anchor.diff:      GestureEventListener onGestureFlingStart,
       GestureEventListener onGestureScrollStart,
       GestureEventListener onGestureScrollUpdate,
  +    GestureEventListener onGestureLongPress,
       GestureEventListener onGestureTap,
       GestureEventListener onGestureTapDown,
  +    GestureEventListener onGestureShowPress,
       PointerEventListener onPointerCancel,
       PointerEventListener onPointerDown,
       PointerEventListener onPointerMove,
  
positive.code:     GestureEventListener onGestureScrollUpdate,
      GestureEventListener onGestureTap,
      GestureEventListener onGestureTapDown,
      PointerEventListener onPointerCancel,
      PointerEventListener onPointerDown,
      PointerEventListener onPointerMove,
  
negative.code:       listeners['gesturetap'] = onGestureTap;
      if (onGestureTapDown != null)
        listeners['gesturetapdown'] = onGestureTapDown;
      if (onGestureLongPress != null)
        listeners['gesturelongpress'] = onGestureLongPress;
      if (onGestureShowPress != null)
        listeners['gestureshowpress'] = onGestureShowPress;
      if (onPointerCancel != null)
        listeners['pointercancel'] = onPointerCancel;
      if (onPointerDown != null)
  