/////////////////////////////////////////////////////////////////////////////
// Name:        property.h
// Purpose:     interface of wxPGProperty
// Author:      wxWidgets team
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////


/** @hideinitializer */
constexpr wxPGProperty* wxNullProperty = nullptr;

/** @class wxPGPaintData

    Contains information related to property's OnCustomPaint.
*/
struct wxPGPaintData
{
    /** wxPropertyGrid */
    const wxPropertyGrid*   m_parent;

    /**
        Normally -1, otherwise index to drop-down list item that has to be
        drawn.
     */
    int                     m_choiceItem;

    /** Set to drawn width in OnCustomPaint (optional). */
    int                     m_drawnWidth;

    /**
        In a measure item call, set this to the height of item at m_choiceItem
        index.
     */
    int                     m_drawnHeight;
};

/**
    @section propgrid_property_attributes wxPropertyGrid Property Attribute Identifiers

    wxPGProperty::SetAttribute() and wxPropertyGridInterface::SetPropertyAttribute()
    accept one of these as attribute name argument.

    You can use strings instead of constants.
    However, some of these constants are redefined to use cached strings which
    may reduce your binary size by some amount.

    If ::wxPG_EX_WRITEONLY_BUILTIN_ATTRIBUTES style is applied to
    wxPropertyGrid, attributes denoted as built-in are not stored into
    property's attribute storage (thus they are write-only) .

    @{
*/

/** Set default value for property.
*/
#define wxPG_ATTR_DEFAULT_VALUE           wxS("DefaultValue")

/** Built-in attribute specific to wxNumericProperty and derived properties,
    like wxIntProperty, wxUIntProperty, wxFloatProperty, @c int or @c double.
    Minimum value for the property.
*/
#define wxPG_ATTR_MIN                     wxS("Min")

/** Built-in attribute specific to wxNumericProperty and derived properties,
    like wxIntProperty, wxUIntProperty, wxFloatProperty, @c int or @c double.
    Maximum value for the property.
*/
#define wxPG_ATTR_MAX                     wxS("Max")

/** Universal, wxString. When set, will be shown as text after the displayed
    text value. Alternatively, if third column is enabled, text will be shown
    there (for any type of property).
*/
#define wxPG_ATTR_UNITS                     wxS("Units")

/** When set, will be shown as 'greyed' text in property's value cell when
    the actual displayed value is blank.
*/
#define wxPG_ATTR_HINT                      wxS("Hint")

/** Universal, wxArrayString. Set to enable auto-completion in any
    wxTextCtrl-based property editor.
*/
#define wxPG_ATTR_AUTOCOMPLETE              wxS("AutoComplete")

/** wxBoolProperty and wxFlagsProperty specific built-in attribute.
    Value type is @c bool. Default value is @false.

    When set to @true, bool property will use check box instead of a
    combo box as its editor control. If you set this attribute
    for a wxFlagsProperty, it is automatically applied to child
    bool properties.
*/
#define wxPG_BOOL_USE_CHECKBOX              wxS("UseCheckbox")

/** wxBoolProperty and wxFlagsProperty specific built-in attribute.
    Value type is @c bool. Default value is @true.

    Set to @true for the bool property to cycle value on double click
    (instead of showing the popup listbox). If you set this attribute
    for a wxFlagsProperty, it is automatically applied to child
    bool properties.
*/
#define wxPG_BOOL_USE_DOUBLE_CLICK_CYCLING  wxS("UseDClickCycling")

/** wxFloatProperty (and similar) specific built-in attribute of type @c int.
    Default value is -1. Sets the (max) precision used when floating point
    value is rendered as text. The default -1 means infinite precision.
*/
#define wxPG_FLOAT_PRECISION                wxS("Precision")

/** Built-in attribute of type @c bool. Default value is @false,
    When set tu @true, the text will be echoed as asterisks (::wxTE_PASSWORD
    will be passed to textctrl etc.).
*/
#define wxPG_STRING_PASSWORD                wxS("Password")

/** Built-in attribute to define base used by a wxUIntProperty. Valid constants
    are ::wxPG_BASE_OCT, ::wxPG_BASE_DEC, ::wxPG_BASE_HEX and
    ::wxPG_BASE_HEXL (lowercase characters).
*/
#define wxPG_UINT_BASE                      wxS("Base")

/** Built-in attribute to define prefix rendered to wxUIntProperty. Accepted
    constants ::wxPG_PREFIX_NONE, ::wxPG_PREFIX_0x
    and ::wxPG_PREFIX_DOLLAR_SIGN.

    @remarks
    Only ::wxPG_PREFIX_NONE works with decimal and octal numbers.
*/
#define wxPG_UINT_PREFIX                    wxS("Prefix")

/** Built-in attribute specific to wxEditorDialogProperty and derivatives,
    wxString, default is empty. Sets a specific title for the editor dialog.

    @since 3.1.3
*/
#define wxPG_DIALOG_TITLE                   wxS("DialogTitle")

/** wxFileProperty and wxImageFileProperty specific built-in attribute,
    @c wxChar*, default is detected/varies. Sets the wildcard used in
    the triggered wxFileDialog. Format is the same.
*/
#define wxPG_FILE_WILDCARD                  wxS("Wildcard")

/** wxFileProperty and wxImageFileProperty specific built-in attribute, @c bool,
    default @true. When @false, only the file name is shown (i.e. drive and
    directory are hidden).
*/
#define wxPG_FILE_SHOW_FULL_PATH            wxS("ShowFullPath")

/** Built-in attribute specific to wxFileProperty and derived properties,
    wxString, default empty. If set, then the filename is shown relative
    to the given path string.
*/
#define wxPG_FILE_SHOW_RELATIVE_PATH        wxS("ShowRelativePath")

/** Built-in attribute specific to wxFileProperty and derived properties,
    wxString, default is empty. Sets the initial path of where to look for files.
*/
#define wxPG_FILE_INITIAL_PATH              wxS("InitialPath")

/** Built-in attribute specific to wxFileProperty and derivatives, @c long,
    default is 0. Sets a specific wxFileDialog style for the file dialog,
    e.g. ::wxFD_SAVE.

    @since 2.9.4
*/
#define wxPG_FILE_DIALOG_STYLE              wxS("DialogStyle")

/**
    Built-in attribute to set wxArrayStringProperty's string delimiter
    character. If this is a quotation mark or hyphen, then strings
    will be quoted instead (with given character).

    Default delimiter is quotation mark.
*/
#define wxPG_ARRAY_DELIMITER                wxS("Delimiter")

/** Built-in attribute to set displayed date format for wxDateProperty.
*/
#define wxPG_DATE_FORMAT                    wxS("DateFormat")

/** Built-in attribute to set wxDatePickerCtrl window style used with
    wxDateProperty. Default is ::wxDP_DEFAULT | ::wxDP_SHOWCENTURY. Using
    ::wxDP_ALLOWNONE will enable better unspecified value support
    in the editor.
*/
#define wxPG_DATE_PICKER_STYLE              wxS("PickerStyle")

/** Built-in attribute specific to wxNumericProperty and derived properties,
    like wxIntProperty, wxUIntProperty, wxFloatProperty, used by SpinCtrl editor,
    @c int or @c double type. How much number changes when button is pressed
    (or up/down on keyboard).
*/
#define wxPG_ATTR_SPINCTRL_STEP             wxS("Step")

/** Built-in attribute specific to wxNumericProperty and derived properties,
    like wxIntProperty, wxUIntProperty, wxFloatProperty, used by SpinCtrl editor,
    @c bool. If @true, value wraps at Min/Max.
*/
#define wxPG_ATTR_SPINCTRL_WRAP             wxS("Wrap")

/** Built-in attribute specific to wxNumericProperty and derived properties,
    like wxIntProperty, wxUIntProperty, wxFloatProperty, used by SpinCtrl editor,
    @c bool. If @true, value can also by changed by moving mouse when left
    mouse button is being pressed.
*/
#define wxPG_ATTR_SPINCTRL_MOTION           wxS("MotionSpin")

/** Built-in attribute of wxMultiChoiceProperty, @c int type. Default value
    is 0. If set to 0, no user strings allowed. If 1, user strings appear
    before list strings. If 2, user strings appear after list string.
*/
#define wxPG_ATTR_MULTICHOICE_USERSTRINGMODE    wxS("UserStringMode")

/** Built-in attribute of wxColourProperty and its kind, type of @c bool,
    default value is @true. Setting this attribute to @false hides custom
    colour from property's list of choices.
*/
#define wxPG_COLOUR_ALLOW_CUSTOM            wxS("AllowCustom")

/**
    Built-in attribute of wxColourProperty and its kind, @c bool type. Default
    value is @false. Set this attribute to @true in order to support editing
    alpha colour component.
*/
#define wxPG_COLOUR_HAS_ALPHA               wxS("HasAlpha")

/** @}
*/


/** @section propgrid_propflags wxPGProperty Flags
    @{
*/

/**
    Strongly typed enums containing properties flags.

    Note that this replaces wxPGPropertyFlags enum used in previous wxWidgets
    versions which defined the same flags using `wxPG_PROP_XXX` naming
    convention.

    @since 3.3.1
 */
enum class wxPGFlags : int
{
    /** No flags.
        @hideinitializer
    */
    Null = 0,

    /** Indicates bold font.
        @hideinitializer
    */
    Modified = 0x0001,

    /** Disables ('greyed' text and editor does not activate) property.
        @hideinitializer
    */
    Disabled = 0x0002,

    /** Hider button will hide this property.
        @hideinitializer
    */
    Hidden = 0x0004,

    /** This property has custom paint image just in front of its value.
        If property only draws custom images into a popup list, then this
        flag should not be set.
        @hideinitializer
    */
    CustomImage = 0x0008,

    /** Do not create text based editor for this property (but button-triggered
        dialog and choice are ok).
        @hideinitializer
    */
    NoEditor = 0x0010,

    /** Property is collapsed, ie. it's children are hidden.
        @hideinitializer
    */
    Collapsed = 0x0020,

    /** If property is selected, then indicates that validation failed for pending
        value.

