Kotlin version of ssinss's EndlessRecyclerOnScrollListener (https://gist.github.com/ssinss/e06f12ef66c51252563e)

InfiniteScroll.kt

import android.support.v7.widget.LinearLayoutManager
import android.support.v7.widget.RecyclerView
import kotlin.properties.Delegates

class InfiniteScroll(private var layoutManager: LinearLayoutManager, private var loadMore: (page: Int) -> Unit) : RecyclerView.OnScrollListener() {

    private var loading = true
    private var previousTotal = 0
    private var visibleThreshold = 5
    private var current_page = 1
    private var firstVisibleItem by Delegates.notNull<Int>()
    private var visibleItemCount by Delegates.notNull<Int>()
    private var totalItemCount by Delegates.notNull<Int>()

    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
        super.onScrolled(recyclerView, dx, dy)

        visibleItemCount = recyclerView.childCount
        totalItemCount = layoutManager.itemCount
        firstVisibleItem = layoutManager.findFirstVisibleItemPosition()

        if (loading) {
            if (totalItemCount > previousTotal) {
                loading = false
                previousTotal = totalItemCount
            }
        }

        if (!loading && (totalItemCount - visibleItemCount) <= (firstVisibleItem + visibleThreshold)) {
            loadMore(++current_page)
            loading = true
        }

    }

}

Sample.kt

val list = RecyclerView(this)
val layoutManager = LinearLayoutManager(this)

list.layoutManager = layoutManager

list.addOnScrollListener(InfiniteScroll(layoutManager) {
  
  println("load page $it")
  
})