void queue_draw_region ( GtkWidget* widget, const cairo_region_t* region )
Invalidates the area of
widget defined by
region by calling
gdk_window_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
GtkDrawingArea or some portion thereof.
Available since: 3.0
Region to draw.
The data is owned by the caller of the function.