list actions.kt

fun actions() = Observable.merge<ListAction>(
    recyclerView.scrollEvents()
        // filter when we do a scroll up
        .filter { it.dy > 0 }
        // filter when recyclerView is currently loading
        .filter { !isLoading }
        // filter threshold
        .filter {
            val layoutManager = it.view.layoutManager as StaggeredGridLayoutManager
            val visibleItemCount = recyclerView.childCount
            val totalItemCount = layoutManager.itemCount
            val firstVisibleItem = layoutManager.findFirstVisibleItemPositions(null).first()

            totalItemCount - visibleItemCount <= firstVisibleItem + GiphyListFragment.VISIBLE_THRESHOLD
        }
        .map { ListAction.LoadMore(adapter.list.size) }
        .doOnNext { isLoading = true },
    swipeRefreshLayout.refreshes().map { ListAction.Refresh() },
    giphyViewItem.itemClick().map { ListAction.OnItemClick(it) }
)