColour != colour )
    {
        m_cellHighlightColour = colour;

        RefreshBlock(m_currentCellCoords);
    }
}

void wxGrid::SetCellHighlightPenWidth(int width)
{
    if (m_cellHighlightPenWidth != width)
    {
        m_cellHighlightPenWidth = width;

        // Just redrawing the cell highlight is not enough since that won't
        // make any visible change if the thickness is getting smaller.
        int row = m_currentCellCoords.GetRow();
        int col = m_currentCellCoords.GetCol();
        if ( row == -1 || col == -1 || GetColWidth(col) <= 0 || GetRowHeight(row) <= 0 )
            return;

        wxRect rect = CellToRect(row, col);
        wxGridWindow *gridWindow = CellToGridWindow(row, col);
        gridWindow->Refresh(true, &rect);
    }
}

void wxGrid::SetCellHighlightROPenWidth(int width)
{
    if (m_cellHighlightROPenWidth != width)
    {
        m_cellHighlightROPenWidth = width;

        // Just redrawing the cell highlight is not enough since that won't
        // make any visible change if the thickness is getting smaller.
        int row = m_currentCellCoords.GetRow();
        int col = m_currentCellCoords.GetCol();
        if ( row == -1 || col == -1 ||
                GetColWidth(col) <= 0 || GetRowHeight(row) <= 0 )
            return;

        wxRect rect = CellToRect(row, col);
        wxGridWindow *gridWindow = CellToGridWindow(row, col);
        gridWindow->Refresh(true, &rect);
    }
}

void wxGrid::SetGridFrozenBorderColour(const wxColour &colour)
{
    if ( m_gridFrozenBorderColour != colour )
    {
        m_gridFrozenBorderColour = colour;

        if ( ShouldRefresh() )
        {
            if ( m_frozenRowGridWin )
                m_frozenRowGridWin->Refresh();
            if ( m_frozenColGridWin )
                m_frozenColGridWin->Refresh();
        }
    }
}

void wxGrid::SetGridFrozenBorderPenWidth(int width)
{
    if ( m_gridFrozenBorderPenWidth != width )
    {
        m_gridFrozenBorderPenWidth = width;

        if ( ShouldRefresh() )
        {
            if ( m_frozenRowGridWin )
                m_frozenRowGridWin->Refresh();
            if ( m_frozenColGridWin )
                m_frozenColGridWin->Refresh();
        }
    }
}

void wxGrid::RedrawGridLines()
{
    // the lines will be redrawn when the window is thawed or shown
    if ( ShouldRefresh() )
        RefreshArea(wxGA_Cells);
}

void wxGrid::EnableGridLines( bool enable )
{
    if ( enable != m_gridLinesEnabled )
    {
        m_gridLinesEnabled = enable;

        RedrawGridLines();
    }
}

void wxGrid::DoClipGridLines(bool& var, bool clip)
{
    if ( clip != var )
    {
        var = clip;

        if ( GridLinesEnabled() )
            RedrawGridLines();
    }
}

int wxGrid::GetDefaultRowSize() const
{
    return m_defaultRowHeight;
}

int wxGrid::GetRowSize( int row ) const
{
    wxCHECK_MSG( row >= 0 && row < m_numRows, 0, wxT("invalid row index") );

    return GetRowHeight(row);
}

int wxGrid::GetDefaultColSize() const
{
    return m_defaultColWidth;
}

int wxGrid::GetColSize( int col ) const
{
    wxCHECK_MSG( col >= 0 && col < m_numCols, 0, wxT("invalid column index") );

    return GetColWidth(col);
}

// ============================================================================
// access to the grid attributes: each of them has a default value in the grid
// itself and may be overidden on a per-cell basis
// ============================================================================

// ----------------------------------------------------------------------------
// setting default attributes
// ----------------------------------------------------------------------------

void wxGrid::SetDefaultCellBackgroundColour( const wxColour& col )
{
    m_defaultCellAttr->SetBackgroundColour(col);
#if defined(__WXGTK__) || defined(__WXQT__)
    m_gridWin->SetBackgroundColour(col);
#endif
}

void wxGrid::SetDefaultCellTextColour( const wxColour& col )
{
    m_defaultCellAttr->SetTextColour(col);
}

void wxGrid::SetDefaultCellAlignment( int horiz, int vert )
{
    m_defaultCellAttr->SetAlignment(horiz, vert);
}

void wxGrid::SetDefaultCellFitMode(wxGridFitMode fitMode)
{
    m_defaultCellAttr->SetFitMode(fitMode);
}

void wxGrid::SetDefaultCellFont( const wxFont& font )
{
    m_defaultCellAttr->SetFont(font);
}

// For editors and renderers the type registry takes precedence over the
// default attr, so we need to register the new editor/renderer for the string
// data type in order to make setting a default editor/renderer appear to
// work correctly.

void wxGrid::SetDefaultRenderer(wxGridCellRenderer *renderer)
{
    RegisterDataType(wxGRID_VALUE_STRING,
                     renderer,
                     GetDefaultEditorForType(wxGRID_VALUE_STRING));
}

void wxGrid::SetDefaultEditor(wxGridCellEditor *editor)
{
    RegisterDataType(wxGRID_VALUE_STRING,
                     GetDefaultRendererForType(wxGRID_VALUE_STRING),
                     editor);
}

// ----------------------------------------------------------------------------
// access to the default attributes
// ----------------------------------------------------------------------------

wxColour wxGrid::GetDefaultCellBackgroundColour() const
{
    return m_defaultCellAttr->GetBackgroundColour();
}

wxColour wxGrid::GetDefaultCellTextColour() const
{
    return m_defaultCellAttr->GetTextColour();
}

wxFont wxGrid::GetDefaultCellFont() const
{
    return m_defaultCellAttr->GetFont();
}

void wxGrid::GetDefaultCellAlignment( int *horiz, int *vert ) const
{
    m_defaultCellAttr->GetAlignment(horiz, vert);
}

wxGridFitMode wxGrid::GetDefaultCellFitMode() const
{
    return m_defaultCellAttr->GetFitMode();
}

wxGridCellRenderer *wxGrid::GetDefaultRenderer() const
{
    return m_defaultCellAttr->GetRenderer(nullptr, 0, 0);
}

wxGridCellEditor *wxGrid::GetDefaultEditor() const
{
    return m_defaultCellAttr->GetEditor(nullptr, 0, 0);
}

// ----------------------------------------------------------------------------
// access to cell attributes
// ----------------------------------------------------------------------------

wxColour wxGrid::GetCellBackgroundColour(int row, int col) const
{
    return GetCellAttrPtr(row, col)->GetBackgroundColour();
}

wxColour wxGrid::GetCellTextColour( int row, int col ) const
{
    return GetCellAttrPtr(row, col)->GetTextColour();
}

wxFont wxGrid::GetCellFont( int row, int col ) const
{
    return  GetCellAttrPtr(row, col)->GetFont();
}

void wxGrid::GetCellAlignment( int row, int col, int *horiz, int *vert ) const
{
    return  GetCellAttrPtr(row, col)->GetAlignment(horiz, vert);
}

wxGridFitMode wxGrid::GetCellFitMode( int row, int col ) const
{
    return GetCellAttrPtr(row, col)->GetFitMode();
}

wxGrid::CellSpan
wxGrid::GetCellSize( int row, int col, int *num_rows, int *num_cols ) const
{
    GetCellAttrPtr(row, col)->GetSize( num_rows, num_cols );

    return GetCellSpan(*num_rows, *num_cols);
}

wxGridCellRenderer* wxGrid::GetCellRenderer(int row, int col) const
{
    return  GetCellAttrPtr(row, col)->GetRenderer(this, row, col);
}

wxGridCellEditor* wxGrid::GetCellEditor(int row, int col) const
{
    return GetCellAttrPtr(row, col)->GetEditor(this, row, col);
}

bool wxGrid::IsReadOnly(int row, int col) const
{
    return GetCellAttrPtr(row, col)->IsReadOnly();
}

bool wxGrid::IsRowLabelHighlighted(int row) const
{
    if ( UsesOverlaySelection() )
    {
        if ( !IsSelection() )
            return m_currentCellCoords.GetRow() == row;

        const auto& blocks = m_selection->GetBlocks();
        if ( blocks.size() == 1 )
        {
            return row >= blocks[0].GetTopRow() &&
                   row <= blocks[0].GetBottomRow();
        }
    }

    return false;
}

bool wxGrid::IsColLabelHighlighted(int col) const
{
    if ( UsesOverlaySelection() )
    {
        if ( !IsSelection() )
            return m_currentCellCoords.GetCol() == col;

        const auto& blocks = m_selection->GetBlocks();
        if ( blocks.size() == 1 )
        {
            return col >= blocks[0].GetLeftCol() &&
                   col <= blocks[0].GetRightCol();
        }
    }

    return false;
}

// ----------------------------------------------------------------------------
// attribute support: cache, automatic provider creation, ...
// ----------------------------------------------------------------------------

bool wxGrid::CanHaveAttributes() const
{
    if ( !m_table )
    {
        return false;
    }

    return m_table->CanHaveAttributes();
}

void wxGrid::ClearAttrCache()
{
    if ( m_attrCache.row != -1 )
    {
        wxGridCellAttr *oldAttr = m_attrCache.attr;
        m_attrCache.attr = nullptr;
        m_attrCache.row = -1;
        // wxSafeDecRec(...) might cause event processing that accesses
        // the cached attribute, if one exists (e.g. by deleting the
        // editor stored within the attribute). Therefore it is important
        // to invalidate the cache  before calling wxSafeDecRef!
        wxSafeDecRef(oldAttr);
    }
}

void wxGrid::RefreshAttr(int row, int col)
{
    if ( m_attrCache.row == row && m_attrCache.col == col )
        ClearAttrCache();
}


void wxGrid::CacheAttr(int row, int col, wxGridCellAttr *attr) const
{
    if ( attr != nullptr )
    {
        wxGrid * const self = const_cast<wxGrid *>(this);

        self->ClearAttrCache();
        self->m_attrCache.row = row;
        self->m_attrCache.col = col;
        self->m_attrCache.attr = attr;
        wxSafeIncRef(attr);
    }
}

bool wxGrid::LookupAttr(int row, int col, wxGridCellAttr **attr) const
{
    if ( row == m_attrCache.row && col == m_attrCache.col )
    {
        *attr = m_attrCache.attr;
        wxSafeIncRef(m_attrCache.attr);

#ifdef DEBUG_ATTR_CACHE
        gs_nAttrCacheHits++;
#endif

        return true;
    }
    else
    {
#ifdef DEBUG_ATTR_CACHE
        gs_nAttrCacheMisses++;
#endif

        return false;
    }
}

wxGridCellAttr *wxGrid::GetCellAttr(int row, int col) const
{
    wxGridCellAttr *attr = nullptr;
    // Additional test to avoid looking at the cache e.g. for
    // wxNoCellCoords, as this will confuse memory management.
    if ( row >= 0 )
    {
        if ( !LookupAttr(row, col, &attr) )
        {
            attr = m_table ? m_table->GetAttr(row, col, wxGridCellAttr::Any)
                           : nullptr;
            CacheAttr(row, col, attr);
        }
    }

    if (attr)
    {
        attr->SetDefAttr(m_defaultCellAttr);
    }
    else
    {
        attr = m_defaultCellAttr;
        attr->IncRef();
    }

    return attr;
}

wxGridCellAttr *wxGrid::GetOrCreateCellAttr(int row, int col) const
{
    wxGridCellAttr *attr = nullptr;
    const bool canHave = CanHaveAttributes();

    wxCHECK_MSG( canHave, attr, wxT("Cell attributes not allowed"));
    wxCHECK_MSG( m_table, attr, wxT("must have a table") );

    attr = m_table->GetAttr(row, col, wxGridCellAttr::Cell);
    if ( !attr )
    {
        attr = new wxGridCellAttr(m_defaultCellAttr);

