package com.audio.record.screen.test.view

import android.graphics.Rect
import android.view.View
import androidx.recyclerview.widget.RecyclerView


class GridSpacingItemDecoration(
    private val spanCount: Int,          // 列数
    private val spacing: Int,            // 间距（px）
    private val includeEdge: Boolean     // 是否包含边缘间距
) : RecyclerView.ItemDecoration() {

    override fun getItemOffsets(
        outRect: Rect, view: View,
        parent: RecyclerView, state: RecyclerView.State
    ) {
        val position = parent.getChildAdapterPosition(view) // item position
        val column = position % spanCount // item column

        if (includeEdge) {
            outRect.left = spacing - column * spacing / spanCount
            outRect.right = (column + 1) * spacing / spanCount

            if (position < spanCount) { // top edge
                outRect.top = spacing
            }
            outRect.bottom = spacing // item bottom
        } else {
            outRect.left = column * spacing / spanCount
            outRect.right = spacing - (column + 1) * spacing / spanCount
            if (position >= spanCount) {
                outRect.top = spacing // item top
            }
        }
    }
}