        If property is not selected, then indicates that the actual property
        value has failed validation (NB: this behaviour is not currently supported,
        but may be used in the future).
        @hideinitializer
    */
    InvalidValue = 0x0040,

    /** Switched via SetWasModified(). Temporary flag - only used when
        setting/changing property value.
        @hideinitializer
    */
    WasModified = 0x0200,

    /** If set, then child properties (if any) are private, and should be
        "invisible" to the application.
        @hideinitializer
    */
    Aggregate = 0x0400,

    /** If set, then child properties (if any) are copies and should not
        be deleted in dtor.
        @hideinitializer
    */
    ChildrenAreCopies = 0x0800,

    /** Classifies this item as a non-category.
        Used for faster item type identification.
        @hideinitializer
    */
    Property = 0x1000,


    /** Classifies this item as a category.
        Used for faster item type identification.
        @hideinitializer
    */
    Category = 0x2000,

    /** Classifies this item as a property that has children, but is not aggregate
        (i.e. children are not private).
        @hideinitializer
    */
    MiscParent = 0x4000,


    /** Property is read-only. Editor is still created for wxTextCtrl-based
        property editors. For others, editor is not usually created because
        they do implement wxTE_READONLY style or equivalent.
        @hideinitializer
    */
    ReadOnly = 0x8000,

    //
    // NB: FLAGS ABOVE 0x8000 CANNOT BE USED WITH PROPERTY ITERATORS
    //

    /** Property's value is composed from values of child properties.
        @remarks
        This flag cannot be used with property iterators.
        @hideinitializer
    */
    ComposedValue = 0x00010000,

    /** Common value of property is selectable in editor.
        @remarks
        This flag cannot be used with property iterators.
        @hideinitializer
    */
    UsesCommonValue = 0x00020000,

    /** Property can be set to unspecified value via editor.
        Currently, this applies to following properties:
        - wxIntProperty, wxUIntProperty, wxFloatProperty, wxEditEnumProperty:
        Clear the text field

        @remarks
        This flag cannot be used with property iterators.

        @see wxPGProperty::SetAutoUnspecified()
        @hideinitializer
    */

    /** Indicates that the property is being deleted and should be ignored.
        @remarks
        This flag cannot be used with property iterators.
        @hideinitializer
    */
    BeingDeleted = 0x00080000,

    /** If set, full path is shown in wxFileProperty.
        @remarks
        This flag cannot be used with property iterators.
        @hideinitializer
    */
    ShowFullFileName = 0x00100000,

    /** Topmost flag.
        @hideinitializer
    */
    Max = ShowFullFileName,

    /** Property with children must have one of these set, otherwise iterators
        will not work correctly.
        Code should automatically take care of this, however.
        @hideinitializer
    */
    ParentalFlags = Aggregate | Category | MiscParent,

    /** Combination of flags that can be stored by GetFlagsAsString().
        @hideinitializer
    */
    StringStoredFlags = Disabled | Hidden | NoEditor | Collapsed
};

/** @}
*/

// -----------------------------------------------------------------------

/**
    @class wxPGProperty

    wxPGProperty is base class for all wxPropertyGrid properties and as such
    it is not intended to be instantiated directly.
    In sections below we cover few related topics.

    @li @ref pgproperty_properties
    @li @ref pgproperty_creating

    @section pgproperty_properties Supplied Ready-to-use Property Classes

    Here is a list and short description of supplied fully-functional
    property classes. They are located in either props.h or advprops.h.

    @li @ref wxArrayStringProperty
    @li @ref wxBoolProperty
    @li @ref wxColourProperty
    @li @ref wxCursorProperty
    @li @ref wxDateProperty
    @li @ref wxDirProperty
    @li @ref wxEditEnumProperty
    @li @ref wxEnumProperty
    @li @ref wxFileProperty
    @li @ref wxFlagsProperty
    @li @ref wxFloatProperty
    @li @ref wxFontProperty
    @li @ref wxImageFileProperty
    @li @ref wxIntProperty
    @li @ref wxLongStringProperty
    @li @ref wxMultiChoiceProperty
    @li @ref wxPropertyCategory
    @li @ref wxStringProperty
    @li @ref wxSystemColourProperty
    @li @ref wxUIntProperty

    @subsection wxPropertyCategory

    Not an actual property per se, but a header for a group of properties.
    Regardless inherits from wxPGProperty, and supports displaying 'labels'
    for columns other than the first one. Easiest way to set category's
    label for second column is to call wxPGProperty::SetValue() with string
    argument.

    @subsection wxStringProperty

    Simple string property.

    Supported special attributes:
    - ::wxPG_STRING_PASSWORD: Set to @true in order to echo value as asterisks and
    to use ::wxTE_PASSWORD on the editor (wxTextCtrl).
    - ::wxPG_ATTR_AUTOCOMPLETE: Set to @true to enable auto-completion
    (use a wxArrayString value), and is also supported by any property that
    happens to use a wxTextCtrl-based editor.
    @see @ref propgrid_property_attributes

    @remarks wxStringProperty has a special trait: if it has value of
            "<composed>", and also has child properties, then its displayed
            value becomes composition of child property values, similar as
            with wxFontProperty, for instance.

    @subsection wxIntProperty

    It derives from wxNumericProperty and displays value as a signed long integer.
    wxIntProperty seamlessly supports 64-bit integers (i.e. wxLongLong) on overflow.
    To safely convert variant to integer, use code like this:

    @code
        wxLongLong ll;
        ll << property->GetValue();

        // or
        wxLongLong ll = propertyGrid->GetPropertyValueAsLong(property);
    @endcode

    Getting 64-bit value:
    @code
        wxLongLong_t value = pg->GetPropertyValueAsLongLong();

        // or

        wxLongLong value;
        wxVariant variant = property->GetValue();
        if ( variant.IsType(wxPG_VARIANT_TYPE_LONGLONG) )
            value = variant.GetLongLong();
        else
            value = variant.GetLong();
    @endcode

    Setting 64-bit value:
    @code
        pg->SetPropertyValue(longLongVal);

        // or

        property->SetValue(WXVARIANT(longLongVal));
    @endcode

    Supported special attributes:
    - ::wxPG_ATTR_MIN, ::wxPG_ATTR_MAX to specify acceptable value range.
    - ::wxPG_ATTR_SPINCTRL_STEP, ::wxPG_ATTR_SPINCTRL_WRAP,
    ::wxPG_ATTR_SPINCTRL_MOTION: Sets SpinCtrl editor parameters.
    @see @ref propgrid_property_attributes

    @subsection wxUIntProperty

    Like wxIntProperty, but displays value as unsigned int. To set
    the prefix used globally, manipulate ::wxPG_UINT_PREFIX string attribute.
    To set the globally used base, manipulate ::wxPG_UINT_BASE int
    attribute. Regardless of current prefix, understands (hex) values starting
    with both "0x" and "$" (apart from edit mode).
    Like wxIntProperty, wxUIntProperty seamlessly supports 64-bit unsigned
    integers (i.e. wxULongLong). Same wxVariant safety rules apply.

    Supported special attributes:
    - ::wxPG_ATTR_MIN, ::wxPG_ATTR_MAX: Specifies acceptable value range.
    - ::wxPG_UINT_BASE: Defines base. Valid constants are ::wxPG_BASE_OCT,
    ::wxPG_BASE_DEC, ::wxPG_BASE_HEX and ::wxPG_BASE_HEXL (lowercase characters).
    Arbitrary bases are <b>not</b> supported.
    - ::wxPG_UINT_PREFIX: Defines displayed prefix. Possible values are
    ::wxPG_PREFIX_NONE, ::wxPG_PREFIX_0x and ::wxPG_PREFIX_DOLLAR_SIGN.
    Only ::wxPG_PREFIX_NONE works with decimal and octal numbers.
    - ::wxPG_ATTR_SPINCTRL_STEP, ::wxPG_ATTR_SPINCTRL_WRAP,
    ::wxPG_ATTR_SPINCTRL_MOTION: Sets SpinCtrl editor parameters.
    @see @ref propgrid_property_attributes

    @remarks
    For example how to use seamless 64-bit integer support, see wxIntProperty
    documentation (just use wxULongLong instead of wxLongLong).

    @subsection wxFloatProperty

    Like wxStringProperty, but converts text to a double-precision floating point.
    Default float-to-text precision is 6 decimals, but this can be changed
    by modifying ::wxPG_FLOAT_PRECISION attribute.

    Note that when displaying the value, sign is omitted if the resulting
    textual representation is effectively zero (for example, -0.0001 with
    precision of 3 will become 0.0 instead of -0.0). This behaviour is unlike
    what C standard library does, but should result in better end-user
    experience in almost all cases.

    Supported special attributes:
    - ::wxPG_ATTR_MIN, ::wxPG_ATTR_MAX: Specifies acceptable value range.
    - ::wxPG_FLOAT_PRECISION: Sets the (max) precision used when floating point
    value is rendered as text. The default -1 means shortest floating-point
    6-digit representation.
    - ::wxPG_ATTR_SPINCTRL_STEP, ::wxPG_ATTR_SPINCTRL_WRAP,
    ::wxPG_ATTR_SPINCTRL_MOTION: Sets SpinCtrl editor parameters.
    @see @ref propgrid_property_attributes

    @subsection wxBoolProperty

    Represents a boolean value. wxChoice is used as editor control, by the
    default. ::wxPG_BOOL_USE_CHECKBOX attribute can be set to @true in order to
    use check box instead.

    Supported special attributes:
    - ::wxPG_BOOL_USE_CHECKBOX: If set to @true uses check box editor instead
    of combo box.
    - ::wxPG_BOOL_USE_DOUBLE_CLICK_CYCLING: If set to @true cycles combo box
    instead showing the list.
    @see @ref propgrid_property_attributes

    @subsection wxLongStringProperty

    Like wxStringProperty, but has a button that triggers a small text editor
    dialog. Note that in long string values, some control characters are
    escaped: tab is represented by `"\t"`, line break by `"\n"`, carriage return
    by `"\r"` and backslash characters are doubled. If another character is
    preceded by backslash, the backslash is skipped.

    Note also that depending on the system (port), some sequences of special
    characters, like e.g. `"\r\n"`, can be interpreted and presented in
    a different way in the editor and therefore such sequences may not be
    the same before and after the edition.

    To display a custom dialog on button press, you can subclass
    wxLongStringProperty and override DisplayEditorDialog, like this:

    @code
        bool DisplayEditorDialog( wxPropertyGrid* propGrid, wxVariant& value ) override
        {
            wxSize dialogSize(...size of your dialog...);

            wxPoint dlgPos = propGrid->GetGoodEditorDialogPosition(this,
                                                                   dialogSize)

            // Create dialog dlg at dlgPos. Use value as initial string
            // value.
            ...

            if ( dlg.ShowModal() == wxID_OK )
            {
                value = dlg.GetStringValue);
                return true;
            }
            return false;
        }
    @endcode

    Supported special attributes:
    - ::wxPG_DIALOG_TITLE: Sets a specific title for the text editor dialog.

    @subsection wxDirProperty

    Like wxLongStringProperty, but the button triggers dir selector instead.