        // artificially inc the ref count to match DecRef() in caller
        attr->IncRef();
        m_table->SetAttr(attr, row, col);
    }

    return attr;
}

// ----------------------------------------------------------------------------
// setting column attributes (wrappers around SetColAttr)
// ----------------------------------------------------------------------------

void wxGrid::SetColFormatBool(int col)
{
    SetColFormatCustom(col, wxGRID_VALUE_BOOL);
}

void wxGrid::SetColFormatNumber(int col)
{
    SetColFormatCustom(col, wxGRID_VALUE_NUMBER);
}

void wxGrid::SetColFormatFloat(int col, int width, int precision)
{
    wxString typeName = wxGRID_VALUE_FLOAT;
    if ( (width != -1) || (precision != -1) )
    {
        typeName << wxT(':') << width << wxT(',') << precision;
    }

    SetColFormatCustom(col, typeName);
}

void wxGrid::SetColFormatDate(int col, const wxString& format)
{
    wxString typeName = wxGRID_VALUE_DATE;
    if ( !format.empty() )
    {
        typeName << ':' << format;
    }
    SetColFormatCustom(col, typeName);
}

void wxGrid::SetColFormatCustom(int col, const wxString& typeName)
{
    wxGridCellAttr *attr = m_table->GetAttr(-1, col, wxGridCellAttr::Col );
    if (!attr)
        attr = new wxGridCellAttr;
    wxGridCellRenderer *renderer = GetDefaultRendererForType(typeName);
    attr->SetRenderer(renderer);
    wxGridCellEditor *editor = GetDefaultEditorForType(typeName);
    attr->SetEditor(editor);

    SetColAttr(col, attr);

}

// ----------------------------------------------------------------------------
// setting cell attributes: this is forwarded to the table
// ----------------------------------------------------------------------------

void wxGrid::SetAttr(int row, int col, wxGridCellAttr *attr)
{
    if ( CanHaveAttributes() )
    {
        m_table->SetAttr(attr, row, col);
        ClearAttrCache();
    }
    else
    {
        wxSafeDecRef(attr);
    }
}

void wxGrid::SetRowAttr(int row, wxGridCellAttr *attr)
{
    if ( CanHaveAttributes() )
    {
        m_table->SetRowAttr(attr, row);
        ClearAttrCache();
    }
    else
    {
        wxSafeDecRef(attr);
    }
}

void wxGrid::SetColAttr(int col, wxGridCellAttr *attr)
{
    if ( CanHaveAttributes() )
    {
        m_table->SetColAttr(attr, col);
        ClearAttrCache();
    }
    else
    {
        wxSafeDecRef(attr);
    }
}

void wxGrid::SetCellBackgroundColour( int row, int col, const wxColour& colour )
{
    if ( CanHaveAttributes() )
    {
        GetOrCreateCellAttrPtr(row, col)->SetBackgroundColour(colour);
    }
}

void wxGrid::SetCellTextColour( int row, int col, const wxColour& colour )
{
    if ( CanHaveAttributes() )
    {
        GetOrCreateCellAttrPtr(row, col)->SetTextColour(colour);
    }
}

void wxGrid::SetCellFont( int row, int col, const wxFont& font )
{
    if ( CanHaveAttributes() )
    {
        GetOrCreateCellAttrPtr(row, col)->SetFont(font);
    }
}

void wxGrid::SetCellAlignment( int row, int col, int horiz, int vert )
{
    if ( CanHaveAttributes() )
    {
        GetOrCreateCellAttrPtr(row, col)->SetAlignment(horiz, vert);
    }
}

void wxGrid::SetCellFitMode( int row, int col, wxGridFitMode fitMode )
{
    if ( CanHaveAttributes() )
    {
        GetOrCreateCellAttrPtr(row, col)->SetFitMode(fitMode);
    }
}

void wxGrid::SetCellSize( int row, int col, int num_rows, int num_cols )
{
    if ( CanHaveAttributes() )
    {
        int cell_rows, cell_cols;

        wxGridCellAttrPtr attr = GetOrCreateCellAttrPtr(row, col);
        attr->GetSize(&cell_rows, &cell_cols);
        attr->SetSize(num_rows, num_cols);

        // Cannot set the size of a cell to 0 or negative values
        // While it is perfectly legal to do that, this function cannot
        // handle all the possibilies, do it by hand by getting the CellAttr.
        // You can only set the size of a cell to 1,1 or greater with this fn
        wxASSERT_MSG( !((cell_rows < 1) || (cell_cols < 1)),
                      wxT("wxGrid::SetCellSize setting cell size that is already part of another cell"));
        wxASSERT_MSG( !((num_rows < 1) || (num_cols < 1)),
                      wxT("wxGrid::SetCellSize setting cell size to < 1"));

        // if this was already a multicell then "turn off" the other cells first
        if ((cell_rows > 1) || (cell_cols > 1))
        {
            int i, j;
            for (j=row; j < row + cell_rows; j++)
            {
                for (i=col; i < col + cell_cols; i++)
                {
                    if ((i != col) || (j != row))
                    {
                        GetOrCreateCellAttrPtr(j, i)->SetSize( 1, 1 );
                    }
                }
            }
        }

        // mark the cells that will be covered by this cell to
        // negative or zero values to point back at this cell
        if (((num_rows > 1) || (num_cols > 1)) && (num_rows >= 1) && (num_cols >= 1))
        {
            int i, j;
            for (j=row; j < row + num_rows; j++)
            {
                for (i=col; i < col + num_cols; i++)
                {
                    if ((i != col) || (j != row))
                    {
                        GetOrCreateCellAttrPtr(j, i)->SetSize( row - j, col - i );
                    }
                }
            }
        }
    }
}

void wxGrid::SetCellRenderer(int row, int col, wxGridCellRenderer *renderer)
{
    if ( CanHaveAttributes() )
    {
        GetOrCreateCellAttrPtr(row, col)->SetRenderer(renderer);
    }
}

void wxGrid::SetCellEditor(int row, int col, wxGridCellEditor* editor)
{
    if ( CanHaveAttributes() )
    {
        GetOrCreateCellAttrPtr(row, col)->SetEditor(editor);
    }
}

void wxGrid::SetReadOnly(int row, int col, bool isReadOnly)
{
    if ( CanHaveAttributes() )
    {
        GetOrCreateCellAttrPtr(row, col)->SetReadOnly(isReadOnly);
    }
}

// ----------------------------------------------------------------------------
// Data type registration
// ----------------------------------------------------------------------------

void wxGrid::RegisterDataType(const wxString& typeName,
                              wxGridCellRenderer* renderer,
                              wxGridCellEditor* editor)
{
    m_typeRegistry->RegisterDataType(typeName, renderer, editor);
}


wxGridCellEditor * wxGrid::GetDefaultEditorForCell(int row, int col) const
{
    if ( !m_table )
        return nullptr;

    wxString typeName = m_table->GetTypeName(row, col);
    return GetDefaultEditorForType(typeName);
}

wxGridCellRenderer * wxGrid::GetDefaultRendererForCell(int row, int col) const
{
    if ( !m_table )
        return nullptr;

    wxString typeName = m_table->GetTypeName(row, col);
    return GetDefaultRendererForType(typeName);
}

wxGridCellEditor * wxGrid::GetDefaultEditorForType(const wxString& typeName) const
{
    int index = m_typeRegistry->FindOrCloneDataType(typeName);
    if ( index == wxNOT_FOUND )
    {
        wxFAIL_MSG(wxString::Format(wxT("Unknown data type name [%s]"), typeName.c_str()));

        return nullptr;
    }

    return m_typeRegistry->GetEditor(index);
}

wxGridCellRenderer * wxGrid::GetDefaultRendererForType(const wxString& typeName) const
{
    int index = m_typeRegistry->FindOrCloneDataType(typeName);
    if ( index == wxNOT_FOUND )
    {
        wxFAIL_MSG(wxString::Format(wxT("Unknown data type name [%s]"), typeName.c_str()));

        return nullptr;
    }

    return m_typeRegistry->GetRenderer(index);
}

// ----------------------------------------------------------------------------
// row/col size
// ----------------------------------------------------------------------------

void wxGrid::DoDisableLineResize(int line, wxGridFixedIndicesSet *& setFixed)
{
    if ( !setFixed )
    {
        setFixed = new wxGridFixedIndicesSet;
    }

    setFixed->insert(line);
}

void wxGrid::DoEnableLineResize(int line, wxGridFixedIndicesSet* setFixed)
{
    if ( setFixed )
        setFixed->erase(line);
}

bool
wxGrid::DoCanResizeLine(int line, const wxGridFixedIndicesSet *setFixed) const
{
    return !setFixed || !setFixed->count(line);
}

void wxGrid::EnableDragRowSize( bool enable )
{
    m_canDragRowSize = enable;
}

void wxGrid::EnableDragColSize( bool enable )
{
    m_canDragColSize = enable;
}

void wxGrid::EnableDragGridSize( bool enable )
{
    m_canDragGridSize = enable;
}

void wxGrid::EnableDragRowLabelSize(bool enable)
{
    m_canDragRowLabelSize = enable;
}

void wxGrid::EnableDragColLabelSize(bool enable)
{
    m_canDragColLabelSize = enable;
}

void wxGrid::EnableDragCell( bool enable )
{
    m_canDragCell = enable;
}

void wxGrid::SetDefaultRowSize( int height, bool resizeExistingRows )
{
    m_defaultRowHeight = wxMax( height, m_minAcceptableRowHeight );

    if ( resizeExistingRows )
    {
        // since we are resizing all rows to the default row size,
        // we can simply clear the row heights and row bottoms
        // arrays (which also allows us to take advantage of
        // some speed optimisations)
        m_rowHeights.Empty();
        m_rowBottoms.Empty();
        CalcDimensions();
    }
}

namespace
{

// This is a common part of SetRowSize() and SetColSize() which takes care of
// updating the height/width of a row/column depending on its current value and
// the new one.
//
// Returns the difference between the new and the old size.
int UpdateRowOrColSize(int& sizeCurrent, int sizeNew)
{
    // On input here sizeCurrent can be negative if it's currently hidden (the
    // real size is its absolute value then). And sizeNew can be 0 to indicate
    // that the row/column should be hidden or -1 to indicate that it should be
    // shown again.

    if ( sizeNew < 0 )
    {
        // We're showing back a previously hidden row/column.
        wxASSERT_MSG( sizeNew == -1, wxS("New size must be positive or -1.") );

        // If it's already visible, simply do nothing.
        if ( sizeCurrent >= 0 )
            return 0;

        // Otherwise show it by restoring its old size.
        sizeCurrent = -sizeCurrent;

        // This is positive which is correct.
        return sizeCurrent;
    }
    else if ( sizeNew == 0 )
    {
        // We're hiding a row/column.

