Bug 259179 [TabbedProperties] TabbedPropertySheetPage extensibility option
bundles/org.eclipse.ui.views.properties.tabbed/src/org/eclipse/ui/views/properties/tabbed/TabbedPropertySheetPage.java
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;
			}
		}
		if (!activePropertySheet && currentTab != null) {
			currentTab.aboutToBeShown();
			currentTab.refresh();
		}
		activePropertySheet = true;
	}
	/**
	 * @see org.eclipse.ui.part.IPage#createControl(org.eclipse.swt.widgets.Composite)
	 */
	public void createControl(Composite parent) {