By default, after showing the first GtkWindow for each GdkScreen, GTK+ calls notify_startup_complete. Pass false to this function to disable the automatic startup notification. You might do this if your first window is a splash screen, and you want to delay notification until after your real main window has been shown, for example.
In that example, you would disable startup notification temporarily, show your splash screen, then re-enable it so that showing the main window would automatically result in notification.
See also: notify_startup_complete
This method must be called statically.