GWT in Action, Second Edition

14.4. Preventing default actions

The browser is quite happy to handle some events by itself—press the Enter key when you’re in a form, and the browser will generally submit it; drag an image to the location bar, and the browser will reload it; press Ctrl+N in most browsers, and a new browser window will open.

Sometimes these default actions are useful, and sometimes not. In the example application from chapter 3 we prevent the logo image from being dragged to the location bar by overriding the onBrowserEvent method when we create it:

logo = new Image(GWT.getModuleBaseURL() + "../" + LOGO_IMAGE_NAME){
   public void onBrowserEvent(Event evt){
      evt.preventDefault();
      super.onBrowserEvent(evt);
   }
};

By calling the preventDefault method on the event, ...