        // If it's already hidden, simply do nothing.
        if ( sizeCurrent <= 0 )
            return 0;

        // Otherwise hide it and also remember the shown size to be able to
        // restore it later.
        sizeCurrent = -sizeCurrent;

        // This is negative which is correct.
        return sizeCurrent;
    }
    else // We're just changing the row/column size.
    {
        // Here it could have been hidden or not previously.
        const int sizeOld = sizeCurrent < 0 ? 0 : sizeCurrent;

        sizeCurrent = sizeNew;

        return sizeCurrent - sizeOld;
    }
}

} // anonymous namespace

void wxGrid::SetRowSize( int row, int height )
{
    // See comment in SetColSize
    if ( height > 0 && height < GetRowMinimalAcceptableHeight())
        return;

    // The value of -1 is special and means to fit the height to the row label.
    // As with the columns, ignore attempts to auto-size the hidden rows.
    if ( height == -1 && GetRowHeight(row) != 0 )
    {
        long w, h;
        wxArrayString lines;
        wxInfoDC dc(m_rowLabelWin);
        dc.SetFont(GetLabelFont());
        StringToLines(GetRowLabelValue( row ), lines);
        GetTextBoxSize( dc, lines, &w, &h );

        // As with the columns, don't make the row smaller than minimal height.
        height = wxMax(h, GetRowMinimalHeight(row));
    }

    DoSetRowSize(row, height);
}

void wxGrid::DoSetRowSize( int row, int height )
{
    wxCHECK_RET( row >= 0 && row < m_numRows, wxT("invalid row index") );

    if ( m_rowHeights.IsEmpty() )
    {
        // need to really create the array
        InitRowHeights();
    }

    const int diff = UpdateRowOrColSize(m_rowHeights[row], height);
    if ( !diff )
        return;


    for ( int rowPos = GetRowPos(row); rowPos < m_numRows; rowPos++ )
    {
        m_rowBottoms[GetRowAt(rowPos)] += diff;
    }

    InvalidateBestSize();

    CalcDimensions();

    if ( ShouldRefresh() )
    {
        // We need to check the size of all the currently visible cells and
        // decrease the row to cover the start of the multirow cells, if any,
        // because we need to refresh such cells entirely when resizing.
        int topRow = row;

        // Note that we don't care about the cells in frozen windows here as
        // they can't have multiple rows currently.
        const wxRect rect = m_gridWin->GetRect();
        int left, right;
        CalcUnscrolledPosition(rect.GetLeft(), 0, &left, nullptr);
        CalcUnscrolledPosition(rect.GetRight(), 0, &right, nullptr);

        const int posLeft = XToPos(left, m_gridWin);
        const int posRight = XToPos(right, m_gridWin);
        for ( int pos = posLeft; pos <= posRight; ++pos )
        {
            int col = GetColAt(pos);

            int numRows, numCols;
            if ( GetCellSize(row, col, &numRows, &numCols) == CellSpan_Inside )
            {
                // Notice that numRows here is negative.
                if ( row + numRows < topRow )
                    topRow = row + numRows;
            }
        }

        int y;
        CalcScrolledPosition(0, GetRowTop(topRow), nullptr, &y);

        // Refresh the lower part of the window below the y position
        int cw, ch;
        GetClientSize(&cw, &ch);

        if (ch > y)
        {
            const wxRect updateRect(0, y, cw, ch - y);
            Refresh(true, &updateRect);
        }

        InvalidateOverlaySelection();
    }
}

void wxGrid::SetDefaultColSize( int width, bool resizeExistingCols )
{
    // we dont allow zero default column width
    m_defaultColWidth = wxMax( wxMax( width, m_minAcceptableColWidth ), 1 );

    if ( resizeExistingCols )
    {
        // since we are resizing all columns to the default column size,
        // we can simply clear the col widths and col rights
        // arrays (which also allows us to take advantage of
        // some speed optimisations)
        m_colWidths.Empty();
        m_colRights.Empty();

        CalcDimensions();
    }
}

void wxGrid::SetColSize( int col, int width )
{
    // we intentionally don't test whether the width is less than
    // GetColMinimalWidth() here but we do compare it with
    // GetColMinimalAcceptableWidth() as otherwise things currently break (see
    // #651) -- and we also always allow the width of 0 as it has the special
    // sense of hiding the column
    if ( width > 0 && width < GetColMinimalAcceptableWidth() )
        return;

    // The value of -1 is special and means to fit the width to the column label.
    //
    // Notice that we currently don't support auto-sizing hidden columns (we
    // could, but it's not clear whether this is really needed and it would
    // make the code more complex), and for them passing -1 simply means to
    // show the column back using its old size.
    if ( width == -1 && GetColWidth(col) != 0 )
    {
        if ( m_useNativeHeader )
        {
            width = GetGridColHeader()->GetColumnTitleWidth(col);
        }
        else
        {
            long w, h;
            wxArrayString lines;
            wxInfoDC dc(m_colLabelWin);
            dc.SetFont(GetLabelFont());
            StringToLines(GetColLabelValue(col), lines);
            if ( GetColLabelTextOrientation() == wxHORIZONTAL )
                GetTextBoxSize( dc, lines, &w, &h );
            else
                GetTextBoxSize( dc, lines, &h, &w );
            width = w + 6;
        }

        // Check that it is not less than the minimal width and do use the
        // possibly greater than minimal-acceptable-width minimal-width itself
        // here as we shouldn't become too small when auto-sizing, otherwise
        // the column could be resized to be too small by double clicking its
        // divider line (which ends up in a call to this function) even though
        // it couldn't be resized to this size by dragging it.
        width = wxMax(width, GetColMinimalWidth(col));
    }

    DoSetColSize(col, width);
}

void wxGrid::DoSetColSize( int col, int width )
{
    wxCHECK_RET( col >= 0 && col < m_numCols, wxT("invalid column index") );

    if ( m_colWidths.IsEmpty() )
    {
        // need to really create the array
        InitColWidths();
    }

    const int diff = UpdateRowOrColSize(m_colWidths[col], width);
    if ( !diff )
        return;

    if ( m_useNativeHeader )
    {
        // We have to update the native control if we're called from the
        // program (directly or indirectly, e.g. via AutoSizeColumn()), but we
        // want to avoid doing it when the column is being resized
        // interactively, as this is unnecessary and results in very visible
        // flicker, so take care to call the special method of our header
        // control checking for whether it's being resized interactively
        // instead of the usual UpdateColumn().
        static_cast<wxGridHeaderCtrl*>(m_colLabelWin)->UpdateIfNotResizing(col);
    }
    //else: will be refreshed when the header is redrawn

    for ( int colPos = GetColPos(col); colPos < m_numCols; colPos++ )
    {
        m_colRights[GetColAt(colPos)] += diff;
    }

    InvalidateBestSize();

    CalcDimensions();

    if ( ShouldRefresh() )
    {
        // This code is symmetric with DoSetRowSize(), see there for more
        // comments.

        int leftCol = col;

        const wxRect rect = m_gridWin->GetRect();
        int top, bottom;
        CalcUnscrolledPosition(0, rect.GetTop(), nullptr, &top);
        CalcUnscrolledPosition(0, rect.GetBottom(), nullptr, &bottom);

        const int posTop = YToPos(top, m_gridWin);
        const int posBottom = YToPos(bottom, m_gridWin);
        for ( int pos = posTop; pos <= posBottom; ++pos )
        {
            int row = GetRowAt(pos);

            int numRows, numCols;
            if ( GetCellSize(row, col, &numRows, &numCols) == CellSpan_Inside )
            {
                if ( col + numCols < leftCol )
                    leftCol = col + numCols;
            }
        }

        int x;
        CalcScrolledPosition(GetColLeft(leftCol), 0, &x, nullptr);

        // Refresh the further part of the window to the right (LTR)
        // or to the left (RTL) of the x position
        int cw, ch;
        GetClientSize(&cw, &ch);

        if (cw > x)
        {
            const wxRect updateRect(x, 0, cw - x, ch);
            Refresh(true, &updateRect);
        }

        InvalidateOverlaySelection();
    }
}

void wxGrid::SetColMinimalWidth( int col, int width )
{
    if (width > GetColMinimalAcceptableWidth())
    {
        m_colMinWidths[col] = width;
    }
}

void wxGrid::SetRowMinimalHeight( int row, int width )
{
    if (width > GetRowMinimalAcceptableHeight())
    {
        m_rowMinHeights[row] = width;
    }
}

int wxGrid::GetColMinimalWidth(int col) const
{
    const auto it = m_colMinWidths.find(col);

    return it != m_colMinWidths.end() ? it->second : m_minAcceptableColWidth;
}

int wxGrid::GetRowMinimalHeight(int row) const
{
    const auto it = m_rowMinHeights.find(row);

    return it != m_rowMinHeights.end() ? it->second : m_minAcceptableRowHeight;
}

void wxGrid::SetColMinimalAcceptableWidth( int width )
{
    // We do allow a width of 0 since this gives us
    // an easy way to temporarily hiding columns.
    if ( width >= 0 )
        m_minAcceptableColWidth = width;
}

void wxGrid::SetRowMinimalAcceptableHeight( int height )
{
    // We do allow a height of 0 since this gives us
    // an easy way to temporarily hiding rows.
    if ( height >= 0 )
        m_minAcceptableRowHeight = height;
}

int  wxGrid::GetColMinimalAcceptableWidth() const
{
    return m_minAcceptableColWidth;
}

int  wxGrid::GetRowMinimalAcceptableHeight() const
{
    return m_minAcceptableRowHeight;
}

void wxGrid::SetNativeHeaderColCount()
{
    wxASSERT_MSG( m_useNativeHeader, "no column header window" );

    GetGridColHeader()->SetColumnCount(m_numCols);

    SetNativeHeaderColOrder();
}

void wxGrid::SetNativeHeaderColOrder()
{
    wxASSERT_MSG( m_useNativeHeader, "no column header window" );

    if ( !m_colAt.empty() )
        GetGridColHeader()->SetColumnsOrder(m_colAt);
    else
        GetGridColHeader()->ResetColumnsOrder();
}

// ----------------------------------------------------------------------------
// auto sizing
// ----------------------------------------------------------------------------

void
wxGrid::AutoSizeColOrRow(int colOrRow, bool setAsMin, wxGridDirection direction)
{
    const bool column = direction == wxGRID_COLUMN;

    // We don't support auto-sizing hidden rows or columns, this doesn't seem
    // to make much sense.
    if ( column )
    {
        if ( GetColWidth(colOrRow) == 0 )
            return;
    }
    else
    {
        if ( GetRowHeight(colOrRow) == 0 )
            return;
    }

    // We need to create wxClientDC here, and not wxInfoDC, as we have to pass
    // a wxDC, and not just wxReadOnlyDC, to the virtual functions of
    // wxGridCellRenderer that we call below.
    wxClientDC dc(m_gridWin);

    AcceptCellEditControlIfShown();

    // initialize both of them just to avoid compiler warnings even if only
    // really needs to be initialized here
    int row,
        col;
    if ( column )
    {
        row = -1;
        col = colOrRow;
    }
    else
    {
        row = colOrRow;
        col = -1;
    }

    // If possible, reuse the same attribute and renderer for all cells: this
    // is an important optimization (resulting in up to 80% speed up of
    // AutoSizeColumns()) as finding the attribute and renderer for the cell
    // are very slow operations, due to the number of steps involved in them.
    const bool canReuseAttr = column && m_table->CanMeasureColUsingSameAttr(col);
    wxGridCellAttrPtr attr;
    wxGridCellRendererPtr renderer;

    wxCoord extent, extentMax = 0;
    int max = column ? m_numRows : m_numCols;
    for ( int rowOrCol = 0; rowOrCol < max; rowOrCol++ )
    {
        if ( column )
        {
            if ( !IsRowShown(rowOrCol) )
                continue;

            row = rowOrCol;
            col = colOrRow;
        }
        else
        {
            if ( !IsColShown(rowOrCol) )
                continue;

            row = colOrRow;
            col = rowOrCol;
        }

        // we need to account for the cells spanning multiple columns/rows:
        // while they may need a lot of space, they don't need all of it in
        // this column/row
        int numRows, numCols;
        const CellSpan span = GetCellSize(row, col, &numRows, &numCols);
        if ( span == CellSpan_Inside )
        {
            // we need to get the size of the main cell, not of a cell hidden
            // by it
            row += numRows;
            col += numCols;

            // get the size of the main cell too
            GetCellSize(row, col, &numRows, &numCols);
        }

        // get cell ( main cell if CellSpan_Inside ) renderer best size
        if ( !canReuseAttr || !attr )
        {
            attr = GetCellAttrPtr(row, col);
            renderer = attr->GetRendererPtr(this, row, col);

            if ( canReuseAttr )
            {
                // Try to get the best width for the entire column at once, if
                // it's supported by the renderer.
                extent = renderer->GetMaxBestSize(*this, *attr, dc).x;

                if ( extent != wxDefaultCoord )
                {
                    extentMax = extent;

                    // No need to check all the values.
                    break;
                }
            }
        }

        if ( renderer )
        {
            extent = column
                        ? renderer->GetBestWidth(*this, *attr, dc, row, col,
                                                 GetRowHeight(row))
                        : renderer->GetBestHeight(*this, *attr, dc, row, col,
                                                  GetColWidth(col));

            if ( span != CellSpan_None )
            {
                // we spread the size of a spanning cell over all the cells it
                // covers evenly -- this is probably not ideal but we can't
                // really do much better here
                //
                // notice that numCols and numRows are never 0 as they
                // correspond to the size of the main cell of the span and not
                // of the cell inside it
                extent /= column ? numCols : numRows;
            }

            if ( extent > extentMax )
                extentMax = extent;
        }
    }

    // now also compare with the column label extent
    wxCoord extentLabel;
    dc.SetFont( GetLabelFont() );

