Bug 256516 [TabbedProperties] TabbedPropertySheetPage to allow some options
bundles/org.eclipse.ui.views.properties.tabbed/src/org/eclipse/ui/views/properties/tabbed/TabbedPropertySheetPage.java
* 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.
		 */
        if (!thisActivated && !part.equals(contributor)
                && !part.getSite().getId().equals(contributor.getContributorId())) {
			/*
			 * Is the part is a IContributedContentsView for the contributor,
			 * for example, outline view.
			 */
			IContributedContentsView view = (IContributedContentsView) part
				.getAdapter(IContributedContentsView.class);
			if (view == null
				|| (view.getContributingPart() != null && !view
					.getContributingPart().equals(contributor))) {
				if (activePropertySheet) {
					if (currentTab != null) {
						currentTab.aboutToBeHidden();
					}
					activePropertySheet = false;
				}
				return;