if (isMac() || isLinux())
        {
            tree.addListener(SWT.MouseDoubleClick, new Listener()
            {
                public void handleEvent(Event event)
                {
                    Point point = new Point(event.x, event.y);
                    TreeItem item = tree.getItem(point);
                    if (item != null)
                    {
                        if (item.getExpanded())
                        {
                            item.setExpanded(false);                            
                        }
                        else
                        {
                            item.setExpanded(true);
                        }
                    }
                }
            });
        }