private SplitMenuButton button;
Runnable showingCallback;
@Inject
public WMenuImpl(@Named(BaseRenderer.CONTEXT_DOM_ELEMENT) MMenu domElement) {
MToolItem item = (MToolItem) ((EObject)domElement).eContainer();
@SuppressWarnings("unchecked")
WToolItem<SplitMenuButton> w = (WToolItem<SplitMenuButton>) item.getWidget();
this.button = (SplitMenuButton) w.getWidget();
this.button.showingProperty().addListener(new ChangeListener<Boolean>() {
@Override
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {