}
private void hookContextualMenu() {
MenuManager manager = new MenuManager();
manager.setRemoveAllWhenShown(true);
manager.addMenuListener(new IMenuListener() {
public void menuAboutToShow(IMenuManager manager) {
manager.add(new Separator(IWorkbenchActionConstants.MB_ADDITIONS));
manager.add(new Separator("open"));
manager.add(new Separator("mark"));
manager.add(new Separator("edit"));