AnimatedContent moves to targetState before Scaffold composes content [268422136]

Duplicate

of 254645321

Bug

Status Update

No update yet.

Description

jb...@google.com

created issue #1

Feb 9, 2023 03:44AM

This is from https://github.com/google/accompanist/issues/1487:

I haven't been able to reproduce it without a lot of experimental APIs along with Navigation. But essentially given the following:

setContent {
val transition = updateTransition(...)
  transition.AnimatedContent {
    MyComposable()
  }
  if (transition.currentState == transition.targetState) {
    // area #3
  }
}

class MyComposable() {
  // area #1
  Scaffold(
    content = {
      // area #2
    }
  )
}

There are cases where the areas end up being composed in this order: 1, 3, 2 with AnimatedContent completing the transition and then the Scaffold composing its content.

The expectation was that it would always be 1, 2, 3 with the composition of the Scaffold content completing before the callback to area 3.

Is the expectation correct? Or does AnimatedContent completion have some priority over the Scaffold?

This could also be something going on in Scaffold, just wondering what the expectations are here.

Comments

lp...@google.com <lp...@google.com> #2Feb 9, 2023 02:58PM

since these are in public API (:/) we need to do this in 1.2

lp...@google.com <lp...@google.com> #3Feb 9, 2023 03:45PM

since it is already marked as deprecated, we can probably do it by now.

ti...@google.com <ti...@google.com> #4Feb 13, 2023 11:14PM

Opening diff shortly

jb...@google.com <jb...@google.com> #5Feb 14, 2023 12:22AM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit d576cbdc911cba16638a44fd8223391a90a07ef7
Author: Mike Nakhimovich <digitalbuddha@users.noreply.github.com>
Date: Tue Aug 11 09:30:34 2020

[GH] Hide deprecated internal API.

## Proposed Changes

* `RoomDatabase.java` has protected `mCallbacks` field which is leaking in the API docs, we should @Hide it.

## Testing

Test: Ran unit tests locally

## Issues Fixed

Fixes: 76109329

This is an imported pull request from

https://github.com/androidx/androidx/pull/61.

Resolves #61
Github-Pr-Head-Sha: 6440daa3a63752c7f9d5ba2a390248cd85bc634f
GitOrigin-RevId: fe92d8466a59b44b218b6ca3cbd57dcda17992f7

Change-Id: Id599cdf5b02b32bdae0166266fb7da967598fe92

A room/runtime/api/current.ignore
M room/runtime/api/current.txt
M room/runtime/api/public_plus_experimental_current.txt
M room/runtime/api/restricted_current.txt
M room/runtime/src/main/java/androidx/room/RoomDatabase.java

https://android-review.googlesource.com/1396827

Illegal State Exception.zip

136 KB

Download

jb...@google.com <jb...@google.com> #6Feb 14, 2023 03:03AM

The additional logging added internal to AnimatedNavHost:

            currentEntry?.LocalOwnersProvider(saveableStateHolder) {
                Log.d("AnimatedNavHost", "Current entry being composed in AnimatedContent ${currentEntry.destination.route}")
                (currentEntry.destination as AnimatedComposeNavigator.Destination)
                    .content(this, currentEntry)
            }
        }
        Log.d("AnimatedNavHost", "Outside of conditional")
        Log.d("AnimatedNavHost", "transition currentState: ${transition.currentState.destination.route}")
        Log.d("AnimatedNavHost", "transition targetState: ${transition.targetState.destination.route}")
        if (transition.currentState == transition.targetState) {
            Log.d("AnimatedNavHost", "Inside of conditional")
            Log.d("AnimatedNavHost", "transition currentState: ${transition.currentState.destination.route}")
            Log.d("AnimatedNavHost", "transition targetState: ${transition.targetState.destination.route}")
            visibleEntries.forEach { entry ->
                composeNavigator.markTransitionComplete(entry)
            }
        }

The resulting logs:

 E  screen2 entry state in Scaffold RESUMED
 D  navigating to screen1
 D  Current entry being composed in AnimatedContent screen2
 E  screen2 entry state outside Scaffold is CREATED
 D  Current entry being composed in AnimatedContent screen1
 D  Outside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen1
 D  Current entry being composed in AnimatedContent screen1
 D  Outside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 D  Inside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 E  screen2 entry state in Scaffold DESTROYED
 E  FATAL EXCEPTION: main
    Process: com.andreirozov.sample, PID: 6388
    java.lang.IllegalStateException: You cannot access the NavBackStackEntry's ViewModels after the NavBackStackEntry is destroyed.

ti...@google.com <ti...@google.com> #7Feb 14, 2023 08:11PM

Thanks for the logs Jeremy.

