Window.setTitle(appParams.getPath() + " - " + "Shiny");
      ShinyApplicationPresenter appPresenter = pPresenter_.get();
      appPresenter.loadApp(appParams);
      
      // make it fill the containing layout panel
      Widget presWidget = appPresenter.asWidget();
      mainPanel.add(presWidget);
      mainPanel.setWidgetLeftRight(presWidget, 0, Unit.PX, 0, Unit.PX);
      mainPanel.setWidgetTopBottom(presWidget, 0, Unit.PX, 0, Unit.PX);
   }