Artifact used : "androidx.compose.ui:ui:$compose_version" "androidx.compose.material:material:$compose_version" "androidx.compose.ui:ui-tooling-preview:$compose_version" 'androidx.lifecycle:lifecycle-runtime-ktx:2.3.1' "androidx.navigation:navigation-compose:2.4.0-alpha09" 'androidx.activity:activity-compose:1.3.1' Version used: compose_version = "1.1.0-alpha04"

• Relevant code to trigger the issue : https://github.com/NitroG42/LifecycleStopped
• A screenrecord or screenshots showing the issue (if UI related) : https://raw.githubusercontent.com/NitroG42/LifecycleStopped/master/lifecycle.gif

Lifecycle issue with Compose and Navigation

Context

Following the sample code, we insert a lifecycle observer :

@Composable
fun LogLifecycle() {
    val owner = LocalLifecycleOwner.current
    val lifecycle = owner.lifecycle
    logcat("MainActivity") { "owner $owner $lifecycle ${lifecycle.currentState}" }

    DisposableEffect(lifecycle) {
        val lifecycleObserver = LifecycleEventObserver { _, event ->
            logcat("MainActivity") { "event $event" }
        }
        lifecycle.addObserver(lifecycleObserver)
        onDispose {
            lifecycle.removeObserver(lifecycleObserver)
        }
    }
}

into a BottomNavigation destination.

Issue

Pressing the same destination twice, or switching rapidly between two destinations will cause the following logs:

2021-09-27 16:16:52.809 20448-20448/com.nitro.lifecyclestopped D/MainActivity: owner androidx.navigation.NavBackStackEntry@6f0ea592 androidx.lifecycle.LifecycleRegistry@9ce9bd6 STARTED
2021-09-27 16:16:52.814 20448-20448/com.nitro.lifecyclestopped D/MainActivity: event ON_CREATE
2021-09-27 16:16:52.814 20448-20448/com.nitro.lifecyclestopped D/MainActivity: event ON_START
2021-09-27 16:16:53.147 20448-20448/com.nitro.lifecyclestopped D/MainActivity: event ON_RESUME
2021-09-27 16:16:54.807 20448-20448/com.nitro.lifecyclestopped D/MainActivity: event ON_PAUSE
2021-09-27 16:16:54.807 20448-20448/com.nitro.lifecyclestopped D/MainActivity: event ON_STOP

meaning the lifecycle is stopped. The issue is we are currently on the screen using the lifecycle, the lifecycle should come back to ON_START then ON_RESUME, but it is never triggered again.

Real use case

A real use case with this issue is using a mapView ( from Crane ) :

@Composable
fun rememberMapViewWithLifecycle(): MapView {
    val context = LocalContext.current
    val mapView = remember {
        MapView(context).apply {
            id = R.id.map
        }
    }

    val lifecycle = LocalLifecycleOwner.current.lifecycle
    DisposableEffect(lifecycle, mapView) {
        // Make MapView follow the current lifecycle
        val lifecycleObserver = getMapLifecycleObserver(mapView)
        lifecycle.addObserver(lifecycleObserver)
        onDispose {
            lifecycle.removeObserver(lifecycleObserver)
        }
    }

    return mapView
}

private fun getMapLifecycleObserver(mapView: MapView): LifecycleEventObserver =
    LifecycleEventObserver { _, event ->
        when (event) {
            Lifecycle.Event.ON_CREATE -> mapView.onCreate(Bundle())
            Lifecycle.Event.ON_START -> mapView.onStart()
            Lifecycle.Event.ON_RESUME -> mapView.onResume()
            Lifecycle.Event.ON_PAUSE -> mapView.onPause()
            Lifecycle.Event.ON_STOP -> mapView.onStop()
            Lifecycle.Event.ON_DESTROY -> mapView.onDestroy()
            else -> throw IllegalStateException()
        }
    }

It means that with the same behavior, a MapView on a Bottom destination will stop working after pressing the destination twice or going/coming quickly between destinations, as mapView.onStop() will be called but mapView.onStart() won't (hence the mapview is frozen and never "wake up").

The only solution is for the user to go to another destination, wait for a second, and come back to the previous destination.

Gif

Gif