Bug 259179 [TabbedProperties] TabbedPropertySheetPage extensibility option
bundles/org.eclipse.ui.views.properties.tabbed/src/org/eclipse/ui/views/properties/tabbed/TabbedPropertySheetPage.java
public TabbedPropertySheetPage(
			ITabbedPropertySheetPageContributor tabbedPropertySheetPageContributor,
			boolean showTitleBar) {
		hasTitleBar = showTitleBar;
		contributor = tabbedPropertySheetPageContributor;
		tabToComposite = new HashMap();
		selectionQueue = new ArrayList(10);
		tabSelectionListeners = new ArrayList();
		initContributor(contributor.getContributorId());
	}
	/**
	 * Handle the part activated event.
	 * 
	 * @param part
	 *            the new activated part.
	 */
	protected void handlePartActivated(IWorkbenchPart part) {
		/*
		 * The properties view has been activated and the current page is this
		 * instance of TabbedPropertySheetPage
		 */
		boolean thisActivated = part instanceof PropertySheet
			&& ((PropertySheet) part).getCurrentPage() == this;
		/*
		 * When the active part changes and the part does not provide a
		 * selection that affects this property sheet page, the PropertySheet
		 * does not send us a selectionChanged() event. We need to be informed
		 * of these events since we want to send aboutToBeHidden() and
		 * aboutToBeShown() when the property sheet is hidden or shown.
		 */