ItemDecoration #view

HorizontalPaddingDecoration.kt

class HorizontalPaddingDecoration(
    private val padding: Float = 2f,
    private val firstLastPadding: Float = 20f
) : RecyclerView.ItemDecoration() {

    override fun getItemOffsets(
        outRect: Rect,
        view: View,
        parent: RecyclerView,
        state: RecyclerView.State
    ) {
        val itemPosition = parent.getChildAdapterPosition(view)
        
        if (itemPosition == RecyclerView.NO_POSITION) {
            return
        }

        //outRect.top = padding.dpToPx()
        //outRect.bottom = padding.dpToPx()

        when {
            itemPosition == 0 -> {
                outRect.left = firstLastPadding.dpToPx()
                outRect.right = padding.dpToPx()
            }

            itemPosition < state.itemCount - 1 -> {
                outRect.left = padding.dpToPx()
                outRect.right = padding.dpToPx()
            }

            itemPosition == state.itemCount - 1 -> {
                outRect.left = padding.dpToPx()
                outRect.right = firstLastPadding.dpToPx()
            }
        }
    }
}