From 2e992e06a71d90f1df597441af36f69ef390089a Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Mon, 9 Oct 2006 16:39:34 +0000
Subject: [PATCH] added wxWindow::IsDoubleBuffered() and improve wxBufferedDC
 (patch 1565330)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@41810 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 build/bakefiles/files.bkl      |   1 +
 docs/changes.txt               |   1 +
 docs/latex/wx/window.tex       |  13 +
 include/wx/cocoa/window.h      |   2 +
 include/wx/combo.h             |   3 -
 include/wx/dc.h                |  29 +-
 include/wx/dcbuffer.h          | 610 ++++++++++++++++++++++++++++++---
 include/wx/dfb/window.h        |   2 +
 include/wx/gtk/dc.h            |   2 +
 include/wx/gtk/dcclient.h      |   2 +
 include/wx/gtk/window.h        |   1 +
 include/wx/gtk1/dc.h           |   2 +
 include/wx/gtk1/dcclient.h     |   2 +
 include/wx/gtk1/window.h       |   2 +
 include/wx/mac/carbon/window.h |   2 +
 include/wx/msw/missing.h       |   4 +
 include/wx/msw/window.h        |   3 +
 include/wx/vlbox.h             |   3 -
 include/wx/window.h            |   3 +
 src/common/combocmn.cpp        |  20 --
 src/common/dcbufcmn.cpp        | 136 ++++++++
 src/generic/combog.cpp         |   2 +-
 src/generic/datavgen.cpp       |  13 +-
 src/generic/vlbox.cpp          |  13 +-
 src/gtk/renderer.cpp           |  58 ++--
 src/gtk/window.cpp             |   5 +
 src/gtk1/renderer.cpp          |  17 +-
 src/msw/combo.cpp              |   2 +-
 src/msw/window.cpp             |  14 +
 29 files changed, 826 insertions(+), 141 deletions(-)
 create mode 100644 src/common/dcbufcmn.cpp

diff --git a/build/bakefiles/files.bkl b/build/bakefiles/files.bkl
index 7d3207e753..8033700998 100644
--- a/build/bakefiles/files.bkl
+++ b/build/bakefiles/files.bkl
@@ -569,6 +569,7 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
     src/common/ctrlsub.cpp
     src/common/datacmn.cpp
     src/common/dcbase.cpp
+    src/common/dcbufcmn.cpp
     src/common/dlgcmn.cpp
     src/common/dndcmn.cpp
     src/common/dobjcmn.cpp
diff --git a/docs/changes.txt b/docs/changes.txt
index e07d2c0d32..cceaf5143d 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -76,6 +76,7 @@ All (GUI):
   consistency with wxRichTextCtrl.
 - wxRichTextCtrl: fixed range out-by-one bug to be consistent with wxTextCtrl API,
   fixed some attribute bugs and added wxRichTextStyleComboCtrl.
+- Added wxWindow::IsDoubleBuffered()
 
 wxMSW:
 
diff --git a/docs/latex/wx/window.tex b/docs/latex/wx/window.tex
index 92eba14297..0d199dedd7 100644
--- a/docs/latex/wx/window.tex
+++ b/docs/latex/wx/window.tex
@@ -1495,6 +1495,19 @@ to the dialog via validators.
 Resets the cached best size value so it will be recalculated the next time it is needed.
 
 
+\membersection{wxWindow::IsDoubleBuffered}\label{wxwindowisdoublebuffered}
+
+\constfunc{virtual bool}{IsDoubleBuffered}{\void}
+
+Returns \true if the window contents is double-buffered by the system, i.e. if
+any drawing done on the window is really done on a temporary backing surface
+and transferred to the screen all at once later.
+
+\wxheading{See also}
+
+\helpref{wxBufferedDC}{wxbuffereddc}
+
+
 \membersection{wxWindow::IsEnabled}\label{wxwindowisenabled}
 
 \constfunc{virtual bool}{IsEnabled}{\void}
diff --git a/include/wx/cocoa/window.h b/include/wx/cocoa/window.h
index c997a01de7..ff7205b96d 100644
--- a/include/wx/cocoa/window.h
+++ b/include/wx/cocoa/window.h
@@ -199,6 +199,8 @@ public:
     virtual bool Close( bool force = false );
     virtual bool Show( bool show = true );
     virtual bool Enable( bool enable = true );
+
+    virtual bool IsDoubleBuffered() const { return true; }
 };
 
 #endif // __WX_COCOA_WINDOW_H__
diff --git a/include/wx/combo.h b/include/wx/combo.h
index 55b1e2d481..4de8d8aa3d 100644
--- a/include/wx/combo.h
+++ b/include/wx/combo.h
@@ -434,9 +434,6 @@ protected:
     virtual void DoSetToolTip( wxToolTip *tip );
 #endif
 
-    // Used by OnPaints of derived classes
-    wxBitmap& GetBufferBitmap(const wxSize& sz) const;
-
     // This is used when m_text is hidden (readonly).
     wxString                m_valueString;
 
diff --git a/include/wx/dc.h b/include/wx/dc.h
index 0b74388dff..0fc5689f39 100644
--- a/include/wx/dc.h
+++ b/include/wx/dc.h
@@ -134,11 +134,6 @@ public:
 
     virtual ~wxDCBase() { }
 
-#if WXWIN_COMPATIBILITY_2_6
-    wxDEPRECATED( virtual void BeginDrawing() );
-    wxDEPRECATED( virtual void EndDrawing() );
-#endif // WXWIN_COMPATIBILITY_2_6
-
     // graphic primitives
     // ------------------
 
@@ -387,6 +382,12 @@ public:
     virtual void StartPage() { }
     virtual void EndPage() { }
 
+#if WXWIN_COMPATIBILITY_2_6
+    wxDEPRECATED( void BeginDrawing() );
+    wxDEPRECATED( void EndDrawing() );
+#endif // WXWIN_COMPATIBILITY_2_6
+
+
     // set objects to use for drawing
     // ------------------------------
 
@@ -503,20 +504,20 @@ public:
     // accessors and setters
     // ---------------------
 
-    int GetBackgroundMode() const { return m_backgroundMode; }
-    const wxBrush&  GetBackground() const { return m_backgroundBrush; }
-    const wxBrush&  GetBrush() const { return m_brush; }
-    const wxFont&   GetFont() const { return m_font; }
-    const wxPen&    GetPen() const { return m_pen; }
+    virtual int GetBackgroundMode() const { return m_backgroundMode; }
+    virtual const wxBrush&  GetBackground() const { return m_backgroundBrush; }
+    virtual const wxBrush&  GetBrush() const { return m_brush; }
+    virtual const wxFont&   GetFont() const { return m_font; }
+    virtual const wxPen&    GetPen() const { return m_pen; }
 
-    const wxColour& GetTextForeground() const { return m_textForegroundColour; }
-    const wxColour& GetTextBackground() const { return m_textBackgroundColour; }
+    virtual const wxColour& GetTextForeground() const { return m_textForegroundColour; }
+    virtual const wxColour& GetTextBackground() const { return m_textBackgroundColour; }
     virtual void SetTextForeground(const wxColour& colour)
         { m_textForegroundColour = colour; }
     virtual void SetTextBackground(const wxColour& colour)
         { m_textBackgroundColour = colour; }
 
-    int GetMapMode() const { return m_mappingMode; }
+    virtual int GetMapMode() const { return m_mappingMode; }
     virtual void SetMapMode(int mode) = 0;
 
     virtual void GetUserScale(double *x, double *y) const
@@ -553,7 +554,7 @@ public:
 
     virtual void SetAxisOrientation(bool xLeftRight, bool yBottomUp) = 0;
 
-    int GetLogicalFunction() const { return m_logicalFunction; }
+    virtual int GetLogicalFunction() const { return m_logicalFunction; }
     virtual void SetLogicalFunction(int function) = 0;
 
 #if WXWIN_COMPATIBILITY_2_4
diff --git a/include/wx/dcbuffer.h b/include/wx/dcbuffer.h
index cac6228a8e..216f4f970b 100644
--- a/include/wx/dcbuffer.h
+++ b/include/wx/dcbuffer.h
@@ -16,6 +16,29 @@
 #include "wx/dcclient.h"
 #include "wx/window.h"
 
+
+// I think this patch should be test on wxMac with
+// wxTEST_PAINTDCDELEGATION as 1, and then with
+// with wxTEST_MEMORYDCDELEGATION as 1.
+#define wxTEST_PAINTDCDELEGATION        0
+#define wxTEST_MEMORYDCDELEGATION       0
+
+
+// Split platforms into two groups - those which have well-working
+// double-buffering by default, and those which do not.
+#if defined(__WXMAC__) || defined(__WXGTK20__)
+    #define wxALWAYS_NATIVE_DOUBLE_BUFFER       1
+#else
+    #define wxALWAYS_NATIVE_DOUBLE_BUFFER       0
+#endif
+
+
+#if wxTEST_PAINTDCDELEGATION || wxTEST_MEMORYDCDELEGATION
+    #undef wxALWAYS_NATIVE_DOUBLE_BUFFER
+    #define wxALWAYS_NATIVE_DOUBLE_BUFFER 0
+#endif
+
+
 // ----------------------------------------------------------------------------
 // Double buffering helper.
 // ----------------------------------------------------------------------------
@@ -28,11 +51,12 @@
 // does not prepare the window DC
 #define wxBUFFER_CLIENT_AREA        0x02
 