    // We add some margin around text for better readability.
    const int margin = FromDIP(column ? 10 : 6);

    if ( column )
    {
        if ( m_useNativeHeader )
        {
            extentLabel = GetGridColHeader()->GetColumnTitleWidth(colOrRow);

            // Note that GetColumnTitleWidth already adds margins internally,
            // so we don't need to add them here.
        }
        else
        {
            const wxSize
                size = dc.GetMultiLineTextExtent(GetColLabelValue(colOrRow));
            extentLabel = GetColLabelTextOrientation() == wxVERTICAL
                            ? size.y
                            : size.x;

            // Add some margins around text for better readability.
            extentLabel += margin;
        }
    }
    else
    {
        extentLabel = dc.GetMultiLineTextExtent(GetRowLabelValue(colOrRow)).y;

        // As above, add some margins for readability, although a smaller one
        // in vertical direction.
        extentLabel += margin;
    }


    // Finally determine the suitable extent fitting both the cells contents
    // and the label.
    if ( !extentMax )
    {
        // Special case: all the cells are empty, use the label extent.
        extentMax = extentLabel;
        if ( !extentMax )
        {
            // But if the label is empty too, use the default width/height.
            extentMax = column ? m_defaultColWidth : m_defaultRowHeight;
        }
    }
    else // We have some data in the column cells.
    {
        // Ensure we have the same margin around the cells text as we use
        // around the label.
        extentMax += margin;

        // And increase it to fit the label if necessary.
        if ( extentLabel > extentMax )
            extentMax = extentLabel;
    }


    if ( column )
    {
        // Ensure automatic width is not less than minimal width. See the
        // comment in SetColSize() for explanation of why this isn't done
        // in SetColSize().
        if ( !setAsMin )
            extentMax = wxMax(extentMax, GetColMinimalWidth(colOrRow));

        SetColSize( colOrRow, extentMax );
        if ( ShouldRefresh() )
        {
            if ( m_useNativeHeader )
            {
                GetGridColHeader()->UpdateColumn(colOrRow);
            }
            else
            {
                int cw, ch;
                m_gridWin->GetClientSize( &cw, &ch );
                wxRect rect ( CellToRect( 0, colOrRow ) );
                rect.y = 0;
                CalcScrolledPosition(rect.x, 0, &rect.x, nullptr);
                rect.width = cw - rect.x;
                rect.height = m_colLabelHeight;
                GetColLabelWindow()->Refresh( true, &rect );
            }
        }
    }
    else
    {
        // Ensure automatic width is not less than minimal height. See the
        // comment in SetColSize() for explanation of why this isn't done
        // in SetRowSize().
        if ( !setAsMin )
            extentMax = wxMax(extentMax, GetRowMinimalHeight(colOrRow));

        SetRowSize(colOrRow, extentMax);
        if ( ShouldRefresh() )
        {
            int cw, ch;
            m_gridWin->GetClientSize( &cw, &ch );
            wxRect rect( CellToRect( colOrRow, 0 ) );
            rect.x = 0;
            CalcScrolledPosition(0, rect.y, nullptr, &rect.y);
            rect.width = m_rowLabelWidth;
            rect.height = ch - rect.y;
            m_rowLabelWin->Refresh( true, &rect );
        }
    }

    if ( setAsMin )
    {
        if ( column )
            SetColMinimalWidth(colOrRow, extentMax);
        else
            SetRowMinimalHeight(colOrRow, extentMax);
    }
}

wxCoord wxGrid::CalcColOrRowLabelAreaMinSize(wxGridDirection direction)
{
    // calculate size for the rows or columns?
    const bool calcRows = direction == wxGRID_ROW;

    wxInfoDC dc(calcRows ? GetGridRowLabelWindow()
                         : GetGridColLabelWindow());
    dc.SetFont(GetLabelFont());

    // which dimension should we take into account for calculations?
    //
    // for columns, the text can be only horizontal so it's easy but for rows
    // we also have to take into account the text orientation
    const bool
        useWidth = calcRows || (GetColLabelTextOrientation() == wxVERTICAL);

    wxArrayString lines;
    wxCoord extentMax = 0;

    const int numRowsOrCols = calcRows ? m_numRows : m_numCols;
    for ( int rowOrCol = 0; rowOrCol < numRowsOrCols; rowOrCol++ )
    {
        lines.Clear();

        wxString label = calcRows ? GetRowLabelValue(rowOrCol)
                                  : GetColLabelValue(rowOrCol);
        StringToLines(label, lines);

        long w, h;
        GetTextBoxSize(dc, lines, &w, &h);

        const wxCoord extent = useWidth ? w : h;
        if ( extent > extentMax )
            extentMax = extent;
    }

    if ( !extentMax )
    {
        // empty column - give default extent (notice that if extentMax is less
        // than default extent but != 0, it's OK)
        extentMax = calcRows ? GetDefaultRowLabelSize()
                             : GetDefaultColLabelSize();
    }

    // leave some space around text (taken from AutoSizeColOrRow)
    if ( calcRows )
        extentMax += 10;
    else
        extentMax += 6;

    return extentMax;
}

void wxGrid::AutoSizeColumns(bool setAsMin)
{
    wxGridUpdateLocker locker(this);

    for ( int col = 0; col < m_numCols; col++ )
        AutoSizeColumn(col, setAsMin);
}

void wxGrid::AutoSizeRows(bool setAsMin)
{
    wxGridUpdateLocker locker(this);

    for ( int row = 0; row < m_numRows; row++ )
        AutoSizeRow(row, setAsMin);
}

void wxGrid::AutoSize()
{
    wxGridUpdateLocker locker(this);

    AutoSizeColumns();
    AutoSizeRows();

    // we know that we're not going to have scrollbars so disable them now to
    // avoid trouble in SetClientSize() which can otherwise set the correct
    // client size but also leave space for (not needed any more) scrollbars
    SetScrollbars(m_xScrollPixelsPerLine, m_yScrollPixelsPerLine,
                  0, 0, 0, 0, true);

    SetSize(DoGetBestSize());
}

void wxGrid::AutoSizeRowLabelSize( int row )
{
    // Hide the edit control, so it
    // won't interfere with drag-shrinking.
    AcceptCellEditControlIfShown();

    // autosize row height depending on label text
    SetRowSize(row, -1);

    ForceRefresh();
}

void wxGrid::AutoSizeColLabelSize( int col )
{
    // Hide the edit control, so it
    // won't interfere with drag-shrinking.
    AcceptCellEditControlIfShown();

    // autosize column width depending on label text
    SetColSize(col, -1);

    ForceRefresh();
}

wxSize wxGrid::DoGetBestSize() const
{
    wxSize size(m_rowLabelWidth + m_extraWidth,
                m_colLabelHeight + m_extraHeight);

    if ( m_colWidths.empty() )
    {
        size.x += m_defaultColWidth*m_numCols;
    }
    else
    {
        for ( int col = 0; col < m_numCols; col++ )
            size.x += GetColWidth(col);
    }

    if ( m_rowHeights.empty() )
    {
        size.y += m_defaultRowHeight*m_numRows;
    }
    else
    {
        for ( int row = 0; row < m_numRows; row++ )
            size.y += GetRowHeight(row);
    }

    return size + GetWindowBorderSize();
}

void wxGrid::Fit()
{
    AutoSize();
}

void wxGrid::SetFocus()
{
    m_gridWin->SetFocus();
}

// ----------------------------------------------------------------------------
// cell value accessor functions
// ----------------------------------------------------------------------------

void wxGrid::SetCellValue( int row, int col, const wxString& s )
{
    if ( s == GetCellValue(row, col) )
    {
        // Avoid flicker by not doing anything in this case.
        return;
    }

    if ( m_table )
    {
        m_table->SetValue( row, col, s );
        if ( ShouldRefresh() )
        {
            wxRect rect( CellToRect( row, col ) );
            CalcScrolledPosition(0, rect.y, nullptr, &rect.y);
            // Refresh the entire row to account for overflowing cells
            rect.x = 0;
            rect.width = GetClientSize().GetWidth() - GetRowLabelSize();
            rect.Offset(GetRowLabelSize(), GetColLabelSize());
            Refresh(true, &rect);
        }

        if ( m_currentCellCoords.GetRow() == row &&
             m_currentCellCoords.GetCol() == col &&
             IsCellEditControlShown())
             // Note: If we are using IsCellEditControlEnabled,
             // this interacts badly with calling SetCellValue from
             // an EVT_GRID_CELL_CHANGE handler.
        {
            HideCellEditControl();
            ShowCellEditControl(); // will reread data from table
        }
    }
}

// ----------------------------------------------------------------------------
// block, row and column selection
// ----------------------------------------------------------------------------

bool wxGrid::UsesOverlaySelection() const
{
#if wxUSE_GRAPHICS_CONTEXT
    return m_usesOverlaySelection;
#else
    // Drawing overlay selection can only be done via a graphics context.
    return false;
#endif
}

void wxGrid::DisableOverlaySelection()
{
#if wxUSE_GRAPHICS_CONTEXT
    m_usesOverlaySelection = false;
#endif
}

void wxGrid::SelectRow( int row, bool addToSelected )
{
    if ( !m_selection )
        return;

    if ( !addToSelected )
        ClearSelection();

    m_selection->SelectRow(row);
}

void wxGrid::SelectCol( int col, bool addToSelected )
{
    if ( !m_selection )
        return;

    if ( !addToSelected )
        ClearSelection();

    m_selection->SelectCol(col);
}

void wxGrid::SelectBlock(int topRow, int leftCol, int bottomRow, int rightCol,
                         bool addToSelected)
{
    if ( !m_selection )
        return;

    if ( !addToSelected )
        ClearSelection();

    m_selection->SelectBlock(topRow, leftCol, bottomRow, rightCol);
}

void wxGrid::SelectAll()
{
    if ( m_selection )
        m_selection->SelectAll();
}

// ----------------------------------------------------------------------------
// cell, row and col deselection
// ----------------------------------------------------------------------------

void wxGrid::DeselectRow(int row)
{
    wxCHECK_RET( row >= 0 && row < m_numRows, wxT("invalid row index") );

    if ( m_selection )
        m_selection->DeselectBlock(wxGridBlockCoords(row, 0, row, m_numCols - 1));
}

void wxGrid::DeselectCol(int col)
{
    wxCHECK_RET( col >= 0 && col < m_numCols, wxT("invalid column index") );

    if ( m_selection )
        m_selection->DeselectBlock(wxGridBlockCoords(0, col, m_numRows - 1, col));
}

void wxGrid::DeselectCell( int row, int col )
{
    wxCHECK_RET( row >= 0 && row < m_numRows &&
                 col >= 0 && col < m_numCols,
                 wxT("invalid cell coords") );

    if ( m_selection )
        m_selection->DeselectBlock(wxGridBlockCoords(row, col, row, col));
}

bool wxGrid::IsSelection() const
{
    return m_selection && m_selection->IsSelection();
}

bool wxGrid::IsInSelection( int row, int col ) const
{
    return m_selection && m_selection->IsInSelection(row, col);
}

wxGridBlocks wxGrid::GetSelectedBlocks() const
{
    if ( !m_selection )
        return wxGridBlocks();

    const wxGridBlockCoordsVector& blocks = m_selection->GetBlocks();
    return wxGridBlocks(blocks.begin(), blocks.end());
}

static
wxGridBlockCoordsVector
DoGetRowOrColBlocks(wxGridBlocks blocks, const wxGridOperations& oper)
{
    wxGridBlockCoordsVector res;

    for ( wxGridBlocks::iterator it = blocks.begin(); it != blocks.end(); ++it )
    {
        const int firstNew = oper.SelectFirst(*it);
        const int lastNew = oper.SelectLast(*it);

        // Check if this block intersects any of the existing ones.
        //
        // We use simple linear search because we assume there are only a few
        // blocks in all, and it's not worth complicating the code to use
        // anything more advanced, but this definitely could be improved to use
        // the fact that the vector is always sorted.
        for ( size_t n = 0;; )
        {
            if ( n == res.size() )
            {
                // We didn't find any overlapping blocks, so add this one to
                // the end.
                res.push_back(*it);
                break;
            }

            wxGridBlockCoords& block = res[n];
            const int firstThis = oper.SelectFirst(block);
            const int lastThis = oper.SelectLast(block);

            if ( lastNew < firstThis )
            {
                // Not only it doesn't overlap this block, but it won't overlap
                // any subsequent ones either, so insert it here and stop.
                res.insert(res.begin() + n, *it);
                break;
            }

            if ( lastThis < firstNew )
            {
                // It doesn't overlap this one, but continue checking.
                n++;
                continue;
            }

            // The blocks overlap, combine them by adjusting the bounds of the
            // current block.

