How to use

HasSelectionHandlers

in

com.google.gwt.event.logical.shared

protected void addSelectionHandler(HasSelectionHandlers<PartDefinition> widget) {
  widget.addSelectionHandler(new SelectionHandler<PartDefinition>() {
    @Override
    public void onSelection(final SelectionEvent<PartDefinition> event) {
      panelManager.onPartLostFocus();
      panelManager.onPartFocus(event.getSelectedItem());
    }
  });
}

/**
 * Fires a selection event on all registered handlers in the handler
 * manager.If no such handlers exist, this method will do nothing.
 * 
 * @param <T> the selected item type
 * @param source the source of the handlers
 * @param selectedItem the selected item
 */
public static <T> void fire(HasSelectionHandlers<T> source, T selectedItem) {
 if (TYPE != null) {
  SelectionEvent<T> event = new SelectionEvent<T>(selectedItem);
  source.fireEvent(event);
 }
}

  /***************************************
   * {@inheritDoc}
   */
  @Override
  @SuppressWarnings("unchecked")
  protected HandlerRegistration initEventDispatching(
    Widget    rWidget,
    EventType eEventType)
  {
    if (eEventType == EventType.SELECTION &&
      rWidget instanceof HasSelectionHandlers)
    {
      return ((HasSelectionHandlers<Integer>) rWidget)
          .addSelectionHandler(this);
    }
    return super.initEventDispatching(rWidget, eEventType);
  }
}

/**
 * Fires a selection event on all registered handlers in the handler
 * manager.If no such handlers exist, this method will do nothing.
 * 
 * @param <T> the selected item type
 * @param source the source of the handlers
 * @param selectedItem the selected item
 */
public static <T> void fire(HasSelectionHandlers<T> source, T selectedItem) {
 if (TYPE != null) {
  SelectionEvent<T> event = new SelectionEvent<T>(selectedItem);
  source.fireEvent(event);
 }
}

public static <T> Observable<SelectionEvent<T>> selection(HasSelectionHandlers<T> source) {
  return Observable.create(s -> register(s, source.addSelectionHandler(s::onNext)), uiBackpressureMode());
}

/**
 * Fires a selection event on all registered handlers in the handler
 * manager.If no such handlers exist, this method will do nothing.
 * 
 * @param <T> the selected item type
 * @param source the source of the handlers
 * @param selectedItem the selected item
 */
public static <T> void fire(HasSelectionHandlers<T> source, T selectedItem) {
 if (TYPE != null) {
  SelectionEvent<T> event = new SelectionEvent<T>(selectedItem);
  source.fireEvent(event);
 }
}

public static <T> Observable<SelectionEvent<T>> selection(HasSelectionHandlers<T> source) {
  return Observable.create(s -> register(s, source.addSelectionHandler(s::onNext)));
}

.addSelectionHandler(this);

protected <H extends MaterialWidget & HasSelectionHandlers> void checkSelectionHandler(H widget, Object selectedItem) {
  // Check Open Event
  final boolean[] fired = {false};
  widget.addSelectionHandler(event -> {
    assertEquals(event.getSelectedItem(), selectedItem);
    fired[0] = true;
  });
  fireSelectionHandler(widget, selectedItem);
  assertTrue(fired[0]);
}

protected <H extends MaterialWidget & HasSelectionHandlers> void checkSelectionHandler(H widget, Object selectedItem) {
  // Check Open Event
  final boolean[] fired = {false};
  widget.addSelectionHandler(event -> {
    assertEquals(event.getSelectedItem(), selectedItem);
    fired[0] = true;
  });
  fireSelectionHandler(widget, selectedItem);
  assertTrue(fired[0]);
}