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
private void setViewerVisibility(boolean showHierarchy) {
		if (showHierarchy) {
			fViewerbook.showPage(getCurrentViewer().getControl());
		} else {
			fViewerbook.showPage(fEmptyTypesViewer);
		}
	}
	
	/**
	 * Sets the member filter. <code>null</code> disables member filtering.
	 */	
	private void setMemberFilter(IMember[] memberFilter) {
		Assert.isNotNull(fAllViewers);
		for (int i= 0; i < fAllViewers.length; i++) {
			fAllViewers[i].setMemberFilter(memberFilter);
		}
	}	
	
	private IType getSelectableType(IJavaElement elem) {
		if (elem.getElementType() != IJavaElement.TYPE) {
			return null; 
		} else {
			return (IType) elem;
		}
	}
	
	private void internalSelectType(IMember elem, boolean reveal) {	
		TypeHierarchyViewer viewer= getCurrentViewer();
		viewer.removeSelectionChangedListener(fSelectionChangedListener);
		viewer.setSelection(elem != null ? new StructuredSelection(elem) : StructuredSelection.EMPTY, reveal);