drop item into recyclerview

DropListener.kt

class DropListener(private val onDrop: () -> Unit) : View.OnDragListener {
  override fun onDrag(view: View, dragEvent: DragEvent): Boolean {
    when (dragEvent.action) {
      // when item has been dropped, notify about it
      DragEvent.ACTION_DROP -> onDrop()
    }

    return true
  }
}