    Supported special attributes:
    - ::wxPG_DIALOG_TITLE: Sets specific title for the dir selector.
    @see @ref propgrid_property_attributes

    @subsection wxFileProperty

    Like wxLongStringProperty, but the button triggers file selector instead.
    Default wildcard is "All files..." but this can be changed by setting
    ::wxPG_FILE_WILDCARD attribute.

    Supported special attributes:
    - ::wxPG_DIALOG_TITLE: Sets a specific title for the file dialog.
    - ::wxPG_FILE_DIALOG_STYLE: Sets a specific wxFileDialog style for the file dialog.
    - ::wxPG_FILE_WILDCARD: Sets wildcard (see wxFileDialog for format details), "All
    files..." is default.
    - ::wxPG_FILE_SHOW_FULL_PATH: Default @true. When @false, only the file name is shown
    (i.e. drive and directory are hidden).
    - ::wxPG_FILE_SHOW_RELATIVE_PATH: If set, then the filename is shown relative to the
    given path string.
    - ::wxPG_FILE_INITIAL_PATH: Sets the initial path of where to look for files.
    @see @ref propgrid_property_attributes

    @subsection wxEnumProperty

    Represents a single selection from a list of choices -
    wxOwnerDrawnComboBox is used to edit the value.

    @subsection wxFlagsProperty

    Represents a bit set that fits in a long integer. wxBoolProperty sub-
    properties are created for editing individual bits. Textctrl is created to
    manually edit the flags as a text; a continuous sequence of spaces, commas
    and semicolons are considered as a flag id separator.

    <b>Note:</b> When changing "choices" (i.e. flag labels) of wxFlagsProperty,
    you will need to use wxPGProperty::SetChoices() - otherwise they will not
    get updated properly.

    wxFlagsProperty supports the same attributes as wxBoolProperty.

    @subsection wxArrayStringProperty

    Property that manages a list of strings. Allows editing of a list
    of strings in wxTextCtrl and in a separate dialog.

    Supported special attributes:
    - ::wxPG_ARRAY_DELIMITER: Sets string delimiter character.
    - ::wxPG_DIALOG_TITLE: Sets a specific title for the editor dialog.
    Default is comma (',').
    @see @ref propgrid_property_attributes

    @subsection wxDateProperty

    Property representing wxDateTime. Default editor is DatePickerCtrl,
    although TextCtrl should work as well.

    Supported special attributes:
    - ::wxPG_DATE_FORMAT: Determines displayed date format (with wxDateTime::Format).
    Default is recommended as it is locale-dependent.
    - ::wxPG_DATE_PICKER_STYLE: Determines window style used with wxDatePickerCtrl.
       Default is ::wxDP_DEFAULT | ::wxDP_SHOWCENTURY. Using ::wxDP_ALLOWNONE
       enables additional support for unspecified property value.
    @see @ref propgrid_property_attributes

    @subsection wxEditEnumProperty

    Represents a string that can be freely edited or selected from list of choices -
    custom combobox control is used to edit the value.

    @remarks
    Uses int value, similar to wxEnumProperty, unless text entered by user is
    not in choices (in which case string value is used).

    @subsection wxMultiChoiceProperty

    Allows editing a multiple selection from a list of strings. This is
    property is pretty much built around concept of wxMultiChoiceDialog.
    It uses wxArrayString value.

    Supported special attributes:
    - ::wxPG_ATTR_MULTICHOICE_USERSTRINGMODE: If > 0, allows user to manually
    enter strings that are not in the list of choices. If this value is 1,
    user strings are preferably placed in front of valid choices. If value
    is 2, then those strings will placed behind valid choices.
    - ::wxPG_DIALOG_TITLE: Sets a specific title for the editor dialog.
    @see @ref propgrid_property_attributes

    @subsection wxImageFileProperty

    Property representing image file(name). Like wxFileProperty,
    but has thumbnail of the image in front of the filename
    and autogenerates wildcard from available image handlers.

    Supported special attributes:
    - ::wxPG_DIALOG_TITLE: Sets a specific title for the file dialog.
    - ::wxPG_FILE_DIALOG_STYLE: Sets a specific wxFileDialog style for the file dialog.
    - ::wxPG_FILE_WILDCARD: Sets wildcard (see wxFileDialog for format details), "All
    files..." is default.
    - ::wxPG_FILE_SHOW_FULL_PATH: Default @true. When @false, only the file name is shown
    (i.e. drive and directory are hidden).
    - ::wxPG_FILE_SHOW_RELATIVE_PATH: If set, then the filename is shown relative to the
    given path string.
    - ::wxPG_FILE_INITIAL_PATH: Sets the initial path of where to look for files.
    @see @ref propgrid_property_attributes

    @subsection wxColourProperty

    <b>Useful alternate editor:</b> Choice.

    Represents wxColour. wxButton is used to trigger a colour picker dialog.
    There are various sub-classing opportunities with this class. See
    below in wxSystemColourProperty section for details.

    Supported special attributes:
    - ::wxPG_COLOUR_HAS_ALPHA: If set to @true allows user to edit the alpha
    colour component.
    @see @ref propgrid_property_attributes

    @subsection wxFontProperty

    Represents wxFont. Various sub-properties are used to edit individual
    subvalues.

    Supported special attributes:
    - ::wxPG_DIALOG_TITLE: Sets a specific title for the font dialog.

    @subsection wxSystemColourProperty

    Represents wxColour and a system colour index. wxChoice is used to edit
    the value. Drop-down list has color images. Note that value type
    is wxColourPropertyValue instead of wxColour (which wxColourProperty
    uses).

    @code
        class wxColourPropertyValue : public wxObject
        {
        public:
            //  An integer value relating to the colour, and which exact
            //  meaning depends on the property with which it is used.
            //
            //  For wxSystemColourProperty:
            //  Any of wxSYS_COLOUR_XXX, or any web-colour ( use wxPG_TO_WEB_COLOUR
            //  macro - (currently unsupported) ), or wxPG_COLOUR_CUSTOM.
            wxUint32    m_type;

            // Resulting colour. Should be correct regardless of type.
            wxColour    m_colour;
        };
    @endcode

    In wxSystemColourProperty, and its derived class wxColourProperty, there
    are various sub-classing features. To set a basic list of colour
    names, call wxPGProperty::SetChoices().

    @code
        // Override in derived class to customize how colours are translated
        // to strings.
        virtual wxString ColourToString( const wxColour& col, int index ) const;

        // Returns index of entry that triggers colour picker dialog
        // (default is last).
        virtual int GetCustomColourIndex() const;

        // Helper function to show the colour dialog
        bool QueryColourFromUser( wxVariant& variant ) const;

        // Returns colour for given choice.
        // Default function returns wxSystemSettings::GetColour(index).
        virtual wxColour GetColour( int index ) const;
    @endcode

    @subsection wxCursorProperty

    Represents a wxCursor. wxChoice is used to edit the value.
    Drop-down list has cursor images under some (wxMSW) platforms.


    @section pgproperty_creating Creating Custom Properties

    New properties can be created by subclassing wxPGProperty or one
    of the provided property classes, and (re)implementing necessary
    member functions. Below, each virtual member function has ample
    documentation about its purpose and any odd details which to keep
    in mind.

    Here is a very simple 'template' code:

    @code
        class MyProperty : public wxPGProperty
        {
        public:
            // Default constructor
            MyProperty() = default;

            // All arguments of this ctor must have a default value -
            // use wxPG_LABEL for label and name
            MyProperty( const wxString& label = wxPG_LABEL,
                        const wxString& name = wxPG_LABEL,
                        const wxString& value = wxString() )
                : wxPGProperty(label, name)
            {
                // m_value is wxVariant
                m_value = value;
            }

            virtual ~MyProperty() = default;

            const wxPGEditor* DoGetEditorClass() const
            {
                // Determines editor used by property.
                // You can replace 'TextCtrl' below with any of these
                // builtin-in property editor identifiers: Choice, ComboBox,
                // TextCtrlAndButton, ChoiceAndButton, CheckBox, SpinCtrl,
                // DatePickerCtrl.
                return wxPGEditor_TextCtrl;
            }

            virtual wxString ValueToString( wxVariant& value,
                                            int flags ) const
            {
                // TODO: Convert given property value to a string
            }

            virtual bool StringToValue( wxVariant& variant, const wxString& text, int flags )
            {
                // TODO: Adapt string to property value.
            }

        protected:
        };
    @endcode

    Since wxPGProperty derives from wxObject, you can use standard
    wxDECLARE_DYNAMIC_CLASS and wxIMPLEMENT_DYNAMIC_CLASS macros. From the
    above example they were omitted for sake of simplicity, and besides,
    they are only really needed if you need to use wxRTTI with your
    property class.

    You can change the 'value type' of a property by simply assigning different
    type of variant with SetValue. <b>It is mandatory to implement
    wxVariantData class for all data types used as property values.</b>
    You can use macros declared in wxPropertyGrid headers. For instance:

    @code
        // In header file:
        // (If you need to have export declaration, use version of macros
        // with _EXPORTED postfix)
        WX_PG_DECLARE_VARIANT_DATA(MyDataClass)

        // In sources file:
        WX_PG_IMPLEMENT_VARIANT_DATA(MyDataClass)

        // Or, if you don't have valid == operator:
        WX_PG_IMPLEMENT_VARIANT_DATA_DUMMY_EQ(MyDataClass)
    @endcode

    @library{wxpropgrid}
    @category{propgrid}
*/
class wxPGProperty : public wxObject
{
public:
    /**
        Virtual destructor. It is customary for derived properties to implement this.
    */
    virtual ~wxPGProperty();

    /**
        This virtual function is called after m_value has been set.

        @remarks
        - If m_value was set to Null variant (i.e. unspecified value), OnSetValue()
          will not be called.
        - m_value may be of any variant type. Typically properties internally support only
          one variant type, and as such OnSetValue() provides a good opportunity to convert
          supported values into internal type.
        - Default implementation does nothing.
    */
    virtual void OnSetValue();

    /**
        Override this to return something else than m_value as the value.
    */
    virtual wxVariant DoGetValue() const;

    /**
        Implement this function in derived class to check the value.
        Return @true if it is ok. Returning @false prevents property change events
        from occurring.

        @remarks
        - Default implementation always returns @true.
    */
    virtual bool ValidateValue( wxVariant& value, wxPGValidationInfo& validationInfo ) const;

    /**
        Converts text into wxVariant value appropriate for this property.

        @param variant
            On function entry this is the old value (should not be null wxVariant
            in normal cases). Translated value must be assigned back to it.

