Remove up button from action bar when navigating using BottomNavigationView with Android Navigation UI library

Question

I\'ve created a small app that has three fragments for top-level navigation through a BottomNavigationView. If you launch the app and click on a navigation button on the bottom

Answer 1

You could set the navigation icon to null, or change the icon only for some destinations eg:

1) In Kotlin:

navController.addOnDestinationChangedListener { _, destination, _ ->
            toolbar.title = destination.label
            toolbar.navigationIcon = null
}

2) In Java:

hostFragment.getNavController().addOnDestinationChangedListener(new OnDestinationChangedListener() {
    public final void onDestinationChanged(@NotNull NavController controller, @NotNull NavDestination destination, @Nullable Bundle arguments) {
        toolbar.setTitle(destination.getLabel());
        toolbar.setNavigationIcon(null);
    }
});

Answer 2

If you are using NavigationUI.setupWithNavController check out onNavDestinationSelected.

Inside your bottom navigation view menu.xml, add android:menuCategory="secondary" to the corresponding MenuItem:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

  <item
    android:id="@+id/profileFragment"
    android:icon="@drawable/bottom_nav_icon_profile"
    android:menuCategory="secondary"
    android:title="@string/profile" />

Answer 3

In Java this works for me:

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

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

    navController = Navigation.findNavController(this, R.id.nav_host_fragment);
    AppBarConfiguration appBarConfiguration = new AppBarConfiguration
            .Builder(navController.getGraph())
            .build();
    NavigationUI.setupWithNavController(toolbar, navController, appBarConfiguration);

    navController.addOnDestinationChangedListener((controller, destination, arguments) -> {
        toolbar.setTitle(destination.getLabel());
        toolbar.setNavigationIcon(null);
    });

Answer 4

I had the same problem and I found a way to get the current fragment with the NavController.addOnNavigatedListener, so I applied the following logic within my Activity and for now it works for me

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_home)
    val navHost = supportFragmentManager
            .findFragmentById(R.id.navHostFragment) as NavHostFragment

    navHost.navController.addOnNavigatedListener { _, destination ->
        val showButton = showUpButton(destination.id)
        //Here occurs the magic
        supportActionBar?.setDisplayShowHomeEnabled(showButton)
        supportActionBar?.setDisplayHomeAsUpEnabled(showButton)
    }
}

//Check according to your convenience which fragment id
//should show or hide the "Up Button"
private fun showUpButton(id: Int): Boolean {
    return id != R.id.your_home_fragment && id != R.id.your_list_fragment 
            && id != R.id.your_profile_fragment
}

And this is my project...

I do not know if it is the best option but if someone has any better suggestion, it will be welcome

Answer 5

Starting with 1.0.0-alpha07 you can use AppBarConfiguration to configure that behaviour.

AppBarConfiguration has a Builder constructor so you can create a new Builder with a specific set of top level destinations, referenced by their id (this id is the one you set on your navigation layout).

Create new AppBarConfiguration:

val appBarConfiguration = AppBarConfiguration
            .Builder(
                    R.id.navigationHomeFragment,
                    R.id.navigationListFragment,
                    R.id.navigationProfileFragment)
            .build()

Then, instead of setupActionBarWithNavController(this, navController) you need to call setupActionBarWithNavController(this, navController, appBarConfiguration)

This is the right way to handle top navigation behaviours.

Answer 6

Use this instead of setupWithNavController:

navController.addOnNavigatedListener(new NavController.OnNavigatedListener() {
     @Override
     public void onNavigated(@NonNull NavController controller, @NonNull NavDestination destination) {
         toolbar.setTitle(destination.getLabel());
     }
});

Or the equivalent in Kotlin.

The only thing setupWithNavController does is add a listener to change the toolbar title, and creates the up button. If you don't want the up button, just add a listener which changes the toolbar title only.