rem: screen.scale_popup = create_ZoomFactorWindow(); gtk_widget_show (screen.scale_popup); gtk_grab_add(screen.scale_popup); }
add: screen.win.scale = create_ZoomFactorWindow(); gtk_widget_show(screen.win.scale); gtk_grab_add(screen.win.scale); }
context: menu_ask_zoom (GtkWidget * widget, gpointer data){    screen.scale_popup = create_ZoomFactorWindow();    gtk_widget_show (screen.scale_popup);    gtk_grab_add(screen.scale_popup);}