Added support for corner, row and column headers renderers to wxGrid.

Make it possible to customize the appearance of wxGrid corner window and its
row and column headers by defining custom renderers for them.

Add demonstration of this new feature to the grid sample and update the
documentation.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@61919 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/grid.h

@@ -642,6 +642,152 @@ public:
     void SetTextColour(const wxColour& colText);
 };
 
+/**
+    Base class for corner window renderer.
+
+    This is the simplest of all header renderers and only has a single
+    function.
+
+    @see wxGridCellAttrProvider::GetCornerRenderer()
+
+    @since 2.9.1
+ */
+class wxGridCornerHeaderRenderer
+{
+public:
+    /**
+        Called by the grid to draw the corner window border.
+
+        This method is responsible for drawing the border inside the given @a
+        rect and adjusting the rectangle size to correspond to the area inside
+        the border, i.e. usually call wxRect::Deflate() to account for the
+        border width.
+
+        @param grid
+            The grid whose corner window is being drawn.
+        @param dc
+            The device context to use for drawing.
+        @param rect
+            Input/output parameter which contains the border rectangle on input
+            and should be updated to contain the area inside the border on
+            function return.
+     */
+    virtual void DrawBorder(const wxGrid& grid,
+                            wxDC& dc,
+                            wxRect& rect) const = 0;
+};
+/**
+    Common base class for row and column headers renderers.
+
+    @see wxGridColumnHeaderRenderer, wxGridRowHeaderRenderer
+
+    @since 2.9.1
+ */
+class wxGridHeaderLabelsRenderer : public wxGridCornerHeaderRenderer
+{
+public:
+    /**
+        Called by the grid to draw the specified label.
+
+        Notice that the base class DrawBorder() method is called before this
+        one.
+
+        The default implementation uses wxGrid::GetLabelTextColour() and
+        wxGrid::GetLabelFont() to draw the label.
+     */
+    virtual void DrawLabel(const wxGrid& grid,
+                           wxDC& dc,
+                           const wxString& value,
+                           const wxRect& rect,
+                           int horizAlign,
+                           int vertAlign,
+                           int textOrientation) const;
+};
+
+/**
+    Base class for row headers renderer.
+
+    This is the same as wxGridHeaderLabelsRenderer currently but we still use a
+    separate class for it to distinguish it from wxGridColumnHeaderRenderer.
+
+    @see wxGridRowHeaderRendererDefault
+
+    @see wxGridCellAttrProvider::GetRowHeaderRenderer()
+
+    @since 2.9.1
+ */
+class wxGridRowHeaderRenderer : public wxGridHeaderLabelsRenderer
+{
+};
+
+/**
+    Base class for column headers renderer.
+
+    This is the same as wxGridHeaderLabelsRenderer currently but we still use a
+    separate class for it to distinguish it from wxGridRowHeaderRenderer.
+
+    @see wxGridColumnHeaderRendererDefault
+
+    @see wxGridCellAttrProvider::GetColumnHeaderRenderer()
+
+    @since 2.9.1
+ */
+class wxGridColumnHeaderRenderer : public wxGridHeaderLabelsRenderer
+{
+};
+
+/**
+    Default row header renderer.
+
+    You may derive from this class if you need to only override one of its
+    methods (i.e. either DrawLabel() or DrawBorder()) but continue to use the
+    default implementation for the other one.
+
+    @see wxGridColumnHeaderRendererDefault
+
+    @since 2.9.1
+ */
+class wxGridRowHeaderRendererDefault : public wxGridRowHeaderRendererDefault
+{
+public:
+    /// Implement border drawing for the row labels.
+    virtual void DrawBorder(const wxGrid& grid,
+                            wxDC& dc,
+                            wxRect& rect) const;
+};
+
+/**
+    Default column header renderer.
+
+    @see wxGridRowHeaderRendererDefault
+
+    @since 2.9.1
+ */
+class wxGridColumnHeaderRendererDefault : public wxGridColumnHeaderRenderer
+{
+public:
+    /// Implement border drawing for the column labels.
+    virtual void DrawBorder(const wxGrid& grid,
+                            wxDC& dc,
+                            wxRect& rect) const;
+};
+
+/**
+    Default corner window renderer.
+
+    @see wxGridColumnHeaderRendererDefault, wxGridRowHeaderRendererDefault
+
+    @since 2.9.1
+ */
+class wxGridCornerHeaderRendererDefault : public wxGridCornerHeaderRenderer
+{
+public:
+    /// Implement border drawing for the corner window.
+    virtual void DrawBorder(const wxGrid& grid,
+                            wxDC& dc,
+                            wxRect& rect) const;
+};
+
 /**
     Class providing attributes to be used for the grid cells.
 
@@ -727,6 +873,50 @@ public:
     virtual void SetColAttr(wxGridCellAttr *attr, int col);
 
     //@}
+
+    /**
+        Getting header renderers.
+
+        These functions return the renderers for the given row or column header
+        label and the corner window. Unlike cell attributes, these objects are
+        not reference counted and are never @NULL so they are returned by
+        reference and not pointer and DecRef() shouldn't (and can't) be called
+        for them.
+
+        All these functions were added in wxWidgets 2.9.1.
+     */
+    //@{
+
+    /**
+        Return the renderer used for drawing column headers.
+
+        By default wxGridColumnHeaderRendererDefault is returned.
+
+        @see wxGrid::SetUseNativeColLabels(), wxGrid::UseNativeColHeader()
+
+        @since 2.9.1
+     */
+    virtual const wxGridColumnHeaderRenderer& GetColumnHeaderRenderer(int col);
+
+    /**
+        Return the renderer used for drawing row headers.
+
+        By default wxGridRowHeaderRendererDefault is returned.
+
+        @since 2.9.1
+     */
+    virtual const wxGridRowHeaderRenderer& GetRowHeaderRenderer(int row);
+
+    /**
+        Return the renderer used for drawing the corner window.
+
+        By default wxGridCornerHeaderRendererDefault is returned.
+
+        @since 2.9.1
+     */
+    virtual const wxGridCornerHeaderRenderer& GetCornerRenderer();
+
+    //@}
 };