Bug 16897 No busy indicator while populating type hierarchy
Build: Freeze 1 In a self-hosting workspace, select the type IAdaptable in an editor and hit F4 to populate the type hiearchy. Since this interface has many sub-types, this takes several seconds to populate. There should be a busy indicator while this is happening.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyLifeCycle.java
fHierarchy= null;
			fInputElement= null;
		}
	}
	
	public void removeChangedListener(ITypeHierarchyLifeCycleListener listener) {
		fChangeListeners.remove(listener);
	}
	
	public void addChangedListener(ITypeHierarchyLifeCycleListener listener) {
		if (!fChangeListeners.contains(listener)) {
			fChangeListeners.add(listener);
		}
	}
	
	private void fireChange(IType[] changedTypes) {
		for (int i= fChangeListeners.size()-1; i>=0; i--) {
			ITypeHierarchyLifeCycleListener curr= (ITypeHierarchyLifeCycleListener) fChangeListeners.get(i);
			curr.typeHierarchyChanged(this, changedTypes);
		}
	}
		
	public void ensureRefreshedTypeHierarchy(final IJavaElement element) throws JavaModelException {
		if (element == null || !element.exists()) {
			freeHierarchy();
			return;
		}
		boolean hierachyCreationNeeded= (fHierarchy == null || !element.equals(fInputElement));
		
		if (hierachyCreationNeeded || fHierarchyRefreshNeeded) {