Seems like AnimatedContent didn't pick up any animation from Scaffold. I see the 2 invocations of AnimatedNavHost, the first one sets up the new target state, and by the 2nd invocation the transition has already considered itself finished, which is likely due to not having any child animations in the list. That seems to me like the scenario 2) as I mentioned in comment #4.

1st invocation:
 E  screen2 entry state in Scaffold RESUMED
 D  navigating to screen1
 D  Current entry being composed in AnimatedContent screen2
 E  screen2 entry state outside Scaffold is CREATED
 D  Current entry being composed in AnimatedContent screen1
 D  Outside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen1

2nd invocation:
 D  Current entry being composed in AnimatedContent screen1
 D  Outside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 D  Inside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 E  screen2 entry state in Scaffold DESTROYED
 E  FATAL EXCEPTION: main

ti...@google.com <ti...@google.com> #8Feb 15, 2023 08:01PM

Jeremy, could you share the steps to reproduce the issue in the app shared in comment #5?

jb...@google.com <jb...@google.com> #9Feb 15, 2023 08:04PM

Pressing the menu and swapping between screen1 and screen2 as seen in https://github.com/google/accompanist/issues/1487#issuecomment-1416890604.

It fails very quickly on API 29 from my testing, on higher API levels it takes a few times.

ti...@google.com <ti...@google.com> #10Feb 15, 2023 09:38PM

Thanks for sharing the repro steps. I was able to repro with a fair amount of rapid switching between destinations.

Here's the stacktrace I see. Since I don't have the logging in AnimatedHost, I'm not sure whether this is the same crash as #6.

Jeremy, it'd be helpful if you could post the full stacktrace with the logging from AnimatedHost, so I can compare the composable involved in the crash with the destination that was removed.

2023-02-15 13:23:25.057 31458-31458 AndroidRuntime          com.andreirozov.sample               E  FATAL EXCEPTION: main
                                                                                                    Process: com.andreirozov.sample, PID: 31458
                                                                                                    java.lang.IllegalStateException: You cannot access the NavBackStackEntry's ViewModels after the NavBackStackEntry is destroyed.
                                                                                                    	at androidx.navigation.NavBackStackEntry.getViewModelStore(NavBackStackEntry.kt:202)
                                                                                                    	at androidx.lifecycle.viewmodel.compose.ViewModelKt.get(ViewModel.kt:206)
                                                                                                    	at androidx.lifecycle.viewmodel.compose.ViewModelKt.get$default(ViewModel.kt:195)
                                                                                                    	at androidx.lifecycle.viewmodel.compose.ViewModelKt.viewModel(ViewModel.kt:120)
                                                                                                    	at com.andreirozov.sample.ui.standings.screen2.Screen2TabKt.AnotherScreen(Screen2Tab.kt:84)
                                                                                                    	at com.andreirozov.sample.ui.AppNavGraphKt$AppNavGraph$5$1$1$2.invoke(AppNavGraph.kt:94)
                                                                                                    	at com.andreirozov.sample.ui.AppNavGraphKt$AppNavGraph$5$1$1$2.invoke(AppNavGraph.kt:89)
                                                                                                    	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:116)
                                                                                                    	at androidx.compose.runtime.internal.ComposableLambdaImpl$invoke$1.invoke(ComposableLambda.jvm.kt:127)
                                                                                                    	at androidx.compose.runtime.internal.ComposableLambdaImpl$invoke$1.invoke(ComposableLambda.jvm.kt:127)
                                                                                                    	at androidx.compose.runtime.RecomposeScopeImpl.compose(RecomposeScopeImpl.kt:162)
                                                                                                    	at androidx.compose.runtime.ComposerImpl.recomposeToGroupEnd(Composer.kt:2435)
                                                                                                    	at androidx.compose.runtime.ComposerImpl.skipCurrentGroup(Composer.kt:2703)
                                                                                                    	at androidx.compose.runtime.ComposerImpl$doCompose$2$5.invoke(Composer.kt:3326)
                                                                                                    	at androidx.compose.runtime.ComposerImpl$doCompose$2$5.invoke(Composer.kt:3304)
                                                                                                    	at androidx.compose.runtime.SnapshotStateKt__DerivedStateKt.observeDerivedStateRecalculations(DerivedState.kt:341)
                                                                                                    	at androidx.compose.runtime.SnapshotStateKt.observeDerivedStateRecalculations(Unknown Source:1)
                                                                                                    	at androidx.compose.runtime.ComposerImpl.doCompose(Composer.kt:3304)
                                                                                                    	at androidx.compose.runtime.ComposerImpl.recompose$runtime_release(Composer.kt:3269)
                                                                                                    	at androidx.compose.runtime.CompositionImpl.recompose(Composition.kt:771)
                                                                                                    	at androidx.compose.runtime.Recomposer.performRecompose(Recomposer.kt:1047)
                                                                                                    	at androidx.compose.runtime.Recomposer.access$performRecompose(Recomposer.kt:124)
                                                                                                    	at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$2.invoke(Recomposer.kt:541)
                                                                                                    	at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$2.invoke(Recomposer.kt:510)
                                                                                                    	at androidx.compose.ui.platform.AndroidUiFrameClock$withFrameNanos$2$callback$1.doFrame(AndroidUiFrameClock.android.kt:34)
                                                                                                    	at androidx.compose.ui.platform.AndroidUiDispatcher.performFrameDispatch(AndroidUiDispatcher.android.kt:109)
                                                                                                    	at androidx.compose.ui.platform.AndroidUiDispatcher.access$performFrameDispatch(AndroidUiDispatcher.android.kt:41)
                                                                                                    	at androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.doFrame(AndroidUiDispatcher.android.kt:69)
                                                                                                    	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1229)
                                                                                                    	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1239)
                                                                                                    	at android.view.Choreographer.doCallbacks(Choreographer.java:899)
                                                                                                    	at android.view.Choreographer.doFrame(Choreographer.java:827)
                                                                                                    	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1214)
                                                                                                    	at android.os.Handler.handleCallback(Handler.java:942)
                                                                                                    	at android.os.Handler.dispatchMessage(Handler.java:99)
                                                                                                    	at android.os.Looper.loopOnce(Looper.java:201)
                                                                                                    	at android.os.Looper.loop(Looper.java:288)
                                                                                                    	at android.app.ActivityThread.main(ActivityThread.java:7898)
                                                                                                    	at java.lang.reflect.Method.invoke(Native Method)
                                                                                                    	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
                                                                                                    	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:936)
                                                                                                    	Suppressed: kotlinx.coroutines.DiagnosticCoroutineContextException: [androidx.compose.runtime.PausableMonotonicFrameClock@9d17257, androidx.compose.ui.platform.MotionDurationScaleImpl@54e6144, StandaloneCoroutine{Cancelling}@29a522d, AndroidUiDispatcher@c8ce362]

