GridLayoutManager-获取项目的行索引

Question

对于我的自定义装饰器，我想在列表末尾添加一些额外的填充。对于这个用例，我需要知道项目是否在网格的最后一行。

这有可能吗？

到目前为止，

装饰代码

class SetupHeaderDecorator(private val paddingHorizontal: Int, private val paddingBeforeHeader: Int, private val paddingTopBottom: Int) : RecyclerView.ItemDecoration() {

    override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State?) {

        val pos = parent.getChildAdapterPosition(view)
        val count = parent.adapter.itemCount
        var firstRow = pos == 0
        val lastRow = pos == count - 1
        var leftColumn = true
        var rightColumn = true
        if (parent.layoutManager is GridLayoutManager) {
            // TODO - this calculation still needs to be done!
            // firstRow = ...
            // lastRow = ...

            val lm = parent.layoutManager as GridLayoutManager
            val span = lm.spanCount
            val col = lm.spanSizeLookup.getSpanIndex(pos, span)
            val colEnd = col + lm.spanSizeLookup.getSpanSize(pos) - 1
            leftColumn = col == 0
            rightColumn = colEnd == (span - 1)
        }

        // Space above each header, if the header is not the first item
        if (pos > 0 && parent.getChildViewHolder(view) is SetupAdapter.ISetupHeaderViewHolder) {
            outRect.top = paddingBeforeHeader
        }

        // First and last row padding top
        if (firstRow && paddingTopBottom != 0) {
            outRect.top = paddingTopBottom
        }
        if (lastRow && paddingTopBottom != 0) {
            outRect.bottom = paddingTopBottom
        }

        // row padding left/right
        if (paddingHorizontal != 0) {
            if (leftColumn)
                outRect.left = paddingHorizontal
            if (rightColumn)
                outRect.right = paddingHorizontal
        }
    }
}