Keycode example

keycode.java

public View.OnKeyListener getOnKeyListener(){
        return (v, keyCode, event) -> {
            if(keyCode == KeyEvent.KEYCODE_DEL && searchText.get().equals("")) {
                if (event.getAction()!=KeyEvent.ACTION_DOWN)
                    return true;
                rxBus.send(new DeleteAddedUserFromKeyboardEvent());
            }
            return false;
        };
    }