code: private void registerMap(final MapWidget mapWidget) {
  		if (mapWidget != null) {
  			onLoadRegistration = mapWidget.getMapModel().addMapModelHandler(new MapModelHandler() {
  
  				public void onMapModelChange(MapModelEvent event) {
  					onLoadRegistration.removeHandler();
  					view.onLoadStart();
  					if (GwtCommandDispatcher.getInstance().isBusy()) {
  						onDispatchStopRegistration = GwtCommandDispatcher.getInstance().addDispatchStoppedHandler(
  								new DispatchStoppedHandler() {
  
  									public void onDispatchStopped(DispatchStoppedEvent event) {
  										fadeOut(mapWidget);
  									}
  								});
  					} else {
  						fadeOut(mapWidget);
  					}
  				}
  			});
  		}
  	}
docs: -------------------------------------------------------------------------