ti...@google.com <ti...@google.com> #11Feb 15, 2023 10:33PM

The log prior to the crash indicates Screen2's Scaffold recomposed after the BackStackEntry's lifecyle has been updated to DESTROYED, presumably from markTransitionComplete, which happens after AnimatedContent remove Screen2 from composition. Recomposing after being removed from composition looks like the same issue as b/254645321

         com.andreirozov.sample               D  navigating to screen1
         com.andreirozov.sample               E  Standing back stack entry state is CREATED
         com.andreirozov.sample               E  Standing back stack entry state is CREATED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold CREATED
         com.andreirozov.sample               E  Standing back stack entry state is CREATED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold CREATED
         com.andreirozov.sample               D  navigating to screen2
         com.andreirozov.sample               E  Standing back stack entry state is STARTED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold STARTED
         com.andreirozov.sample               E  Standing back stack entry state is STARTED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold STARTED
         com.andreirozov.sample               E  Standing back stack entry state is STARTED
         com.andreirozov.sample               E  Standing back stack entry state is RESUMED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold RESUMED
         com.andreirozov.sample               E  Standing back stack entry state is RESUMED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold RESUMED
         com.andreirozov.sample               E  Standing back stack entry state is RESUMED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold RESUMED
         com.andreirozov.sample               E  Standing back stack entry state is RESUMED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold RESUMED
         com.andreirozov.sample               D  navigating to screen1
         com.andreirozov.sample               E  Standing back stack entry state is CREATED
         com.andreirozov.sample               E  Standing back stack entry state is CREATED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold CREATED
         com.andreirozov.sample               E  Standing back stack entry state is CREATED
         com.andreirozov.sample               E  Standing back stack entry state in Scaffold DESTROYED
         com.andreirozov.sample               E  FATAL EXCEPTION: main

jb...@google.com <jb...@google.com> #12Feb 15, 2023 10:34PM

Yep same one:

