Ensure Cairo is installed before setting wxUSE_GRAPHICS_CONTEXT for

[wxWidgets.git] / include / wx / dcbuffer.h

diff --git a/include/wx/dcbuffer.h b/include/wx/dcbuffer.h
index cac6228a8e30413b7213803c1873e9b0a6b17c70..6916ff7eefdf2b3775b09285cf82248163ca632c 100644 (file)
--- a/include/wx/dcbuffer.h
+++ b/include/wx/dcbuffer.h
@@ -16,6 +16,15 @@
 #include "wx/dcclient.h"
 #include "wx/window.h"
 
+// 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
+
+
 // ----------------------------------------------------------------------------
 // Double buffering helper.
 // ----------------------------------------------------------------------------
@@ -100,7 +109,7 @@ public:
         wxCoord x=0, y=0;
 
         if (m_style & wxBUFFER_CLIENT_AREA)
-            GetDeviceOrigin(& x, & y);
+            GetDeviceOrigin(&x, &y);
 
         m_dc->Blit( 0, 0,
                     m_buffer.GetWidth(), m_buffer.GetHeight(), this,
@@ -192,5 +201,66 @@ 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
+
+
+// Check if the window is natively double buffered and will return a wxPaintDC
+// if it is, a wxBufferedPaintDC otherwise.  It is the caller's responsibility
+// to delete the wxDC pointer when finished with it.
+inline wxDC* wxAutoBufferedPaintDCFactory(wxWindow* window)
+{
+    if ( window->IsDoubleBuffered() )
+        return new wxPaintDC(window);
+    else
+        return new wxBufferedPaintDC(window);
+}
+            
+
+#endif  // _WX_DCBUFFER_H_