Update SlidingTabLayout

Sample images:

• Empty PagerView
  
  

2. PagerView
   
   with new content ( SlidingTabLayout
   
   not updated)

3. New instance of the view ( SlidingTabLayout
   
   updated);

This is my code:

public class CharSortFragment extends Fragment {

    private final String TAG = "CharSortFragment";

    private ViewPager viewPager;
    private TabsPagerAdapter tabsAdapter;
    private SlidingTabLayout slidingTabLayout;

    private FragmentActivity activity;

    public CharSortFragment() {}

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        Log.d(TAG, "OnCreate view...");
        final View view = inflater.inflate(R.layout.char_sort_fragment, container, false);
        activity = getActivity();

        Log.d(TAG, "Init add button...");
        FloatingActionButton addButton = (FloatingActionButton) view.findViewById(R.id.add_button);
        addButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.d(TAG, "Add button was clicked...");
                startActivityForResult(new Intent(getActivity(), EditActivity.class), 1);
            }
        });

        viewPager = (ViewPager) view.findViewById(R.id.pager);
        tabsAdapter = new TabsPagerAdapter(activity.getSupportFragmentManager());
        viewPager.setAdapter(tabsAdapter);

        Log.d(TAG, "Connecting PagerSlidingTabStrip...");
        slidingTabLayout = (SlidingTabLayout) view.findViewById(R.id.tabs);
        slidingTabLayout.setViewPager(viewPager);

        Log.d(TAG, "OnCreate finished!");
        return view;
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        Log.d(TAG, "On activity result: " + resultCode);

        if(resultCode == 1) {
            Log.d(TAG, "Notify data changes...");
            tabsAdapter.updateCharSet();
            tabsAdapter.notifyDataSetChanged();
            slidingTabLayout.invalidate();
            CardListFragment cardListFragment = tabsAdapter.currentFragment;
            /*  TabsAdapter ,    
            if(tabsAdapter.currentFragment == null) {
                tabsAdapter.updateCharSet();
                tabsAdapter.notifyDataSetChanged();
                cardListFragment = tabsAdapter.currentFragment;
            }
            */
            RecyclerViewAdapter recyclerViewAdapter = cardListFragment.getAdapter();
            recyclerViewAdapter.updateDataSet();
            recyclerViewAdapter.notifyDataSetChanged();
            Log.d(TAG, "Views was notified!");
        }
    }

    public class TabsPagerAdapter extends FragmentPagerAdapter {

        private final String TAG = "TabsPagerAdapter";

        private final HashSet<TongueTwister> data = TongueTwistersStorageManager.getInstance().getData();
        private final ArrayList<Character> characters = new ArrayList<>();

        private CardListFragment currentFragment;

        public TabsPagerAdapter(FragmentManager fm) {
            super(fm);
            Log.i(TAG, "Creating TabsPagerAdapter...");
            updateCharSet();
        }

        @Override
        public Fragment getItem(int position) {
            char charAtCurrentPos = characters.get(position);
            return CardListFragment.newInstance(charAtCurrentPos);
        }

        protected void updateCharSet() {
            this.characters.clear();
            this.characters.addAll(generateCharList());
        }

        private ArrayList<Character> generateCharList() {
            Log.i(TAG, "Generating char list...");
            Log.i(TAG, "Total tongue twisters: " + data.size());
            HashSet<Character> hashCharacters = new HashSet<>();
            for (TongueTwister tongueTwister : data) {
                for(char character : tongueTwister.getCharacters()) {
                    if(!hashCharacters.contains(character)) {
                        Log.i(TAG, "Char: " + character);
                        hashCharacters.add(character);
                    }
                }
            }
            Log.i(TAG, "Sorting...");
            ArrayList<Character> characters = new ArrayList<>(hashCharacters);
            Collections.sort(characters);
            Log.i(TAG, "Char list was generated!");
            return characters;
        }

        @Override
        public int getCount() {
            return characters.size();
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return String.valueOf(characters.get(position));
        }

        @Override
        public void setPrimaryItem(ViewGroup container, int position, Object object) {
            currentFragment = (CardListFragment) object;
        }

    }

}

      

        
        
        
      

    

How to update SlidingTabLayout

? ( slidingTabLayout.invalidate()

doesn't work for me)