-class wxBufferedDC : public wxMemoryDC
+class WXDLLEXPORT wxBufferedDC : public wxDC
 {
 public:
     // Default ctor, must subsequently call Init for two stage construction.
-    wxBufferedDC() : m_dc( 0 ), m_style(0)
+    wxBufferedDC() : wxDC(), m_targetDc(NULL), m_mainDc(NULL),
+                     m_buffer(NULL), m_style(0)
     {
     }
 
@@ -40,23 +64,38 @@ public:
     wxBufferedDC(wxDC *dc,
                  const wxBitmap &buffer = wxNullBitmap,
                  int style = wxBUFFER_CLIENT_AREA)
-        : m_dc( dc ),
-          m_buffer( buffer ),
-          m_style(style)
+        : wxDC(),
+          m_targetDc(NULL),
+          m_mainDc(NULL)
     {
-        UseBuffer();
+        // All other members except dcs are initialized in Init
+        Init(dc, buffer, style);
     }
 
     // Construct a wxBufferedDC with an internal buffer of 'area'
     // (where area is usually something like the size of the window
     // being buffered)
     wxBufferedDC(wxDC *dc, const wxSize &area, int style = wxBUFFER_CLIENT_AREA)
-        : m_dc( dc ),
-          m_buffer( area.GetWidth(), area.GetHeight() ),
-          m_style(style)
+        : wxDC(),
+          m_targetDc(NULL),
+          m_mainDc(NULL)
+    {
+        // All other members except dcs are initialized in Init
+        Init(NULL, dc, area, style);
+    }
 
+    // Same, but also receives window to detect whether it is
+    // natively double-buffered.
+    wxBufferedDC(wxWindow* win,
+                 wxDC *dc,
+                 const wxSize &area,
+                 int style = wxBUFFER_CLIENT_AREA)
+        : wxDC(),
+          m_targetDc(NULL),
+          m_mainDc(NULL)
     {
-        UseBuffer();
+        // All other members except dcs are initialized in Init
+        Init(win, dc, area, style);
     }
 
     // default copy ctor ok.
@@ -64,26 +103,55 @@ public:
     // The usually desired  action in the dtor is to blit the buffer.
     virtual ~wxBufferedDC()
     {
-        if ( m_dc ) UnMask();
+        UnMask();
     }
 
-    // These reimplement the actions of the ctors for two stage creation, but
-    // are not used by the ctors themselves to save a few cpu cycles.
     void Init(wxDC *dc,
-              const wxBitmap &buffer=wxNullBitmap,
+              const wxBitmap &buffer,
               int style = wxBUFFER_CLIENT_AREA)
     {
-        wxASSERT_MSG( m_dc == 0 && m_buffer == wxNullBitmap,
-                      _T("wxBufferedDC already initialised") );
-        m_dc = dc;
-        m_buffer = buffer;
+        wxASSERT_MSG( m_mainDc == NULL,
+                      wxT("wxBufferedDC already initialised") );
+        wxASSERT_MSG( buffer.Ok(),
+                      wxT("invalid bitmap") );
+        m_mainDc = dc;
+        m_buffer = &buffer;
         m_style = style;
         UseBuffer();
     }
 
-    void Init(wxDC *dc, const wxSize &area, int style = wxBUFFER_CLIENT_AREA)
+    void Init(wxWindow* win,
+              wxDC *dc,
+              const wxSize &area = wxDefaultSize,
+              int style = wxBUFFER_CLIENT_AREA)
     {
-        Init(dc, wxBitmap(area.GetWidth(), area.GetHeight()), style);
+        wxASSERT_MSG( m_mainDc == NULL,
+                      wxT("wxBufferedDC already initialised") );
+
+        m_mainDc = dc;
+        m_style = style;
+
+#if wxTEST_MEMORYDCDELEGATION
+        if ( 0 )
+#elif wxTEST_PAINTDCDELEGATION
+        if ( 1 )
+#else
+        if ( win && win->IsDoubleBuffered() )
+#endif
+        {
+            AttachDC(dc);
+            m_buffer = NULL;
+        }
+        else
+        {
+            PrepareBuffer(win, area);
+            UseBuffer();
+        }
+    }
+
+    void Init(wxDC *dc, const wxSize &area = wxDefaultSize, int style = wxBUFFER_CLIENT_AREA)
+    {
+        Init(NULL, dc, area, style);
     }
 
     // Blits the buffer to the dc, and detaches the dc from the buffer (so it
@@ -92,54 +160,439 @@ public:
     // Usually called in the dtor or by the dtor of derived classes if the
     // BufferedDC must blit before the derived class (which may own the dc it's
     // blitting to) is destroyed.
-    void UnMask()
-    {
-        wxASSERT_MSG( m_dc != 0,
-                      _T("No underlying DC associated with wxBufferedDC (anymore)") );
-
-        wxCoord x=0, y=0;
-
-        if (m_style & wxBUFFER_CLIENT_AREA)
-            GetDeviceOrigin(& x, & y);
-
-        m_dc->Blit( 0, 0,
-                    m_buffer.GetWidth(), m_buffer.GetHeight(), this,
-                    -x, -y );
-        m_dc = NULL;
-    }
+    void UnMask();
 
     // Set and get the style
     void SetStyle(int style) { m_style = style; }
     int GetStyle() const { return m_style; }
 
 private:
-    // check that the bitmap is valid and use it
-    void UseBuffer()
-    {
-        if (!m_buffer.Ok())
-        {
-            wxCoord w, h;
-            m_dc->GetSize(&w, &h);
-            m_buffer = wxBitmap(w, h);
-        }
+    // Prepares wxMemoryDC.
+    void UseBuffer();
 
-        SelectObject(m_buffer);
-    }
+    // Allocate m_buffer, if necessary.
+    void PrepareBuffer(wxWindow* win, const wxSize& area);
+
+    // DC to which calls are delegated.
+    wxDC*           m_targetDc;
 
-    // the underlying DC to which we copy everything drawn on this one in
-    // UnMask()
+    // This the underlying DC to which we copy everything drawn on
+    // this one in UnMask().
     //
     // NB: Without the existence of a wxNullDC, this must be a pointer, else it
     //     could probably be a reference.
-    wxDC *m_dc;
+    wxDC*           m_mainDc;
 
     // the buffer (selected in this DC)
-    wxBitmap m_buffer;
+    const wxBitmap* m_buffer;
 
     // the buffering style
-    int m_style;
+    int             m_style;
 
