Android - update toolbar title in activity while handle back navigation with fragment

Question

I have Activity hosted slide menu with fragments , when user click at any item in slidemenu fragment is opened , I need to handle back navigation

when user click at item in list I call this method to display proper fragment

public void SelectItem(int position) {

        Fragment _fragment = null;
        switch (position) {
            case 0:
                _fragment = Test_Home.newInstance();
                break;

            case 1:
                _fragment = Diseases_Fragment.newInstance();
                break;

          ........

            case 8:
                Logout();
                break;

            default:
               break;

        }

        if (_fragment != null) {
            FragmentManager fragmentManager = getSupportFragmentManager();
            fragmentManager.beginTransaction().replace(R.id.view_content, _fragment).addToBackStack(null).commit();
             // set title , this textview in toolbar 
            _frag_title.setText(nav_items[position]);
            mDrawerLayout.closeDrawer(GravityCompat.START);
        }

this method to handle back button

@Override
    public void onBackPressed() {
        if (getFragmentManager().getBackStackEntryCount() > 0) {
            getFragmentManager().popBackStack();
        } else {
            super.onBackPressed();
        }
    }

my onCreate method

 @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.home_view);
            Toolbar _toolbar = (Toolbar) findViewById(R.id.toolbar);

           setSupportActionBar(_toolbar);
           getSupportActionBar().setHomeButtonEnabled(true);
           getSupportActionBar().setDisplayHomeAsUpEnabled(true);
           _frag_title = (TextView) _toolbar.findViewById(R.id.frag_title);
    }

in fact it work just fine , but my problem is displayed fragment show old title dont show new title

is there way call my method _frag_title.setText(nav_items[position]);

my problem not in back navigation , my problem how to update toolbar title in navigation

Possible duplicate of [Programmatically go back to the previous fragment in the backstack](http://stackoverflow.com/questions/10863572/programmatically-go-back-to-the-previous-fragment-in-the-backstack) — Dhaval Parmar, Dec 01 '15 at 11:16
my problem not in back navigation , I provide working code , my problem in update tool bar title — Mina Fawzy, Dec 01 '15 at 11:23
you are using different title for different fragment. and you want to to change that title on toolbar whenever change fragment? m i right? — Dhaval Parmar, Dec 01 '15 at 12:00
ok then check my answer http://stackoverflow.com/a/34020202/1168654 — Dhaval Parmar, Dec 01 '15 at 12:13

score 6 · Accepted Answer · answered Dec 01 '15 at 12:13

to change title of tool bar whenever change fragment you have to do below way.

must have to use fragment with TAG name or by ID, i will show you how to use that using TAG name(you can also use by id in that case you have to change my code).

to use by TAG, you have to add fragment TAG, whenever you add fragment in layout, let's add fragment by TAG

Fragment fragmentA = new FragmentA();
getFragmentManager().beginTransaction()
    .replace(R.id.MainFrameLayout,fragmentA,"YOUR_TARGET_FRAGMENT_TAG")
    .addToBackStack("YOUR_SOURCE_FRAGMENT_TAG").commit();

after do above way, in onBackPressed check which fragment on you are, using below code

@Override
public void onBackPressed(){
    FragmentManager fm = getFragmentManager();
    if (fm.getBackStackEntryCount() > 0) {
        Log.i("MainActivity", "popping backstack");
        fm.popBackStack();
        Fragment fragment = getFragmentManager().findFragmentByTag("YOUR_TARGET_FRAGMENT_TAG");
        if (fragment instanceof FragmentA) {
            // add your code to change title of toolbar
        }
    } else {
        Log.i("MainActivity", "nothing on backstack, calling super");
        super.onBackPressed();  
    }
}

What if using `getFragmentManager().beginTransaction() .add(R.id.MainFrameLayout,fragmentA,"YOUR_TARGET_FRAGMENT_TAG") .addToBackStack("YOUR_SOURCE_FRAGMENT_TAG").commit(); `? Becuase if I use `add` method instead of `replace` it doesn't call `onResume` — virengujariya, Feb 20 '17 at 23:32

score 1 · Answer 2 · answered Dec 13 '15 at 14:35

here is a piece of my code after resolve this issue

public void SelectItem(int position) {
        Fragment _fragment = null;
        switch (position) {
            case 0:
                _fragment = Test_Home.newInstance();
                break;

            case 1:
                _fragment = Diseases_Fragment.newInstance();
                break;

          ........
          .....

            case 8:
                Logout();
                break;

            default:
               break;

        }

        if (_fragment != null) {
         // I add tag when I add fragment to BackStack
          String backStackName = fragment.getClass().getName();
        FragmentManager fragmentManager = getSupportFragmentManager();
        fragmentManager.beginTransaction().replace(R.id.view_content, fragment, "TARGET_TAG")
                .setTransitionStyle(FragmentTransaction.TRANSIT_FRAGMENT_FADE)
                .addToBackStack(backStackName)
                .commit();
        _frag_title.setText(nav_items[position]);
        mDrawerLayout.closeDrawer(GravityCompat.START);
        } 
       }

I add BackStackChangedListener on onCreate method

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

        ......
        ....

        .
        getSupportFragmentManager().addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
            @Override
            public void onBackStackChanged() {
                Fragment f = getSupportFragmentManager().findFragmentById(R.id.view_content);
                if (f != null) {
                    updateTitleAndDrawer(f);
                }
            }
        });
}

   private void updateTitleAndDrawer(Fragment f) {
        String name = f.getClass().getName();
        if (name != null) {
            ChangeTitle(name);
        }
    }
 private void ChangeTitle(String fragmentName) {
        if (fragmentName.equals(Test_Home.class.getName())) {
            _frag_title.setText(nav_items[0]);
        } else if (fragmentName.equals(Diseases_Fragment.class.getName())) {
            _frag_title.setText(nav_items[1]);
        } else if (fragmentName.equals(Questions_Fragment.class.getName())) {
            _frag_title.setText(nav_items[2]);

       .......... 
       .......
}

}

score 0 · Answer 3 · edited Feb 25 '16 at 12:13

0

You have to handle this on resume of each oh your Fragment to specify the title when it comes back to the fragment.

Currently what happens is, you are setting the title in onCreate or somewhere when it actually creates the fragment, But since the tool bar is not something that resides inside Activity (Not in the Fragment) You have to make changes to that specifically. Best place is onResume method of the fragment.

So try setting up the TextView in your onResume of your Fragment

edited Feb 25 '16 at 12:13

Dhaval Parmar

18,812
8
82
177

answered Dec 01 '15 at 10:40

diyoda_

5,274
8
57
89

my problem not in setting title , the problem when user click back tool bar keep old title not update to display fragment , let consider it show fragment two with title two , when user click back it show fragment one but the title still two – Mina Fawzy Dec 01 '15 at 10:50
@MinaFawzy were you able to figure out the issue? – diyoda_ Dec 01 '15 at 19:33
I think I will find way to do that, but your answer is wrong – Mina Fawzy Dec 01 '15 at 19:45
What part is wrong, is the onResume not called on back button pressed? – diyoda_ Dec 01 '15 at 20:50
I am using textview inside toolbar – Mina Fawzy Dec 01 '15 at 21:06
can you check if the onResume of Fragment is called on back button pressed? – diyoda_ Dec 01 '15 at 21:51

Android - update toolbar title in activity while handle back navigation with fragment

3 Answers3