Navigation bar

The navigation bar allows users to switch between destinations in an app. You should use navigation bars for:

  • Three to five destinations of equal importance
  • Compact window sizes
  • Consistent destinations across app screens
A navigation bar with 4 destinations. Each destination has a placeholder name called "Label", with the selected destination appearing with a circle icon, and the rest of the destinations as triangles.
Figure 1. A navigation bar with 4 destinations.

This page shows you how to display a navigation bar in your app with related screens and basic navigation.

API surface

Use the NavigationBar and NavigationBarItem composables to implement destination switching logic. Each NavigationBarItem represents a singular destination.

NavigationBarItem includes the following key parameters:

  • selected: Determines whether the current item is visually highlighted.
  • onClick(): Defines the action to be performed when the user clicks on the item. Logic for handling navigation events, updating the selected item state, or loading corresponding content belongs here.
  • label: Displays text within the item. Optional.
  • icon: Displays an icon within the item. Optional.

Example: Bottom navigation bar

The following snippet implements a bottom navigation bar with items so users can navigate between different screens in an app:

@Composable
fun NavigationBarExample(modifier: Modifier = Modifier) {
    val navController = rememberNavController()
    val startDestination = Destination.SONGS
    var selectedDestination by rememberSaveable { mutableIntStateOf(startDestination.ordinal) }

    Scaffold(
        modifier = modifier,
        bottomBar = {
            NavigationBar(windowInsets = NavigationBarDefaults.windowInsets) {
                Destination.entries.forEachIndexed { index, destination ->
                    NavigationBarItem(
                        selected = selectedDestination == index,
                        onClick = {
                            navController.navigate(route = destination.route)
                            selectedDestination = index
                        },
                        icon = {
                            Icon(
                                destination.icon,
                                contentDescription = destination.contentDescription
                            )
                        },
                        label = { Text(destination.label) }
                    )
                }
            }
        }
    ) { contentPadding ->
        AppNavHost(navController, startDestination, modifier = Modifier.padding(contentPadding))
    }
}

Key points

  • NavigationBar displays a collection of items, with each item corresponding to a Destination.
  • val navController = rememberNavController() creates and remembers an instance of NavHostController, which manages the navigation within a NavHost.
  • var selectedDestination by rememberSaveable { mutableIntStateOf(startDestination.ordinal) } manages the state of the selected item.
    • startDestination.ordinal gets the numerical index (position) of the Destination.SONGS enum entry.
  • When an item is clicked, navController.navigate(route = destination.route) is called to navigate to the corresponding screen.
  • The onClick lambda of the NavigationBarItem updates the selectedDestination state to visually highlight the clicked item.
  • The navigation logic calls the AppNavHost composable, passing the navController and startDestination, to display the actual content of the selected screen.

Result

The following image shows the navigation bar resulting from the previous snippet:

An app screen with 3 destinations listed horizontally in a bottom navigation bar: Songs, Album, and Playlist. Each destination has a relevant icon paired with it (e.g., a music note for "Songs").
Figure 2. A navigation bar that contains 3 destinations with associated icons: Songs, Album, and Playlist.

Additional resources