/**
  * Overridden method to capture browser event
  *
  * @param event Event object
  */
 public void onBrowserEvent(Event event) {
   switch (DOM.eventGetType(event)) {
     case Event.ONCLICK:
       if (clickListeners != null) {
         clickListeners.fireClick(this);
       }
       break;
   }
 }
 /**
  * Removes a previously added listener.
  *
  * @param listener the listener interface to remove
  */
 public void removeClickListener(ClickListener listener) {
   if (clickListeners != null) {
     clickListeners.remove(listener);
   }
 }
 /**
  * Adds a listener to receive click events.
  *
  * @param listener the listener interface to add
  */
 public void addClickListener(ClickListener listener) {
   if (clickListeners == null) {
     clickListeners = new ClickListenerCollection();
   }
   clickListeners.add(listener);
 }