        @param text
            Text to be translated into variant.

        @param flags
            If wxPGPropValFormatFlags::FullValue is set, returns complete, storable value
            instead of displayable one (they may be different).
            If wxPGPropValFormatFlags::CompositeFragment is set, text is interpreted as
            a part of composite property string value (as generated by
            ValueToString() called with this same flag).

        @return Returns @true if resulting wxVariant value was different.

        @remarks Default implementation converts semicolon delimited tokens into
                child values. Only works for properties with children.

                You might want to take into account that m_value is Null variant
                if property value is unspecified (which is usually only case if
                you explicitly enabled that sort behaviour).
    */
    virtual bool StringToValue(wxVariant& variant, const wxString& text,
                               wxPGPropValFormatFlags flags = wxPGPropValFormatFlags::Null) const;

    /**
        Converts integer (possibly a choice selection) into wxVariant value
        appropriate for this property.

        @param variant
            On function entry this is the old value (should not be null wxVariant
            in normal cases). Translated value must be assigned back to it.
        @param number
            Integer to be translated into variant.
        @param flags
            If wxPGPropValFormatFlags::FullValue is set, returns complete, storable value
            instead of displayable one.

        @return Returns @true if resulting wxVariant value was different.

        @remarks
        - If property is not supposed to use choice or spinctrl or other editor
          with int-based value, it is not necessary to implement this method.
        - Default implementation simply assign given int to m_value.
        - If property uses choice control, and displays a dialog on some choice
          items, then it is preferred to display that dialog in IntToValue
          instead of OnEvent.
        - You might want to take into account that m_value is Mull variant if
          property value is unspecified (which is usually only case if you
          explicitly enabled that sort behaviour).
    */
    virtual bool IntToValue(wxVariant& variant, int number,
                            wxPGPropValFormatFlags flags = wxPGPropValFormatFlags::Null) const;

    /**
        Converts property value into a text representation.

        @param value
            Value to be converted.
        @param flags
            If wxPGPropValFormatFlags::Null (default value), then displayed string is returned.
            If wxPGPropValFormatFlags::FullValue is set, returns complete, storable string value
            instead of displayable. If wxPGPropValFormatFlags::EditableValue is set, returns
            string value that must be editable in textctrl.
            If wxPGPropValFormatFlags::CompositeFragment is set, returns text that is appropriate to
            display as a part of string property's composite text representation.

        @remarks Default implementation calls GenerateComposedValue().
    */
    virtual wxString ValueToString(wxVariant& value, wxPGPropValFormatFlags flags = wxPGPropValFormatFlags::Null) const;

    /**
        Converts string to a value, and if successful, calls SetValue() on it.
        Default behaviour is to do nothing.

        @param text
            String to get the value from.
        @param flags
            If wxPGPropValFormatFlags::FullValue is set, the function sets complete, storable
            value instead of displayable one (they may be different).
            wxPGPropValFormatFlags::ProgrammaticValue flag is used to indicate that value is
            being set programmatically (i.e. operation is not caused by user
            input).
            If wxPGPropValFormatFlags::ReportError is set, a special action should be
            performed if string couldn't have been successfully converted
            to the valid value (e.g. a special value can be set in this case).

        @return @true if value was changed.
    */
    bool SetValueFromString(const wxString& text,
                            wxPGPropValFormatFlags flags = wxPGPropValFormatFlags::ProgrammaticValue);

    /**
        Converts integer to a value, and if successful, calls SetValue() on it.
        Default behaviour is to do nothing.

        @param value
            Int to get the value from.
        @param flags
            If has wxPGPropValFormatFlags::FullValue, then the value given is an actual value and not an index.

        @return @true if value was changed.
    */
    bool SetValueFromInt(long value, wxPGPropValFormatFlags flags = wxPGPropValFormatFlags::Null);

    /**
        Returns size of the custom painted image in front of property. This method
        must be overridden to return non-default value if OnCustomPaint is to be
        called.

        @param item
            Normally -1, but can be an index to the property's list of items.

        @remarks
        - Default behaviour is to return wxSize(0,0), which means no image.
        - Default image width or height is indicated with dimension -1.
        - You can also return ::wxPG_DEFAULT_IMAGE_SIZE which equals wxDefaultSize.
    */
    virtual wxSize OnMeasureImage( int item = -1 ) const;

    /**
        Events received by editor widgets are processed here. Note that editor class
        usually processes most events. Some, such as button press events of
        TextCtrlAndButton class, can be handled here. Also, if custom handling
        for regular events is desired, then that can also be done (for example,
        wxSystemColourProperty custom handles @c wxEVT_CHOICE
        to display colour picker dialog when 'custom' selection is made).

        If the event causes value to be changed, SetValueInEvent() should be called
        to set the new value.

        The parameter @a event is the associated wxEvent.

        @retval
            Should return @true if any changes in value should be reported.

        @remarks
        - If property uses choice control, and displays a dialog on some choice items,
          then it is preferred to display that dialog in IntToValue instead of OnEvent.
    */
    virtual bool OnEvent( wxPropertyGrid* propgrid, wxWindow* wnd_primary, wxEvent& event );

    /**
        Called after value of a child property has been altered. Must return
        new value of the whole property (after any alterations warranted by
        child's new value).

        Note that this function is usually called at the time that value of
        this property, or given child property, is still pending for change,
        and as such, result of GetValue() or m_value should not be relied
        on.

        Sample pseudo-code implementation:

        @code
        wxVariant MyProperty::ChildChanged( wxVariant& thisValue,
                                            int childIndex,
                                            wxVariant& childValue ) const
        {
            // Acquire reference to actual type of data stored in variant
            // (TFromVariant only exists if wxPropertyGrid's wxVariant-macros
            // were used to create the variant class).
            T& data = TFromVariant(thisValue);

            // Copy childValue into data.
            switch ( childIndex )
            {
                case 0:
                    data.SetSubProp1( childvalue.GetLong() );
                    break;
                case 1:
                    data.SetSubProp2( childvalue.GetString() );
                    break;
                ...
            }

            // Return altered data
            return data;
        }
        @endcode

        @param thisValue
            Value of this property. Changed value should be returned (in
            previous versions of wxPropertyGrid it was only necessary to
            write value back to this argument).
        @param childIndex
            Index of child changed (you can use Item(childIndex) to get
            child property).
        @param childValue
            (Pending) value of the child property.

        @return
            Modified value of the whole property.
    */
    virtual wxVariant ChildChanged( wxVariant& thisValue,
                                    int childIndex,
                                    wxVariant& childValue ) const;

    /**
        Returns pointer to an instance of used editor.
    */
    virtual const wxPGEditor* DoGetEditorClass() const;

    /**
        Returns pointer to the wxValidator that should be used
        with the editor of this property (@NULL for no validator).
        Setting validator explicitly via SetPropertyValidator
        will override this.

        In most situations, code like this should work well
        (macros are used to maintain one actual validator instance,
        so on the second call the function exits within the first
        macro):

        @code

        wxValidator* wxMyPropertyClass::DoGetValidator () const
        {
            WX_PG_DOGETVALIDATOR_ENTRY()

            wxMyValidator* validator = new wxMyValidator(...);

            ... prepare validator...

            WX_PG_DOGETVALIDATOR_EXIT(validator)
        }

        @endcode

        @remarks
        You can get common filename validator by returning
        wxFileProperty::GetClassValidator(). wxDirProperty,
        for example, uses it.
    */
    virtual wxValidator* DoGetValidator () const;

    /**
        Override to paint an image in front of the property value text or drop-down
        list item (but only if wxPGProperty::OnMeasureImage is overridden as well).

        If property's OnMeasureImage() returns size that has height != 0 but less than
        row height ( < 0 has special meanings), wxPropertyGrid calls this method to
        draw a custom image in a limited area in front of the editor control or
        value text/graphics, and if control has drop-down list, then the image is
        drawn there as well (even in the case OnMeasureImage() returned higher height
        than row height).

        NOTE: Following applies when OnMeasureImage() returns a "flexible" height (
        using @c wxPG_FLEXIBLE_SIZE(W,H) macro), which implies variable height items:
        If (rect.x+rect.width) is < 0, then this is a measure item call, which
        means that dc is invalid and only thing that should be done is to set
        paintdata.m_drawnHeight to the height of the image of item at index
        paintdata.m_choiceItem. This call may be done even as often as once every
        drop-down popup show.

        @param dc
        wxDC to paint on.
        @param rect
        Box reserved for custom graphics. Includes surrounding rectangle, if any.
        If x+width is < 0, then this is a measure item call (see above).
        @param paintdata
        wxPGPaintData structure with much useful data about painted item.
        @code
        struct wxPGPaintData
        {
            // wxPropertyGrid.
            const wxPropertyGrid*   m_parent;

            // Normally -1, otherwise index to drop-down list item that has to be drawn.
            int                     m_choiceItem;

            // Set to drawn width in OnCustomPaint (optional).
            int                     m_drawnWidth;

            // In a measure item call, set this to the height of item at m_choiceItem index
            int                     m_drawnHeight;
        };
        @endcode

        @remarks
            - You can actually exceed rect width, but if you do so then paintdata.m_drawnWidth
              must be set to the full width drawn in pixels.
            - Due to technical reasons, rect's height will be default even if custom height
              was reported during measure call.
            - Brush is guaranteed to be default background colour. It has been already used to
              clear the background of area being painted. It can be modified.
            - Pen is guaranteed to be 1-wide 'black' (or whatever is the proper colour) pen for
              drawing framing rectangle. It can be changed as well.

        @see ValueToString()
    */
    virtual void OnCustomPaint( wxDC& dc, const wxRect& rect, wxPGPaintData& paintdata );

    /**
        Returns used wxPGCellRenderer instance for given property column (label=0, value=1).

        Default implementation returns editor's renderer for all columns.
    */
    virtual wxPGCellRenderer* GetCellRenderer( int column ) const;

    /**
        Returns which choice is currently selected. Only applies to properties
        which have choices.

        Needs to reimplemented in derived class if property value does not
        map directly to a choice. Integer as index, bool, and string usually do.
    */
    virtual int GetChoiceSelection() const;

    /**
        Refresh values of child properties. Automatically called after value is set.
    */
    virtual void RefreshChildren();

    /**
        Reimplement this member function to add special handling for
        attributes of this property.

        @return Return @false to have the attribute automatically stored in
                m_attributes. Default implementation simply does that and
                nothing else.

        @remarks To actually set property attribute values from the
                 application, use wxPGProperty::SetAttribute() instead.
    */
    virtual bool DoSetAttribute( const wxString& name, wxVariant& value );

    /**
        Returns value of an attribute.

