gdkWindowBeginPaintRegion and gdkWindowEndPaint are called
automatically around expose events sent to the
widget. gdkWindowBeginPaint() diverts all drawing to a widget's
window to an offscreen buffer, and gdkWindowEndPaint draws the
buffer to the screen. The result is that users see the window
update in one smooth step, and don't see individual graphics
primitives being rendered.gtkWidgetSetDoubleBuffered(object, double.buffered)objectdouble.bufferedTRUE to double-buffer a widgetgdkWindowBeginPaint()).