     DECLARE_NO_COPY_CLASS(wxBufferedDC)
+public:
+    //
+    // BEGIN DC-DELEGATION IMPLEMENTATION
+    //
+
+    wxDC& GetAttachedDC()
+    {
+        return *m_targetDc;
+    }
+
+    // Use this to set the DC which receives delegated calls.
+    void AttachDC(wxDC* dc)
+    {
+        m_targetDc = dc;
+    #ifdef __WXMSW__
+        SetHDC( dc ? dc->GetHDC() : NULL );
+    #endif
+    }
+
+    // Sets DC to NULL
+    wxDC* DetachDC()
+    {
+        wxDC* retDc = m_targetDc;
+        AttachDC(NULL);
+        return retDc;
+    }
+
+#ifdef __WXGTK__
+    virtual GdkWindow* GetGDKWindow() const
+    {
+        return m_targetDc->GetGDKWindow();
+    }
+#endif
+
+    bool Blit(wxCoord xdest, wxCoord ydest, wxCoord width, wxCoord height,
+              wxDC *source, wxCoord xsrc, wxCoord ysrc,
+              int rop = wxCOPY, bool useMask = false, wxCoord xsrcMask = wxDefaultCoord, wxCoord ysrcMask = wxDefaultCoord)
+        { return m_targetDc->Blit(xdest, ydest, width, height,
+                                  source, xsrc, ysrc, rop,
+                                  useMask, xsrcMask, ysrcMask); }
+    bool Blit(const wxPoint& destPt, const wxSize& sz,
+              wxDC *source, const wxPoint& srcPt,
+              int rop = wxCOPY, bool useMask = false, const wxPoint& srcPtMask = wxDefaultPosition)
+        { return m_targetDc->Blit(destPt, sz, source, srcPt,
+                                  rop, useMask, srcPtMask); }
+    virtual void CalcBoundingBox(wxCoord x, wxCoord y) { m_targetDc->CalcBoundingBox(x, y); }
+#if defined(__WXWINCE__)
+    void CalculateEllipticPoints( wxList* points,
+                                  wxCoord xStart, wxCoord yStart,
+                                  wxCoord w, wxCoord h,
+                                  double sa, double ea )
+        { m_targetDc->CalculateEllipticPoints(points, xStart, yStart, w,
+                                              h, sa, ea); }
+#endif // defined(__WXWINCE__)
+    virtual bool CanDrawBitmap() const { return m_targetDc->CanDrawBitmap(); }
+    virtual bool CanGetTextExtent() const { return m_targetDc->CanGetTextExtent(); }
+    virtual void Clear() { m_targetDc->Clear(); }
+    virtual void ComputeScaleAndOrigin() { m_targetDc->ComputeScaleAndOrigin(); }
+    void CrossHair(wxCoord x, wxCoord y) { m_targetDc->CrossHair(x, y); }
+    void CrossHair(const wxPoint& pt) { m_targetDc->CrossHair(pt); }
+    virtual void DestroyClippingRegion() { m_targetDc->DestroyClippingRegion(); }
+    wxCoord DeviceToLogicalX(wxCoord x) const { return m_targetDc->DeviceToLogicalX(x); }
+    wxCoord DeviceToLogicalXRel(wxCoord x) const { return m_targetDc->DeviceToLogicalXRel(x); }
+    wxCoord DeviceToLogicalY(wxCoord y) const { return m_targetDc->DeviceToLogicalY(y); }
+    wxCoord DeviceToLogicalYRel(wxCoord y) const { return m_targetDc->DeviceToLogicalYRel(y); }
+#if defined(__WXWINCE__)
+    virtual void DoDrawEllipticArcRot( wxCoord x, wxCoord y,
+                                       wxCoord w, wxCoord h,
+                                       double sa = 0, double ea = 0, double angle = 0 )
+        { m_targetDc->DoDrawEllipticArcRot(x, y, w, h,
+                                           sa, ea, angle); }
+#endif // defined(__WXWINCE__)
+    void DrawArc(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2,
+                 wxCoord xc, wxCoord yc)
+        { m_targetDc->DrawArc(x1, y1, x2, y2,
+                              xc, yc); }
+    void DrawArc(const wxPoint& pt1, const wxPoint& pt2, const wxPoint& centre)
+        { m_targetDc->DrawArc(pt1, pt2, centre); }
+    void DrawBitmap(const wxBitmap &bmp, wxCoord x, wxCoord y,
+                    bool useMask = false)
+        { m_targetDc->DrawBitmap(bmp, x, y, useMask); }
+    void DrawBitmap(const wxBitmap &bmp, const wxPoint& pt,
+                    bool useMask = false)
+        { m_targetDc->DrawBitmap(bmp, pt, useMask); }
+    void DrawCheckMark(wxCoord x, wxCoord y,
+                       wxCoord width, wxCoord height)
+        { m_targetDc->DrawCheckMark(x, y, width, height); }
+    void DrawCheckMark(const wxRect& rect) { m_targetDc->DrawCheckMark(rect); }
+    void DrawCircle(wxCoord x, wxCoord y, wxCoord radius) { m_targetDc->DrawCircle(x, y, radius); }
+    void DrawCircle(const wxPoint& pt, wxCoord radius) { m_targetDc->DrawCircle(pt, radius); }
+    void DrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
+        { m_targetDc->DrawEllipse(x, y, width, height); }
+    void DrawEllipse(const wxPoint& pt, const wxSize& sz) { m_targetDc->DrawEllipse(pt, sz); }
+    void DrawEllipse(const wxRect& rect) { m_targetDc->DrawEllipse(rect); }
+    void DrawEllipticArc(wxCoord x, wxCoord y, wxCoord w, wxCoord h,
+                         double sa, double ea)
+        { m_targetDc->DrawEllipticArc(x, y, w, h,
+                                      sa, ea); }
+    void DrawEllipticArc(const wxPoint& pt, const wxSize& sz,
+                         double sa, double ea)
+        { m_targetDc->DrawEllipticArc(pt, sz, sa, ea); }
+#if defined(__WXWINCE__)
+    void DrawEllipticArcRot( wxCoord x, wxCoord y,
+                             wxCoord width, wxCoord height,
+                             double sa = 0, double ea = 0, double angle = 0 )
+        { m_targetDc->DrawEllipticArcRot(x, y, width, height,
+                                         sa, ea, angle); }
+    void DrawEllipticArcRot( const wxPoint& pt,
+                             const wxSize& sz,
+                             double sa = 0, double ea = 0, double angle = 0 )
+        { m_targetDc->DrawEllipticArcRot(pt, sz, sa, ea,
+                                         angle); }
+    void DrawEllipticArcRot( const wxRect& rect,
+                             double sa = 0, double ea = 0, double angle = 0 )
+        { m_targetDc->DrawEllipticArcRot(rect, sa, ea, angle); }
+#endif // defined(__WXWINCE__)
+    void DrawIcon(const wxIcon& icon, wxCoord x, wxCoord y) { m_targetDc->DrawIcon(icon, x, y); }
+    void DrawIcon(const wxIcon& icon, const wxPoint& pt) { m_targetDc->DrawIcon(icon, pt); }
+    virtual void DrawLabel(const wxString& text,
+                           const wxBitmap& image,
+                           const wxRect& rect,
+                           int alignment = wxALIGN_LEFT | wxALIGN_TOP,
+                           int indexAccel = -1,
+                           wxRect *rectBounding = NULL)
+        { m_targetDc->DrawLabel(text, image, rect, alignment,
+                                indexAccel, rectBounding); }
+    void DrawLabel(const wxString& text, const wxRect& rect,
+                   int alignment = wxALIGN_LEFT | wxALIGN_TOP,
+                   int indexAccel = -1)
+        { m_targetDc->DrawLabel(text, rect, alignment, indexAccel); }
+    void DrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2)
+        { m_targetDc->DrawLine(x1, y1, x2, y2); }
+    void DrawLine(const wxPoint& pt1, const wxPoint& pt2) { m_targetDc->DrawLine(pt1, pt2); }
+    void DrawLines(int n, wxPoint points[],
+                   wxCoord xoffset = 0, wxCoord yoffset = 0)
+        { m_targetDc->DrawLines(n, points, xoffset, yoffset); }
+    void DrawLines(const wxList *list,
+                   wxCoord xoffset = 0, wxCoord yoffset = 0)
+        { m_targetDc->DrawLines(list, xoffset, yoffset); }
+    virtual void DrawObject(wxDrawObject* drawobject) { m_targetDc->DrawObject(drawobject); }
+    void DrawPoint(wxCoord x, wxCoord y) { m_targetDc->DrawPoint(x, y); }
+    void DrawPoint(const wxPoint& pt) { m_targetDc->DrawPoint(pt); }
+    void DrawPolyPolygon(int n, int count[], wxPoint points[],
+                         wxCoord xoffset = 0, wxCoord yoffset = 0,
+                         int fillStyle = wxODDEVEN_RULE)
+        { m_targetDc->DrawPolyPolygon(n, count, points, xoffset,
+                                      yoffset, fillStyle); }
+    void DrawPolygon(int n, wxPoint points[],
+                     wxCoord xoffset = 0, wxCoord yoffset = 0,
+                     int fillStyle = wxODDEVEN_RULE)
+        { m_targetDc->DrawPolygon(n, points, xoffset, yoffset,
+                                  fillStyle); }
+    void DrawPolygon(const wxList *list,
+                     wxCoord xoffset = 0, wxCoord yoffset = 0,
+                     int fillStyle = wxODDEVEN_RULE)
+        { m_targetDc->DrawPolygon(list, xoffset, yoffset, fillStyle); }
+    void DrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
+        { m_targetDc->DrawRectangle(x, y, width, height); }
+    void DrawRectangle(const wxPoint& pt, const wxSize& sz) { m_targetDc->DrawRectangle(pt, sz); }
+    void DrawRectangle(const wxRect& rect) { m_targetDc->DrawRectangle(rect); }
+    void DrawRotatedText(const wxString& text, wxCoord x, wxCoord y, double angle)
+        { m_targetDc->DrawRotatedText(text, x, y, angle); }
+    void DrawRotatedText(const wxString& text, const wxPoint& pt, double angle)
+        { m_targetDc->DrawRotatedText(text, pt, angle); }
+    void DrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height,
+                              double radius)
+        { m_targetDc->DrawRoundedRectangle(x, y, width, height,
+                                           radius); }
+    void DrawRoundedRectangle(const wxPoint& pt, const wxSize& sz,
+                             double radius)
+        { m_targetDc->DrawRoundedRectangle(pt, sz, radius); }
+    void DrawRoundedRectangle(const wxRect& r, double radius)
+        { m_targetDc->DrawRoundedRectangle(r, radius); }
+#if wxUSE_SPLINES
+    void DrawSpline(wxCoord x1, wxCoord y1,
+                    wxCoord x2, wxCoord y2,
+                    wxCoord x3, wxCoord y3)
+        { m_targetDc->DrawSpline(x1, y1, x2, y2,
+                                 x3, y3); }
+    void DrawSpline(int n, wxPoint points[]) { m_targetDc->DrawSpline(n, points); }
+    void DrawSpline(wxList *points) { m_targetDc->DrawSpline(points); }
+#endif // wxUSE_SPLINES
+    void DrawText(const wxString& text, wxCoord x, wxCoord y)
+        { m_targetDc->DrawText(text, x, y); }
+    void DrawText(const wxString& text, const wxPoint& pt) { m_targetDc->DrawText(text, pt); }
+    virtual void EndDoc() { m_targetDc->EndDoc(); }
+    virtual void EndPage() { m_targetDc->EndPage(); }
+    bool FloodFill(wxCoord x, wxCoord y, const wxColour& col,
+                   int style = wxFLOOD_SURFACE)
+        { return m_targetDc->FloodFill(x, y, col, style); }
+    bool FloodFill(const wxPoint& pt, const wxColour& col,
+                   int style = wxFLOOD_SURFACE)
+        { return m_targetDc->FloodFill(pt, col, style); }
+    virtual const wxBrush&  GetBackground() const { return m_targetDc->GetBackground(); }
+    virtual int GetBackgroundMode() const { return m_targetDc->GetBackgroundMode(); }
+    virtual const wxBrush&  GetBrush() const { return m_targetDc->GetBrush(); }
+    virtual wxCoord GetCharHeight() const { return m_targetDc->GetCharHeight(); }
+    virtual wxCoord GetCharWidth() const { return m_targetDc->GetCharWidth(); }
+    void GetClippingBox(wxCoord *x, wxCoord *y, wxCoord *w, wxCoord *h) const
+        { m_targetDc->GetClippingBox(x, y, w, h); }
+    void GetClippingBox(wxRect& rect) const { m_targetDc->GetClippingBox(rect); }
+    void GetClippingBox(long *x, long *y, long *w, long *h) const
+        { m_targetDc->GetClippingBox(x, y, w, h); }
+    virtual int GetDepth() const { return m_targetDc->GetDepth(); }
+    void GetDeviceOrigin(wxCoord *x, wxCoord *y) const { m_targetDc->GetDeviceOrigin(x, y); }
+    wxPoint GetDeviceOrigin() const { return m_targetDc->GetDeviceOrigin(); }
+    void GetDeviceOrigin(long *x, long *y) const { m_targetDc->GetDeviceOrigin(x, y); }
+    virtual const wxFont&   GetFont() const { return m_targetDc->GetFont(); }
+    virtual int GetLogicalFunction() const { return m_targetDc->GetLogicalFunction(); }
+    void GetLogicalOrigin(wxCoord *x, wxCoord *y) const { m_targetDc->GetLogicalOrigin(x, y); }
+    wxPoint GetLogicalOrigin() const { return m_targetDc->GetLogicalOrigin(); }
+    void GetLogicalOrigin(long *x, long *y) const { m_targetDc->GetLogicalOrigin(x, y); }
+    virtual void GetLogicalScale(double *x, double *y) { m_targetDc->GetLogicalScale(x, y); }
+    virtual int GetMapMode() const { return m_targetDc->GetMapMode(); }