        Override if custom handling of attributes is needed.

        Default implementation simply return @NULL variant.
    */
    virtual wxVariant DoGetAttribute( const wxString& name ) const;

    /**
        Returns instance of a new wxPGEditorDialogAdapter instance, which is
        used when user presses the (optional) button next to the editor control;

        Default implementation returns @NULL (i.e. no action is generated when
        button is pressed).
    */
    virtual wxPGEditorDialogAdapter* GetEditorDialog() const;

    /**
        Called whenever validation has failed with given pending value.

        @remarks If you implement this in your custom property class, please
                 remember to call the base implementation as well, since they
                 may use it to revert property into pre-change state.
    */
    virtual void OnValidationFailure( wxVariant& pendingValue );

    /**
        Append a new choice to property's list of choices.

        @param label
            Label for added choice.

        @param value
            Value for new choice. Do not specify if you wish this
            to equal choice index.

        @return
            Index to added choice.
    */
    int AddChoice( const wxString& label, int value = wxPG_INVALID_VALUE );

    /**
        Adds a private child property. If you use this instead of
        wxPropertyGridInterface::Insert() or
        wxPropertyGridInterface::AppendIn(), then property's parental
        type will automatically be set up to wxPGFlags::Aggregate.
        In other words, all properties of this property will become private.
    */
    void AddPrivateChild( wxPGProperty* prop );

    /**
        Adapts list variant into proper value using consecutive
        ChildChanged() calls.
    */
    void AdaptListToValue( wxVariant& list, wxVariant* value ) const;

    /**
        Use this member function to add independent (i.e. regular) children to
        a property.

        @return Appended childProperty.

        @remarks wxPropertyGrid is not automatically refreshed by this
                function.

        @see InsertChild(), AddPrivateChild()
    */
    wxPGProperty* AppendChild( wxPGProperty* childProperty );

    /**
        Determines, recursively, if all children are not unspecified.

        @param pendingList
            Assumes members in this wxVariant list as pending
            replacement values.
    */
    bool AreAllChildrenSpecified( const wxVariant* pendingList = nullptr ) const;

    /**
        Returns @true if children of this property are component values (for instance,
        points size, face name, and is_underlined are component values of a font).
    */
    bool AreChildrenComponents() const;

    /**
        Sets or clears given property flag. Mainly for internal use.

        @remarks Setting a property flag never has any side-effect, and is
                 intended almost exclusively for internal use. So, for
                 example, if you want to disable a property, call
                 @code Enable(false) @endcode instead of setting
                 wxPGFlags::Disabled flag.

        @see HasFlag(), GetFlags()
    */
    void ChangeFlag( wxPGFlags flag, bool set );

    /**
        Deletes children of the property.
    */
    void DeleteChildren();

    /**
        Removes entry from property's wxPGChoices and editor control (if it is active).

        If selected item is deleted, then the value is set to unspecified.
    */
    void DeleteChoice( int index );

    /**
        Enables or disables the property. Disabled property usually appears
        as having grey text.

        @param enable
            If @false, property is disabled instead.

        @see wxPropertyGridInterface::EnableProperty()
    */
    void Enable( bool enable = true );

    /**
        Call to enable or disable usage of common value (integer value that can
        be selected for properties instead of their normal values) for this
        property.

        Common values are disabled by the default for all properties.
    */
    void EnableCommonValue( bool enable = true );

    /**
        Composes text from values of child properties.
    */
    wxString GenerateComposedValue() const;

    /**
        Returns property's label.
    */
    const wxString& GetLabel() const;

    /**
        Returns property attribute value, null variant if not found.

        @remarks
        For built-in attribute returns null variant if extra style
        ::wxPG_EX_WRITEONLY_BUILTIN_ATTRIBUTES is set.
    */
    wxVariant GetAttribute( const wxString& name ) const;

    /** Returns named attribute, as string, if found. Otherwise @a defVal is returned.

        @remarks
        For built-in attribute returns @a defVal if extra style
        ::wxPG_EX_WRITEONLY_BUILTIN_ATTRIBUTES is set.
    */
    wxString GetAttribute( const wxString& name, const wxString& defVal ) const;

    /** Returns named attribute, as long, if found. Otherwise @a defVal is returned.

        @remarks
        For built-in attribute returns @a defVal if extra style
        ::wxPG_EX_WRITEONLY_BUILTIN_ATTRIBUTES is set.
    */
    long GetAttributeAsLong( const wxString& name, long defVal ) const;

    /** Returns named attribute, as double, if found. Otherwise @a defVal is returned.

        @remarks
        For built-in attribute returns @a defVal if extra style
        ::wxPG_EX_WRITEONLY_BUILTIN_ATTRIBUTES is set.
    */
    double GetAttributeAsDouble( const wxString& name, double defVal ) const;

    /**
        Returns map-like storage of property's attributes.

        @remarks
        If extra style ::wxPG_EX_WRITEONLY_BUILTIN_ATTRIBUTES is set,
        then builtin-attributes are not included in the storage.
    */
    const wxPGAttributeStorage& GetAttributes() const;

    /**
        Returns attributes as list wxVariant.

        @remarks
        If extra style ::wxPG_EX_WRITEONLY_BUILTIN_ATTRIBUTES is set,
        then builtin-attributes are not included in the list.
    */
    wxVariant GetAttributesAsList() const;

    /**
        Returns editor used for given column. @NULL for no editor.
    */
    const wxPGEditor* GetColumnEditor( int column ) const;

    /** Returns property's base name (i.e. parent's name is not added
        in any case).
    */
    const wxString& GetBaseName() const;

    /**
        Returns wxPGCell of given column.

        @remarks const version of this member function returns 'default'
                 wxPGCell object if the property itself didn't hold
                 cell data.
    */
    const wxPGCell& GetCell( unsigned int column ) const;

    /**
        Returns wxPGCell of given column, creating one if necessary.
    */
    wxPGCell& GetCell( unsigned int column );

    /**
        Returns wxPGCell of given column, creating one if necessary.
    */
    wxPGCell& GetOrCreateCell( unsigned int column );

    /**
        Returns number of child properties.
    */
    unsigned int GetChildCount() const;

    /**
        Checks if there is any child property.

        @since 3.3.0
    */
    bool HasAnyChild() const;

    /**
        Returns height of children, recursively, and
        by taking expanded/collapsed status into account.

        @param lh
            Line height. Pass result of GetGrid()->GetRowHeight() here.

        @param iMax
            Only used (internally) when finding property y-positions.
    */
    int GetChildrenHeight( int lh, int iMax = -1 ) const;

    /**
        Returns read-only reference to property's list of choices.
    */
    const wxPGChoices& GetChoices() const;

    /**
        Returns client data (void*) of a property.
    */
    void* GetClientData() const;

    /** Gets managed client object of a property.
    */
    wxClientData *GetClientObject() const;

    /**
        Returns property's default value. If property's value type is not
        a built-in one, and "DefaultValue" attribute is not defined, then
        this function usually returns Null variant.
    */
    wxVariant GetDefaultValue() const;

    /**
        Returns common value selected for this property. -1 for none.
    */
    int GetCommonValue() const;

    unsigned int GetDepth() const;

    /**
        Return number of displayed common values for this property.
    */
    int GetDisplayedCommonValueCount() const;

    /** Returns property's displayed text.
    */
    wxString GetDisplayedString() const;

    /**
        Returns wxPGEditor that will be used and created when
        property becomes selected. Returns more accurate value
        than DoGetEditorClass().
    */
    const wxPGEditor* GetEditorClass() const;

    /**
        Returns property's hint text (shown in empty value cell).
    */
    inline wxString GetHintText() const;

    /** Returns property grid where property lies. */
    wxPropertyGrid* GetGrid() const;

    /**
        Returns owner wxPropertyGrid, but only if one is currently on a page
        displaying this property.
    */
    wxPropertyGrid* GetGridIfDisplayed() const;

    /**
        Returns property's help or description text.

        @see SetHelpString()
    */
    const wxString& GetHelpString() const;

    /** Gets flags as a'|' delimited string. Note that flag names are not
        prepended with 'wxPGFlags'.

        @param flagsMask
        String will only be made to include flags combined by this parameter.
    */
    wxString GetFlagsAsString(wxPGFlags flagsMask) const;

    /**
        Returns position in parent's array.
    */
    unsigned int GetIndexInParent() const;

    /**
        Returns last visible child property, recursively.
    */
    const wxPGProperty* GetLastVisibleSubItem() const;

    /**
        Returns highest level non-category, non-root parent. Useful when you
        have nested properties with children.

        @remarks If immediate parent is root or category, this will return the
                property itself.
    */
    wxPGProperty* GetMainParent() const;

    /**
        Returns maximum allowed length of the text the user can enter in
        the property text editor.

        @remarks
        0 is returned if length is not explicitly limited and the text can be
        as long as it is supported by the underlying native text control
        widget.
    */
    int GetMaxLength() const;

    /** Returns property's name with all (non-category, non-root) parents. */
    wxString GetName() const;

    /** Return parent of property */
    wxPGProperty* GetParent() const;

    /**
        Returns (direct) child property with given name (or @NULL if not found).

        @param name
            Name of the child property to look for.
    */
    wxPGProperty* GetPropertyByName( const wxString& name ) const;

    /** Gets assignable version of property's validator. */
    wxValidator* GetValidator() const;

    /**
        Returns property's value.
    */
    wxVariant GetValue() const;

    /**
        Returns bitmap that appears next to value text. Only returns non-null
        bitmap if one was set with SetValueImage().
    */
    wxBitmap* GetValueImage() const;

    /** Returns text representation of property's value.

        @param flags
            If wxPGPropValFormatFlags::Null (default value), then displayed string is returned.
            If wxPGPropValFormatFlags::FullValue is set, returns complete, storable string value
            instead of displayable. If wxPGPropValFormatFlags::EditableValue is set, returns
            string value that must be editable in textctrl. If
            wxPGPropValFormatFlags::CompositeFragment is set, returns text that is appropriate to
            display as a part of string property's composite text
            representation.

        @remarks In older versions, this function used to be overridden to convert
                 property's value into a string representation. This function is
                 now handled by ValueToString(), and overriding this function now
                 will result in run-time assertion failure.
    */
    virtual wxString GetValueAsString(wxPGPropValFormatFlags flags = wxPGPropValFormatFlags::Null) const;

    /**
        Returns value type used by this property.
    */
    wxString GetValueType() const;

    /**
        Returns coordinate to the top y of the property. Note that the
        position of scrollbars is not taken into account.
    */
    int GetY() const;

    /**
        Converts image width into full image offset, with margins.
    */
    int GetImageOffset( int imageWidth ) const;

    /** Returns property at given virtual y coordinate.
    */
    wxPGProperty* GetItemAtY( unsigned int y ) const;

    /**
        Returns @true if property has given flag set.