 D  Current entry being composed in AnimatedContent screen1
 D  Outside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 D  Inside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 I  Skipped 40 frames!  The application may be doing too much work on its main thread.
 D  Installing profile for com.andreirozov.sample
 D  Current entry being composed in AnimatedContent screen1
 D  Outside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 D  Inside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 D  Current entry being composed in AnimatedContent screen1
 D  Outside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 D  Inside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 D  navigating to screen2
 D  Current entry being composed in AnimatedContent screen1
 D  Current entry being composed in AnimatedContent screen2
 E  screen2 entry state outside Scaffold is STARTED
 D  Outside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen2
 E  screen2 entry state in Scaffold STARTED
 D  Current entry being composed in AnimatedContent screen2
 E  screen2 entry state outside Scaffold is STARTED
 D  Outside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen2
 D  Inside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen2
 D  Current entry being composed in AnimatedContent screen2
 E  screen2 entry state outside Scaffold is RESUMED
 D  Outside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen2
 D  Inside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen2
 E  screen2 entry state in Scaffold RESUMED
 D  Current entry being composed in AnimatedContent screen2
 E  screen2 entry state outside Scaffold is RESUMED
 D  Outside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen2
 D  Inside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen2
 D  Current entry being composed in AnimatedContent screen2
 E  screen2 entry state outside Scaffold is RESUMED
 D  Outside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen2
 D  Inside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen2
 E  screen2 entry state in Scaffold RESUMED
 D  navigating to screen1
 D  Current entry being composed in AnimatedContent screen2
 E  screen2 entry state outside Scaffold is CREATED
 D  Current entry being composed in AnimatedContent screen1
 D  Outside of conditional
 D  transition currentState: screen2
 D  transition targetState: screen1
 I  Background young concurrent copying GC freed 53694(1896KB) AllocSpace objects, 0(0B) LOS objects, 25% free, 4767KB/6441KB, paused 7.336ms total 70.605ms
 D  Current entry being composed in AnimatedContent screen1
 D  Outside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 D  Inside of conditional
 D  transition currentState: screen1
 D  transition targetState: screen1
 E  screen2 entry state in Scaffold DESTROYED
 E  FATAL EXCEPTION: main
    Process: com.andreirozov.sample, PID: 2772
    java.lang.IllegalStateException: You cannot access the NavBackStackEntry's ViewModels after the NavBackStackEntry is destroyed.
    	at androidx.navigation.NavBackStackEntry.getViewModelStore(NavBackStackEntry.kt:202)
    	at androidx.lifecycle.viewmodel.compose.ViewModelKt.get(ViewModel.kt:206)
    	at androidx.lifecycle.viewmodel.compose.ViewModelKt.get$default(ViewModel.kt:195)
    	at androidx.lifecycle.viewmodel.compose.ViewModelKt.viewModel(ViewModel.kt:120)
    	at com.andreirozov.sample.ui.standings.screen2.Screen2TabKt.AnotherScreen(Screen2Tab.kt:84)
    	at com.andreirozov.sample.ui.AppNavGraphKt$AppNavGraph$5$1$1$2.invoke(AppNavGraph.kt:94)
    	at com.andreirozov.sample.ui.AppNavGraphKt$AppNavGraph$5$1$1$2.invoke(AppNavGraph.kt:89)
    	at androidx.compose.runtime.internal.ComposableLambdaImpl.invoke(ComposableLambda.jvm.kt:116)
    	at androidx.compose.runtime.internal.ComposableLambdaImpl$invoke$1.invoke(ComposableLambda.jvm.kt:127)
    	at androidx.compose.runtime.internal.ComposableLambdaImpl$invoke$1.invoke(ComposableLambda.jvm.kt:127)
    	at androidx.compose.runtime.RecomposeScopeImpl.compose(RecomposeScopeImpl.kt:162)
    	at androidx.compose.runtime.ComposerImpl.recomposeToGroupEnd(Composer.kt:2435)
    	at androidx.compose.runtime.ComposerImpl.skipCurrentGroup(Composer.kt:2703)
    	at androidx.compose.runtime.ComposerImpl$doCompose$2$5.invoke(Composer.kt:3326)
    	at androidx.compose.runtime.ComposerImpl$doCompose$2$5.invoke(Composer.kt:3304)
    	at androidx.compose.runtime.SnapshotStateKt__DerivedStateKt.observeDerivedStateRecalculations(DerivedState.kt:341)
    	at androidx.compose.runtime.SnapshotStateKt.observeDerivedStateRecalculations(Unknown Source:1)
    	at androidx.compose.runtime.ComposerImpl.doCompose(Composer.kt:3304)
    	at androidx.compose.runtime.ComposerImpl.recompose$runtime_release(Composer.kt:3269)
    	at androidx.compose.runtime.CompositionImpl.recompose(Composition.kt:771)
    	at androidx.compose.runtime.Recomposer.performRecompose(Recomposer.kt:1047)
    	at androidx.compose.runtime.Recomposer.access$performRecompose(Recomposer.kt:124)
    	at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$2.invoke(Recomposer.kt:541)
    	at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$2.invoke(Recomposer.kt:510)
    	at androidx.compose.ui.platform.AndroidUiFrameClock$withFrameNanos$2$callback$1.doFrame(AndroidUiFrameClock.android.kt:34)
    	at androidx.compose.ui.platform.AndroidUiDispatcher.performFrameDispatch(AndroidUiDispatcher.android.kt:109)
    	at androidx.compose.ui.platform.AndroidUiDispatcher.access$performFrameDispatch(AndroidUiDispatcher.android.kt:41)
    	at androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.doFrame(AndroidUiDispatcher.android.kt:69)
    	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:964)
    	at android.view.Choreographer.doCallbacks(Choreographer.java:790)
    	at android.view.Choreographer.doFrame(Choreographer.java:721)
    	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:951)
    	at android.os.Handler.handleCallback(Handler.java:883)
    	at android.os.Handler.dispatchMessage(Handler.java:100)
    	at android.os.Looper.loop(Looper.java:214)
    	at android.app.ActivityThread.main(ActivityThread.java:7356)
    	at java.lang.reflect.Method.invoke(Native Method)
    	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
    	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)
    	Suppressed: kotlinx.coroutines.DiagnosticCoroutineContextException: [androidx.compose.runtime.PausableMonotonicFrameClock@7ebb51b, androidx.compose.ui.platform.MotionDurationScaleImpl@e6c86b8, StandaloneCoroutine{Cancelling}@f919c91, AndroidUiDispatcher@7da07f6]
 I  Sending signal. PID: 2772 SIG: 9

