smoothScrollToPositionWithOffset.kt

smoothScrollToPositionWithOffset.kt

private fun RecyclerView.smoothScrollToPositionWithOffset(position: Int, offset: Int) {
    if (position < 0 || position >= (adapter?.itemCount ?: 0)) return

    val linearSmoothScroller = object : LinearSmoothScroller(context) {
        override fun onTargetFound(targetView: View, state: RecyclerView.State, action: Action) {
            super.onTargetFound(targetView, state, action)
            val dx = calculateDxToMakeVisible(targetView, horizontalSnapPreference)
            val dy = calculateDyToMakeVisible(targetView, SNAP_TO_START)

            val distance = sqrt((dx * dx + dy * dy).toDouble()).toInt()
            val time = calculateTimeForDeceleration(distance)
            if (time > 0) {
                action.update(-dx, -dy - offset, time, mDecelerateInterpolator)
            }
        }
    }
    linearSmoothScroller.targetPosition = position
    layoutManager?.startSmoothScroll(linearSmoothScroller)
}