This function is only useful on the X11/freedesktop.org platform. It returns a window ID for the widget in the underlying status icon implementation. This is useful for the Galago notification service, which can send a window ID in the protocol in order for the server to position notification windows pointing to a status icon reliably. This function is not intended for other use cases which are more likely to be met by one of the non-X11 specific methods, such as gtk_status_icon_position_menu(). underlying X11 Window