on
open fun onLayoutChange(v: View, left: Int, top: Int, right: Int, bottom: Int, oldLeft: Int, oldTop: Int, oldRight: Int, oldBottom: Int)
Called when a mContentView's layout has changed. Fixes the scroll position if it's too large after the content resizes. Without this, the user would see a blank ScrollView when the scroll position is larger than the ScrollView's max scroll position after the content shrinks.