private void loadPage(int page) {
   api.getActivities(categories[currentCategory], page, PAGE_SIZE)
       .subscribeOn(Schedulers.io())
       .observeOn(AndroidSchedulers.mainThread())
       .subscribe(
           new Action1<List<Activity>>() {
             @Override
             public void call(List<Activity> activities) {
               ActivitiesFragment.this.activities.addAll(activities);
               list.getAdapter().notifyDataSetChanged();
             }
           },
           new Action1<Throwable>() {
             @Override
             public void call(Throwable throwable) {
               Timber.e(
                   "failed to fetch " + categories[currentCategory] + " activities", throwable);
               throwable.printStackTrace();
             }
           });
 }
  public View onCreateView(
      LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    ActivitiesFragmentBinding binding =
        DataBindingUtil.inflate(inflater, R.layout.activities_fragment, container, false);
    binding.setCategory(category);

    Toolbar toolbar = binding.toolbar;
    AppCompatActivity activity = (AppCompatActivity) getActivity();
    activity.setSupportActionBar(toolbar);
    assert activity.getSupportActionBar() != null;
    final ActionBar ab = activity.getSupportActionBar();
    ab.setDisplayShowTitleEnabled(false);
    ab.setDisplayHomeAsUpEnabled(false);

    Spinner spinner = binding.spinner;
    spinner.setAdapter(
        new ArrayAdapter<>(
            ab.getThemedContext(), android.R.layout.simple_spinner_item, localizedCategory));
    spinner.setOnItemSelectedListener(
        new AdapterView.OnItemSelectedListener() {
          @Override
          public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            if (currentCategory != position) {
              currentCategory = position;
              category.set(localizedCategory[currentCategory]);
              activities.clear();
              list.getAdapter().notifyDataSetChanged();
            }
          }

          @Override
          public void onNothingSelected(AdapterView<?> parent) {}
        });

    slider = binding.slider;
    slider.setCustomIndicator(binding.customIndicator);
    slider.setDuration(3500);
    slider.setPresetTransformer(SliderLayout.Transformer.Fade);
    api.getActivities("recommendations", 0, 5)
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(
            new Action1<List<Activity>>() {
              @Override
              public void call(List<Activity> activities) {
                slider.stopAutoCycle();
                slider.removeAllSliders();
                for (Activity activity : activities) {
                  ActivitySliderView view = new ActivitySliderView(getContext(), activity);
                  view.bundle(new Bundle());
                  view.getBundle().putLong("id", activity.getId());
                  view.setOnSliderClickListener(sliderClickListener);
                  slider.addSlider(view);
                }
                slider.startAutoCycle();
              }
            },
            new Action1<Throwable>() {
              @Override
              public void call(Throwable throwable) {
                Timber.e("failed to fetch recommended activities", throwable);
                throwable.printStackTrace();
              }
            });

    list = binding.list;
    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext());
    list.setLayoutManager(linearLayoutManager);
    list.addItemDecoration(new MarginDownDecoration(getContext()));
    list.setAdapter(new ActivitiesAdapter(activities));
    list.addOnScrollListener(
        new EndlessRecyclerOnScrollListener(linearLayoutManager) {
          @Override
          public void onLoadMore(int currentPage) {
            loadPage(currentPage);
          }
        });

    // loadPage(0);

    return binding.getRoot();
  }