+    virtual void GetMultiLineTextExtent(const wxString& text,
+                                        wxCoord *width,
+                                        wxCoord *height,
+                                        wxCoord *heightLine = NULL,
+                                        wxFont *font = NULL)
+        { m_targetDc->GetMultiLineTextExtent(text, width, height, heightLine,
+                                             font); }
+#if WXWIN_COMPATIBILITY_2_4
+    virtual bool GetOptimization() { return m_targetDc->GetOptimization(); }
+#endif // WXWIN_COMPATIBILITY_2_4
+    virtual wxSize GetPPI() const { return m_targetDc->GetPPI(); }
+    bool GetPartialTextExtents(const wxString& text, wxArrayInt& widths) const
+        { return m_targetDc->GetPartialTextExtents(text, widths); }
+    virtual const wxPen&    GetPen() const { return m_targetDc->GetPen(); }
+    bool GetPixel(wxCoord x, wxCoord y, wxColour *col) const
+        { return m_targetDc->GetPixel(x, y, col); }
+    bool GetPixel(const wxPoint& pt, wxColour *col) const { return m_targetDc->GetPixel(pt, col); }
+    void GetSize(int *width, int *height) const { m_targetDc->GetSize(width, height); }
+    wxSize GetSize() const { return m_targetDc->GetSize(); }
+    void GetSizeMM(int* width, int* height) const { m_targetDc->GetSizeMM(width, height); }
+    wxSize GetSizeMM() const { return m_targetDc->GetSizeMM(); }
+    virtual const wxColour& GetTextBackground() const { return m_targetDc->GetTextBackground(); }
+    void GetTextExtent(const wxString& string,
+                       wxCoord *x, wxCoord *y,
+                       wxCoord *descent = NULL,
+                       wxCoord *externalLeading = NULL,
+                       wxFont *theFont = NULL) const
+        { m_targetDc->GetTextExtent(string, x, y, descent,
+                                    externalLeading, theFont); }
+    void GetTextExtent(const wxString& string,
+                       long *x, long *y,
+                       long *descent = NULL,
+                       long *externalLeading = NULL,
+                       wxFont *theFont = NULL) const
+        { m_targetDc->GetTextExtent(string, x, y, descent,
+                                    externalLeading, theFont); }
+    virtual const wxColour& GetTextForeground() const { return m_targetDc->GetTextForeground(); }
+    virtual void GetUserScale(double *x, double *y) const { m_targetDc->GetUserScale(x, y); }
+    void GradientFillConcentric(const wxRect& rect,
+                                const wxColour& initialColour,
+                                const wxColour& destColour)
+        { m_targetDc->GradientFillConcentric(rect, initialColour, destColour); }
+    void GradientFillConcentric(const wxRect& rect,
+                                const wxColour& initialColour,
+                                const wxColour& destColour,
+                                const wxPoint& circleCenter)
+        { m_targetDc->GradientFillConcentric(rect, initialColour, destColour, circleCenter); }
+    void GradientFillLinear(const wxRect& rect,
+                            const wxColour& initialColour,
+                            const wxColour& destColour,
+                            wxDirection nDirection = wxEAST)
+        { m_targetDc->GradientFillLinear(rect, initialColour, destColour, nDirection); }
+    wxCoord LogicalToDeviceX(wxCoord x) const { return m_targetDc->LogicalToDeviceX(x); }
+    wxCoord LogicalToDeviceXRel(wxCoord x) const { return m_targetDc->LogicalToDeviceXRel(x); }
+    wxCoord LogicalToDeviceY(wxCoord y) const { return m_targetDc->LogicalToDeviceY(y); }
+    wxCoord LogicalToDeviceYRel(wxCoord y) const { return m_targetDc->LogicalToDeviceYRel(y); }
+    wxCoord MaxX() const { return m_targetDc->MaxX(); }
+    wxCoord MaxY() const { return m_targetDc->MaxY(); }
+    wxCoord MinX() const { return m_targetDc->MinX(); }
+    wxCoord MinY() const { return m_targetDc->MinY(); }
+    virtual bool Ok() const { return m_targetDc->Ok(); }
+    void ResetBoundingBox()
+        { m_targetDc->ResetBoundingBox(); }
+#if defined(__WXWINCE__)
+    void Rotate( wxList* points, double angle, wxPoint center = wxPoint(0,0) )
+        { m_targetDc->Rotate(points, angle, center, 0)); }
+#endif // defined(__WXWINCE__)
+    virtual void SetAxisOrientation(bool xLeftRight, bool yBottomUp)
+        { m_targetDc->SetAxisOrientation(xLeftRight, yBottomUp); }
+    virtual void SetBackground(const wxBrush& brush) { m_targetDc->SetBackground(brush); }
+    virtual void SetBackgroundMode(int mode) { m_targetDc->SetBackgroundMode(mode); }
+    virtual void SetBrush(const wxBrush& brush) { m_targetDc->SetBrush(brush); }
+    void SetClippingRegion(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
+        { m_targetDc->SetClippingRegion(x, y, width, height); }
+    void SetClippingRegion(const wxPoint& pt, const wxSize& sz)
+        { m_targetDc->SetClippingRegion(pt, sz); }
+    void SetClippingRegion(const wxRect& rect) { m_targetDc->SetClippingRegion(rect); }
+    void SetClippingRegion(const wxRegion& region) { m_targetDc->SetClippingRegion(region); }
+    virtual void SetDeviceOrigin(wxCoord x, wxCoord y) { m_targetDc->SetDeviceOrigin(x, y); }
+    virtual void SetFont(const wxFont& font) { m_targetDc->SetFont(font); }
+    virtual void SetLogicalFunction(int function) { m_targetDc->SetLogicalFunction(function); }
+    virtual void SetLogicalOrigin(wxCoord x, wxCoord y) { m_targetDc->SetLogicalOrigin(x, y); }
+    virtual void SetLogicalScale(double x, double y) { m_targetDc->SetLogicalScale(x, y); }
+    virtual void SetMapMode(int mode) { m_targetDc->SetMapMode(mode); }
+#if WXWIN_COMPATIBILITY_2_4
+    virtual void SetOptimization(bool opt) { m_targetDc->SetOptimization(opt); }
+#endif // WXWIN_COMPATIBILITY_2_4
+#if wxUSE_PALETTE
+    virtual void SetPalette(const wxPalette& palette) { m_targetDc->SetPalette(palette); }
+#endif // wxUSE_PALETTE
+    virtual void SetPen(const wxPen& pen) { m_targetDc->SetPen(pen); }
+    virtual void SetTextBackground(const wxColour& colour) { m_targetDc->SetTextBackground(colour); }
+    virtual void SetTextForeground(const wxColour& colour) { m_targetDc->SetTextForeground(colour); }
+    virtual void SetUserScale(double x, double y) { m_targetDc->SetUserScale(x, y); }
+    virtual bool StartDoc(const wxString& message) { return m_targetDc->StartDoc(message); }
+    virtual void StartPage() { m_targetDc->StartPage(); }
+protected:
+    virtual bool DoBlit(wxCoord xdest, wxCoord ydest,
+                        wxCoord width, wxCoord height,
+                        wxDC *source, wxCoord xsrc, wxCoord ysrc,
+                        int rop = wxCOPY, bool useMask = false, wxCoord xsrcMask = wxDefaultCoord, wxCoord ysrcMask = wxDefaultCoord)
+        { return m_targetDc->Blit(xdest, ydest, width, height,
+                                  source, xsrc, ysrc, rop,
+                                  useMask, xsrcMask, ysrcMask); }
+    virtual void DoCrossHair(wxCoord x, wxCoord y) { m_targetDc->CrossHair(x, y); }
+    virtual void DoDrawArc(wxCoord x1, wxCoord y1,
+                           wxCoord x2, wxCoord y2,
+                           wxCoord xc, wxCoord yc)
+        { m_targetDc->DrawArc(x1, y1, x2, y2,
+                              xc, yc); }
+    virtual void DoDrawBitmap(const wxBitmap &bmp, wxCoord x, wxCoord y,
+                              bool useMask = false)
+        { m_targetDc->DrawBitmap(bmp, x, y, useMask); }
+    virtual void DoDrawCheckMark(wxCoord x, wxCoord y,
+                                 wxCoord width, wxCoord height)
+        { m_targetDc->DrawCheckMark(x, y, width, height); }
+    virtual void DoDrawEllipse(wxCoord x, wxCoord y,
+                               wxCoord width, wxCoord height)
+        { m_targetDc->DrawEllipse(x, y, width, height); }
+    virtual void DoDrawEllipticArc(wxCoord x, wxCoord y, wxCoord w, wxCoord h,
+                                   double sa, double ea)
+        { m_targetDc->DrawEllipticArc(x, y, w, h,
+                                      sa, ea); }
+    virtual void DoDrawIcon(const wxIcon& icon, wxCoord x, wxCoord y)
+        { m_targetDc->DrawIcon(icon, x, y); }
+    virtual void DoDrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2)
+        { m_targetDc->DrawLine(x1, y1, x2, y2); }
+    virtual void DoDrawLines(int n, wxPoint points[],
+                             wxCoord xoffset, wxCoord yoffset)
+        { m_targetDc->DrawLines(n, points, xoffset, yoffset); }
+    virtual void DoDrawPoint(wxCoord x, wxCoord y) { m_targetDc->DrawPoint(x, y); }
+    virtual void DoDrawPolyPolygon(int n, int count[], wxPoint points[],
+                               wxCoord xoffset, wxCoord yoffset,
+                               int fillStyle)
+        { m_targetDc->DrawPolyPolygon(n, count, points, xoffset,
+                                      yoffset, fillStyle); }
+    virtual void DoDrawPolygon(int n, wxPoint points[],
+                               wxCoord xoffset, wxCoord yoffset,
+                               int fillStyle = wxODDEVEN_RULE)
+        { m_targetDc->DrawPolygon(n, points, xoffset, yoffset,
+                                  fillStyle); }
+    virtual void DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
+        { m_targetDc->DrawRectangle(x, y, width, height); }
+    virtual void DoDrawRotatedText(const wxString& text,
+                                   wxCoord x, wxCoord y, double angle)
+        { m_targetDc->DrawRotatedText(text, x, y, angle); }
+    virtual void DoDrawRoundedRectangle(wxCoord x, wxCoord y,
+                                        wxCoord width, wxCoord height,
+                                        double radius)
+        { m_targetDc->DrawRoundedRectangle(x, y, width, height,
+                                           radius); }
+#if wxUSE_SPLINES
+    virtual void DoDrawSpline(wxList *points) { m_targetDc->DrawSpline(points); }
+#endif // wxUSE_SPLINES
+    virtual void DoDrawText(const wxString& text, wxCoord x, wxCoord y)
+        { m_targetDc->DrawText(text, x, y); }
+    virtual bool DoFloodFill(wxCoord x, wxCoord y, const wxColour& col,
+                             int style = wxFLOOD_SURFACE)
+        { return m_targetDc->FloodFill(x, y, col, style); }
+    virtual void DoGetClippingBox(wxCoord *x, wxCoord *y,
+                                  wxCoord *w, wxCoord *h) const
+        { m_targetDc->GetClippingBox(x, y, w, h); }
+    virtual void DoGetDeviceOrigin(wxCoord *x, wxCoord *y) const
+        { m_targetDc->GetDeviceOrigin(x, y); }
+    virtual void DoGetLogicalOrigin(wxCoord *x, wxCoord *y) const
+        { m_targetDc->GetLogicalOrigin(x, y); }
+    virtual bool DoGetPartialTextExtents(const wxString& text, wxArrayInt& widths) const
+        { return m_targetDc->GetPartialTextExtents(text, widths); }
+    virtual bool DoGetPixel(wxCoord x, wxCoord y, wxColour *col) const
+        { return m_targetDc->GetPixel(x, y, col); }
+    virtual void DoGetSize(int *width, int *height) const { m_targetDc->GetSize(width, height); }
+    virtual void DoGetSizeMM(int* width, int* height) const { m_targetDc->GetSizeMM(width, height); }
+    virtual void DoGetTextExtent(const wxString& string,
+                                 wxCoord *x, wxCoord *y,
+                                 wxCoord *descent = NULL,
+                                 wxCoord *externalLeading = NULL,
+                                 wxFont *theFont = NULL) const
+        { m_targetDc->GetTextExtent(string, x, y, descent,
+                                    externalLeading, theFont); }
+    virtual void DoGradientFillLinear(const wxRect& rect,
+                                      const wxColour& initialColour,
+                                      const wxColour& destColour,
+                                      wxDirection nDirection = wxEAST)
+        { m_targetDc->GradientFillLinear(rect, initialColour, destColour, nDirection); }
+    virtual void DoSetClippingRegion(wxCoord x, wxCoord y,
+                                     wxCoord width, wxCoord height)
+        { m_targetDc->SetClippingRegion(x, y, width, height); }
+    virtual void DoSetClippingRegionAsRegion(const wxRegion& region)
+        { m_targetDc->SetClippingRegion(region); }
 };
 
