Bug 64855 QuickMenuAction leaks the context menus
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/actions/QuickMenuAction.java
StyledText styledText= (StyledText)focus;
			clientArea= styledText.getClientArea();
			result= computeMenuLocation(styledText);
		} else if (focus instanceof Tree) {
			Tree tree= (Tree)focus;
			clientArea= tree.getClientArea();
			result= computeMenuLocation(tree);
		} else if (focus instanceof Table) {
			Table table= (Table)focus;
			clientArea= table.getClientArea();
			result= computeMenuLocation(table);
		}
		if (result == null) {
			result= focus.toControl(cursorLocation);
		}
		if (clientArea != null && !clientArea.contains(result)) {
			result= new Point(
				clientArea.x + clientArea.width  / 2, 
				clientArea.y + clientArea.height / 2);
		}
		Rectangle shellArea= focus.getShell().getClientArea();
		if (!shellArea.contains(focus.getShell().toControl(focus.toDisplay(result)))) {
			result= new Point(
				shellArea.x + shellArea.width  / 2,
				shellArea.y + shellArea.height / 2);
		}
		return focus.toDisplay(result);
	}
	
	/**