class Pop(context: Context, attrs: AttributeSet) : Visibility(context, attrs) {

    override fun onAppear(sceneRoot: ViewGroup, view: View, startValues: TransitionValues,
                          endValues: TransitionValues): Animator {
        view.alpha = 0f
        view.scaleX = 0f
        view.scaleY = 0f
        return ObjectAnimator.ofPropertyValuesHolder(
                view,
                PropertyValuesHolder.ofFloat(View.ALPHA, 1f),
                PropertyValuesHolder.ofFloat(View.SCALE_X, 1f),
                PropertyValuesHolder.ofFloat(View.SCALE_Y, 1f))
    }

    override fun onDisappear(sceneRoot: ViewGroup, view: View, startValues: TransitionValues,
                             endValues: TransitionValues): Animator {
        return ObjectAnimator.ofPropertyValuesHolder(
                view,
                PropertyValuesHolder.ofFloat(View.ALPHA, 0f),
                PropertyValuesHolder.ofFloat(View.SCALE_X, 0f),
                PropertyValuesHolder.ofFloat(View.SCALE_Y, 0f))
    }
}