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 updateMainToolbar(int orientation) {
		IActionBars actionBars= getViewSite().getActionBars();
		IToolBarManager tbmanager= actionBars.getToolBarManager();	
				
		if (orientation == VIEW_ORIENTATION_HORIZONTAL) {
			clearMainToolBar(tbmanager);
			ToolBar typeViewerToolBar= new ToolBar(fTypeViewerViewForm, SWT.FLAT | SWT.WRAP);
			fillMainToolBar(new ToolBarManager(typeViewerToolBar));
			fTypeViewerViewForm.setTopLeft(typeViewerToolBar);
		} else {
			fTypeViewerViewForm.setTopLeft(null);
			fillMainToolBar(tbmanager);
		}
	}
	
	private void fillMainToolBar(IToolBarManager tbmanager) {
		tbmanager.removeAll();
		tbmanager.add(fHistoryDropDownAction);
		for (int i= 0; i < fViewActions.length; i++) {
			tbmanager.add(fViewActions[i]);
		}
		tbmanager.update(false);	
	}
	private void clearMainToolBar(IToolBarManager tbmanager) {
		tbmanager.removeAll();
		tbmanager.update(false);		
	}