 
@@ -163,7 +616,7 @@ public:
         if( buffer != wxNullBitmap )
             Init(&m_paintdc, buffer, style);
         else
-            Init(&m_paintdc, window->GetClientSize(), style);
+            Init(window, &m_paintdc, window->GetClientSize(), style);
     }
 
     // If no bitmap is supplied by the user, a temporary one will be created.
@@ -174,7 +627,7 @@ public:
         if (style & wxBUFFER_VIRTUAL_AREA)
             window->PrepareDC( m_paintdc );
 
-        Init(&m_paintdc, window->GetClientSize(), style);
+        Init(window, &m_paintdc, window->GetClientSize(), style);
     }
 
     // default copy ctor ok.
@@ -192,5 +645,54 @@ private:
     DECLARE_NO_COPY_CLASS(wxBufferedPaintDC)
 };
 
-#endif  // _WX_DCBUFFER_H_
 
+
+//
+// wxAutoBufferedPaintDC is a wxPaintDC in toolkits which have double-
+// buffering by default. Otherwise it is a wxBufferedPaintDC. Thus,
+// you can only expect it work with a simple constructor that
+// accepts single wxWindow* argument.
+//
+#if wxALWAYS_NATIVE_DOUBLE_BUFFER
+    #define wxAutoBufferedPaintDCBase           wxPaintDC
+#else
+    #define wxAutoBufferedPaintDCBase           wxBufferedPaintDC
+#endif
+
+
+#ifdef __WXDEBUG__
+
+class wxAutoBufferedPaintDC : public wxAutoBufferedPaintDCBase
+{
+public:
+
+    wxAutoBufferedPaintDC(wxWindow* win)
+        : wxAutoBufferedPaintDCBase(win)
+    {
+        TestWinStyle(win);
+    }
+
+    virtual ~wxAutoBufferedPaintDC() { }
+
+private:
+
+    void TestWinStyle(wxWindow* win)
+    {
+        // Help the user to get the double-buffering working properly.
+        wxASSERT_MSG( win->GetBackgroundStyle() == wxBG_STYLE_CUSTOM,
+                      wxT("In constructor, you need to call GetBackgroundStyle(wxBG_STYLE_CUSTOM), ")
+                      wxT("and also, if needed, paint the background manually in the paint event handler."));
+    }
+
+    DECLARE_NO_COPY_CLASS(wxAutoBufferedPaintDC)
+};
+
+#else // !__WXDEBUG__
+
+// In release builds, just use typedef
+typedef wxAutoBufferedPaintDCBase wxAutoBufferedPaintDC;
+
+#endif
+
+
+#endif  // _WX_DCBUFFER_H_
diff --git a/include/wx/dfb/window.h b/include/wx/dfb/window.h
index a7ad48ad09..5ae337f2bf 100644
--- a/include/wx/dfb/window.h
+++ b/include/wx/dfb/window.h
@@ -109,6 +109,8 @@ public:
 
     void OnInternalIdle();
 
+    virtual bool IsDoubleBuffered() const { return true; }
+
 protected:
     // implement the base class pure virtuals
     virtual void DoClientToScreen(int *x, int *y) const;
diff --git a/include/wx/gtk/dc.h b/include/wx/gtk/dc.h
index 9534317f42..19f11b607c 100644
--- a/include/wx/gtk/dc.h
+++ b/include/wx/gtk/dc.h
@@ -94,6 +94,8 @@ public:
 
     virtual void ComputeScaleAndOrigin();
 
+    virtual GdkWindow* GetGDKWindow() const { return NULL; }
+
 protected:
     // implementation
     // --------------
diff --git a/include/wx/gtk/dcclient.h b/include/wx/gtk/dcclient.h
index ac3208bda3..7ed817ac56 100644
--- a/include/wx/gtk/dcclient.h
+++ b/include/wx/gtk/dcclient.h
@@ -99,6 +99,8 @@ public:
     virtual void SetDeviceOrigin( wxCoord x, wxCoord y );
     virtual void SetAxisOrientation( bool xLeftRight, bool yBottomUp );
 
