code: func (ww *WidgetWatchers) PostEventWidgetMove(w Widget) {
  	ev := &EventWidgetMove{}
  	ev.SetWidget(w)
  	ev.SetEventNow()
  	ww.PostEvent(ev)
  }
docs: // PostEventWidgetMove is called by the Widget when it is moved to a new
  // location, delivering EventWidgetMove to all watchers.