ItemDecorator for RecyclerView + no decorator on the last item + offset for decorator

DividerItemWithoutLastDecoration.kt

class DividerItemWithoutLastDecoration(
    val divider: Drawable,
    val dividerOffset: ItemDecoratorOffset = ItemDecoratorOffset.asEmpty(),
) : RecyclerView.ItemDecoration() {

    override fun onDrawOver(canvas: Canvas, parent: RecyclerView, state: RecyclerView.State) {
        val dividerLeft = parent.paddingLeft + dividerOffset.start
        val dividerRight = parent.width - parent.paddingRight - dividerOffset.end
        val childCount = parent.childCount
        for (i in 0..childCount - 2) {
            val child = parent.getChildAt(i)
            val params = child.layoutParams as RecyclerView.LayoutParams
            val dividerTop = child.bottom + params.bottomMargin + dividerOffset.top
            val dividerBottom = dividerTop + divider.intrinsicHeight
            divider.setBounds(dividerLeft, dividerTop, dividerRight, dividerBottom)
            divider.draw(canvas)
        }
    }

    override fun getItemOffsets(
        outRect: Rect,
        view: View,
        parent: RecyclerView,
        state: RecyclerView.State
    ) {
        super.getItemOffsets(outRect, view, parent, state)
        if (!isLastItem(parent, view)) {
            outRect.set(
                0,
                0,
                0,
                dividerOffset.top + dividerOffset.bottom,
            )
        }
    }

    private fun isLastItem(
        parent: RecyclerView,
        itemView: View,
    ): Boolean {
        val childCount = parent.adapter?.itemCount ?: 0
        val childPosition = parent.getChildAdapterPosition(itemView)
        return childPosition == childCount - 1
    }
}