+    virtual GdkWindow* GetGDKWindow() const { return m_window; }
+
 // protected:
     // implementation
     // --------------
diff --git a/include/wx/gtk/window.h b/include/wx/gtk/window.h
index f1857ba42d..9761331c2c 100644
--- a/include/wx/gtk/window.h
+++ b/include/wx/gtk/window.h
@@ -124,6 +124,7 @@ public:
 
     // currently wxGTK2-only
     void SetDoubleBuffered(bool on);
+    virtual bool IsDoubleBuffered() const;
 
     // implementation
     // --------------
diff --git a/include/wx/gtk1/dc.h b/include/wx/gtk1/dc.h
index 418ef426b0..82f2ae49e7 100644
--- a/include/wx/gtk1/dc.h
+++ b/include/wx/gtk1/dc.h
@@ -66,6 +66,8 @@ public:
 
     virtual void ComputeScaleAndOrigin();
 
+    virtual GdkWindow* GetGDKWindow() const { return NULL; }
+
     wxCoord XDEV2LOG(wxCoord x) const
     {
         wxCoord new_x = x - m_deviceOriginX;
diff --git a/include/wx/gtk1/dcclient.h b/include/wx/gtk1/dcclient.h
index 94cdb1d83d..c1654ba42a 100644
--- a/include/wx/gtk1/dcclient.h
+++ b/include/wx/gtk1/dcclient.h
@@ -100,6 +100,8 @@ public:
     virtual wxSize GetPPI() const;
     virtual int GetDepth() const;
 
+    virtual GdkWindow* GetGDKWindow() const { return m_window; }
+
     // implementation
     // --------------
 
diff --git a/include/wx/gtk1/window.h b/include/wx/gtk1/window.h
index 4ed4c68ea0..21adf05d3c 100644
--- a/include/wx/gtk1/window.h
+++ b/include/wx/gtk1/window.h
@@ -108,6 +108,8 @@ public:
     virtual void SetDropTarget( wxDropTarget *dropTarget );
 #endif // wxUSE_DRAG_AND_DROP
 
+    virtual bool IsDoubleBuffered() const { return false; }
+
     // implementation
     // --------------
 
diff --git a/include/wx/mac/carbon/window.h b/include/wx/mac/carbon/window.h
index 68a0a4f36b..f7f5e8b337 100644
--- a/include/wx/mac/carbon/window.h
+++ b/include/wx/mac/carbon/window.h
@@ -142,6 +142,8 @@ public:
 
     bool AcceptsFocus() const;
 
+    virtual bool IsDoubleBuffered() const { return true; }
+
 public:
     static long         MacRemoveBordersFromStyle( long style ) ;
 
diff --git a/include/wx/msw/missing.h b/include/wx/msw/missing.h
index 2acd3983c2..ae8f4b055f 100644
--- a/include/wx/msw/missing.h
+++ b/include/wx/msw/missing.h
@@ -126,6 +126,10 @@
 #define WS_EX_LAYOUTRTL 0x00400000
 #endif
 
+#ifndef WS_EX_COMPOSITED
+#define WS_EX_COMPOSITED 0x02000000L
+#endif
+
 #ifndef WS_EX_LAYERED
 #define WS_EX_LAYERED 0x00080000
 #endif
diff --git a/include/wx/msw/window.h b/include/wx/msw/window.h
index d9a4f67610..281e88278d 100644
--- a/include/wx/msw/window.h
+++ b/include/wx/msw/window.h
@@ -420,6 +420,9 @@ public:
     // check if mouse is in the window
     bool IsMouseInWindow() const;
 
+    // check if a native double-buffering applies for this window
+    virtual bool IsDoubleBuffered() const;
+
     // synthesize a wxEVT_LEAVE_WINDOW event and set m_mouseInWindow to false
     void GenerateMouseLeave();
 
diff --git a/include/wx/vlbox.h b/include/wx/vlbox.h
index bc61c0d542..ac1d0286da 100644
--- a/include/wx/vlbox.h
+++ b/include/wx/vlbox.h
@@ -287,9 +287,6 @@ private:
     // the selection bg colour
     wxColour m_colBgSel;
 
-    // double buffer
-    wxBitmap* m_doubleBuffer;
-
     DECLARE_EVENT_TABLE()
     DECLARE_NO_COPY_CLASS(wxVListBox)
     DECLARE_ABSTRACT_CLASS(wxVListBox)
diff --git a/include/wx/window.h b/include/wx/window.h
index ae32b47368..38c73a5c10 100644
--- a/include/wx/window.h
+++ b/include/wx/window.h
@@ -725,6 +725,9 @@ public:
         // adjust DC for drawing on this window
     virtual void PrepareDC( wxDC & WXUNUSED(dc) ) { }
 
+        // return true if the window contents is double buffered by the system
+    virtual bool IsDoubleBuffered() const { return false; }
+
         // the update region of the window contains the areas which must be
         // repainted by the program
     const wxRegion& GetUpdateRegion() const { return m_updateRegion; }
diff --git a/src/common/combocmn.cpp b/src/common/combocmn.cpp
index 44bdce8103..7f613330e3 100644
--- a/src/common/combocmn.cpp
+++ b/src/common/combocmn.cpp
@@ -35,7 +35,6 @@
     #include "wx/timer.h"
 #endif
 
-#include "wx/dcbuffer.h"
 #include "wx/tooltip.h"
 
 #include "wx/combo.h"
@@ -610,9 +609,6 @@ END_EVENT_TABLE()
 
 IMPLEMENT_ABSTRACT_CLASS(wxComboCtrlBase, wxControl)
 
-// Have global double buffer - should be enough for multiple combos
-static wxBitmap* gs_doubleBuffer = (wxBitmap*) NULL;
-
 void wxComboCtrlBase::Init()
 {
     m_winPopup = (wxWindow *)NULL;
@@ -737,9 +733,6 @@ wxComboCtrlBase::~wxComboCtrlBase()
     if ( HasCapture() )
         ReleaseMouse();
 
-    delete gs_doubleBuffer;
-    gs_doubleBuffer = (wxBitmap*) NULL;
-
 #if INSTALL_TOPLEV_HANDLER
     delete ((wxComboFrameEventHandler*)m_toplevEvtHandler);
     m_toplevEvtHandler = (wxEvtHandler*) NULL;
@@ -1238,19 +1231,6 @@ void wxComboCtrlBase::RecalcAndRefresh()
     }
 }
 
-wxBitmap& wxComboCtrlBase::GetBufferBitmap( const wxSize& sz ) const
-{
-    // If size is larger, recalculate double buffer bitmap
-    if ( !gs_doubleBuffer ||
-         sz.x > gs_doubleBuffer->GetWidth() ||
-         sz.y > gs_doubleBuffer->GetHeight() )
-    {
-        delete gs_doubleBuffer;
-        gs_doubleBuffer = new wxBitmap(sz.x+25,sz.y);
-    }
-    return *gs_doubleBuffer;
-}
-
 // ----------------------------------------------------------------------------
 // miscellaneous event handlers
 // ----------------------------------------------------------------------------
diff --git a/src/common/dcbufcmn.cpp b/src/common/dcbufcmn.cpp
new file mode 100644
index 0000000000..fe80752412
--- /dev/null
+++ b/src/common/dcbufcmn.cpp
@@ -0,0 +1,136 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        src/common/dcbufcmn.cpp
+// Purpose:     Buffered DC implementation
+// Author:      Ron Lee, Jaakko Salli
+// Modified by:
+// Created:     Sep-20-2006
+// RCS-ID:      $Id$
+// Copyright:   (c) wxWidgets team
+// Licence:     wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+// ============================================================================
+// declarations
+// ============================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#ifdef __BORLANDC__
+    #pragma hdrstop
+#endif
+
+#ifndef WX_PRECOMP
+#endif
+
+#include "wx/dcbuffer.h"
+
+
+// ============================================================================
+// implementation
+// ============================================================================
+
+// ============================================================================
+// wxSharedDCBufferManager
+//   Helper class to free shared buffer when the app exists.
+// ============================================================================
+
+class wxSharedDCBufferManager
+{
+    friend class wxBufferedDC;
+public:
+
+    wxSharedDCBufferManager()
+    {
+        m_buffer = NULL;
+    }
+
+    ~wxSharedDCBufferManager()
+    {
+        delete m_buffer;
+    }
+
+    wxBitmap* GetBuffer(wxWindow* win, const wxSize& area)
+    {
+        int width = area.x;
+        int height = area.y;
+
+        if ( width <= 0 )
+            win->GetClientSize(&width, &height);
+
+        if ( !m_buffer ||
+             width > m_buffer->GetWidth() ||
+             height > m_buffer->GetHeight() )
+        {
+            delete m_buffer;
+
+            // Create slightly larger bitmap so we don't need to
+            // be reallocating constantly when the user enlarges
+            // the frame for the first time.
+            m_buffer = new wxBitmap(width+20, height+20);
+        }
+
+        return m_buffer;
+    }
+
+private:
+    wxBitmap*   m_buffer;
+};
+
+static wxSharedDCBufferManager gs_sharedDCBufferManager;
+
+// ============================================================================
+// wxBufferedDC
+// ============================================================================
+
+// Blits the buffer to the dc, and detaches the dc from the buffer (so it
+// can be effectively used once only).
+//
+// Usually called in the dtor or by the dtor of derived classes if the
+// BufferedDC must blit before the derived class (which may own the dc it's
+// blitting to) is destroyed.
+void wxBufferedDC::UnMask()
+{
+    if ( m_buffer )
+    {
+        wxASSERT_MSG( m_mainDc != NULL,
+                      _T("No underlying DC associated with wxBufferedDC (anymore)") );
+
+        wxDC* bufferDc = DetachDC();
+
+        wxASSERT( bufferDc->IsKindOf(CLASSINFO(wxMemoryDC)) );
+
+        wxCoord x=0, y=0;
+
+        if (m_style & wxBUFFER_CLIENT_AREA)
+            bufferDc->GetDeviceOrigin(& x, & y);
+
+        m_mainDc->Blit( 0, 0,
+                        m_buffer->GetWidth(), m_buffer->GetHeight(), bufferDc,
+                        -x, -y );
+        m_mainDc = NULL;
+        m_buffer = NULL;
+        delete bufferDc;
+    }
+}
+
+void wxBufferedDC::PrepareBuffer(wxWindow* win, const wxSize& area)
+{
+    m_buffer = gs_sharedDCBufferManager.GetBuffer(win, area);
+}
+
+void wxBufferedDC::UseBuffer()
+{
+    wxASSERT(m_buffer);
+
+    wxMemoryDC* memoryDc = new wxMemoryDC(m_mainDc);
+    memoryDc->SelectObject(*m_buffer);
+
+    AttachDC(memoryDc);
+}
+
+
diff --git a/src/generic/combog.cpp b/src/generic/combog.cpp
index 5864782b95..b8a193a68c 100644
--- a/src/generic/combog.cpp
+++ b/src/generic/combog.cpp
@@ -201,7 +201,7 @@ void wxGenericComboCtrl::OnResize()
 void wxGenericComboCtrl::OnPaintEvent( wxPaintEvent& WXUNUSED(event) )
 {
     wxSize sz = GetClientSize();
-    wxBufferedPaintDC dc(this,GetBufferBitmap(sz));
+    wxAutoBufferedPaintDC dc(this);
 