        @see propgrid_propflags
    */
    bool HasFlag(wxPGFlags flag) const;

    /**
        Returns @true if property has all given flags set.
    */
    bool HasFlagsExact(wxPGFlags flags) const;

    /**
        Returns @true if property has even one visible child.
    */
    bool HasVisibleChildren() const;

    /**
        Hides or reveals the property.

        @param hide
            @true for hide, @false for reveal.

        @param flags
            By default changes are applied recursively. Set this parameter to
            wxPGPropertyValuesFlags::DontRecurse to prevent this.
    */
    bool Hide(bool hide, wxPGPropertyValuesFlags flags = wxPGPropertyValuesFlags::Recurse);

    /**
        Returns index of given child property. wxNOT_FOUND if
        given property is not child of this.
    */
    int Index( const wxPGProperty* p ) const;

    /**
        Use this member function to add independent (i.e. regular) children to
        a property.

        @return Inserted childProperty.

        @remarks wxPropertyGrid is not automatically refreshed by this
                function.

        @see AppendChild(), AddPrivateChild()
    */
    wxPGProperty* InsertChild( int index, wxPGProperty* childProperty );

    /**
        Inserts a new choice to property's list of choices.

        @param label
            Text for new choice

        @param index
            Insertion position. Use wxNOT_FOUND to append.

        @param value
            Value for new choice. Do not specify if you wish this
            to equal choice index.
    */
    int InsertChoice( const wxString& label, int index, int value = wxPG_INVALID_VALUE );

    /**
        Returns @true if this property is actually a wxPropertyCategory.
    */
    bool IsCategory() const;

    /**
        Returns @true if property is enabled.
    */
    bool IsEnabled() const;

    /**
        Returns @true if property has visible children.
    */
    bool IsExpanded() const;

    /**
        Returns @true if this property is actually a wxRootProperty.
    */
    bool IsRoot() const;

    /**
       Returns true if this is a sub-property.
    */
    bool IsSubProperty() const;


    /**
        Returns @true if candidateParent is some parent of this property.
        Use, for example, to detect if item is inside collapsed section.
    */
    bool IsSomeParent( wxPGProperty* candidateParent ) const;

    /**
        Returns @true if property has editable wxTextCtrl when selected.

        @remarks Although disabled properties do not displayed editor, they still
                return @true here as being disabled is considered a temporary
                condition (unlike being read-only or having limited editing enabled).
    */
    bool IsTextEditable() const;

    /**
        Returns @true if property's value is considered unspecified. This
        usually means that value is Null variant.
    */
    bool IsValueUnspecified() const;

    /**
        Returns @true if all parents expanded.
    */
    bool IsVisible() const;

    /**
        Returns child property at index @a i.
    */
    wxPGProperty* Item( unsigned int i ) const;

    /**
        Returns last sub-property.
    */
    wxPGProperty* Last() const;

    /**
        If property's editor is created this forces its recreation.
        Useful in SetAttribute etc. Returns @true if actually did anything.
    */
    bool RecreateEditor();

    /**
        If property's editor is active, then update it's value.
    */
    void RefreshEditor();

    /**
        Sets an attribute for this property.

        @param name
            Text identifier of attribute. See @ref propgrid_property_attributes.

        @param value
            Value of attribute.

        @remarks Setting attribute's value to Null variant will simply remove it
                from property's set of attributes.
    */
    void SetAttribute( const wxString& name, wxVariant value );

    void SetAttributes( const wxPGAttributeStorage& attributes );

    /**
        Set if user can change the property's value to unspecified by
        modifying the value of the editor control (usually by clearing
        it).  Currently, this can work with following properties:
        wxIntProperty, wxUIntProperty, wxFloatProperty, wxEditEnumProperty.

        @param enable
            Whether to enable or disable this behaviour (it is disabled by
            default).
    */
    void SetAutoUnspecified( bool enable = true );

    /**
        Sets property's background colour.

        @param colour
            Background colour to use.

        @param flags
            Default is wxPGPropertyValuesFlags::Recurse which causes colour
            to be set recursively.
            Omit this flag to only set colour for the property in question
            and not any of its children.

        @remarks
        Unlike wxPropertyGridInterface::SetPropertyBackgroundColour(),
        this does not automatically update the display.
    */
    void SetBackgroundColour(const wxColour& colour,
                             wxPGPropertyValuesFlags flags = wxPGPropertyValuesFlags::Recurse);

    /**
        Sets editor for a property.

        @param editor
            For builtin editors, use wxPGEditor_X, where X is builtin editor's
            name (TextCtrl, Choice, etc. see wxPGEditor documentation for full list).

        For custom editors, use pointer you received from wxPropertyGrid::RegisterEditorClass().
    */
    void SetEditor( const wxPGEditor* editor );

    /**
        Sets editor for a property, by editor name.
    */
    void SetEditor( const wxString& editorName );

    /**
        Sets cell information for given column.
    */
    void SetCell( int column, const wxPGCell& cell );

    /**
        Sets common value selected for this property. -1 for none.
    */
    void SetCommonValue( int commonValue );

    /**
        Sets new set of choices for the property.

        @remarks This operation deselects the property and clears its
                 value.
    */
    bool SetChoices( wxPGChoices& choices );

    /**
        Sets client data (void*) of a property.

        @remarks This untyped client data has to be deleted manually.
    */
    void SetClientData( void* clientData );

    /** Sets client object of a property.
    */
    void SetClientObject(wxClientData* clientObject);

    /**
        Sets selected choice and changes property value.

        Tries to retain value type, although currently if it is not string,
        then it is forced to integer.

        If @a newValue is wxNOT_FOUND (`-1`), then the property's value is
        reset to unspecified, as if SetValueToUnspecified() was called.
    */
    void SetChoiceSelection( int newValue );

    /** Set default value of a property. Synonymous to

        @code
            SetAttribute("DefaultValue", value);
        @endcode
    */
    void SetDefaultValue( wxVariant& value );

    void SetExpanded( bool expanded );

    /** Sets flags from a '|' delimited string. Note that flag names are not
        prepended with 'wxPGFlags'.
    */
    void SetFlagsFromString( const wxString& str );

    /**
        Sets or clears given property flag, recursively. This function is
        primarily intended for internal use.

        @see ChangeFlag()
    */
    void SetFlagRecursively( wxPGFlags flag, bool set );

    /**
        Sets property's help string, which is shown, for example, in
        wxPropertyGridManager's description text box.
    */
    void SetHelpString( const wxString& helpString );

    /**
        Sets property's label.

        @remarks
        - Properties under same parent may have same labels. However,
        property names must still remain unique.
        - Unlike wxPropertyGridInterface::SetPropertyLabel(),
        this does not automatically update the display.
    */
    void SetLabel( const wxString& label );

    /**
        Set maximum length of the text the user can enter in the text editor
        associated with property.
        It does not affect a text representation of the value already stored
        when the limit is set, nor does it affect the length of the text
        representation of the value set programmatically e.g. with SetValue()
        or wxPropertyGridInterface::SetPropertyValue().
        If @a maxLen is 0, the length is not limited and the text can be
        as long as it is supported by the underlying native text control
        widget.

        @return
        Returns @true if maximum length was set.
    */
    bool SetMaxLength( int maxLen );

    /**
        Sets property's "is it modified?" flag. Affects children recursively.
    */
    void SetModifiedStatus( bool modified );

    /**
        Sets new (base) name for property.
    */
    void SetName( const wxString& newName );

    /**
        Changes what sort of parent this property is for its children.

        @param flag
            Use one of the following values: wxPGFlags::MiscParent (for
            generic parents), wxPGFlags::Category (for categories), or
            wxPGFlags::Aggregate (for derived property classes with
            private children).

        @remarks You generally do not need to call this function.
    */
    void SetParentalType(wxPGFlags flag);

    /**
        Sets property's text colour.

        @param colour
            Text colour to use.

        @param flags
            Default is wxPGPropertyValuesFlags::Recurse which causes colour
            to be set recursively.
            Omit this flag to only set colour for the property in question
            and not any of its children.

        @remarks
        Unlike wxPropertyGridInterface::SetPropertyTextColour(),
        this does not automatically update the display.
    */
    void SetTextColour(const wxColour& colour,
                       wxPGPropertyValuesFlags flags = wxPGPropertyValuesFlags::Recurse);

    /**
        Sets property's default text and background colours.

        @param flags
            Default is wxPGPropertyValuesFlags::Recurse which
            causes colours to be set recursively.
            Omit this flag to only set colours for the property in question
            and not any of its children.

        @remarks
        Unlike wxPropertyGridInterface::SetPropertyColoursToDefault(),
        this does not automatically update the display.

        @since 3.1.0
    */
    void SetDefaultColours(wxPGPropertyValuesFlags flags = wxPGPropertyValuesFlags::Recurse);

    /** Sets wxValidator for a property */
    void SetValidator( const wxValidator& validator );

    /**
        Call this to set value of the property. Unlike methods in wxPropertyGrid,
        this does not automatically update the display.

        @remarks
            Use wxPropertyGrid::ChangePropertyValue() instead if you need to run through
            validation process and send property change event.

            If you need to change property value in event, based on user input, use
            SetValueInEvent() instead.

        @param value
            The value to set.
        @param pList
            Pointer to list variant that contains child values. Used to indicate
            which children should be marked as modified. Usually you just use @NULL.
        @param flags
            wxPGSetValueFlags::RefreshEditor is set by default, to refresh editor
            and redraw properties.
    */
    void SetValue(wxVariant value, wxVariant* pList = nullptr,
                  wxPGSetValueFlags flags = wxPGSetValueFlags::RefreshEditor );

    /**
        Set wxBitmap taken from wxBitmapBundle in front of the value.
        This bitmap may be ignored by custom cell renderers.
    */
    void SetValueImage( wxBitmapBundle& bmp );

    /**
        Call this function in OnEvent(), OnButtonClick() etc. to change the
        property value based on user input.

        @remarks This method is const since it doesn't actually modify value, but posts
                given variant as pending value, stored in wxPropertyGrid.
    */
    void SetValueInEvent( const wxVariant& value ) const;

    /**
        Sets property's value to unspecified (i.e. Null variant).
    */
    void SetValueToUnspecified();

    /**
        Call with @false in OnSetValue() to cancel value changes after all
        (i.e. cancel @true returned by StringToValue() or IntToValue()).
    */
    void SetWasModified( bool set = true );

    /**
        Updates composed values of parent non-category properties, recursively.
        Returns topmost property updated.