ti...@google.com <ti...@google.com> #13Feb 15, 2023 10:39PM

Status: Duplicate of

254645321

Thanks Jeremy.

The logging in #12 also confirms Scaffold's behavior of recomposing after being removed from composition. Marking this a dup of b/254645321

mo...@gmail.com <mo...@gmail.com> #14May 31, 2023 10:20AM

Comment has been deleted.

Message last modified on May 31, 2023 10:21AM

ap...@google.com <ap...@google.com> #15Aug 10, 2023 08:23PM

Project: platform/frameworks/support
Branch: androidx-main

commit aeb4b9fc4ddeca49fcb2812ce828cc7be11beb30
Author: Jeremy Woods <jbwoods@google.com>
Date: Tue Aug 08 17:15:11 2023

Fix issue with changing state as part of composition

We should not change state as part of composition as that can cause
inconsistent behavior when reading state. We should instead only ever
change state in an Effect.

RelNote: "Fixed an issues in Navigation with Compose where when using a
Scaffold it was possible to get an error trying to access a DESTROYED
ViewModel"
Test: Added test in NavHostTest
Bug: 268422136

Change-Id: I1dc115fc2b454d68c1a23c78e72707d6d4c739a5

M navigation/navigation-compose/src/androidTest/java/androidx/navigation/compose/NavHostTest.kt
M navigation/navigation-compose/src/main/java/androidx/navigation/compose/NavHost.kt

https://android-review.googlesource.com/2698513

na...@google.com <na...@google.com> #16Jan 24, 2024 07:53PM

The following release(s) address this bug.It is possible this bug has only been partially addressed:

androidx.navigation:navigation-compose:2.8.0-alpha01

pa...@gmail.com <pa...@gmail.com> #17Apr 4, 2024 09:58PM

Hello, these changes in fact introduced in 2.7.1 are creating issues in our architecture. Basically we are no longer able to receive Lifecycle.Event.ON_DESTROY as it is now triggered after onDispose where we are unsubscribing a lifecycle observer. (Sample attached)

fun attachLifeCycleObserver(onDestroy:() -> Unit) {

    val lifecycle = LocalLifecycleOwner.current.lifecycle
    DisposableEffect(lifecycle) {
        val eventObserver = LifecycleEventObserver { source, event ->
            println("PACMAC -- event:${event.name}  targetState:${event.targetState.name} source:${source.toString()}")
            if (event == Lifecycle.Event.ON_DESTROY) {
                onDestroy()
            }
        }
        
        lifecycle.addObserver(eventObserver)
        onDispose {
            // We unsubscribe here but since 2.7.1 we are no longer receiving ON_DESTROY as it is actually triggered after onDispose
            lifecycle.removeObserver(eventObserver)
        }
    }
}

We are using onDestroy to run some cleanup but only if the nav destination is popped of the backstack.

NavigationLibSample.zip

109 KB