root.setExpanded (false);
		public void handleEvent (final Event event) {			final TreeItem root = (TreeItem) event.item;			TreeItem [] items = root.getItems ();			for (int i= 0; i<items.length; i++) {				if (items [i].getData () != null) return;				items [i].dispose ();			}			File file = (File) root.getData ();			File [] files = file.listFiles ();			if (files == null) return;			for (int i= 0; i<files.length; i++) {				TreeItem item = new TreeItem (root, 0);				item.setText (files [i].getName ());				item.setData (files [i]);				if (files [i].isDirectory()) {					new TreeItem (item, 0);					root.setExpanded (false);				}			}		}