Bug 32384 Cannot open type hierarchy after a cancel
JUnit setup 1) open the type hierarchy on TestCase 2) press F4 on Object 3) cancel in progress bar 4) press F4 on Object again ->nothing happens
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
updateTitle();
			enableMemberFilter(false);
			fPagebook.showPage(fTypeMethodsSplitter);
		}
	}
	
	private void processOutstandingEvents() {
		Display display= getDisplay();
		if (display != null && !display.isDisposed())
			display.update();
	}	
	
	private void clearInput() {
		fInputElement= null;
		fHierarchyLifeCycle.freeHierarchy();
		
		updateHierarchyViewer(false);
		updateToolbarButtons();
	}
	/*
	 * @see IWorbenchPart#setFocus
	 */	
	public void setFocus() {
		fPagebook.setFocus();
	}
	/*
	 * @see IWorkbenchPart#dispose
	 */	
	public void dispose() {
		fHierarchyLifeCycle.freeHierarchy();