/******************************************************************************* * Copyright (c) 2005 IBM Corporation 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: *     IBM Corporation - initial API and implementation ******************************************************************************/package org.eclipse.ui.internal.menus;import org.eclipse.core.commands.common.NotDefinedException;import org.eclipse.jface.util.PropertyChangeEvent;import org.eclipse.jface.util.Util;/** * <p> * A menu container is a menu element that can contain other elements. This * means that it can optionally have a class the will control the appearance of * elements on a dynamic basis. * </p> * <p> * Clients must not implement or extend. * </p> * <p> * <strong>PROVISIONAL</strong>. This class or interface has been added as * part of a work in progress. There is a guarantee neither that this API will * work nor that it will remain the same. Please do not use this API without * consulting with the Platform/UI team. * </p> * <p> * This class will eventually exist in <code>org.eclipse.jface.menus</code>. * </p> *  * @since 3.2 * @see org.eclipse.ui.internal.menus.SMenu * @see org.eclipse.ui.internal.menus.SGroup */public abstract class MenuContainer extends MenuElement {	/**	 * The property for a property change event indicating that the dynamic	 * class for this menu container has changed.	 */	public static final String PROPERTY_DYNAMIC = "DYNAMIC"; //$NON-NLS-1$	/**	 * The class providing dynamic menu elements to this menu container. If this	 * value is <code>null</code>, then there are no dynamic elements.	 */	protected IDynamicMenu dynamic;	/**	 * Constructs a new instance of <code>MenuCollection</code>.	 * 	 * @param id	 *            The identifier of the container to create; must not be	 *            <code>null</code>.	 */	protected MenuContainer(final String id) {		super(id);	}	/**	 * Returns the class generating dynamic menu elements for this menu	 * container.	 * 	 * @return The class generating dynamic menu elements for this menu	 *         container; never <code>null</code>.	 * @throws NotDefinedException	 *             If the handle is not currently defined.	 */	public final IDynamicMenu getDynamic() throws NotDefinedException {		if (!isDefined()) {			throw new NotDefinedException(					"Cannot get the dynamic class from an undefined menu container"); //$NON-NLS-1$		}		return dynamic;	}	protected final void setDynamic(final IDynamicMenu dynamic) {		if (!Util.equals(this.dynamic, dynamic)) {			PropertyChangeEvent event = null;			if (isListenerAttached()) {				event = new PropertyChangeEvent(this, PROPERTY_DYNAMIC,						this.dynamic, dynamic);			}			this.dynamic = dynamic;			firePropertyChangeEvent(event);		}	}}