smooth scroll to center of item

CenterSnappedSmoothScroller.kt

class CenterSnappedSmoothScroller(context: Context) : LinearSmoothScroller(context) {
        override fun calculateDtToFit(viewStart: Int, viewEnd: Int, boxStart: Int, boxEnd: Int, snapPreference: Int): Int {
            return center(super.calculateDtToFit(viewStart, viewEnd, boxStart, boxEnd, snapPreference), viewEnd - viewStart)
        }

        private fun center(dx: Int, viewWidth: Int): Int {
            return if (dx < 0) {
                dx + (viewWidth / 2)
            } else {
                dx - (viewWidth / 2)
            }
        }
    }