public virtual void queue_draw_region (Region region)
Invalidates the area of this defined by
region by calling
invalidate_region on the widget’s window and all its child windows.
Once the main loop becomes idle (after the current batch of events has been processed, roughly), the window will receive expose events for the union of all regions that have been invalidated.
Normally you would only use this function in widget implementations. You might also use it to schedule a redraw of a DrawingArea or some portion thereof.
region to draw