Infinite Scrolling Android RecyclerView with RxJava

ApiService.java

public static Observable<List<String>> paginatedThings(final Observable<Void> onNextObservable) {
        return Observable.create(new Observable.OnSubscribe<List<String>>() {
            @Override
            public void call(final Subscriber<? super List<String>> subscriber) {

                onNextObservable.subscribe(new Observer<Void>() {
                    int latestPage = -1;
                    @Override
                    public void onCompleted() {
                        subscriber.onCompleted();
                    }

                    @Override
                    public void onError(Throwable e) {
                        subscriber.onError(e);
                    }

                    @Override
                    public void onNext(Void aVoid) {
                        latestPage++;
                        List<String> pageItems = new ArrayList<String>();
                        for (int i = 0; i < 10; i++) {
                            pageItems.add("page " + latestPage + " item " + i);
                        }
                        subscriber.onNext(pageItems);
                    }
                });
            }
        });
    }

ReactiveList.java

package com.example.rxandroid;

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.example.rxandroid.api.RepresentativeApi;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

import butterknife.ButterKnife;
import butterknife.InjectView;
import rx.Observable;
import rx.Observer;
import rx.Subscriber;
import rx.android.schedulers.AndroidSchedulers;
import rx.subscriptions.CompositeSubscription;
import timber.log.Timber;

import static rx.android.app.AppObservable.bindActivity;

/**
 * Created by Dustin on 2/14/15.
 */
public class ReactiveList extends Activity {

    @InjectView(R.id.reactiveList)
    RecyclerView reactiveList;

    private ReactiveRecyclerAdapter adapter = new ReactiveRecyclerAdapter();
    private LinearLayoutManager layoutManager;

    private CompositeSubscription subscriptions = new CompositeSubscription();

    private List<String> mockItems = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.reactive_list);
        ButterKnife.inject(this);

        for (int i = 0; i < 100; i++) {
            mockItems.add(String.valueOf(i));
        }

        reactiveList.setHasFixedSize(true);
        reactiveList.setAdapter(adapter);
        layoutManager = new LinearLayoutManager(this);
        reactiveList.setLayoutManager(layoutManager);

        adapter.addAll(mockItems);

        Observable<Void> pageDetector = Observable.create(new Observable.OnSubscribe<Void>() {
            @Override
            public void call(final Subscriber<? super Void> subscriber) {
                reactiveList.setOnScrollListener(new RecyclerView.OnScrollListener() {
                    int pastVisibleItems, visibleItemCount, totalItemCount;
                    @Override
                    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                        visibleItemCount = layoutManager.getChildCount();
                        totalItemCount = layoutManager.getItemCount();
                        pastVisibleItems = layoutManager.findFirstVisibleItemPosition();

                        if ((visibleItemCount+pastVisibleItems) >= totalItemCount) {
                            subscriber.onNext(null);
                        }
                    }
                });
            }
        }).debounce(400, TimeUnit.MILLISECONDS);

        bindActivity(this, pageDetector);
        Observable<List<String>> listItemObservable = RepresentativeApi.paginatedThings(pageDetector);
        bindActivity(this, listItemObservable);
        subscriptions.add(listItemObservable.observeOn(AndroidSchedulers.mainThread()).subscribe(new Observer<List<String>>() {
            @Override
            public void onCompleted() {
                Timber.d("completed");
            }

            @Override
            public void onError(Throwable e) {
                Timber.e("error: " + e.getMessage());
            }

            @Override
            public void onNext(List<String> strings) {
                adapter.addAll(strings);
            }
        }));
    }

    public static class ReactiveRecyclerAdapter extends RecyclerView.Adapter<ReactiveRecyclerAdapter.ReactiveViewHolder> {

        private List<String> items = new ArrayList<>();

        public void addAll(List<String> moreItems) {
            items.addAll(moreItems);
            notifyDataSetChanged();
        }

        @Override
        public ReactiveViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View v = LayoutInflater.from(parent.getContext()).inflate(android.R.layout.simple_list_item_1,parent,false);
            ReactiveViewHolder vh = new ReactiveViewHolder(v);
            return vh;
        }

        @Override
        public void onBindViewHolder(ReactiveViewHolder holder, int position) {
            String item = items.get(position);
            holder.label.setText(item);
        }

        @Override
        public int getItemCount() {
            return items.size();
        }

        public static class ReactiveViewHolder extends RecyclerView.ViewHolder {

            TextView label;
            public ReactiveViewHolder(View itemView) {
                super(itemView);
                label = (TextView) itemView.findViewById(android.R.id.text1);
            }
        }
    }
}