Bug 266862 [CommonNavigator] Unused copy of QuickMenuAction in common navigator
bundles/org.eclipse.ui.navigator.resources/src/org/eclipse/ui/internal/navigator/resources/actions/QuickMenuAction.java
*            the tree widget that has the focus
	 * 
	 * @return a widget relative position of the menu to pop up or <code>null</code> if now
	 *         position inside the widget can be computed
	 */
	protected Point computeMenuLocation(Tree tree) {
		TreeItem[] items = tree.getSelection();
		Rectangle clientArea = tree.getClientArea();
		switch (items.length) {
			case 0 :
				return null;
			case 1 :
				Rectangle bounds = items[0].getBounds();
				Rectangle intersect = clientArea.intersection(bounds);
				if (intersect != null && intersect.height == bounds.height) {
					return new Point(Math.max(0, bounds.x + getAvarageCharWith(tree) * CHAR_INDENT), bounds.y + bounds.height);
				}
				return null;
			default :
				Rectangle[] rectangles = new Rectangle[items.length];
				for (int i = 0; i < rectangles.length; i++) {
					rectangles[i] = items[i].getBounds();
				}
				Point cursorLocation = tree.getDisplay().getCursorLocation();
				Point result = findBestLocation(getIncludedPositions(rectangles, clientArea), tree.toControl(cursorLocation));
				if (result != null) {
					result.x = result.x + getAvarageCharWith(tree) * CHAR_INDENT;
				}
				return result;
		}