Bug 28575 Hierarchy view updates items twice [type hierarchy]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
new TypeHierarchyTransferDropAdapter(this, viewer)
		};
		viewer.addDropSupport(ops, transfers, new DelegatingDropAdapter(dropListeners));
	}
	private void addDragAdapters(StructuredViewer viewer, int ops, Transfer[] transfers){
		Control control= viewer.getControl();
		TransferDragSourceListener[] dragListeners= new TransferDragSourceListener[] {
			new SelectionTransferDragAdapter(viewer)
		};
		DragSource source= new DragSource(control, ops);
		
		source.addDragListener(new DelegatingDragAdapter(dragListeners));		
	}	
	
	private void viewPartKeyShortcuts(KeyEvent event) {
		if (event.stateMask == SWT.CTRL) {
			if (event.character == '1') {
				setView(VIEW_ID_TYPE);
			} else if (event.character == '2') {
				setView(VIEW_ID_SUPER);
			} else if (event.character == '3') {
				setView(VIEW_ID_SUB);
			}
		}	
	}
	
		
	/**
	 * Returns the inner component in a workbench part.
	 * @see IWorkbenchPart#createPartControl