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/TypeHierarchyLifeCycle.java
pm.done();
						}
					}
				}
			};
			
			try {
				context.run(true, true, op);
			} catch (InvocationTargetException e) {
				Throwable th= e.getTargetException();
				if (th instanceof JavaModelException) {
					throw (JavaModelException)th;
				} else {
					throw new JavaModelException(th, IStatus.ERROR);
				}
			} catch (InterruptedException e) {
				
			}
			
			fHierarchyRefreshNeeded= false;
		}
	}
	
	private void doHierarchyRefresh(IJavaElement element, IProgressMonitor pm) throws JavaModelException {
		boolean hierachyCreationNeeded= (fHierarchy == null || !element.equals(fInputElement));
		
		
		if (fHierarchy != null) {
			fHierarchy.removeTypeHierarchyChangedListener(this);
			JavaCore.removeElementChangedListener(this);