private void detectDoubleClick() {
    viewer.addDoubleClickListener(new IDoubleClickListener() {
    public void doubleClick(DoubleClickEvent event) {
        IHandlerService handlerService=IHandlerService)getSite().getService(IHandlerService.class);
        try {
            System.out.println("DoubleClick Detected!!!");
            //???
        } catch (Exception ex) {
           throw new RuntimeException("error");
        }
     }
 });