void gdk_window_invalidate_region ( GdkWindow* window, const cairo_region_t* region, gboolean invalidate_children )
region to the update area for
window. The update area is the
region that needs to be redrawn, or “dirty region.” The call
gdk_window_process_updates() sends one or more expose events to the
window, which together cover the entire update area. An
application would normally redraw the contents of
response to those expose events.
GDK will call
gdk_window_process_all_updates() on your behalf
whenever your program returns to the main loop and becomes idle, so
normally there’s no need to do that manually, you just need to
invalidate regions that you know should be redrawn.
invalidate_children parameter controls whether the region of
each child window that intersects
region will also be invalidated.
FALSE, then the update area for child windows will remain
unaffected. See gdk_window_invalidate_maybe_recurse if you need
fine grained control over which children are invalidated.
The data is owned by the caller of the method.
TRUEto also invalidate child windows.