Bug 168888 [Wizards] PageTransition classes may need rename/reorg
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/PageTransitionEvent.java
*/
	public static final int EVENT_BACK = 1;
	/**
	 * Constant describing a forward page navigation
	 */
	public static final int EVENT_NEXT = 2;
	
	/**
	 * Public field that determines if page change will continue.
	 */
	public boolean doit = true;
	
	/**
	 * Creates a new event for the given source,selected page and direction.
	 * 
	 * @param source
	 *            the page changing provider
	 * @param selectedPage
	 *            the selected page. In the JFace provided dialogs this will be
	 *            an <code>IDialogPage</code>.
	 * @param eventType
	 *            indicates the action that triggered the page change
	 */
	public PageTransitionEvent(IPageTransitionProvider source, Object selectedPage,
			int eventType) {
		super(source);
		Assert.isNotNull(selectedPage);
		Assert.isTrue(eventType == EVENT_BACK || eventType == EVENT_NEXT);
		this.type = eventType;
		this.selectedPage = selectedPage;