/*******************************************************************************
 * Copyright (c) 2000, 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.jface.dialogs;

import java.util.EventObject;

import org.eclipse.jface.util.Assert;

/**
 * Event object describing a page selection change. The source of these events
 * is a page change provider.
 * 
 * @see IPageChangeProvider
 * @see IPageChangedListener
 * 
 * @since 3.1
 */
public class PageChangedEvent extends EventObject {

	/**
	 * Generated serial version UID for this class.
	 * 
	 * @since 3.1
	 */
	private static final long serialVersionUID = 3835149545519723574L;

	/**
	 * The selected page.
	 */
	protected Object selectedPage;

	/**
	 * Creates a new event for the given source and selected page.
	 * 
	 * @param source
	 *            the page change provider
	 * @param selectedPage
	 *            the selected page. In the JFace provided dialogs this
	 *            will be an <code>IDialogPage</code>.
	 */
	public PageChangedEvent(IPageChangeProvider source,
			Object selectedPage) {
		super(source);
		Assert.isNotNull(selectedPage);
		this.selectedPage = selectedPage;
	}

	/**
	 * Returns the selected page.
	 * 
	 * @return the selected page. In dialogs implemented by JFace, 
	 * 		this will be an <code>IDialogPage</code>.
	 */
	public Object getSelectedPage() {
		return selectedPage;
	}

	/**
	 * Returns the page change provider that is the source of this event.
	 * 
	 * @return the originating page change provider
	 */
	public IPageChangeProvider getPageChangeProvider() {
		return (IPageChangeProvider) getSource();
	}
}