RV-scrollListener.kt

// ...(略)

mPresenter.loadFirstPage()

mList.addOnScrollListener(object : RecyclerView.OnScrollListener() {
    var mShouldReload = false

    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
        super.onScrolled(recyclerView, dx, dy)
        val layoutManager = recyclerView.layoutManager as LinearLayoutManager
        val firstVisibleItem = layoutManager.findFirstVisibleItemPosition()
        val visibleItemCount = layoutManager.childCount
        val totalItemCount: Int = layoutManager.itemCount
        mShouldReload = firstVisibleItem + visibleItemCount == totalItemCount && dy > 0
    }

    override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
        super.onScrollStateChanged(recyclerView, newState)
        if (newState == RecyclerView.SCROLL_STATE_IDLE && mShouldReload)
            mPresenter.loadNextPage()
    }
})