        @remarks
        Must not call SetValue() (as can be called in it).
    */
    wxPGProperty* UpdateParentValues();

    /**
        Returns @true if containing grid uses ::wxPG_EX_AUTO_UNSPECIFIED_VALUES.
    */
    bool UsesAutoUnspecified() const;

    /** This member is public so scripting language bindings
        wrapper code can access it freely.
    */
    void*                       m_clientData;

protected:

    /**
        Default constructor. It is protected because wxPGProperty is only
        a base class for other property classes.
    */
    wxPGProperty();

    /**
        Constructor. It is protected because wxPGProperty is only a base
        class for other property classes.
        Non-abstract property classes should have constructor of this style:

        @code

        MyProperty( const wxString& label, const wxString& name, const T& value )
            : wxPGProperty(label, name)
        {
            // Generally recommended way to set the initial value
            // (as it should work in pretty much 100% of cases).
            wxVariant variant;
            variant << value;
            SetValue(variant);

            // If has private child properties then create them here.
            // For example:
            //     AddPrivateChild( new wxStringProperty("Subprop 1",
            //                                           wxPG_LABEL,
            //                                           value.GetSubProp1()));
        }

        @endcode
    */
    wxPGProperty( const wxString& label, const wxString& name );

    /**
        Sets property cell in fashion that reduces number of exclusive
        copies of cell data. Used when setting, for instance, same
        background colour for a number of properties.

        @param firstCol
            First column to affect.

        @param lastCol
            Last column to affect.

        @param preparedCell
            Pre-prepared cell that is used for those which cell data
            before this matched unmodCellData.

        @param srcData
            If unmodCellData did not match, valid cell data from this
            is merged into cell (usually generating new exclusive copy
            of cell's data).

        @param unmodCellData
            If cell's cell data matches this, its cell is now set to
            preparedCell.

        @param ignoreWithFlags
            Properties with any one of these flags are skipped.

        @param recursively
            If @true, apply this operation recursively in child properties.
    */
    void AdaptiveSetCell( unsigned int firstCol,
                          unsigned int lastCol,
                          const wxPGCell& preparedCell,
                          const wxPGCell& srcData,
                          wxPGCellData* unmodCellData,
                          wxPGFlags ignoreWithFlags,
                          bool recursively );

    /**
        Clear cells associated with property.

        @param ignoreWithFlags
            Cells will not be cleared for properties having these flags set.

        @param recursively
            If @true, apply this operation recursively in child properties.

        @since 3.1.0
    */
    void ClearCells(wxPGFlags ignoreWithFlags, bool recursively);

    /**
        Makes sure m_cells has size of column+1 (or more).
    */
    void EnsureCells( unsigned int column );

    /** Returns (direct) child property with given name (or @NULL if not found),
        with hint index.

        @param name
            Name of the child property to look for.

        @param hintIndex
            Start looking for the child at this index.

        @remarks
            Does not support scope (i.e. Parent.Child notation).
    */
    wxPGProperty* GetPropertyByNameWH( const wxString& name,
                                       unsigned int hintIndex ) const;

    /** This is used by Insert etc. */
    void DoAddChild( wxPGProperty* prop,
                     int index = -1,
                     bool correct_mode = true );

    /** Deletes all child properties. */
    void Empty();

    /**
        Returns @true if child property is selected.
    */
    bool IsChildSelected( bool recursive = false ) const;
};

// -----------------------------------------------------------------------

/** @class wxPGCellRenderer

    Base class for wxPropertyGrid cell renderers.

    @library{wxpropgrid}
    @category{propgrid}
*/
class wxPGCellRenderer : public wxObjectRefData
{
public:
    wxPGCellRenderer();
    virtual ~wxPGCellRenderer();

    /**
        @anchor pgcellrenderer_render_flags

        Flags for Render(), PreDrawCell() and PostDrawCell().
    */
    enum
    {
        /** We are painting selected item.
            @hideinitializer
        */
        Selected        = 0x00010000,

        /** We are painting item in choice popup.
            @hideinitializer
        */
        ChoicePopup     = 0x00020000,

        /**
            We are rendering wxOwnerDrawnComboBox control
            or other owner drawn control, but that is only
            officially supported one ATM).
            @hideinitializer
        */
        Control         = 0x00040000,

        /** We are painting a disable property.
            @hideinitializer
        */
        Disabled        = 0x00080000,

        /**
            We are painting selected, disabled, or similar
            item that dictates fore- and background colours,
            overriding any cell values.
            @hideinitializer
        */
        DontUseCellFgCol    = 0x00100000,
        /**
            @hideinitializer
        */
        DontUseCellBgCol    = 0x00200000,
        /**
            @hideinitializer
        */
        DontUseCellColours  = DontUseCellFgCol |
                              DontUseCellBgCol
    };

    /**
        Returns @true if rendered something in the foreground (text or
        bitmap).

        @param dc
            wxDC to paint on.

        @param rect
            Box reserved for drawing.

        @param propertyGrid
            Property grid in which property is displayed.

        @param property
            Property to be rendered.

        @param column
            Property cell column.

        @param item
            Index of chosen item if combo popup is drawn, -1 otherwise.

        @param flags
            See @ref pgcellrenderer_render_flags "list of render flags".
    */
    virtual bool Render( wxDC& dc,
                         const wxRect& rect,
                         const wxPropertyGrid* propertyGrid,
                         wxPGProperty* property,
                         int column,
                         int item,
                         int flags ) const = 0;

    /** Returns size of the image in front of the editable area.

        @remarks
        If property is @NULL, then this call is for a custom value. In that case
        the item is index to wxPropertyGrid's custom values.
    */
    virtual wxSize GetImageSize( const wxPGProperty* property,
                                 int column,
                                 int item ) const;

    /** Paints property category selection rectangle.
    */
    virtual void DrawCaptionSelectionRect(wxDC& dc,
                                          int x, int y, int w, int h) const;

    /** Utility to draw vertically centered text.
    */
    void DrawText( wxDC& dc,
                   const wxRect& rect,
                   int imageWidth,
                   const wxString& text ) const;

    /**
        Utility to draw editor's value, or vertically aligned text if editor is
        @NULL.
    */
    void DrawEditorValue( wxDC& dc, const wxRect& rect,
                          int xOffset, const wxString& text,
                          wxPGProperty* property,
                          const wxPGEditor* editor ) const;

    /**
        Utility to render cell bitmap and set text colour plus bg brush
        colour.

        @param dc
            wxDC to paint on.

        @param rect
            Box reserved for drawing.

        @param propGrid
            Property grid to which the cell belongs.

        @param cell
            Cell information.

        @param flags
            See @ref pgcellrenderer_render_flags "list of render flags".

        @return
            Returns image width, which, for instance, can be passed to
            DrawText().
    */
    int PreDrawCell( wxDC& dc,
                     const wxRect& rect,
                     const wxPropertyGrid* propGrid,
                     const wxPGCell& cell,
                     int flags ) const;

    /**
        Utility to be called after drawing is done, to revert whatever
        changes PreDrawCell() did.

        @param dc
            wxDC which was used to paint on.

        @param propGrid
            Property grid to which the cell belongs.

        @param cell
            Cell information.

        @param flags
            Same as those passed to PreDrawCell().
            See @ref pgcellrenderer_render_flags "list of render flags".
    */
    void PostDrawCell( wxDC& dc,
                       const wxPropertyGrid* propGrid,
                       const wxPGCell& cell,
                       int flags ) const;
};

// -----------------------------------------------------------------------

/**
    @class wxPGDefaultRenderer

    Default cell renderer, that can handles the common
    scenarios.

    @library{wxpropgrid}
    @category{propgrid}
*/
class wxPGDefaultRenderer : public wxPGCellRenderer
{
public:
    /**
        Returns @true if rendered something in the foreground (text or
        bitmap.

        @param dc
            wxDC to paint on.

        @param rect
            Box reserved for drawing.

        @param propertyGrid
            Property grid in which property is displayed.

        @param property
            Property to be rendered.

        @param column
            Property cell column.

        @param item
            Index of chosen item if combo popup is drawn, -1 otherwise.

        @param flags
            See @ref pgcellrenderer_render_flags "list of render flags".
    */
    virtual bool Render( wxDC& dc,
                         const wxRect& rect,
                         const wxPropertyGrid* propertyGrid,
                         wxPGProperty* property,
                         int column,
                         int item,
                         int flags ) const;

    virtual wxSize GetImageSize( const wxPGProperty* property,
                                 int column,
                                 int item ) const;
};

// -----------------------------------------------------------------------

/**
    @class wxPGCellData

    @library{wxpropgrid}
    @category{propgrid}
*/
class wxPGCellData : public wxObjectRefData
{
    friend class wxPGCell;
public:
    wxPGCellData();

    void SetText( const wxString& text );
    void SetBitmap( const wxBitmapBundle& bitmap );
    void SetFgCol( const wxColour& col );
    void SetBgCol( const wxColour& col );
    void SetFont( const wxFont& font );

protected:
    virtual ~wxPGCellData();

    wxString    m_text;
    wxBitmapBundle m_bitmapBundle;
    wxColour    m_fgCol;
    wxColour    m_bgCol;
    wxFont      m_font;

    /** @true if m_text is valid and specified.
    */
    bool        m_hasValidText;
};


/**
    @class wxPGCell

    Base class for wxPropertyGrid cell information.

    @library{wxpropgrid}
    @category{propgrid}
*/
class wxPGCell : public wxObject
{
public:
    wxPGCell();
    wxPGCell(const wxPGCell& other);
    wxPGCell( const wxString& text,
              const wxBitmapBundle& bitmap = wxBitmapBundle(),
              const wxColour& fgCol = wxNullColour,
              const wxColour& bgCol = wxNullColour );

    virtual ~wxPGCell();

    wxPGCellData* GetData();
    const wxPGCellData* GetData() const;

    /**
        Returns @true if this cell has custom text stored within.
    */
    bool HasText() const;

    /**
        Sets empty but valid data to this cell object.
    */
    void SetEmptyData();

    /**
        Merges valid data from srcCell into this.
    */
    void MergeFrom( const wxPGCell& srcCell );

    void SetText( const wxString& text );
    void SetBitmap( const wxBitmapBundle& bitmap );
    void SetFgCol( const wxColour& col );

    /**
        Sets font of the cell.

