Android Expand & Collapse Animation
Android Animation 코드 중 Expand & Collapse 잘 구현해놓은 예제가 있다.
단, 사용법에 주의사항이 한가지가 있다면
Layout XML 상에서 height를 0dp로 설정했을때 크기가 정상적으로 변경되는 경우에만 작동하므로,
적용전에 Layout XML을 반드시 정리해놓아야한다.
- Expand
fun expand(view: View) {
val matchParentMeasureSpec = View.MeasureSpec.makeMeasureSpec((view.parent as View).width, View.MeasureSpec.EXACTLY)
val wrapContentMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED)
view.measure(matchParentMeasureSpec, wrapContentMeasureSpec)
val targetHeight = view.measuredHeight
view.layoutParams.height = 0
view.visibility = View.VISIBLE
val animation = object: Animation() {
override fun applyTransformation(interpolatedTime: Float, t: Transformation?) {
when(interpolatedTime.toInt() == 1){
true->view.layoutParams.height = ConstraintLayout.LayoutParams.WRAP_CONTENT
false->view.layoutParams.height = (targetHeight * interpolatedTime).toInt()
}
Timber.v("diver:/"+view.layoutParams.height)
view.requestLayout()
}
override fun willChangeBounds(): Boolean {
return true
}
}
animation.duration = (targetHeight / view.context.resources.displayMetrics.density).toLong() * 2
view.startAnimation(animation)
}- Collapse
fun collapse(view: View) {
val initialHeight = view.measuredHeight
val animation = object: Animation() {
override fun applyTransformation(interpolatedTime: Float, t: Transformation?) {
when(interpolatedTime.toInt() == 1){
true->view.visibility = View.GONE
false->{
view.layoutParams.height = initialHeight - (initialHeight * interpolatedTime).toInt()
view.requestLayout()
}
}
}
override fun willChangeBounds(): Boolean {
return true
}
}
animation.duration = (initialHeight / view.context.resources.displayMetrics.density).toLong()
view.startAnimation(animation)
}
