MenuItemRidget.java

/*******************************************************************************
 * Copyright (c) 2007, 2014 compeople AG and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    compeople AG - initial API and implementation
 *******************************************************************************/
package org.eclipse.riena.internal.ui.ridgets.swt;

import org.eclipse.core.databinding.BindingException;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.MenuAdapter;
import org.eclipse.swt.events.MenuEvent;
import org.eclipse.swt.events.MenuListener;
import org.eclipse.swt.widgets.MenuItem;

import org.eclipse.riena.ui.ridgets.AbstractMarkerSupport;
import org.eclipse.riena.ui.ridgets.IMenuItemRidget;
import org.eclipse.riena.ui.swt.utils.SwtUtilities;

/**
 * Ridget of a menu item.
 */
public class MenuItemRidget extends AbstractItemRidget implements IMenuItemRidget {

	/**
	 * Workaround for bug #397884
	 */
	private final MenuListener enablementWatcher = new MenuAdapter() {
		@Override
		public void menuShown(final MenuEvent e) {
			if (!SwtUtilities.isDisposed(getUIControl()) && isEnabled() != getUIControl().getEnabled()) {
				getUIControl().setEnabled(isEnabled());
			}
		}
	};

	/**
	 * Returns whether the given menu item is a cascade menu.
	 * 
	 * @param menuItem
	 *            menu item
	 * @return {@code true} if item is cascade menu; otherwise {@code false}
	 */
	protected boolean isMenu(final MenuItem menuItem) {
		if (menuItem == null) {
			return false;
		}
		return ((menuItem.getStyle() & SWT.CASCADE) == SWT.CASCADE);
	}

	@Override
	protected void bindUIControl() {
		super.bindUIControl();
		final MenuItem menuItem = getUIControl();
		if (!SwtUtilities.isDisposed(menuItem)) {
			menuItem.addSelectionListener(getActionObserver());
			menuItem.getParent().addMenuListener(enablementWatcher);
		}
	}

	@Override
	protected void unbindUIControl() {
		savedVisibleState = isVisible();
		final MenuItem menuItem = getUIControl();

		if (!SwtUtilities.isDisposed(menuItem) && !isMenu(menuItem)) {
			menuItem.getParent().removeMenuListener(enablementWatcher);
			menuItem.removeSelectionListener(getActionObserver());
		}
		super.unbindUIControl();
	}

	@Override
	protected void checkUIControl(final Object uiControl) {
		checkType(uiControl, MenuItem.class);
		if (isMenu((MenuItem) uiControl)) {
			throw new BindingException("Menu item is a cascade menu item!"); //$NON-NLS-1$
		}
	}

	@Override
	public MenuItem getUIControl() {
		return (MenuItem) super.getUIControl();
	}

	@Override
	protected AbstractMarkerSupport createMarkerSupport() {
		return new MenuItemMarkerSupport(this, propertyChangeSupport);
	}

	@Override
	protected void updateEnabled() {
		if (!SwtUtilities.isDisposed(getUIControl())) {
			getUIControl().setEnabled(isEnabled());
		}
	}

	@Override
	AbstractItemProperties createProperties() {
		return new MenuItemProperties(this);
	}

}