Safety checks.
Safety checks.

  Make sure we have associated widget and the widget is actually on stage.

jonnylamb/mx,jonnylamb/mx,jonnylamb/mx,pwithnall/mx,jonnylamb/mx,clutter-project/mx,pwithnall/mx,pwithnall/mx,pwithnall/mx,clutter-project/mx,clutter-project/mx,clutter-project/mx