        @remarks Because wxPropertyGrid does not support rows of
                 different height, it makes little sense to change
                 size of the font. Therefore it is recommended
                 to use return value of wxPropertyGrid::GetFont()
                 or wxPropertyGrid::GetCaptionFont() as a basis
                 for the font that, after modifications, is passed
                 to this member function.
    */
    void SetFont( const wxFont& font );

    void SetBgCol( const wxColour& col );

    const wxString& GetText() const;
    const wxBitmapBundle& GetBitmap() const;
    const wxColour& GetFgCol() const;

    /**
        Returns font of the cell. If no specific font is set for this
        cell, then the font will be invalid.
    */
    const wxFont& GetFont() const;

    const wxColour& GetBgCol() const;

    wxPGCell& operator=( const wxPGCell& other );
};

// -----------------------------------------------------------------------

/** @class wxPGAttributeStorage

    wxPGAttributeStorage is somewhat optimized storage for
    key=variant pairs (i.e. a map).
*/
class wxPGAttributeStorage
{
public:
    wxPGAttributeStorage();
    ~wxPGAttributeStorage();

    void Set( const wxString& name, const wxVariant& value );
    unsigned int GetCount() const;
    wxVariant FindValue( const wxString& name ) const;

    typedef wxPGHashMapS2P::const_iterator const_iterator;
    const_iterator StartIteration() const;
    bool GetNext( const_iterator& it, wxVariant& variant ) const;
};

// -----------------------------------------------------------------------


/**
    @class wxPGChoiceEntry
    Data of a single wxPGChoices choice.
*/
class wxPGChoiceEntry : public wxPGCell
{
public:
    wxPGChoiceEntry();
    wxPGChoiceEntry(const wxPGChoiceEntry& other);
    wxPGChoiceEntry( const wxString& label,
                     int value = wxPG_INVALID_VALUE );

    virtual ~wxPGChoiceEntry();

    void SetValue( int value );
    int GetValue() const;

    wxPGChoiceEntry& operator=( const wxPGChoiceEntry& other );
};


class wxPGChoicesData : public wxObjectRefData
{
public:
    // Constructor sets m_refCount to 1.
    wxPGChoicesData();

    void CopyDataFrom( wxPGChoicesData* data );

    wxPGChoiceEntry& Insert( int index, const wxPGChoiceEntry& item );

    // Delete all entries
    void Clear();

    unsigned int GetCount() const;

    const wxPGChoiceEntry& Item( unsigned int i ) const;
    wxPGChoiceEntry& Item( unsigned int i );

protected:
    virtual ~wxPGChoicesData();
};

/** @hideinitializer
*/
constexpr wxPGChoicesData* wxPGChoicesEmptyData = nullptr;


/**
    @class wxPGChoices

    Helper class for managing choices of wxPropertyGrid properties.
    Each entry can have label, value, bitmap, text colour, and background
    colour.

    wxPGChoices uses reference counting, similar to other wxWidgets classes.
    This means that assignment operator and copy constructor only copy the
    reference and not the actual data. Use Copy() member function to create a
    real copy.

    @remarks If you do not specify value for entry, index is used.

    @library{wxpropgrid}
    @category{propgrid}
*/
class wxPGChoices
{
public:
    typedef long ValArrItem;

    /**
        Default constructor.
    */
    wxPGChoices();

    /**
        Copy constructor, uses reference counting. To create a real copy,
        use Copy() member function instead.
    */
    wxPGChoices( const wxPGChoices& a );

    /**
        Constructor.

        @param count
            Number of the strings in @a labels array.
        @param labels
            Labels for choices.
        @param values
            Values for choices. If @NULL, indexes are used. Otherwise must have
            at least @a count elements.

        @since 3.1.2
     */
    wxPGChoices(size_t count, const wxString* labels, const long* values = nullptr);

    /**
        Constructor overload taking wxChar strings.

        This constructor is provided mostly for compatibility, prefer to use
        one of the other constructor overloads in the new code.

        @param labels
            Labels for choices, @NULL-terminated.

        @param values
            Values for choices. If @NULL, indexes are used. Otherwise must have
            at least the same size as @a labels.
    */
    wxPGChoices( const wxChar** labels, const long* values = nullptr );

    /**
        Constructor.

        @param labels
            Labels for choices.

        @param values
            Values for choices. If empty, indexes are used. Otherwise must have
            at least the same size as @a labels.
    */
    wxPGChoices( const wxArrayString& labels, const wxArrayInt& values = wxArrayInt() );

    /**
        Simple interface constructor.
    */
    wxPGChoices( wxPGChoicesData* data );

    /**
        Destructor.
    */
    ~wxPGChoices();

    /**
        Adds to current. If did not have own copies, creates them now. If was empty,
        identical to set except that creates copies.

        @param count
            Number of the strings in @a labels array.
        @param labels
            Labels for choices.
        @param values
            Values for choices. If @NULL, indexes are used. Otherwise must have
            at least @a count elements.

        @since 3.1.2
     */
    void Add(size_t count, const wxString* labels, const long* values = nullptr);

    /**
        Adds to current.

        This overload is provided mostly for compatibility, prefer to use one
        of the other ones in the new code.

        @param labels
            Labels for added choices, @NULL-terminated.

        @param values
            Values for added choices. If empty, relevant entry indexes are
            used. Otherwise must have at least the same size as @a labels.
    */
    void Add( const wxChar** labels, const long* values = nullptr );

    /**
        @overload
    */
    void Add( const wxArrayString& arr, const wxArrayInt& arrint );

    /**
        Adds a single choice item.

        @param label
            Label for added choice.

        @param value
            Value for added choice. If unspecified, index is used.
    */
    wxPGChoiceEntry& Add( const wxString& label, int value = wxPG_INVALID_VALUE );

    /**
        Adds a single item, with bitmap.
    */
    wxPGChoiceEntry& Add( const wxString& label, const wxBitmap& bitmap,
                          int value = wxPG_INVALID_VALUE );

    /**
        Adds a single item with full entry information.
    */
    wxPGChoiceEntry& Add( const wxPGChoiceEntry& entry );

    /**
        Adds a single item, sorted.
    */
    wxPGChoiceEntry& AddAsSorted( const wxString& label, int value = wxPG_INVALID_VALUE );

    /**
        Assigns choices data, using reference counting. To create a real copy,
        use Copy() member function instead.
    */
    void Assign( const wxPGChoices& a );

    /**
        Assigns data from another set of choices.
    */
    void AssignData( wxPGChoicesData* data );

    /**
        Deletes all items.
    */
    void Clear();

    /**
        Returns a real copy of the choices.
    */
    wxPGChoices Copy() const;

    void EnsureData();

    /**
        Gets an unsigned number identifying this list.
    */
    wxPGChoicesId GetId() const;

    /**
        Returns label of item.
    */
    const wxString& GetLabel( unsigned int ind ) const;

    /**
        Returns number of items.
    */
    unsigned int GetCount() const;

    /**
        Returns value of item.
    */
    int GetValue( unsigned int ind ) const;

    /**
        Returns array of values matching the given strings. Unmatching strings
        result in ::wxPG_INVALID_VALUE entry in array.
    */
    wxArrayInt GetValuesForStrings( const wxArrayString& strings ) const;

    /**
        Returns array of indices matching given strings. Unmatching strings
        are added to 'unmatched', if not @NULL.
    */
    wxArrayInt GetIndicesForStrings( const wxArrayString& strings,
                                     wxArrayString* unmatched = nullptr ) const;

    /**
        Returns index of item with given label.
    */
    int Index( const wxString& label ) const;

    /**
        Returns index of item with given value.
    */
    int Index( int val ) const;

    /**
        Inserts a single item.
    */
    wxPGChoiceEntry& Insert( const wxString& label, int index, int value = wxPG_INVALID_VALUE );

    /**
        Inserts a single item with full entry information.
    */
    wxPGChoiceEntry& Insert( const wxPGChoiceEntry& entry, int index );

    /**
        Returns @false if this is a constant empty set of choices,
        which should not be modified.
    */
    bool IsOk() const;

    /**
        Returns item at given index.
    */
    const wxPGChoiceEntry& Item( unsigned int i ) const;

    /**
        Returns item at given index.
    */
    wxPGChoiceEntry& Item( unsigned int i );

    /**
        Removes count items starting at position nIndex.
    */
    void RemoveAt(size_t nIndex, size_t count = 1);

    /**
        Sets contents from lists of strings and values.

        This is similar to calling Clear() and the corresponding overload of Add().
    */
    void Set(size_t count, const wxString* labels, const long* values = nullptr);

    /**
        @overload
     */
    void Set( const wxChar** labels, const long* values = nullptr );

    /**
        @overload
     */
    void Set( const wxArrayString& labels, const wxArrayInt& values = wxArrayInt() );

    /**
        Creates exclusive copy of current choices.
    */
    void AllocExclusive();

    /**
        Returns data, increases refcount.
    */
    wxPGChoicesData* GetData();

    /**
        Returns plain data ptr - no refcounting stuff is done.
    */
    wxPGChoicesData* GetDataPtr() const;

    /**
        Changes ownership of data to you.
    */
    wxPGChoicesData* ExtractData();

    /**
        Returns array of choice labels.
    */
    wxArrayString GetLabels() const;

    void operator= (const wxPGChoices& a);

    wxPGChoiceEntry& operator[](unsigned int i);
    const wxPGChoiceEntry& operator[](unsigned int i) const;

protected:
    wxPGChoicesData*    m_data;

    void Init();
    void Free();
};

// -----------------------------------------------------------------------

/** @class wxPGRootProperty

    Root parent property.
*/
class wxPGRootProperty : public wxPGProperty
{
public:

    /** Constructor. */
    wxPGRootProperty( const wxString& name = wxS("<Root>") );
    virtual ~wxPGRootProperty();

    virtual bool StringToValue( wxVariant&, const wxString&, wxPGPropValFormatFlags ) const;
};

// -----------------------------------------------------------------------

/** @class wxPropertyCategory

    Category (caption) property.
*/
class wxPropertyCategory : public wxPGProperty
{
    friend class wxPropertyGridPageState;
public:

    /** Default constructor is only used in special cases. */
    wxPropertyCategory();

    wxPropertyCategory( const wxString& label,
                        const wxString& name = wxPG_LABEL );
    virtual ~wxPropertyCategory();

    int GetTextExtent( const wxWindow* wnd, const wxFont& font ) const;

    virtual wxString ValueToString(wxVariant& value, wxPGPropValFormatFlags flags) const;
    virtual wxString GetValueAsString(wxPGPropValFormatFlags flags = wxPGPropValFormatFlags::Null) const;
};