            // The first bound is simple as we know that firstNew must be
            // strictly greater than the last coordinate of all the previous
            // elements, otherwise we would have combined it with them earlier.
            if ( firstNew < firstThis )
                oper.SetFirst(block, firstNew);

            // But for the last one, we need to find the last element it
            // overlaps (which may be this block itself). We call its index n2
            // to avoid confusion with "last" used for the block component.
            size_t n2 = n;
            for ( ;; )
            {
                const wxGridBlockCoords& block2 = res[n2];
                if ( lastNew < oper.SelectFirst(block2) )
                {
                    oper.SetLast(block, lastNew);
                    break;
                }

                // Do it here as we'll need to remove the current block if it's
                // the last overlapping one and we break just below.
                n2++;

                if ( lastNew < oper.SelectLast(block2) )
                {
                    oper.SetLast(block, oper.SelectLast(block2));
                    break;
                }

                if ( n2 == res.size() )
                {
                    oper.SetLast(block, lastNew);
                    break;
                }
            }

            if ( n2 > n + 1 )
                res.erase(res.begin() + n + 1, res.begin() + n2);

            break;
        }
    }

    // This is another inefficiency: it would be also possible to do everything
    // in one pass, combining the adjacent ranges in the loop above. But this
    // is more complicated and doesn't seem to be worth it, for the arrays of
    // small sizes that we work with here, so do an extra path combining the
    // adjacent ranges.
    for ( size_t n = 0;; )
    {
        if ( n + 1 >= res.size() )
            break;

        if ( oper.SelectFirst(res[n + 1]) == oper.SelectLast(res[n]) + 1 )
        {
            // The ranges touch, combine them.
            oper.SetLast(res[n], oper.SelectLast(res[n + 1]));

            // And erase the subsumed range.
            res.erase(res.begin() + n + 1, res.begin() + n + 2);
        }
        else // Just go to the next one.
        {
            n++;
        }
    }

    return res;
}

wxGridBlockCoordsVector wxGrid::GetSelectedRowBlocks() const
{
    if ( !m_selection || m_selection->GetSelectionMode() != wxGridSelectRows )
        return wxGridBlockCoordsVector();

    return DoGetRowOrColBlocks(GetSelectedBlocks(), wxGridRowOperations());
}

wxGridBlockCoordsVector wxGrid::GetSelectedColBlocks() const
{
    if ( !m_selection || m_selection->GetSelectionMode() != wxGridSelectColumns )
        return wxGridBlockCoordsVector();

    return DoGetRowOrColBlocks(GetSelectedBlocks(), wxGridColumnOperations());
}

wxGridCellCoordsArray wxGrid::GetSelectedCells() const
{
    if (!m_selection)
        return {};

    return m_selection->GetCellSelection();
}

wxGridCellCoordsArray wxGrid::GetSelectionBlockTopLeft() const
{
    if (!m_selection)
        return {};

    return m_selection->GetBlockSelectionTopLeft();
}

wxGridCellCoordsArray wxGrid::GetSelectionBlockBottomRight() const
{
    if (!m_selection)
        return {};

    return m_selection->GetBlockSelectionBottomRight();
}

wxArrayInt wxGrid::GetSelectedRows() const
{
    if (!m_selection)
    {
        wxArrayInt a;
        return a;
    }

    return m_selection->GetRowSelection();
}

wxArrayInt wxGrid::GetSelectedCols() const
{
    if (!m_selection)
    {
        wxArrayInt a;
        return a;
    }

    return m_selection->GetColSelection();
}

void wxGrid::ClearSelection()
{
    if ( IsSelection() )
        m_selection->ClearSelection();
}

bool wxGrid::CopySelection()
{
#if wxUSE_CLIPBOARD
    // Coordinates of the selected block to copy to clipboard.
    wxGridBlockCoords sel;

    // Check if we have any selected blocks and if we don't
    // have too many of them.
    const wxGridBlocks blocks = GetSelectedBlocks();
    wxGridBlocks::iterator iter = blocks.begin();
    if (iter == blocks.end())
    {
        // No selection, copy just the current cell.
        if (m_currentCellCoords == wxGridNoCellCoords)
        {
            // But we don't even have it -- nothing to do then.
            return false;
        }

        sel = wxGridBlockCoords(GetGridCursorRow(),
            GetGridCursorCol(),
            GetGridCursorRow(),
            GetGridCursorCol());
    }
    else // We do have at least one selected block.
    {
        sel = *blocks.begin();

        if (++iter != blocks.end())
        {
            // As we use simple text format, we can't copy more
            // than one block to clipboard.
            return false;
        }
    }

    wxClipboardLocker lockClipboard;
    if (!lockClipboard)
    {
        return false;
    }

    bool firstRow = true;
    wxString buf;
    for (int row = sel.GetTopRow(); row <= sel.GetBottomRow(); row++)
    {
        if (firstRow)
            firstRow = false;
        else
            buf += wxTextFile::GetEOL();

        bool firstColumn = true;

        for (int col = sel.GetLeftCol(); col <= sel.GetRightCol(); col++)
        {
            if (firstColumn)
                firstColumn = false;
            else
                buf += '\t';

            buf += GetCellValue(row, col);
        }
    }

    wxTheClipboard->SetData(new wxTextDataObject(buf));
#endif // wxUSE_CLIPBOARD

    return true;
}

void wxGrid::GetSelectedRectangles(std::vector<wxRect>& rectangles, const wxRect& renderExtent) const
{
    wxGridBlocks range = GetSelectedBlocks();
    for ( const auto& coords : range )
    {
        const int topRow     = coords.GetTopRow();
        const int bottomRow  = coords.GetBottomRow();
        const int leftCol    = coords.GetLeftCol();
        const int rightCol   = coords.GetRightCol();

        int row = topRow;
        int col = leftCol;

        // corner grid
        if ( GetRowPos(topRow) < m_numFrozenRows && GetColPos(leftCol) < m_numFrozenCols && m_frozenCornerGridWin )
        {
            row = wxMin(bottomRow, m_numFrozenRows - 1);
            col = wxMin(rightCol, m_numFrozenCols - 1);

            BlockToDeviceRect(wxGridCellCoords(topRow, leftCol),
                              wxGridCellCoords(row, col),
                              m_frozenCornerGridWin, rectangles, renderExtent);
            ++row; ++col;
        }

        // frozen cols grid
        if ( GetColPos(leftCol) < m_numFrozenCols && GetRowPos(bottomRow) >= m_numFrozenRows && m_frozenColGridWin )
        {
            col = wxMin(rightCol, m_numFrozenCols - 1);
            BlockToDeviceRect(wxGridCellCoords(row, leftCol),
                              wxGridCellCoords(bottomRow, col),
                              m_frozenColGridWin, rectangles, renderExtent);
            ++col;
        }

        // frozen rows grid
        if ( GetRowPos(topRow) < m_numFrozenRows && GetColPos(rightCol) >= m_numFrozenCols && m_frozenRowGridWin )
        {
            row = wxMin(bottomRow, m_numFrozenRows - 1);

            BlockToDeviceRect(wxGridCellCoords(topRow, col),
                              wxGridCellCoords(row, rightCol),
                              m_frozenRowGridWin, rectangles, renderExtent);
            ++row;
        }

        // main grid
        if ( GetRowPos(bottomRow) >= m_numFrozenRows && GetColPos(rightCol) >= m_numFrozenCols )
        {
            BlockToDeviceRect(wxGridCellCoords(row, col),
                              wxGridCellCoords(bottomRow, rightCol),
                              m_gridWin, rectangles, renderExtent);
        }
    }

    wxGridPrivate::MergeAdjacentRects(rectangles);
}

void wxGrid::BlockToDeviceRect(const wxGridCellCoords& topLeft,
                               const wxGridCellCoords& bottomRight,
                               wxGridWindow* gridWin, std::vector<wxRect>& rectangles,
                               const wxRect& renderExtent) const
{
    int cw, ch;
    wxPoint offset;

    int gridOriginX = 0;
    int gridOriginY = 0;

    if ( renderExtent.IsEmpty() )
    {
        offset = GetGridWindowOffset(gridWin);

        gridWin->GetClientSize(&cw, &ch);
        // Get the origin coordinates: notice that they will be negative if the
        // grid is scrolled downwards/to the right.
        CalcGridWindowScrolledPosition(gridOriginX, gridOriginY,
                                       &gridOriginX, &gridOriginY, gridWin);
    }
    else
    {
        // We are rendering on external DC. Offset and scroll position are already
        // calculated in wxGrid::Render().

        cw = renderExtent.width;
        ch = renderExtent.height;

        gridOriginX = -renderExtent.x;
        gridOriginY = -renderExtent.y;
    }

    const int onScreenLeftmostCol  = internalXToCol(-gridOriginX + offset.x, gridWin);
    const int onScreenUppermostRow = internalYToRow(-gridOriginY + offset.y, gridWin);

    const int onScreenRightmostCol  = internalXToCol(-gridOriginX + offset.x + cw, gridWin);
    const int onScreenBottommostRow = internalYToRow(-gridOriginY + offset.y + ch, gridWin);

    // Bound our loop so that we only examine the portion of the selected block
    // that is shown on screen. Therefore, we compare the Top-Left block values
    // to the Top-Left screen values, and the Bottom-Right block values to the
    // Bottom-Right screen values, choosing appropriately.
    int visibleTopRow     = wxMax(topLeft.GetRow(),       onScreenUppermostRow);
    int visibleBottomRow  = wxMin(bottomRight.GetRow(),   onScreenBottommostRow);
    int visibleLeftCol    = wxMax(topLeft.GetCol(),       onScreenLeftmostCol);
    int visibleRightCol   = wxMin(bottomRight.GetCol(),   onScreenRightmostCol);

    // help drawing selected multicells if/when their main cells are scrolled out of view.
    bool isBlockVisible = true;

    if ( visibleTopRow > visibleBottomRow )
    {
        isBlockVisible = false;
        wxSwap(visibleTopRow, visibleBottomRow);
    }

    if ( visibleLeftCol > visibleRightCol )
    {
        isBlockVisible = false;
        wxSwap(visibleLeftCol, visibleRightCol);
    }

    std::vector<wxGridCellCoords> coords;

    for ( int j = visibleTopRow; j <= visibleBottomRow; ++j )
    {
        for ( int i = visibleLeftCol; i <= visibleRightCol; ++i )
        {
            int row = j, col = i;

            int cell_rows = 0, cell_cols = 0;
            const wxGrid::CellSpan cellSpan = GetCellSize(j, i, &cell_rows, &cell_cols);

            if ( cellSpan == CellSpan_None && !isBlockVisible )
            {
                continue;
            }

            if ( cellSpan == CellSpan_Inside )
            {
                row += cell_rows;
                col += cell_cols;
            }

            if ( IsInSelection(row, col) )
            {
                coords.push_back(wxGridCellCoords(row, col));
            }
        }
    }

    for ( const auto& coord : coords )
    {
        wxRect rect = CellToRect(coord);

        // For one hand, we need to compensate for the 1 subtracted in CellToRect().
        // for the other hand, the algorithm responsible for generating the polygons
        // from these rectangles expects them to overlap. see PolyPolygonHelper.
        rect.Inflate(1);

        if ( renderExtent.IsEmpty() )
        {
            int left, top, right, bottom;

