Bug 28269 type hierarchy makes work much slower even though it's invisible
20021210 i had a big type hierarchy open but put in the background - behind the package explorer i added 1 type to the workspace boom - tyhe whole thing froze for 2 minutes because the type hierarchy was doing a lot of work that i did not ask for and no busy cursor it makes it quite impossible to work if you have a type hierarchy open anywhere
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
for (int i= 0; i < fAllViewers.length; i++) {
			fAllViewers[i].setQualifiedTypeName(on);
		}
	}
	
	private boolean isShowQualifiedTypeNames() {
		return fShowQualifiedTypeNamesAction.isChecked();
	}
	
	
	
	/**
	 * Called from ITypeHierarchyLifeCycleListener.
	 * Can be called from any thread
	 */
	private void doTypeHierarchyChanged(final TypeHierarchyLifeCycle typeHierarchy, final IType[] changedTypes) {
		Display display= getDisplay();
		if (display != null) {
			display.asyncExec(new Runnable() {
				public void run() {
					if (fPagebook != null && !fPagebook.isDisposed()) {
						doTypeHierarchyChangedOnViewers(changedTypes);
					}
				}
			});
		}
	}
	
	private void doTypeHierarchyChangedOnViewers(IType[] changedTypes) {
		if (fHierarchyLifeCycle.getHierarchy() == null || !fHierarchyLifeCycle.getHierarchy().exists()) {