реализация search-view на панели действий основного действия, возможно, не работает

Question

Я столкнулся с проблемой при реализации searchview на панели действий основного действия ... где основное действие имеет нижнее навигационное меню с тремя фрагментами ...

, и представление поиска должно работать с каждым фрагментом...

открытый класс MainActivity расширяет AppCompatActivity, реализует SearchView.OnQueryTextListener {

private Boolean LoadContact = false ;
private BottomNavigationView navigationView ;
private String SearchText;
int page;

AllContactFrag allContactFrag = new AllContactFrag();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

  final Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
   setSupportActionBar(toolbar);

   toolbar.setTitle("Special Contact");


    navigationView =(BottomNavigationView) findViewById(R.id.navigationView);

    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    ft.replace(R.id.frame, new SpecialContactFrag());
    ft.commit();
   // navigationView.setSelectedItemId();


    navigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {

            int id = item.getItemId();
            switch (id)
            {
                case R.id.action_MyNotes:

                    Bundle bundle = new Bundle();
                    bundle.putString("text",SearchText);
                    Fragment AllNotes = new NotesFrag();
                    AllNotes.setArguments(bundle);
                    FragmentManager manager = getSupportFragmentManager();
                    FragmentTransaction transaction = manager.beginTransaction();
                    transaction.replace(R.id.frame,AllNotes);
                    transaction.addToBackStack(null);
                    transaction.commit();

                    toolbar.setTitle("My Note");
                    return true;

                case R.id.action_AllContact:

                    Bundle bundle2 = new Bundle();
                    bundle2.putString("text",SearchText);
                    Fragment AlxlContact = new AllContactFrag();
                    AlxlContact.setArguments(bundle2);
                    FragmentManager xmanager = getSupportFragmentManager();
                    FragmentTransaction xtransaction = xmanager.beginTransaction();
                    xtransaction.replace(R.id.frame,AlxlContact);
                    xtransaction.addToBackStack(null);
                    xtransaction.commit();
                    toolbar.setTitle("Phone Contact");
                    return true;

                case R.id.action_Spec:
                    Fragment AlxxlContact = new SpecialContactFrag();
                    FragmentManager xxmanager = getSupportFragmentManager();
                    FragmentTransaction xxtransaction = xxmanager.beginTransaction();
                    xxtransaction.replace(R.id.frame,AlxxlContact);
                    xxtransaction.addToBackStack(null);
                    xxtransaction.commit();
                    toolbar.setTitle("Special Contact");
                    return true;

            }

            return true;
        }
    });

}



@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);

    SearchManager searchManager = (SearchManager)getSystemService(Context.SEARCH_SERVICE);

MenuItem menuItem = menu.findItem (R.id.search);SearchView searchView = (SearchView) menuItem.getActionView ();searchView.setSearchableInfo (searchManager.getSearchableInfo (getComponentName ()));

    searchView.setOnQueryTextListener(this);
    return true;
}



@Override
protected void onResume() {
    super.onResume();


}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@Override
public boolean onQueryTextSubmit(String query) {


    int id = navigationView.getSelectedItemId();

    switch (id)
    {
        case R.id.action_MyNotes:

            Fragment NoteFrgment = new NotesFrag();
            ((NotesFrag) NoteFrgment).onQueryTextSubmit(query);

        case R.id.action_AllContact:
            Fragment AllCont = new AllContactFrag();
            ((AllContactFrag) AllCont).onQueryTextSubmit(query);
            return true;
        case R.id.action_Spec :
            Fragment Spec = new SpecialContactFrag();
            ((SpecialContactFrag) Spec).onQueryTextSubmit(query);

    }

    return true;
}

@Override
public boolean onQueryTextChange(String newText) {

   // Toast.makeText(getBaseContext(),newText,Toast.LENGTH_LONG).show();
    SearchText = newText ;

    int id = navigationView.getSelectedItemId();

    switch (id)
    {
        case R.id.action_MyNotes:

            Fragment NoteFrgment = new NotesFrag();
            ((NotesFrag) NoteFrgment).onQueryTextChange(newText);

        case R.id.action_AllContact:
                AllContactFrag AllCont = (AllContactFrag)getSupportFragmentManager().findFragmentById(R.id.frame);
                ((AllContactFrag) AllCont).onQueryTextChange(newText);
            return true;
        case R.id.action_Spec :
            Fragment Spec = new SpecialContactFrag();

            ((SpecialContactFrag) Spec).onQueryTextChange(newText);

    }

    return true;
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);

    allContactFrag.onRequestPermissionsResult(requestCode, permissions, grantResults);

}

/*   public class SectionsPagerAdapter extends FragmentPagerAdapter {


    List<Fragment> fragmentList = new ArrayList<>();
    List<String> fragmentListTitle = new ArrayList<>();


    public SectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {

        if(LoadContact){
            return fragmentList.get(position);
        }else {
            return fragmentList.get(position);
        }

    }

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

    public void AddFragment(Fragment fragment, String fragmentTitle)
    {
        fragmentList.add(fragment);
        fragmentListTitle.add(fragmentTitle);
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return fragmentListTitle.get(position);
    }
}
*/

}

//

 @Override
public boolean onQueryTextChange(String newText) {

   // Toast.makeText(getBaseContext(),newText,Toast.LENGTH_LONG).show();
    SearchText = newText ;

    int id = navigationView.getSelectedItemId();

    switch (id)
    {
        case R.id.action_MyNotes:

            Fragment NoteFrgment = new NotesFrag();
            ((NotesFrag) NoteFrgment).onQueryTextChange(newText);

        case R.id.action_AllContact:
                AllContactFrag AllCont = (AllContactFrag)getSupportFragmentManager().findFragmentById(R.id.frame);
                ((AllContactFrag) AllCont).onQueryTextChange(newText);
            return true;
        case R.id.action_Spec :
            Fragment Spec = new SpecialContactFrag();

            ((SpecialContactFrag) Spec).onQueryTextChange(newText);

    }

    return true;
}

// во фрагменте

   @Override
public boolean onQueryTextSubmit(String s) {

    Log.d("", "onQueryTextSubmit: ");
    search_list = new ArrayList<>();
    search_list.clear();

    Context context = getContext();
    db = new dbhandler(mcontext);
 phoneList = new ArrayList<>();
   phoneList = db.getAllPhoneContact();


    String name;
    contact contact  = new contact();
    for (int i = 0; i < phoneList.size(); i++)
    {
        contact = phoneList.get(i);
        name = phoneList.get(i).getName();
        if(name.contains(s))
        {
            search_list.add(contact);
        }
     }


    allConAdapter = new AllConAdapter(getActivity(),search_list, 0);

    RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getContext());

    recyclerView.setLayoutManager(layoutManager);

    recyclerView.setAdapter(allConAdapter);

    allConAdapter.notifyDataSetChanged();

    return true ;

}

private Context mcontext;

@Override
public void onAttach(Context context) {
    super.onAttach(context);

    mcontext = context ;
    Log.d("", "onAttach: ");
}

у фрагмента в onQueryTextSubmit значение контекста становится нулевым, поэтому приложение вылетает, потому что я хочу прочитать данные из SQLite, а контекст - ноль