Bug 28575 Hierarchy view updates items twice [type hierarchy]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
import org.eclipse.jdt.internal.ui.JavaPlugin;
import org.eclipse.jdt.internal.ui.actions.AddMethodStubAction;
import org.eclipse.jdt.internal.ui.actions.CompositeActionGroup;
import org.eclipse.jdt.internal.ui.actions.NewWizardsActionGroup;
import org.eclipse.jdt.internal.ui.actions.SelectAllAction;
import org.eclipse.jdt.internal.ui.dnd.DelegatingDragAdapter;
import org.eclipse.jdt.internal.ui.dnd.DelegatingDropAdapter;
import org.eclipse.jdt.internal.ui.dnd.LocalSelectionTransfer;
import org.eclipse.jdt.internal.ui.dnd.TransferDragSourceListener;
import org.eclipse.jdt.internal.ui.dnd.TransferDropTargetListener;
import org.eclipse.jdt.internal.ui.javaeditor.EditorUtility;
import org.eclipse.jdt.internal.ui.packageview.SelectionTransferDragAdapter;
import org.eclipse.jdt.internal.ui.util.BusyIndicatorRunnableContext;
import org.eclipse.jdt.internal.ui.viewsupport.IViewPartInputProvider;
import org.eclipse.jdt.internal.ui.viewsupport.JavaElementLabels;
import org.eclipse.jdt.internal.ui.viewsupport.JavaUILabelProvider;
import org.eclipse.jdt.internal.ui.viewsupport.StatusBarUpdater;
/**
 * view showing the supertypes/subtypes of its input.
 */
public class TypeHierarchyViewPart extends ViewPart implements ITypeHierarchyViewPart, IViewPartInputProvider {
	public static final int VIEW_ID_TYPE= 2;
	public static final int VIEW_ID_SUPER= 0;
	public static final int VIEW_ID_SUB= 1;
	
	public static final int VIEW_ORIENTATION_VERTICAL= 0;
	public static final int VIEW_ORIENTATION_HORIZONTAL= 1;
	public static final int VIEW_ORIENTATION_SINGLE= 2;
	
	private static final String DIALOGSTORE_HIERARCHYVIEW= "TypeHierarchyViewPart.hierarchyview";