Generated when the window visibility status has changed.
%TRUE if the event was sent explicitly.
the new visibility state (%GDK_VISIBILITY_FULLY_OBSCURED, %GDK_VISIBILITY_PARTIAL or %GDK_VISIBILITY_UNOBSCURED).
the type of the event (%GDK_VISIBILITY_NOTIFY).
the window which received the event.
Generated when the window visibility status has changed.