GtkWidget::unmap
    
     This method destroys information regards the dimensions of the screen
     area where the widget is displayed .  It is mostly used internally, 
     being one of the methods that is called as part of the 
     hide()  routine.  It causes
     the "unmap" signal to be
     emitted by the widget, which in turn switches a flag causing the
     widget to be unmapped.
    
    
     At the point of a widget's becoming unmapped, the 
     GdkEvent GDK_UNMAP is
     triggered, causing the 
     "unmap-event" signal to
     also be emitted by that widget.  Use this signal to trigger functions
     that rely on the unmap event having occurred.
    
    
     See also: map()