setHomeButtonEnabled on toolbar in a fragment

Question

Android studio 1.3
com.android.support:appcompat-v7:22.1.1

Hello,

I am using the new toolbar and displaying in my fragment. However, I want to be able to navigate back to the previous fragment by having the setHomeButtonEnabled(true). However, in my fragment in the onCreateView there is no such function. This works in the Activity, but doesn't work in the fragment.

Is there anyway to have the toolbar display the setHomeButtonEnabled so that an arrow is displayed so the user can nagivate back.

public class FileTransferFragment extends Fragment {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setHasOptionsMenu(true);

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_file_transfer, container, false);

        final Toolbar toolbar = (Toolbar)view.findViewById(R.id.app_bar);
        AppCompatActivity appCompatActivity = (AppCompatActivity)getActivity();
        appCompatActivity.setSupportActionBar(toolbar);

    /* TRIED THIS BUT DIDN'T WORK */
        appCompatActivity.getActionBar().setHomeButtonEnabled(true);
        appCompatActivity.getActionBar().setDisplayHomeAsUpEnabled(true);
        return view;
    }
}

In my Activity I am extending the AppCompatActivity and using appcompat-v7:22.1.1

public class FileTransferActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_file_transfer);

        if(savedInstanceState == null) {
            FragmentManager fragmentManager = getFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
            fragmentTransaction.add(R.id.fragment_container,
                    FileTransferFragment.getFileTransferFragment(1234), "FileTransferFragment");
            fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
            fragmentTransaction.commit();
        }
    }
}

As you can see on the image there is no arraw on the left of the toolbar to allow the user to nagivate back.

Answer 1

use

   appCompatActivity.getSupportActionBar().setDisplayHomeAsUpEnabled(true);

instead of

   appCompatActivity.getActionBar().setDisplayHomeAsUpEnabled(true);

Answer 2

If you have actionBar enabled in your fragment, its good thing. For now, navigationDrawer icon, known as hamburger icon, if want to enable that , you need the following method in your fragment.

first of all create instances.

private ActionBarDrawerToggle drawerToggle;
private DrawerLayout mDrawerLayout;

you need above instances.

drawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.drawer_open, R.string.drawer_close){

        @Override
        public void onDrawerOpened(View drawerView) {
            super.onDrawerOpened(drawerView);
            //Todo
            //you don't have to write here anything to enable icon
        }

        @Override
        public void onDrawerClosed(View drawerView) {
            super.onDrawerClosed(drawerView);
            //Todo
            //you dont have to write here anything to enable icon
        }

    };
    mDrawerLayout.setDrawerListener(drawerToggle); 

after this, your fragment should have some way to inform the mainActivity when the drawer is closed or opened you can do that by syncState() method.

    mDrawerLayout.post(new Runnable(){

        @Override
        public void run(){
            //enable hamburger icon
            drawerToggle.syncState();
        }

    });

you can implement this whole as separate method in fragment and call from main.

Read documentation here to get more information. about the whole class

ActionBarDrawerToggle