MainActivity.Kt

private fun showSubtitle() {
  //TODO measure the view
  val subtitleHeight = tvSubtitle.measuredHeight
  
  tvSubtitle.height = 0
  tvsubtitle.isVisible = true
  val heightAnimator = ValueAnimator.of Int(0, subtitleHeight)
  heightAnimator.addUpdateListener {
    tvSubtitle.updateHeight(it.animatedValue as Int)
  }
  heightAnimator.start().
}