+ /**
+ Use this in conjunction with EndDrawingOnTop() to ensure that drawing
+ to the screen occurs on top of existing windows. Without this, some
+ window systems (such as X) only allow drawing to take place underneath
+ other windows.
+
+ This version of StartDrawingOnTop() is used to specify an area of the
+ screen which is to be drawn on. If @NULL is passed, the whole screen is
+ available. It is recommended that an area of the screen is specified
+ with this function rather than with StartDrawingOnTop(wxWindow*),
+ because with large regions, flickering effects are noticeable when
+ destroying the temporary transparent window used to implement this
+ feature.
+
+ You might use this function when implementing a drag feature, for
+ example as in the wxSplitterWindow implementation.
+
+ @remarks This function is probably obsolete since the X implementations
+ allow drawing directly on the screen now. However, the fact
+ that this function allows the screen to be refreshed
+ afterwards, may be useful to some applications.
+ */
+ bool StartDrawingOnTop(wxRect* rect = NULL);