I'm trying out your library (0.5.0) and it's great. But I ran into an issue. I will post code here to reproduce it. I might be using the library wrong though.

class MainActivity : AppCompatActivity() {
    private val backPressHandler = BackPressHandler()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            MaterialTheme {
                Providers(AmbientBackPressHandler provides backPressHandler) {
                    MyRouter(startRoute = SplashRoute)
                }
            }
        }
    }

    override fun onBackPressed() {
        if (!backPressHandler.handle()) {
            super.onBackPressed()
        }
    }

    override fun onSaveInstanceState(outState: Bundle) {
        super.onSaveInstanceState(outState)
        outState.saveAmbient()
    }
}

sealed class MyRoute {
    object SplashRoute : MyRoute()
    object HomeRoute : MyRoute()
    object DetailsRoute : MyRoute()
}

@Composable
fun MyRouter(startRoute: MyRoute) {
    Router(contextId = "app", defaultRouting = startRoute) { backStack ->
        when (backStack.last()) {
            SplashRoute -> SplashRouteScreen(onInitialized = { backStack.newRoot(HomeRoute) })
            HomeRoute -> HomeRouteScreen(onShowDetails = { backStack.push(DetailsRoute) })
            DetailsRoute -> DetailsRouteScreen()
        }
    }
}

@Composable
fun SplashRouteScreen(onInitialized: () -> Unit) {
    onActive {
        onInitialized()
    }
}

@Composable
fun HomeRouteScreen(onShowDetails: () -> Unit) {
    onActive {
        Log.d("HomeRouteScreen", "onActive ${System.currentTimeMillis()}")

        onDispose {
            Log.d("HomeRouteScreen", "onDispose ${System.currentTimeMillis()}")
        }
    }

    Center {
        Button(onClick = onShowDetails) {
            Text(text = "Show details")
        }
    }
}

@Composable
fun DetailsRouteScreen() {
    Center {
        Text("Details")
    }
}

So if you open the app and you navigate through screens everything is fine. Logs in HomeRouteScreen work as intended. But if you leave the app with back button (don't kill the app), then:

1. Open app again
2. Tap "Show details"
3. Press back

Logs will look like this:

D/HomeRouteScreen: onActive 1582533598703
D/HomeRouteScreen: onDispose 1582533600692
D/HomeRouteScreen: onDispose 1582533600697
D/HomeRouteScreen: onActive 1582533602550
D/HomeRouteScreen: onActive 1582533602551

If you leave the app again, and repeat those steps:

HomeRouteScreen: onActive 1582533684493
HomeRouteScreen: onDispose 1582533699006
HomeRouteScreen: onDispose 1582533699009
HomeRouteScreen: onDispose 1582533699011
HomeRouteScreen: onActive 1582533699988
HomeRouteScreen: onActive 1582533699989
HomeRouteScreen: onActive 1582533699989

Seems like every time you close the app with back button then reopen, something gets duplicated.

Assuming you have two destinations, A and B. A displays a long list. You click on an item in the list to navigate to B. Once in B you click on the back button. The A view is entirely recreated. The list is at the top again. I am unsure if this is by design or not.

sealed class Routing {
  object A: Routing()
  data class B(val slug: String) : Routing()
}
@Composable
fun AppStore(routing: Routing = Routing.A) {
  Router(routing) { backStack ->
    val onItemClicked: (String) = { slug ->
      backStack.push(Routing.B(slug))
    }
    when (val value = backStack.last()) {
      is Routing.A-> AController(onItemClicked)
      is Routing.B-> BController(value.slug)
    }
  }
}

I've already added a rememberLazyListState but this seems to be recreated entirely as well

I am using version 0.24.2

Hello, I noticed this library does not work on jetpack-compose dev16 (with errors like Composable functions can only be used from other Composable functions.). This is probably because @Composable annotation had been refactored to another package in dev16 and so the compiler cannot match the two different @Composable annotations.

In this MR I have updated the dependency version to 0.1.0-dev16 and adjusted all the imports. It compiles on dev16 and works in my application.

Hi,

I'd find it really useful to know what the top item in the backstack is - I'm using bottom navigation and knowing the top item on the backstack would help in deciding which item at the bottom should be highlighted (even when a few destinations deep in that stack).