            // Convert to scrolled coords
            CalcGridWindowScrolledPosition( rect.GetLeft() - offset.x, rect.GetTop() - offset.y,
                                            &left, &top, gridWin );
            CalcGridWindowScrolledPosition( rect.GetRight() - offset.x, rect.GetBottom() - offset.y,
                                            &right, &bottom, gridWin );

            if ( right < 0 || bottom < 0 || left > cw || top > ch )
            {
                continue;
            }

            rect.SetLeft( wxMax(0, left) );
            rect.SetTop( wxMax(0, top) );
            rect.SetRight( wxMin(cw, right) );
            rect.SetBottom( wxMin(ch, bottom) );

            rect.Offset(offset);
        }
        else
        {
            if ( rect.x < 0 )
            {
                rect.x = 0;
                rect.width -= 1;
            }

            if ( rect.y < 0 )
            {
                rect.y = 0;
                rect.height -= 1;
            }
        }

        if ( std::find(rectangles.begin(), rectangles.end(), rect) == rectangles.end() )
        {
            rectangles.push_back(rect);
        }
    }
}

// This function returns the rectangle that encloses the given block
// in device coords clipped to the client size of the grid window.
//
wxRect wxGrid::BlockToDeviceRect( const wxGridCellCoords& topLeft,
                                  const wxGridCellCoords& bottomRight,
                                  const wxGridWindow *gridWindow) const
{
    wxRect resultRect;
    wxRect tempCellRect = CellToRect(topLeft);
    if ( tempCellRect != wxGridNoCellRect )
    {
        resultRect = tempCellRect;
    }
    else
    {
        resultRect = wxRect(0, 0, 0, 0);
    }

    tempCellRect = CellToRect(bottomRight);
    if ( tempCellRect != wxGridNoCellRect )
    {
        resultRect += tempCellRect;
    }
    else
    {
        // If both inputs were "wxGridNoCellRect," then there's nothing to do.
        return wxGridNoCellRect;
    }

    // Ensure that left/right and top/bottom pairs are in order.
    int left = resultRect.GetLeft();
    int top = resultRect.GetTop();
    int right = resultRect.GetRight();
    int bottom = resultRect.GetBottom();

    int leftCol = topLeft.GetCol();
    int topRow = topLeft.GetRow();
    int rightCol = bottomRight.GetCol();
    int bottomRow = bottomRight.GetRow();

    if (left > right)
    {
        int tmp = left;
        left = right;
        right = tmp;

        tmp = leftCol;
        leftCol = rightCol;
        rightCol = tmp;
    }

    if (top > bottom)
    {
        int tmp = top;
        top = bottom;
        bottom = tmp;

        tmp = topRow;
        topRow = bottomRow;
        bottomRow = tmp;
    }

    if ( !gridWindow )
        gridWindow = m_gridWin;

    int cw, ch;
    gridWindow->GetClientSize( &cw, &ch );
    wxPoint offset = GetGridWindowOffset(gridWindow);

    // The following loop is ONLY necessary to detect and handle merged cells.
    if ( gridWindow == m_gridWin )
    {
        // Get the origin coordinates: notice that they will be negative if the
        // grid is scrolled downwards/to the right.
        int gridOriginX = offset.x;
        int gridOriginY = offset.y;
        CalcScrolledPosition(gridOriginX, gridOriginY, &gridOriginX, &gridOriginY);

        int onScreenLeftmostCol = internalXToCol(-gridOriginX, m_gridWin);
        int onScreenUppermostRow = internalYToRow(-gridOriginY, m_gridWin);

        int onScreenRightmostCol = internalXToCol(-gridOriginX + cw, m_gridWin);
        int onScreenBottommostRow = internalYToRow(-gridOriginY + ch, m_gridWin);

        // Bound our loop so that we only examine the portion of the selected block
        // that is shown on screen. Therefore, we compare the Top-Left block values
        // to the Top-Left screen values, and the Bottom-Right block values to the
        // Bottom-Right screen values, choosing appropriately.
        const int visibleTopRow = wxMax(topRow, onScreenUppermostRow);
        const int visibleBottomRow = wxMin(bottomRow, onScreenBottommostRow);
        const int visibleLeftCol = wxMax(leftCol, onScreenLeftmostCol);
        const int visibleRightCol = wxMin(rightCol, onScreenRightmostCol);

        for ( int j = visibleTopRow; j <= visibleBottomRow; j++ )
        {
            for ( int i = visibleLeftCol; i <= visibleRightCol; i++ )
            {
                if ( (j == visibleTopRow) || (j == visibleBottomRow) ||
                        (i == visibleLeftCol) || (i == visibleRightCol) )
                {
                    tempCellRect = CellToRect( j, i );

                    if (tempCellRect.x < left)
                        left = tempCellRect.x;
                    if (tempCellRect.y < top)
                        top = tempCellRect.y;
                    if (tempCellRect.x + tempCellRect.width > right)
                        right = tempCellRect.x + tempCellRect.width;
                    if (tempCellRect.y + tempCellRect.height > bottom)
                        bottom = tempCellRect.y + tempCellRect.height;
                }
                else
                {
                    i = visibleRightCol; // jump over inner cells.
                }
            }
        }
    }

    // Convert to scrolled coords
    CalcGridWindowScrolledPosition( left - offset.x, top - offset.y, &left, &top, gridWindow );
    CalcGridWindowScrolledPosition( right - offset.x, bottom - offset.y, &right, &bottom, gridWindow );

    if ( right < 0 || bottom < 0 || left > cw || top > ch )
        return wxRect(0,0,0,0);

    resultRect.SetLeft( wxMax(0, left) );
    resultRect.SetTop( wxMax(0, top) );
    resultRect.SetRight( wxMin(cw, right) );
    resultRect.SetBottom( wxMin(ch, bottom) );

    return resultRect;
}

void wxGrid::DoSetSizes(const wxGridSizesInfo& sizeInfo,
                        const wxGridOperations& oper)
{
    BeginBatch();
    oper.SetDefaultLineSize(this, sizeInfo.m_sizeDefault, true);
    const int numLines = oper.GetNumberOfLines(this, nullptr);
    for ( int i = 0; i < numLines; i++ )
    {
        int size = sizeInfo.GetSize(i);
        if ( size != sizeInfo.m_sizeDefault)
            oper.SetLineSize(this, i, size);
    }
    EndBatch();
}

void wxGrid::SetColSizes(const wxGridSizesInfo& sizeInfo)
{
    DoSetSizes(sizeInfo, wxGridColumnOperations());
}

void wxGrid::SetRowSizes(const wxGridSizesInfo& sizeInfo)
{
    DoSetSizes(sizeInfo, wxGridRowOperations());
}

#if wxUSE_ACCESSIBILITY

bool wxGrid::Show(bool show)
{
    bool changed = wxWindow::Show(show);
    if ( changed )
    {
        wxAccessible::NotifyEvent(show ? wxACC_EVENT_OBJECT_SHOW : wxACC_EVENT_OBJECT_HIDE,
                                  this, wxOBJID_CLIENT, wxACC_SELF);
    }

    return changed;
}

void wxGrid::SetName(const wxString &name)
{
    wxWindow::SetName(name);
    wxAccessible::NotifyEvent(wxACC_EVENT_OBJECT_NAMECHANGE, this, wxOBJID_CLIENT, wxACC_SELF);
}

bool wxGrid::Reparent(wxWindowBase *newParent)
{
    bool changed = wxScrolledCanvas::Reparent(newParent);
    if ( changed )
    {
        wxAccessible::NotifyEvent(wxACC_EVENT_OBJECT_PARENTCHANGE, this, wxOBJID_CLIENT, wxACC_SELF);
    }

    return changed;
}

wxAccessible* wxGrid::CreateAccessible()
{
    return new wxGridAccessible(this);
}

#endif // wxUSE_ACCESSIBILITY

wxGridSizesInfo::wxGridSizesInfo(int defSize, const wxArrayInt& allSizes)
{
    m_sizeDefault = defSize;
    for ( size_t i = 0; i < allSizes.size(); i++ )
    {
        if ( allSizes[i] != defSize )
            m_customSizes[i] = allSizes[i];
    }
}

int wxGridSizesInfo::GetSize(unsigned pos) const
{
    wxUnsignedToIntHashMap::const_iterator it = m_customSizes.find(pos);

    // if it's not found return the default
    if ( it == m_customSizes.end() )
      return m_sizeDefault;

    // otherwise return 0 if it's hidden, currently there is no way to get
    // its size before it had been hidden
    if ( it->second < 0 )
      return 0;

    return it->second;
}

// ----------------------------------------------------------------------------
// drop target
// ----------------------------------------------------------------------------

#if wxUSE_DRAG_AND_DROP

// this allow setting drop target directly on wxGrid
void wxGrid::SetDropTarget(wxDropTarget *dropTarget)
{
    GetGridWindow()->SetDropTarget(dropTarget);
}

wxDropTarget* wxGrid::GetDropTarget() const
{
    return GetGridWindow()->GetDropTarget();
}

#endif // wxUSE_DRAG_AND_DROP

// ----------------------------------------------------------------------------
// grid event classes
// ----------------------------------------------------------------------------

wxIMPLEMENT_DYNAMIC_CLASS(wxGridEvent, wxNotifyEvent);

wxGridEvent::wxGridEvent( int id, wxEventType type, wxObject* obj,
                          int row, int col, int x, int y, bool sel,
                          bool control, bool shift, bool alt, bool meta )
        : wxNotifyEvent( type, id ),
          wxKeyboardState(control, shift, alt, meta)
{
    Init(row, col, x, y, sel);

    SetEventObject(obj);
}

wxIMPLEMENT_DYNAMIC_CLASS(wxGridSizeEvent, wxNotifyEvent);

wxGridSizeEvent::wxGridSizeEvent( int id, wxEventType type, wxObject* obj,
                                  int rowOrCol, int x, int y,
                                  bool control, bool shift, bool alt, bool meta )
        : wxNotifyEvent( type, id ),
          wxKeyboardState(control, shift, alt, meta)
{
    Init(rowOrCol, x, y);

    SetEventObject(obj);
}


wxIMPLEMENT_DYNAMIC_CLASS(wxGridRangeSelectEvent, wxNotifyEvent);

wxGridRangeSelectEvent::wxGridRangeSelectEvent(int id, wxEventType type, wxObject* obj,
                                               const wxGridCellCoords& topLeft,
                                               const wxGridCellCoords& bottomRight,
                                               bool sel, bool control,
                                               bool shift, bool alt, bool meta )
        : wxNotifyEvent( type, id ),
          wxKeyboardState(control, shift, alt, meta)
{
    Init(topLeft, bottomRight, sel);

    SetEventObject(obj);
}


wxIMPLEMENT_DYNAMIC_CLASS(wxGridEditorCreatedEvent, wxCommandEvent);

wxGridEditorCreatedEvent::wxGridEditorCreatedEvent(int id, wxEventType type,
                                                   wxObject* obj, int row,
                                                   int col, wxWindow* window)
    : wxCommandEvent(type, id)
{
    SetEventObject(obj);
    m_row = row;
    m_col = col;
    m_window = window;
}


// ----------------------------------------------------------------------------
// wxGridTypeRegistry
// ----------------------------------------------------------------------------

wxGridTypeRegistry::~wxGridTypeRegistry()
{
    size_t count = m_typeinfo.GetCount();
    for ( size_t i = 0; i < count; i++ )
        delete m_typeinfo[i];
}

void wxGridTypeRegistry::RegisterDataType(const wxString& typeName,
                                          wxGridCellRenderer* renderer,
                                          wxGridCellEditor* editor)
{
    wxGridDataTypeInfo* info = new wxGridDataTypeInfo(typeName, renderer, editor);

