/******************************************************************************* * 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;/** * <p> * A reference to an already existing menu element. A reference is used to * modify or extend the meaning of an existing menu element. * </p> * <p> * Clients may instantiate this class, but must not 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 */public final class SReference {	/**	 * The constant for a reference that refers to an unspecified type of menu	 * element.	 */	public static final int TYPE_UNSPECIFIED = 0;	/**	 * The constant for a reference that refers to a menu.	 */	public static final int TYPE_MENU = 1;	/**	 * The constant for a reference that refers to a group.	 */	public static final int TYPE_GROUP = 2;	/**	 * The constant for a reference that refers to an item.	 */	public static final int TYPE_ITEM = 3;	/**	 * The constant for a reference that refers to a widget.	 */	public static final int TYPE_WIDGET = 4;	/**	 * The type of reference. This must be one of the type constants given in	 * this class.	 */	private final int type;	/**	 * The identifier of the menu element this refers to. Must not be	 * <code>null</code>.	 */	private final String id;	/**	 * Constructs a new instance of <code>SReference</code>.	 * 	 * @param type	 *            The type of menu element this is making reference to. This	 *            must be one of <code>TYPE_UNSPECIFIED</code>,	 *            <code>TYPE_MENU</code>, <code>TYPE_GROUP</code>,	 *            <code>TYPE_ITEM</code> or <code>TYPE_WIDGET</code>.	 * @param id	 *            The identifier of the menu element this refers to; must not be	 *            <code>null</code>.	 */	public SReference(final int type, final String id) {		if ((type < TYPE_UNSPECIFIED) || (type > TYPE_WIDGET)) {			throw new IllegalArgumentException(					"The type of reference is not understood"); //$NON-NLS-1$		}		if (id == null) {			throw new NullPointerException(					"The identifier of the menu element must be null"); //$NON-NLS-1$		}		this.type = type;		this.id = id;	}	/**	 * Returns the identifier of the menu element to which this refers.	 * 	 * @return The identifier of the menu element; never <code>null</code>.	 */	public final String getId() {		return id;	}	/**	 * Returns the type of reference. This will be one of the type constants in	 * this class.	 * 	 * @return The type of reference.	 */	public final int getType() {		return type;	}}