onItemAtEndLoaded not always called

I’m using the PagingNetworkExample (room + network) where onItemAtEndLoaded is not called when i fast scroll down the list and to make it load more data from the network i have to scroll up a little and scroll back down.

This is my list:

        val config = PagedList.Config.Builder()
                .setPageSize(20)
                .setInitialLoadSizeHint(20)
//                .setPrefetchDistance(10)
                .setEnablePlaceholders(false)
                .build()

        runBlocking {

            moviesList = LivePagedListBuilder(
                    CinemaDatabase.getInstance(application)
                            .popularMoviesDao()
                            .getMoviesDataSource(), config)
                    .setBackgroundThreadExecutor(BackgroundThreadExecutor())
                    .setBoundaryCallback(PopularMoviesBoundaryCallback(application))
                    .build()
        }

The Room part:

     @Query(...)
    fun getMoviesDataSource(): DataSource.Factory<Int, MoviesEntity>

The BoundaryCallback:

class PopularMoviesBoundaryCallback(val context: Context) : PagedList.BoundaryCallback<MoviesEntity>() {

    override fun onZeroItemsLoaded() = SyncUtils.initialize(context)

    override fun onItemAtEndLoaded(itemAtEnd: MoviesEntity) {

        val prefs = defaultPrefs(context)

        fetchPopularMoviesData(context = context, page = prefs[KEY_PAGE_POPULAR, 1] + 1)

        prefs[KEY_PAGE_POPULAR] = prefs[KEY_PAGE_POPULAR, 1] + 1
    }
}

[fxmeister]

@msayan Did changing placeholders help you? I think this bug is related to the paging library, as the link you provided claims to have been fixed on Jan 18th, 2018, but we are experiencing this bug with the latest provided code sample, still.

[dlam]

Thanks for all the replies here - appreciate filing against our issuetracker as well. As noted in the bug, this v2 api has been superseded by RemoteMediator in v3, so I don’t really anticipate fixes as there is still a lot to do and realistically this won’t make it before v3 goes stable 😦