     const wxRect& rectb = m_btnArea;
     wxRect rect = m_tcArea;
diff --git a/src/generic/datavgen.cpp b/src/generic/datavgen.cpp
index e3886ffcf4..73aa09f1ae 100644
--- a/src/generic/datavgen.cpp
+++ b/src/generic/datavgen.cpp
@@ -35,6 +35,7 @@
 #include "wx/calctrl.h"
 #include "wx/popupwin.h"
 #include "wx/renderer.h"
+#include "wx/dcbuffer.h"
 #include "wx/icon.h"
 
 //-----------------------------------------------------------------------------
@@ -682,6 +683,7 @@ wxDataViewHeaderWindow::wxDataViewHeaderWindow( wxDataViewCtrl *parent, wxWindow
     m_resizeCursor = new wxCursor( wxCURSOR_SIZEWE );
 
     wxVisualAttributes attr = wxPanel::GetClassDefaultAttributes();
+    SetBackgroundStyle( wxBG_STYLE_CUSTOM );
     SetOwnForegroundColour( attr.colFg );
     SetOwnBackgroundColour( attr.colBg );
     if (!m_hasFont)
@@ -698,7 +700,10 @@ void wxDataViewHeaderWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
     int w, h;
     GetClientSize( &w, &h );
 
-    wxPaintDC dc( this );
+    wxAutoBufferedPaintDC dc( this );
+
+    dc.SetBackground(GetBackgroundColour());
+    dc.Clear();
 
     int xpix;
     m_owner->GetScrollPixelsPerUnit( &xpix, NULL );
@@ -953,6 +958,7 @@ wxDataViewMainWindow::wxDataViewMainWindow( wxDataViewCtrl *parent, wxWindowID i
 
     m_hasFocus = false;
 
+    SetBackgroundStyle( wxBG_STYLE_CUSTOM );
     SetBackgroundColour( *wxWHITE );
 
     UpdateDisplay();
@@ -1094,7 +1100,10 @@ void wxDataViewMainWindow::ScrollWindow( int dx, int dy, const wxRect *rect )
 
 void wxDataViewMainWindow::OnPaint( wxPaintEvent &WXUNUSED(event) )
 {
-    wxPaintDC dc( this );
+    wxAutoBufferedPaintDC dc( this );
+
+    dc.SetBackground(GetBackgroundColour());
+    dc.Clear();
 
     GetOwner()->PrepareDC( dc );
 
diff --git a/src/generic/vlbox.cpp b/src/generic/vlbox.cpp
index 7cdf248b6a..2a3ca54d1c 100644
--- a/src/generic/vlbox.cpp
+++ b/src/generic/vlbox.cpp
@@ -64,7 +64,6 @@ void wxVListBox::Init()
     m_current =
     m_anchor = wxNOT_FOUND;
     m_selStore = NULL;
-    m_doubleBuffer = NULL;
 }
 
 bool wxVListBox::Create(wxWindow *parent,
@@ -94,7 +93,6 @@ bool wxVListBox::Create(wxWindow *parent,
 
 wxVListBox::~wxVListBox()
 {
-    delete m_doubleBuffer;
     delete m_selStore;
 }
 
@@ -360,18 +358,9 @@ void wxVListBox::OnDrawBackground(wxDC& dc, const wxRect& rect, size_t n) const
 
 void wxVListBox::OnPaint(wxPaintEvent& WXUNUSED(event))
 {
-    // If size is larger, recalculate double buffer bitmap
     wxSize clientSize = GetClientSize();
 
-    if ( !m_doubleBuffer ||
-         clientSize.x > m_doubleBuffer->GetWidth() ||
-         clientSize.y > m_doubleBuffer->GetHeight() )
-    {
-        delete m_doubleBuffer;
-        m_doubleBuffer = new wxBitmap(clientSize.x+25,clientSize.y+25);
-    }
-
-    wxBufferedPaintDC dc(this,*m_doubleBuffer);
+    wxAutoBufferedPaintDC dc(this);
 
     // the update rectangle
     wxRect rectUpdate = GetUpdateClientRect();
diff --git a/src/gtk/renderer.cpp b/src/gtk/renderer.cpp
index 71205427d4..2802f9274a 100644
--- a/src/gtk/renderer.cpp
+++ b/src/gtk/renderer.cpp
@@ -192,6 +192,10 @@ wxRendererGTK::DrawHeaderButton(wxWindow *win,
 
     GtkWidget *button = GetButtonWidget();
 
+    GdkWindow* gdk_window = dc.GetGDKWindow();
+    wxASSERT_MSG( gdk_window,
+                  wxT("cannot use wxRendererNative on wxDC of this type") );
+
     int x_diff = 0;
     if (win->GetLayoutDirection() == wxLayout_RightToLeft)
         x_diff = rect.width;
@@ -199,9 +203,7 @@ wxRendererGTK::DrawHeaderButton(wxWindow *win,
     gtk_paint_box
     (
         button->style,
-        // FIXME: I suppose GTK_PIZZA(win->m_wxwindow)->bin_window doesn't work with wxMemoryDC.
-        //   Maybe use code similar as in DrawPushButton below?
-        GTK_PIZZA(win->m_wxwindow)->bin_window,
+        gdk_window,
         flags & wxCONTROL_DISABLED ? GTK_STATE_INSENSITIVE : GTK_STATE_NORMAL,
         GTK_SHADOW_OUT,
         NULL,
@@ -220,6 +222,10 @@ wxRendererGTK::DrawTreeItemButton(wxWindow* win,
 {
     GtkWidget *tree = GetTreeWidget();
 
+    GdkWindow* gdk_window = dc.GetGDKWindow();
+    wxASSERT_MSG( gdk_window,
+                  wxT("cannot use wxRendererNative on wxDC of this type") );
+
     GtkStateType state;
     if ( flags & wxCONTROL_CURRENT )
         state = GTK_STATE_PRELIGHT;
@@ -229,13 +235,13 @@ wxRendererGTK::DrawTreeItemButton(wxWindow* win,
     int x_diff = 0;
     if (win->GetLayoutDirection() == wxLayout_RightToLeft)
         x_diff = rect.width;
-        
+
     // VZ: I don't know how to get the size of the expander so as to centre it
     //     in the given rectangle, +2/3 below is just what looks good here...
     gtk_paint_expander
     (
         tree->style,
-        GTK_PIZZA(win->m_wxwindow)->bin_window,
+        gdk_window,
         state,
         NULL,
         tree,
@@ -299,6 +305,10 @@ wxRendererGTK::DrawSplitterSash(wxWindow *win,
         return;
     }
 
+    GdkWindow* gdk_window = dc.GetGDKWindow();
+    wxASSERT_MSG( gdk_window,
+                  wxT("cannot use wxRendererNative on wxDC of this type") );
+
     wxCoord full_size = GetGtkSplitterFullSize();
 
