code: func (app *Application) Refresh() {
  	ev := &eventAppRefresh{}
  	ev.SetEventNow()
  	if scr := app.screen; scr != nil {
  		go func() { scr.PostEventWait(ev) }()
  	}
  }
docs: // Refresh causes the application forcibly redraw everything.  Use this
  // to clear up screen corruption, etc.