    // is it already registered?
    int loc = FindRegisteredDataType(typeName);
    if ( loc != wxNOT_FOUND )
    {
        delete m_typeinfo[loc];
        m_typeinfo[loc] = info;
    }
    else
    {
        m_typeinfo.Add(info);
    }
}

int wxGridTypeRegistry::FindRegisteredDataType(const wxString& typeName)
{
    size_t count = m_typeinfo.GetCount();
    for ( size_t i = 0; i < count; i++ )
    {
        if ( typeName == m_typeinfo[i]->m_typeName )
        {
            return i;
        }
    }

    return wxNOT_FOUND;
}

int wxGridTypeRegistry::FindDataType(const wxString& typeName)
{
    int index = FindRegisteredDataType(typeName);
    if ( index == wxNOT_FOUND )
    {
        // check whether this is one of the standard ones, in which case
        // register it "on the fly"
#if wxUSE_TEXTCTRL
        if ( typeName == wxGRID_VALUE_STRING )
        {
            RegisterDataType(wxGRID_VALUE_STRING,
                             new wxGridCellStringRenderer,
                             new wxGridCellTextEditor);
        }
        else
#endif // wxUSE_TEXTCTRL
#if wxUSE_CHECKBOX
        if ( typeName == wxGRID_VALUE_BOOL )
        {
            RegisterDataType(wxGRID_VALUE_BOOL,
                             new wxGridCellBoolRenderer,
                             new wxGridCellBoolEditor);
        }
        else
#endif // wxUSE_CHECKBOX
#if wxUSE_TEXTCTRL
        if ( typeName == wxGRID_VALUE_NUMBER )
        {
            RegisterDataType(wxGRID_VALUE_NUMBER,
                             new wxGridCellNumberRenderer,
                             new wxGridCellNumberEditor);
        }
        else if ( typeName == wxGRID_VALUE_FLOAT )
        {
            RegisterDataType(wxGRID_VALUE_FLOAT,
                             new wxGridCellFloatRenderer,
                             new wxGridCellFloatEditor);
        }
        else
#endif // wxUSE_TEXTCTRL
#if wxUSE_COMBOBOX
        if ( typeName == wxGRID_VALUE_CHOICE )
        {
            RegisterDataType(wxGRID_VALUE_CHOICE,
                             new wxGridCellChoiceRenderer,
                             new wxGridCellChoiceEditor);
        }
        else
#endif // wxUSE_COMBOBOX
#if wxUSE_DATEPICKCTRL
        if ( typeName == wxGRID_VALUE_DATE )
        {
            RegisterDataType(wxGRID_VALUE_DATE,
                             new wxGridCellDateRenderer,
                             new wxGridCellDateEditor);
        }
        else
#endif // wxUSE_DATEPICKCTRL
        {
            return wxNOT_FOUND;
        }

        // we get here only if just added the entry for this type, so return
        // the last index
        index = m_typeinfo.GetCount() - 1;
    }

    return index;
}

int wxGridTypeRegistry::FindOrCloneDataType(const wxString& typeName)
{
    int index = FindDataType(typeName);
    if ( index == wxNOT_FOUND )
    {
        // the first part of the typename is the "real" type, anything after ':'
        // are the parameters for the renderer
        index = FindDataType(typeName.BeforeFirst(wxT(':')));
        if ( index == wxNOT_FOUND )
        {
            return wxNOT_FOUND;
        }

        wxGridCellRenderer* const
            renderer = wxGridCellRendererPtr(GetRenderer(index))->Clone();

        wxGridCellEditor* const
            editor = wxGridCellEditorPtr(GetEditor(index))->Clone();

        // do it even if there are no parameters to reset them to defaults
        wxString params = typeName.AfterFirst(wxT(':'));
        renderer->SetParameters(params);
        editor->SetParameters(params);

        // register the new typename
        RegisterDataType(typeName, renderer, editor);

        // we just registered it, it's the last one
        index = m_typeinfo.GetCount() - 1;
    }

    return index;
}

wxGridCellRenderer* wxGridTypeRegistry::GetRenderer(int index)
{
    wxGridCellRenderer* renderer = m_typeinfo[index]->m_renderer;
    if (renderer)
        renderer->IncRef();

    return renderer;
}

wxGridCellEditor* wxGridTypeRegistry::GetEditor(int index)
{
    wxGridCellEditor* editor = m_typeinfo[index]->m_editor;
    if (editor)
        editor->IncRef();

    return editor;
}

wxRect
wxGetContentRect(wxSize contentSize,
                 const wxRect& cellRect,
                 int hAlign,
                 int vAlign)
{
    // Keep square aspect ratio for the checkbox, but ensure that it fits into
    // the available space, even if it's smaller than the standard size.
    const wxCoord minSize = wxMin(cellRect.width, cellRect.height);
    if ( contentSize.x >= minSize || contentSize.y >= minSize )
    {
        // It must still have positive size, however.
        const int fittingSize = wxMax(1, minSize - 2*GRID_CELL_CHECKBOX_MARGIN);

        contentSize.x =
        contentSize.y = fittingSize;
    }

    wxRect contentRect(contentSize);

    if ( hAlign & wxALIGN_CENTER_HORIZONTAL )
    {
        contentRect = contentRect.CentreIn(cellRect, wxHORIZONTAL);
    }
    else if ( hAlign & wxALIGN_RIGHT )
    {
        contentRect.SetX(cellRect.x + cellRect.width
                          - contentSize.x - GRID_CELL_CHECKBOX_MARGIN);
    }
    else // ( hAlign == wxALIGN_LEFT ) and invalid alignment value
    {
        contentRect.SetX(cellRect.x + GRID_CELL_CHECKBOX_MARGIN);
    }

    if ( vAlign & wxALIGN_CENTER_VERTICAL )
    {
        contentRect = contentRect.CentreIn(cellRect, wxVERTICAL);
    }
    else if ( vAlign & wxALIGN_BOTTOM )
    {
        contentRect.SetY(cellRect.y + cellRect.height
                          - contentSize.y - GRID_CELL_CHECKBOX_MARGIN);
    }
    else // wxALIGN_TOP
    {
        contentRect.SetY(cellRect.y + GRID_CELL_CHECKBOX_MARGIN);
    }

    return contentRect;
}


#if wxUSE_ACCESSIBILITY

//-----------------------------------------------------------------------------
// helpers for wxGridAccessible and wxGridCellAccessible
//-----------------------------------------------------------------------------

namespace
{

// Helper for converting between grid coordinates and child IDs.
//
// Child IDs are 1-based and are used to identify individual cells in the grid
// in the top-down, left-to-right order.

// Return the child ID corresponding to the given grid cell coordinates.
int ConvertCoordsToChildId(wxGrid* grid, wxGridCellCoords coords)
{
    int childId = 0;
    int numberCols = grid->GetNumberCols();
    if ( grid->GetRowLabelSize() )
        numberCols++;

    if ( !coords )
        childId = 1;
    else if ( coords.GetRow() == -1 )
    {
        childId = coords.GetCol() + 1;
        if ( grid->GetRowLabelSize() )
            childId++;
    }
    else if ( coords.GetCol() == -1 )
    {
        childId = coords.GetRow() * numberCols + 1;
        if ( grid->GetColLabelSize() )
            childId += numberCols;
    }
    else
    {
        childId = coords.GetRow() * numberCols + coords.GetCol() + 1;
        if ( grid->GetColLabelSize() )
            childId += numberCols;
        if ( grid->GetRowLabelSize() )
            childId++;
    }
    return childId;
}

// Get coordinates corresponding to the given child ID (see the converse
// function above).
wxGridCellCoords ConvertChildIdToCoords(wxGrid* grid, int childId)
{
    wxGridCellCoords coords;

    if ( childId != 1 || !grid->GetColLabelSize() || !grid->GetRowLabelSize() )
    {
        int numCols = grid->GetNumberCols();
        if ( grid->GetRowLabelSize() )
            numCols++;

        // Ensure we don't divide by 0 below, even though this shouldn't
        // normally happen because we should be only passed valid child IDs.
        wxCHECK_MSG( numCols, coords, "childId invalid for empty grid" );

        int row = (childId - 1) / numCols;
        int col = (childId - 1) % numCols;
        if ( grid->GetRowLabelSize() )
        {
            if ( col == 0 )
                col = -1;
            else
                col--;
        }
        if ( grid->GetColLabelSize() )
        {
            if ( row == 0 )
                row = -1;
            else
                row--;
        }
        coords.SetCol(col);
        coords.SetRow(row);
    }

    return coords;
}

} // anonymous namespace

//-----------------------------------------------------------------------------
// wxGridAccessible
//-----------------------------------------------------------------------------

wxGridAccessible::wxGridAccessible(wxGrid* win)
    : wxWindowAccessible(win)
{
}

// Can return either a child object, or an integer
// representing the child element, starting from 1.
wxAccStatus wxGridAccessible::HitTest(const wxPoint& pt, int* childId, wxAccessible** childObject)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK(grid, wxACC_FAIL);

    wxPoint pos = grid->ScreenToClient(pt);

    if ( grid->HitTest(pos) != wxHT_WINDOW_INSIDE )
    {
        *childId = wxACC_SELF;
        return wxACC_OK;
    }

    // this one is reduced by the sizes of the labels
    wxPoint gridPos = pos;
    gridPos.x -= grid->m_rowLabelWidth;
    gridPos.y -= grid->m_colLabelHeight;

    // depending on window type, the unscrolled position x and/or y will be picked
    wxPoint unscrolledPos = grid->CalcUnscrolledPosition(gridPos);

    // pick the correct scrolled or unscrolled x/y values and calculate row, col etc.
    // merged cells are not handled
    int row = -1, col = -1;
    bool isColHeader = false, isRowHeader = false;

    if ( grid->m_gridWin->GetRect().Contains(pos) )
    {
        // x and y scrolling
        row = grid->YToRow(unscrolledPos.y, false, nullptr);
        col = grid->XToCol(unscrolledPos.x, false, nullptr);
    }
    else if ( grid->m_frozenCornerGridWin && grid->m_frozenCornerGridWin->GetRect().Contains(pos) )
    {
        // fixed, no scrolling
        row = grid->YToRow(gridPos.y, false, nullptr);
        col = grid->XToCol(gridPos.x, false, nullptr);
    }
    else if ( grid->m_frozenRowGridWin && grid->m_frozenRowGridWin->GetRect().Contains(pos) )
    {
        // only x scrolling
        row = grid->YToRow(gridPos.y, false, nullptr);
        col = grid->XToCol(unscrolledPos.x, false, nullptr);
    }
    else if ( grid->m_frozenColGridWin && grid->m_frozenColGridWin->GetRect().Contains(pos) )
    {
        // only y scrolling
        row = grid->YToRow(unscrolledPos.y, false, nullptr);
        col = grid->XToCol(gridPos.x, false, nullptr);
    }
    else if ( grid->m_cornerLabelWin && grid->m_cornerLabelWin->GetRect().Contains(pos) )
    {
        // on corner label, fixed, no scrolling
        isColHeader = isRowHeader = true;
    }
    else if ( grid->m_rowLabelWin && grid->m_rowLabelWin->GetRect().Contains(pos) )
    {
        // on row labels, only y scrolling
        isRowHeader = true;
        row = grid->YToRow(unscrolledPos.y, false, nullptr);
    }
    else if ( grid->m_rowFrozenLabelWin && grid->m_rowFrozenLabelWin->GetRect().Contains(pos) )
    {
        // on frozen row labels, no scrolling
        isRowHeader = true;
        row = grid->YToRow(gridPos.y, false, nullptr);
    }
    else if ( grid->m_colLabelWin && grid->m_colLabelWin->GetRect().Contains(pos) )
    {
        // on col labels, only x scrolling
        isColHeader = true;
        col = grid->XToCol(unscrolledPos.x, false, nullptr);
    }
    else if ( grid->m_colFrozenLabelWin && grid->m_colFrozenLabelWin->GetRect().Contains(pos) )
    {
        // on frozen col labels, no scrolling
        isColHeader = true;
        col = grid->XToCol(gridPos.x, false, nullptr);
    }

    if ( ( !isRowHeader && col == -1 ) || ( !isColHeader && row == -1 ) )
    {
        // not over label or grid cell, but over the grid
        *childId = wxACC_SELF;
        *childObject = this;
        return wxACC_OK;
    }

    if ( isRowHeader )
        col = -1;
    if ( isColHeader )
        row = -1;

    *childId = ConvertCoordsToChildId(grid, wxGridCellCoords(row, col));

    return wxACC_OK;
}

// Returns the rectangle for this object (id = 0)
wxAccStatus wxGridAccessible::GetLocation(wxRect& rect, int childId)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    if ( childId != wxACC_SELF )
        return wxACC_NOT_IMPLEMENTED;

    rect = grid->GetScreenRect();

    return wxACC_OK;
}

// Gets the name of the specified object.
wxAccStatus wxGridAccessible::GetName(int childId, wxString* name)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    if ( childId != wxACC_SELF )
        return wxACC_NOT_IMPLEMENTED;

