Add onRegisterHoverKey to accessibility delegate

        // Make sure we're not getting an EXIT event because the user slid

        // off the keyboard area, then force a key press.

        if (key != null) {

            simulateTouchEvent(MotionEvent.ACTION_DOWN, event);

            simulateTouchEvent(MotionEvent.ACTION_UP, event);

            onRegisterHoverKey(key, event);

            onHoverExitKey(key);

        }

        setLastHoverKey(null);

    }

    /**

     * Register a key that is selected by a hover event

     *

     * @param key A key to be registered.

     * @param event A hover exit event that triggers key registering.

     */

    protected void onRegisterHoverKey(final Key key, final MotionEvent event) {

        simulateTouchEvent(MotionEvent.ACTION_DOWN, event);

        simulateTouchEvent(MotionEvent.ACTION_UP, event);

    }

    /**

     * Simulating a touch event by injecting a synthesized touch event into {@link PointerTracker}.

     *