Allows you to smoothly hide the View

RecyclerView.attachScrollToFade

fun RecyclerView.attachScrollToFade(view: View? = null) {
	addOnScrollListener(object : RecyclerView.OnScrollListener() {
		override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
			super.onScrolled(recyclerView, dx, dy)
			val linearLayoutManager = layoutManager as LinearLayoutManager
			if (linearLayoutManager.findFirstVisibleItemPosition() == 0) {
				val firstVisible = linearLayoutManager.findViewByPosition(linearLayoutManager.findFirstVisibleItemPosition())
				if (firstVisible != null) {
					val distanceTop = firstVisible.top

					val itemSize = firstVisible.height + (firstVisible.layoutParams as ViewGroup.MarginLayoutParams).bottomMargin // view size
					val alpha = (recyclerView.bottom - recyclerView.paddingBottom - distanceTop) / (itemSize.toFloat()) // view transparency

					view?.alpha = alpha
				}
			}else{
				view?.alpha = 0f
			}
		}
	})
}