val receiver: DragSelectReceiver = // ...
val touchListener = DragSelectTouchListener.create(context, receiver)

DragSelectTouchListener.create(context, adapter) {
  // Configure the auto-scroll hotspot
  hotspotHeight = resources.getDimensionPixelSize(R.dimen.default_56dp)
  hotspotOffsetTop = 0 // default
  hotspotOffsetBottom = 0 // default
  
  // Listen for auto scroll start/end
  autoScrollListener = { isScrolling -> } 

  // Or instead of the above...
  disableAutoScroll()
  
  // The drag selection mode, RANGE is the default
  mode = RANGE
}

class MyReceiver : DragSelectReceiver {

  override fun setSelected(index: Int, selected: Boolean) {
    // do something to mark this index as selected/unselected
    if(selected && !selectedIndices.contains(index)) {
      selectedIndices.add(index)
    } else if(!selected) {
      selectedIndices.remove(index)
    }
  }
  
  override fun isSelected(index: Int): Boolean {
    // return true if this index is currently selected
    return selectedItems.contains(index)
  }
  
  override fun isIndexSelectable(index: Int): Boolean {
    // if you return false, this index can't be used with setIsActive()
    return true
  }

  override fun getItemCount(): Int {
    // return size of your data set
    return 0
  }
}

val recyclerView: RecyclerView = // ...
val receiver: DragSelectReceiver = // ...

val touchListener = DragSelectTouchListener.create(context, receiver)
recyclerView.addOnItemTouchListener(touchListener) // important!!

// true for active = true, 0 is the initial selected index
touchListener.setIsActive(true, 0)