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

include/wx/generic/grid.h

@@ -282,6 +282,82 @@ protected:
     wxDECLARE_NO_COPY_CLASS(wxGridCellEditor);
 };
 
+// ----------------------------------------------------------------------------
+// wxGridHeaderRenderer and company: like wxGridCellRenderer but for headers
+// ----------------------------------------------------------------------------
+
+// Base class for corner window renderer: it is the simplest of all renderers
+// and only has a single function
+class WXDLLIMPEXP_ADV wxGridCornerHeaderRenderer
+{
+public:
+    // Draw the border around the corner window.
+    virtual void DrawBorder(const wxGrid& grid,
+                            wxDC& dc,
+                            wxRect& rect) const = 0;
+};
+
+
+// Base class for the row/column header cells renderers
+class WXDLLIMPEXP_ADV wxGridHeaderLabelsRenderer
+    : public wxGridCornerHeaderRenderer
+{
+public:
+    // Draw header cell label
+    virtual void DrawLabel(const wxGrid& grid,
+                           wxDC& dc,
+                           const wxString& value,
+                           const wxRect& rect,
+                           int horizAlign,
+                           int vertAlign,
+                           int textOrientation) const;
+};
+
+// Currently the row/column/corner renders don't need any methods other than
+// those already in wxGridHeaderLabelsRenderer but still define separate classes
+// for them for future extensions and also for better type safety (i.e. to
+// avoid inadvertently using a column header renderer for the row headers)
+class WXDLLIMPEXP_ADV wxGridRowHeaderRenderer
+    : public wxGridHeaderLabelsRenderer
+{
+};
+
+class WXDLLIMPEXP_ADV wxGridColumnHeaderRenderer
+    : public wxGridHeaderLabelsRenderer
+{
+};
+
+// Also define the default renderers which are used by wxGridCellAttrProvider
+// by default
+class WXDLLIMPEXP_ADV wxGridRowHeaderRendererDefault
+    : public wxGridRowHeaderRenderer
+{
+public:
+    virtual void DrawBorder(const wxGrid& grid,
+                            wxDC& dc,
+                            wxRect& rect) const;
+};
+
+// Column header cells renderers
+class WXDLLIMPEXP_ADV wxGridColumnHeaderRendererDefault
+    : public wxGridColumnHeaderRenderer
+{
+public:
+    virtual void DrawBorder(const wxGrid& grid,
+                            wxDC& dc,
+                            wxRect& rect) const;
+};
+
+// Header corner renderer
+class WXDLLIMPEXP_ADV wxGridCornerHeaderRendererDefault
+    : public wxGridCornerHeaderRenderer
+{
+public:
+    virtual void DrawBorder(const wxGrid& grid,
+                            wxDC& dc,
+                            wxRect& rect) const;
+};
+
 
 // ----------------------------------------------------------------------------
 // wxGridCellAttr: this class can be used to alter the cells appearance in
@@ -464,11 +540,40 @@ public:
     void UpdateAttrRows( size_t pos, int numRows );
     void UpdateAttrCols( size_t pos, int numCols );
 
+
+    // get renderers for the given row/column header label and the corner
+    // window: unlike cell renderers, these objects are not reference counted
+    // and are never NULL so they are returned by reference
+    virtual const wxGridColumnHeaderRenderer&
+        GetColumnHeaderRenderer(int WXUNUSED(col))
+    {
+        return m_defaultHeaderRenderers.colRenderer;
+    }
+
+    virtual const wxGridRowHeaderRenderer&
+        GetRowHeaderRenderer(int WXUNUSED(row))
+    {
+        return m_defaultHeaderRenderers.rowRenderer;
+    }
+
+    virtual const wxGridCornerHeaderRenderer& GetCornerRenderer()
+    {
+        return m_defaultHeaderRenderers.cornerRenderer;
+    }
+
 private:
     void InitData();
 
     wxGridCellAttrProviderData *m_data;
 
+    // this struct simply combines together the default header renderers
+    struct
+    {
+        wxGridColumnHeaderRendererDefault colRenderer;
+        wxGridRowHeaderRendererDefault rowRenderer;
+        wxGridCornerHeaderRendererDefault cornerRenderer;
+    } m_defaultHeaderRenderers;
+
     wxDECLARE_NO_COPY_CLASS(wxGridCellAttrProvider);
 };
 
@@ -923,12 +1028,12 @@ public:
     void DrawTextRectangle( wxDC& dc, const wxString&, const wxRect&,
                             int horizontalAlignment = wxALIGN_LEFT,
                             int verticalAlignment = wxALIGN_TOP,
-                            int textOrientation = wxHORIZONTAL );
+                            int textOrientation = wxHORIZONTAL ) const;
 
     void DrawTextRectangle( wxDC& dc, const wxArrayString& lines, const wxRect&,
                             int horizontalAlignment = wxALIGN_LEFT,
                             int verticalAlignment = wxALIGN_TOP,
-                            int textOrientation = wxHORIZONTAL );
+                            int textOrientation = wxHORIZONTAL ) const;
 
 
     // Split a string containing newline characters into an array of
@@ -2001,10 +2106,12 @@ protected:
     friend class wxGridColLabelWindow;
     friend class wxGridRowLabelWindow;
     friend class wxGridWindow;
+    friend class wxGridHeaderRenderer;
 
     friend class wxGridHeaderCtrl;
 
 private:
+
     // implement wxScrolledWindow method to return m_gridWin size
     virtual wxSize GetSizeAvailableForScrollTarget(const wxSize& size);