Vertical and Horizontal RecyclerView Divider Item

RecyclerviewDividerItem.kt

import android.graphics.Canvas
import android.graphics.drawable.Drawable
import android.util.TypedValue
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView

/**
 * [RecyclerView] item decoration which adds horizontal divider between items.
 *
 * @author Muhammad Saeed
 */
@Suppress("unused")
class DividerItemDecoration(
    private val drawable: Drawable,
    private val marginLeft: Float = 16f,
    private val marginRight: Float = 16f,
    private val marginTop: Float = 16f,
    private val marginBottom: Float = 16f,
    private val dividerWidth: Int = 2
) : RecyclerView.ItemDecoration() {

    override fun onDrawOver(c: Canvas, parent: RecyclerView, state: RecyclerView.State) {
        super.onDrawOver(c, parent, state)

        for (i in 0 until parent.childCount - 1) {
            val child = parent.getChildAt(i)
            val params = child.layoutParams as RecyclerView.LayoutParams

            if (parent.layoutManager !is LinearLayoutManager) {
                return
            }

            if ((parent.layoutManager as LinearLayoutManager).orientation == RecyclerView.VERTICAL) {
                val top = child.bottom - params.bottomMargin - dividerWidth
                val bottom = child.bottom - params.bottomMargin

                val left = child.left - params.leftMargin + TypedValue.applyDimension(
                    TypedValue.COMPLEX_UNIT_DIP,
                    marginLeft,
                    parent.context?.resources?.displayMetrics
                ).toInt()

                val right = child.right - params.rightMargin - TypedValue.applyDimension(
                    TypedValue.COMPLEX_UNIT_DIP,
                    marginRight,
                    parent.context?.resources?.displayMetrics
                ).toInt()

                drawable.setBounds(left, top, right, bottom)
                drawable.draw(c)
            } else {
                val top = child.top - params.topMargin + TypedValue.applyDimension(
                    TypedValue.COMPLEX_UNIT_DIP,
                    marginTop,
                    parent.context?.resources?.displayMetrics
                ).toInt()
                val bottom = child.bottom - params.bottomMargin - TypedValue.applyDimension(
                    TypedValue.COMPLEX_UNIT_DIP,
                    marginBottom,
                    parent.context?.resources?.displayMetrics
                ).toInt()

                val left = child.right - params.rightMargin - dividerWidth
                val right = child.right - params.rightMargin

                drawable.setBounds(left, top, right, bottom)
                drawable.draw(c)
            }
        }

    }
}