Is there a reason this shouldn't be exposed?

Updates to dev13, update compile and target sdk to 30.

I know you did not want the samples to reference the router module directly. And it should instead reference an existing release. But after being forced to update gradle, the only way I could get the lifelike module to compile was to update it to dev13. Which meant it needed access to router built with dev13.

Also I couldn't get the nested sample to build using dev09 with the gradle update so I was able to update that one to dev12

Version of Jetpack Compose: alpha07 Version of Compose router: 0.21.0

The following runtime error is thrown

 java.lang.NoSuchFieldError: No field Companion of type Landroidx/compose/runtime/SlotTable$Companion; in class Landroidx/compose/runtime/SlotTable; or its superclasses (declaration of 'androidx.compose.runtime.SlotTable' appears in /data/data/com.metamythlabs.theseries/code_cache/.overlay/base.apk/classes.dex)
        at com.github.zsoltk.compose.router.RouterKt.Router(Router.kt:105)
        at com.metamythlabs.theseries.screens.MainRouter$Companion.Content(MainRouter.kt:28)

Usage of router (excerpt)

 companion object {
        @Composable
        fun Content(defaultRouting: Routing = Routing.Home) {
            Router("Main", defaultRouting) { backStack ->

                Providers(
                    AppNavigatorAmbient provides TheSeenNavigator(backStack)
                ) {
                    when (val routing = backStack.last()) {
                        is Routing.Home -> HomeRouter.Content()
                        is Routing.MoviesDetail -> MovieRouter.Content(movieId = routing.movieId)
                        is Routing.SeriesDetail -> SeriesRouter.Content(seriesId = routing.seriesId)
                        is Routing.UniverseDetail -> UniverseRouter.Content(universeId = routing.universeId)
                    }
                }
            }
        }
    }
}

Sadly I couldn't solve it quickly, hence I wanna report it.

I got everything working, however I can't figure out the correct way to handle the three unchecked casts properly. I left the @Suppress("UNCHECKED_CAST") commented near each one.

I guess this is something to do with Covariance / Contravariance etc, but I dont know enough about how to solve it. Seems theres a List and a Map with BackStack<*>. Would one solution be to have some kind of known Routing interface or class which is subclassed or implemented so that the type and its sub/super are known?

I would be interested in knowing how this should be fixed so that I can understand this whole <*> thing in Kotlin.

I wonder if there is any way to retrieve all elements from BackStack? It can be useful in the following cases:

1. We want to render all screens from BackStack on top of each other, so after navigating back we will not re-render some screens.
2. Integration with compose-backstack (library for rendering animated transitions between backstacks of screens) would be much simpler, because nowadays it requires list of screens as one of args to its Composable. There are some workarounds, such as using Kotlin Reflection or using state/remember for maintaining backstack yourself, but it would be great to have read access directly to BackStack#elements.

@zsoltk WDYT?

I mentioned this bug in https://github.com/zsoltk/compose-router/pull/21. Probably needs to be reported to Google. It still does not work with 4.1.0-alpha09.

For some reason with com.android.tools.build:gradle versions 4.1.0-alpha06 - 4.1.0-alpha08 the META-INF folder isn't added to the classes.jar in the .aar outputs

My branch built with com.android.tools.build:gradle:4.1.0-alpha05 includes the META-INF folder and I can successfully build my project

Update gradle to 4.1.0-alpha03 Change left/right to start/end Use new package for Surface component DrawImage -> Image LayoutFlexible -> LayoutWeight

Right now Router needs an explicit unique id for back stack store/retrieval from parent. It would be nice to make this implicitly without having to ask client code to define id.

The ViewModels provided in the composition by hilt, are never destroyed when a new root destination is selected. With compose navigation this is different because models are cleared as soon as the destination gets cleared from the back stack.

With deeplink I think it's support between Dynamice Feature navigation, cmiiw or does it requires any setup/configuration differences than using Deeplink?

Initial setup of BackPressHandler in the MainActivity works well with navigation but how to handle Appbar navback button click event? Now I've forked and created RootBackPressHandler Ambient which is set once in root Router and then I'm accessing it from anywhere

Version 0.11.1 crashes withbackPressHandler is not initialized at a certain route depth. Downgrading to 0.9.0 fixes the issue. I'm having trouble reproducing this properly.