IssueTracker

Components used:

• Navigation
• Compose

Versions used:

• Navigation: 2.4.0-alpha04
• Compose: 1.0.0

Devices/Android versions reproduced on: Pixel 2

Setup:

The setup can be demonstrated with the following code.

private sealed class BottomBarItem(val route: String) {
  object Landing : BottomBarItem("landing")
  object Settings : BottomBarItem("settings")
}

private val bottomBarItems = listOf(BottomBarItem.Landing, BottomBarItem.Settings)

class MainActivity : ComponentActivity() {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContent {
      TestNavigationTheme {
        val navController = rememberNavController()
        NavHost(navController = navController, startDestination = "home") {
          composable("home") { Home { navController.navigate("about") } }
          composable("about") { Text("In About") }
        }
      }
    }
  }
}

@Composable
fun Home(onAboutClick: () -> Unit) {
  val navController = rememberNavController()
  val currentRoute = navController.currentBackStackEntryAsState().value?.destination?.route

  Scaffold(
    bottomBar = {
      BottomNavigation {
        bottomBarItems.forEach { screen ->
          Text(
            text = screen.route,
            color = if (currentRoute == screen.route) Color.Black else Color.White,
            modifier = Modifier.clickable {
              if (currentRoute != screen.route) {
                navController.navigate(screen.route) {
                  popUpTo(navController.graph.startDestinationId)
                  launchSingleTop = true
                }
              }
            }
          )
        }
      }
    }
  ) {
    Box(Modifier.padding(it)) {
      NavHost(navController = navController, startDestination = BottomBarItem.Landing.route) {
        composable(BottomBarItem.Landing.route) { Text(text = "Landing") }
        composable(BottomBarItem.Settings.route) {
          Text(
            text = "Go to about",
            modifier = Modifier.clickable(onClick = onAboutClick)
          )
        }
      }
    }
  }
}

Issue:

1. Run the following code
2. Navigate to Settings
3. Click on Go to about
4. Click back (effectively go back in Settings)
5. Repeat 3 & 4 numerous times
6. Click back to exit the app

Result: We need to click back as many times as we visited the About screen.

Expected result: Only 2 back clicks are needed to close the app:

• one to go back to Landing
• one to actually close the app

Screen recording: There is an attached demo of the behaviour.