    *name = grid->GetName();

    return wxACC_OK;
}

// Gets the number of children.
wxAccStatus wxGridAccessible::GetChildCount(int* childCount)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    int numberCols = grid->GetNumberCols();
    int numberRows = grid->GetNumberRows();
    if (grid->m_colLabelHeight)
        numberRows++;
    if (grid->m_rowLabelWidth)
        numberCols++;

    *childCount = numberRows * numberCols;

    return wxACC_OK;
}

// Gets the specified child (starting from 1).
// If *child is null and return value is wxACC_OK, this means that the child
// is a simple element and not an accessible object.
wxAccStatus wxGridAccessible::GetChild(int childId, wxAccessible** child)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    if ( childId == wxACC_SELF )
    {
        *child = this;
    }
    else
    {
        if ( !m_gridCellAccessible )
        {
            m_gridCellAccessible.reset(new wxGridCellAccessible(grid, childId));
        }
        else if ( m_gridCellAccessible->m_childId != childId )
        {
            // pass on the information whether the cell is on the same row or
            // column than the previous one to avoid redundant coordinate info
            wxGridCellCoords previous_coords = m_gridCellAccessible->m_coords;
            m_gridCellAccessible.reset(new wxGridCellAccessible(grid, childId));
            if ( m_gridCellAccessible->m_coords.GetRow() == previous_coords.GetRow() )
            {
                m_gridCellAccessible->m_isSameRow = true;
            }
            if ( m_gridCellAccessible->m_coords.GetCol() == previous_coords.GetCol() )
            {
                m_gridCellAccessible->m_isSameCol = true;
            }
        }
        *child = m_gridCellAccessible.get();
    }
    return wxACC_OK;
}

// Returns a role constant.
wxAccStatus wxGridAccessible::GetRole(int childId, wxAccRole* role)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    if ( childId == wxACC_SELF )
    {
        *role = wxROLE_SYSTEM_TABLE;
    }
    else
    {
        // children can be cells or headers
        wxGridCellCoords coords = ConvertChildIdToCoords(grid, childId);
        if ( coords.GetRow() == -1 )
            *role = wxROLE_SYSTEM_COLUMNHEADER;
        else if ( coords.GetCol() == -1 )
            *role = wxROLE_SYSTEM_ROWHEADER;
        else
            *role = wxROLE_SYSTEM_CELL;
    }

    return wxACC_OK;
}

// Returns a state constant.
wxAccStatus wxGridAccessible::GetState(int childId, long* state)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    if ( childId > 0 )
        return wxACC_NOT_IMPLEMENTED;

    long st = 0;
    if ( !grid->IsEnabled() )
        st |= wxACC_STATE_SYSTEM_UNAVAILABLE;
    if ( !grid->IsShown() )
        st |= wxACC_STATE_SYSTEM_INVISIBLE;

    if( grid->IsFocusable() )
        st |= wxACC_STATE_SYSTEM_FOCUSABLE;

    // this needs to be returned such that a child below is recognized as focused
    // (check for cursorRow and cursorCol being != -1?)
    if ( grid->HasFocus() )
        st |= wxACC_STATE_SYSTEM_FOCUSED;

    *state = st;
    return wxACC_OK;
}

// Returns a localized string representing the value for the object.
wxAccStatus wxGridAccessible::GetValue(int childId, wxString* WXUNUSED(strValue))
{

    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    if ( childId != wxACC_SELF )
        return wxACC_NOT_IMPLEMENTED;

    // we don't have a value for the grid
    return wxACC_NOT_SUPPORTED;
}

// Gets the window with the keyboard focus.
// If childId is 0 and child is null, no object in this subhierarchy has the focus.
// If this object has the focus, child should be 'this'.
wxAccStatus wxGridAccessible::GetFocus(int* childId, wxAccessible** child)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    if ( grid->HasFocus() )
    {
        wxGridCellCoords coord = grid->GetGridCursorCoords();
        if ( coord == wxGridNoCellCoords )
        {
            *childId = wxACC_SELF;
            *child = this;
        }
        else
        {
            *child = nullptr;
            *childId = ConvertCoordsToChildId(grid, coord);
        }
    }
    else
    {
        *childId = 0;
        *child = nullptr;
    }

    return wxACC_OK;
}


//-----------------------------------------------------------------------------
// wxGridCellAccessible
//-----------------------------------------------------------------------------

wxGridCellAccessible::wxGridCellAccessible(wxGrid* grid, int childId)
    : wxAccessible(grid),
      m_childId{childId},
      m_coords{ConvertChildIdToCoords(grid, childId)}
{
}

// Gets the parent
wxAccStatus wxGridCellAccessible::GetParent(wxAccessible** parent)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK(grid, wxACC_FAIL);

    *parent = grid->m_accessible;
    return wxACC_OK;
}

// Can return either a child object, or an integer
// representing the child element, starting from 1.
wxAccStatus wxGridCellAccessible::HitTest(const wxPoint& pt, int* childId, wxAccessible** childObject)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    wxPoint pos = grid->ScreenToClient(pt);
    wxRect cellRect;
    DoGetLocation(grid, cellRect);

    if ( grid->HitTest(pos) != wxHT_WINDOW_INSIDE || !cellRect.Contains(pt) )
    {
        *childId = wxACC_SELF;
        return wxACC_OK;
    }

    *childObject = this;

    return wxACC_OK;
}

// helper to return the screen rectangle for this cell
void wxGridCellAccessible::DoGetLocation(wxGrid* grid, wxRect& rect)
{
    rect = grid->GetScreenRect();
    wxPoint unscrolledPos = grid->CalcScrolledPosition(rect.GetLeftTop());

    int row = m_coords.GetRow();
    if ( row == -1 )
    {
        rect.height = grid->m_colLabelHeight;
    }
    else
    {
        if ( row >= grid->m_numFrozenRows )
            rect.y = unscrolledPos.y;
        rect.y = rect.y + grid->m_colLabelHeight + grid->GetRowTop(row);
        rect.height = grid->GetRowHeight(row);
    }
    int col = m_coords.GetCol();
    if ( col == -1 )
        rect.width = grid->m_rowLabelWidth;
    else
    {
        if ( col >= grid->m_numFrozenCols )
            rect.x = unscrolledPos.x;
        rect.x = rect.x + grid->m_rowLabelWidth + grid->GetColLeft(col);
        rect.width = grid->GetColWidth(col);
    }
}

// Returns the rectangle for this object (id = 0) or a child element (id > 0).
wxAccStatus wxGridCellAccessible::GetLocation(wxRect& rect, int childId)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );
    if ( childId != wxACC_SELF )
        return wxACC_FAIL;

    DoGetLocation(grid, rect);

    return wxACC_OK;
}

// Gets the name of the specified object.
wxAccStatus wxGridCellAccessible::GetName(int childId, wxString* name)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    if ( childId != wxACC_SELF )
        return wxACC_FAIL;

    // combine coordinate info and value, as JAWS will not handle Name and Value
    if ( !m_coords )
        *name = _("Grid Corner");
    else if ( m_coords.GetRow() == -1 )
        *name = wxString::Format(_("Column %s Header"), grid->GetColLabelValue(m_coords.GetCol()));
    else if ( m_coords.GetCol()  == -1 )
        *name = wxString::Format(_("Row %s Header"), grid->GetRowLabelValue(m_coords.GetRow()));
    else if ( m_isSameRow )
        *name = wxString::Format(_("Column %s: %s"),
            grid->GetColLabelValue(m_coords.GetCol()),
            grid->GetCellValue(m_coords));
    else if ( m_isSameCol )
        *name = wxString::Format(_("Row %s: %s"),
            grid->GetRowLabelValue(m_coords.GetRow()),
            grid->GetCellValue(m_coords));
    else
        *name = wxString::Format(_("Row %s, Column %s: %s"),
            grid->GetRowLabelValue(m_coords.GetRow()), grid->GetColLabelValue(m_coords.GetCol()),
            grid->GetCellValue(m_coords));

    return wxACC_OK;
}

// Gets the number of children.
wxAccStatus wxGridCellAccessible::GetChildCount(int* childCount)
{
    *childCount = 0;
    return wxACC_OK;
}

// Gets the specified child (starting from 1).
wxAccStatus wxGridCellAccessible::GetChild(int childId, wxAccessible** child)
{
    if (childId != wxACC_SELF)
        return wxACC_FAIL;

    *child = this;
    return wxACC_OK;
}

// Returns a role constant.
wxAccStatus wxGridCellAccessible::GetRole(int childId, wxAccRole* role)
{
    if ( childId != wxACC_SELF )
        return wxACC_FAIL;

    if ( m_coords.GetRow() == -1 )
        *role = wxROLE_SYSTEM_COLUMNHEADER;
    else if ( m_coords.GetCol() == -1 )
        *role = wxROLE_SYSTEM_ROWHEADER;
    else
        *role = wxROLE_SYSTEM_CELL;

    return wxACC_OK;
}

// Returns a state constant.
wxAccStatus wxGridCellAccessible::GetState(int childId, long* state)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );
    if ( childId != wxACC_SELF )
        return wxACC_FAIL;

    long st = 0;

    if ( !grid->IsEnabled() )
        st |= wxACC_STATE_SYSTEM_UNAVAILABLE;

    if ( m_coords.GetRow() != -1 && !grid->IsRowShown(m_coords.GetRow()) )
        st |= wxACC_STATE_SYSTEM_INVISIBLE;
    else if ( m_coords.GetCol() != -1 && !grid->IsColShown(m_coords.GetCol()) )
        st |= wxACC_STATE_SYSTEM_INVISIBLE;

    if( grid->IsFocusable() )
        st |= wxACC_STATE_SYSTEM_FOCUSABLE;

    st |= wxACC_STATE_SYSTEM_SELECTABLE;

    if ( grid->HasFocus() && grid->GetGridCursorCoords() == m_coords )
        st |= wxACC_STATE_SYSTEM_FOCUSED;

    // check selection and visibility
    if ( !m_coords )
    {
        // check whether complete grid is selected?
    }
    else if ( m_coords.GetCol() == -1 )
    {
        wxArrayInt selectedRows = grid->GetSelectedRows();
        if ( selectedRows.Index(m_coords.GetRow()) != wxNOT_FOUND )
            st |= wxACC_STATE_SYSTEM_SELECTED;
    }
    else if ( m_coords.GetRow() == -1 )
    {
        wxArrayInt selectedCols = grid->GetSelectedCols();
        if ( selectedCols.Index(m_coords.GetCol()) != wxNOT_FOUND )
            st |= wxACC_STATE_SYSTEM_SELECTED;
    }
    else
    {
        if ( grid->IsInSelection(m_coords) )
            st |= wxACC_STATE_SYSTEM_SELECTED;
        if ( grid->IsVisible(m_coords, false) )
            st |= wxACC_STATE_SYSTEM_OFFSCREEN;
        if ( grid->IsReadOnly(m_coords.GetRow(), m_coords.GetCol()) )
            st |= wxACC_STATE_SYSTEM_READONLY;
    }

    *state = st;
    return wxACC_OK;
}

// Returns a localized string representing the value for the object or child.
wxAccStatus wxGridCellAccessible::GetValue(int childId, wxString* WXUNUSED(strValue))
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    if ( childId != wxACC_SELF )
        return wxACC_FAIL;
    // GetName now returns coordinate and value info at the same time
    return wxACC_NOT_IMPLEMENTED;
}

// Gets the window with the keyboard focus.
// If childId is 0 and child is nullptr, no object in this subhierarchy has the focus.
// If this object has the focus, child should be 'this'.
wxAccStatus wxGridCellAccessible::GetFocus(int* childId, wxAccessible** child)
{
    wxGrid* grid = wxDynamicCast(GetWindow(), wxGrid);
    wxCHECK( grid, wxACC_FAIL );

    *childId = wxACC_SELF;

    if ( grid->GetGridCursorCoords() == m_coords )
        *child = this;

    return wxACC_OK;
}

#endif // wxUSE_ACCESSIBILITY

#endif // wxUSE_GRID
