* @param delegate the {@link Delegate} in charge of Window-related events
*/
public PlaceController(EventBus eventBus, Delegate delegate) {
this.eventBus = eventBus;
this.delegate = delegate;
delegate.addWindowClosingHandler(new ClosingHandler() {
public void onWindowClosing(ClosingEvent event) {
String warning = maybeGoTo(Place.NOWHERE);
if (warning != null) {
event.setMessage(warning);
}