@Override
    protected void onPostExecute(Void v) {
      mPager.setAdapter(mPagerAdapter);
      mPagerAdapter.notifyDataSetChanged();
      mPager.setCurrentItem(sFavoriteIndex);

      if (PrefHelper.subtitleEnabled() && MainActivity.sCurrentFragment == R.id.nav_favorites) {
        mActionBar.setSubtitle(String.valueOf(sFavorites[sFavoriteIndex]));
      }

      Toolbar toolbar = ((MainActivity) getActivity()).toolbar;
      if (toolbar.getAlpha() == 0) {
        toolbar.setTranslationY(-300);
        toolbar.animate().setDuration(300).translationY(0).alpha(1);
        View view;
        for (int i = 0; i < toolbar.getChildCount(); i++) {
          view = toolbar.getChildAt(i);
          view.setTranslationY(-300);
          view.animate().setStartDelay(50 * (i + 1)).setDuration(70 * (i + 1)).translationY(0);
        }
      }
    }
  @TargetApi(Build.VERSION_CODES.LOLLIPOP)
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main_activity);

    // Assign Toolbar to the activity
    tToolbar = (Toolbar) findViewById(R.id.tToolbar);
    setSupportActionBar(tToolbar);
    getSupportActionBar().setTitle(R.string.app_name);

    // RecyclerView with sample data
    rvCities = (RecyclerView) findViewById(R.id.rvCities);
    rvCities.setLayoutManager(new LinearLayoutManager(this));
    rvCities.setAdapter(new CitiesAdapter(CityUtils.CITIES));

    if (savedInstanceState != null) {
      if (AndroidUtils.isLollipop()) {
        tToolbar.setElevation(savedInstanceState.getFloat(STATE_TOOLBAR_ELEVATION));
      }
      tToolbar.setTranslationY(savedInstanceState.getFloat(STATE_TOOLBAR_TRANSLATION_Y));
      verticalOffset = savedInstanceState.getInt(STATE_VERTICAL_OFFSET);
      scrollingOffset = savedInstanceState.getInt(STATE_SCROLLING_OFFSET);
      rvCities
          .getLayoutManager()
          .onRestoreInstanceState(savedInstanceState.getParcelable(STATE_RECYCLER_VIEW));
    }

    // We need to detect scrolling changes in the RecyclerView
    rvCities.addOnScrollListener(
        new RecyclerView.OnScrollListener() {
          @Override
          public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            if (newState == RecyclerView.SCROLL_STATE_IDLE) {
              if (scrollingOffset > 0) {
                if (verticalOffset > tToolbar.getHeight()) {
                  toolbarAnimateHide();
                } else {
                  toolbarAnimateShow(verticalOffset);
                }
              } else if (scrollingOffset < 0) {
                if (tToolbar.getTranslationY() < tToolbar.getHeight() * -0.6
                    && verticalOffset > tToolbar.getHeight()) {
                  toolbarAnimateHide();
                } else {
                  toolbarAnimateShow(verticalOffset);
                }
              }
            }
          }

          @Override
          public final void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            verticalOffset = rvCities.computeVerticalScrollOffset();
            scrollingOffset = dy;
            int toolbarYOffset = (int) (dy - tToolbar.getTranslationY());
            tToolbar.animate().cancel();
            if (scrollingOffset > 0) {
              if (toolbarYOffset < tToolbar.getHeight()) {
                if (verticalOffset > tToolbar.getHeight()) {
                  toolbarSetElevation(TOOLBAR_ELEVATION);
                }
                tToolbar.setTranslationY(-toolbarYOffset);
              } else {
                toolbarSetElevation(0);
                tToolbar.setTranslationY(-tToolbar.getHeight());
              }
            } else if (scrollingOffset < 0) {
              if (toolbarYOffset < 0) {
                if (verticalOffset <= 0) {
                  toolbarSetElevation(0);
                }
                tToolbar.setTranslationY(0);
              } else {
                if (verticalOffset > tToolbar.getHeight()) {
                  toolbarSetElevation(TOOLBAR_ELEVATION);
                }
                tToolbar.setTranslationY(-toolbarYOffset);
              }
            }
          }
        });
  }