     // are we drawing vertical or horizontal splitter?
@@ -332,7 +342,7 @@ wxRendererGTK::DrawSplitterSash(wxWindow *win,
     gtk_paint_handle
     (
         win->m_wxwindow->style,
-        GTK_PIZZA(win->m_wxwindow)->bin_window,
+        gdk_window,
         flags & wxCONTROL_CURRENT ? GTK_STATE_PRELIGHT : GTK_STATE_NORMAL,
         GTK_SHADOW_NONE,
         NULL /* no clipping */,
@@ -347,7 +357,7 @@ wxRendererGTK::DrawSplitterSash(wxWindow *win,
 }
 
 void
-wxRendererGTK::DrawDropArrow(wxWindow *win,
+wxRendererGTK::DrawDropArrow(wxWindow *WXUNUSED(win),
                              wxDC& dc,
                              const wxRect& rect,
                              int flags)
@@ -359,11 +369,9 @@ wxRendererGTK::DrawDropArrow(wxWindow *win,
     // work for wxMemoryDC. So that is why we assume wxDC
     // is wxWindowDC (wxClientDC, wxMemoryDC and wxPaintDC
     // are derived from it) and use its m_window.
-    wxWindowDC& wdc = (wxWindowDC&)dc;
-
-    // only doing debug-time checking here (it should
-    // probably be enough)
-    wxASSERT ( wdc.IsKindOf(CLASSINFO(wxWindowDC)) );
+    GdkWindow* gdk_window = dc.GetGDKWindow();
+    wxASSERT_MSG( gdk_window,
+                  wxT("cannot use wxRendererNative on wxDC of this type") );
 
     // draw arrow so that there is even space horizontally
     // on both sides
@@ -390,7 +398,7 @@ wxRendererGTK::DrawDropArrow(wxWindow *win,
     gtk_paint_arrow
     (
         button->style,
-        wdc.m_window,
+        gdk_window,
         state,
         flags & wxCONTROL_PRESSED ? GTK_SHADOW_IN : GTK_SHADOW_OUT,
         NULL,
@@ -416,7 +424,7 @@ wxRendererGTK::DrawComboBoxDropButton(wxWindow *win,
 }
 
 void
-wxRendererGTK::DrawCheckBox(wxWindow *win,
+wxRendererGTK::DrawCheckBox(wxWindow *WXUNUSED(win),
                             wxDC& dc,
                             const wxRect& rect,
                             int flags )
@@ -424,8 +432,9 @@ wxRendererGTK::DrawCheckBox(wxWindow *win,
     GtkWidget *button = GetCheckButtonWidget();
 
     // for reason why we do this, see DrawDropArrow
-    wxWindowDC& wdc = (wxWindowDC&)dc;
-    wxASSERT ( wdc.IsKindOf(CLASSINFO(wxWindowDC)) );
+    GdkWindow* gdk_window = dc.GetGDKWindow();
+    wxASSERT_MSG( gdk_window,
+                  wxT("cannot use wxRendererNative on wxDC of this type") );
 
     GtkStateType state;
 
@@ -441,7 +450,7 @@ wxRendererGTK::DrawCheckBox(wxWindow *win,
     gtk_paint_check
     (
         button->style,
-        wdc.m_window,
+        gdk_window,
         state,
         flags & wxCONTROL_CHECKED ? GTK_SHADOW_IN : GTK_SHADOW_OUT,
         NULL,
@@ -454,7 +463,7 @@ wxRendererGTK::DrawCheckBox(wxWindow *win,
 }
 
 void
-wxRendererGTK::DrawPushButton(wxWindow *win,
+wxRendererGTK::DrawPushButton(wxWindow *WXUNUSED(win),
                               wxDC& dc,
                               const wxRect& rect,
                               int flags)
@@ -462,8 +471,9 @@ wxRendererGTK::DrawPushButton(wxWindow *win,
     GtkWidget *button = GetButtonWidget();
 
     // for reason why we do this, see DrawDropArrow
-    wxWindowDC& wdc = (wxWindowDC&)dc;
-    wxASSERT ( wdc.IsKindOf(CLASSINFO(wxWindowDC)) );
+    GdkWindow* gdk_window = dc.GetGDKWindow();
+    wxASSERT_MSG( gdk_window,
+                  wxT("cannot use wxRendererNative on wxDC of this type") );
 
     // draw button
     GtkStateType state;
@@ -480,7 +490,7 @@ wxRendererGTK::DrawPushButton(wxWindow *win,
     gtk_paint_box
     (
         button->style,
-        wdc.m_window,
+        gdk_window,
         state,
         flags & wxCONTROL_PRESSED ? GTK_SHADOW_IN : GTK_SHADOW_OUT,
         NULL,
@@ -496,6 +506,10 @@ wxRendererGTK::DrawItemSelectionRect(wxWindow *win,
                                      const wxRect& rect,
                                      int flags )
 {
+    GdkWindow* gdk_window = dc.GetGDKWindow();
+    wxASSERT_MSG( gdk_window,
+                  wxT("cannot use wxRendererNative on wxDC of this type") );
+
     GtkStateType state;
     if (flags & wxCONTROL_SELECTED)
     {
@@ -505,7 +519,7 @@ wxRendererGTK::DrawItemSelectionRect(wxWindow *win,
             state = GTK_STATE_INSENSITIVE;
 
         gtk_paint_flat_box( win->m_wxwindow->style,
-                        GTK_PIZZA(win->m_wxwindow)->bin_window,
+                        gdk_window,
                         state,
                         GTK_SHADOW_NONE,
                         NULL,
diff --git a/src/gtk/window.cpp b/src/gtk/window.cpp
index 2db80f3896..3862a4826e 100644
--- a/src/gtk/window.cpp
+++ b/src/gtk/window.cpp
@@ -3935,6 +3935,11 @@ void wxWindowGTK::SetDoubleBuffered( bool on )
         gtk_widget_set_double_buffered( m_wxwindow, on );
 }
 
+bool wxWindowGTK::IsDoubleBuffered() const
+{
+    return GTK_WIDGET_DOUBLE_BUFFERED( m_wxwindow );
+}
+
 void wxWindowGTK::ClearBackground()
 {
     wxCHECK_RET( m_widget != NULL, wxT("invalid window") );
diff --git a/src/gtk1/renderer.cpp b/src/gtk1/renderer.cpp
index ebbb1e17b7..04d03ae16d 100644
--- a/src/gtk1/renderer.cpp
+++ b/src/gtk1/renderer.cpp
@@ -309,11 +309,9 @@ wxRendererGTK::DrawDropArrow(wxWindow *win,
     // work for wxMemoryDC. So that is why we assume wxDC
     // is wxWindowDC (wxClientDC, wxMemoryDC and wxPaintDC
     // are derived from it) and use its m_window.
-    wxWindowDC& wdc = (wxWindowDC&)dc;
-
-    // only doing debug-time checking here (it should
-    // probably be enough)
-    wxASSERT ( wdc.IsKindOf(CLASSINFO(wxWindowDC)) );
+    GdkWindow* gdk_window = dc.GetGDKWindow();
+    wxASSERT_MSG( gdk_window,
+                  wxT("cannot use wxRendererNative on wxDC of this type") );
 
     // draw arrow so that there is even space horizontally
     // on both sides
@@ -340,7 +338,7 @@ wxRendererGTK::DrawDropArrow(wxWindow *win,
     gtk_paint_arrow
     (
         button->style,
-        wdc.m_window,
+        gdk_window,
         state,
         flags & wxCONTROL_PRESSED ? GTK_SHADOW_IN : GTK_SHADOW_OUT,
         NULL,
@@ -364,8 +362,9 @@ wxRendererGTK::DrawComboBoxDropButton(wxWindow *win,
     GtkWidget *button = GetButtonWidget();
 
     // for reason why we do this, see DrawDropArrow
-    wxWindowDC& wdc = (wxWindowDC&)dc;
-    wxASSERT ( wdc.IsKindOf(CLASSINFO(wxWindowDC)) );
+    GdkWindow* gdk_window = dc.GetGDKWindow();
+    wxASSERT_MSG( gdk_window,
+                  wxT("cannot use wxRendererNative on wxDC of this type") );
 
     // draw button
     GtkStateType state;
@@ -382,7 +381,7 @@ wxRendererGTK::DrawComboBoxDropButton(wxWindow *win,
     gtk_paint_box
     (
         button->style,
-        wdc.m_window,
+        gdk_window,
         state,
         flags & wxCONTROL_PRESSED ? GTK_SHADOW_IN : GTK_SHADOW_OUT,
         NULL,
diff --git a/src/msw/combo.cpp b/src/msw/combo.cpp
index 85866cb9eb..762b82eadc 100644
--- a/src/msw/combo.cpp
+++ b/src/msw/combo.cpp
@@ -388,7 +388,7 @@ void wxComboCtrl::OnPaintEvent( wxPaintEvent& WXUNUSED(event) )
     // TODO: Convert drawing in this function to Windows API Code
 
     wxSize sz = GetClientSize();
-    wxBufferedPaintDC dc(this,GetBufferBitmap(sz));
+    wxAutoBufferedPaintDC dc(this);
 
     const wxRect& rectb = m_btnArea;
     wxRect rect = m_tcArea;
diff --git a/src/msw/window.cpp b/src/msw/window.cpp
index 6908a7b317..e077df91af 100644
--- a/src/msw/window.cpp
+++ b/src/msw/window.cpp
@@ -3950,6 +3950,20 @@ bool wxWindowMSW::HandlePower(WXWPARAM WXUNUSED_IN_WINCE(wParam),
 #endif
 }
 
+bool wxWindowMSW::IsDoubleBuffered() const
+{
+    const wxWindow* wnd = this;
+
+    while ( wnd )
+    {
+        if ( ::GetWindowLong((HWND)wnd->GetHWND(), GWL_EXSTYLE) & WS_EX_COMPOSITED )
+            return true;
+        wnd = wnd->GetParent();
+    }
+
+    return false;
+}
+
 // ---------------------------------------------------------------------------
 // owner drawn stuff
 // ---------------------------------------------------------------------------
-- 
2.50.0

