IllegalStateException when popping nested graph [190265699]

Fixed

Bug

Status Update

No update yet.

Description

jo...@olavstoppen.no

created issue #1

Jun 7, 2021 10:19AM

Component used: Navigation

Version used: 2.4.0-beta02

Devices/Android versions reproduced on: Pixel 3, Huawei P20 Pro, emulator, Android 11, 12

I have a main graph and a login graph. When login is done, I want to pop the entire login graph, and return to the main graph.

This action in the login graph used to work in version 2.3.0, but throws an exception in 2.4.0-beta01/2:

<action
    android:id="@+id/to_main_screen"
    app:destination="@id/main_nav_graph"
    app:popUpTo="@id/login_nav_graph"
    app:popUpToInclusive="true" />

The stack trace:

java.lang.IllegalStateException: popBackStack was called with androidx.navigation.NavBackStackEntry@c554768 which does not exist in back stack []
        at androidx.navigation.Navigator.popBackStack(Navigator.kt:185)
        at androidx.navigation.NavController.popBackStackInternal(NavController.kt:202)
        at androidx.navigation.NavController.popBackStackInternal(NavController.kt:455)
        at androidx.navigation.NavController.popBackStackInternal$default(NavController.kt:413)
        at androidx.navigation.NavController.addEntryToBackStack(NavController.kt:1533)
        at androidx.navigation.NavController.addEntryToBackStack$default(NavController.kt:1466)
        at androidx.navigation.NavController$navigate$7.invoke(NavController.kt:1437)
        at androidx.navigation.NavController$navigate$7.invoke(NavController.kt:1435)
        at androidx.navigation.NavController$NavControllerNavigatorState.add(NavController.kt:215)
        at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.kt:246)
        at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.kt:162)
        at androidx.navigation.NavGraphNavigator.navigate(NavGraphNavigator.kt:83)
        at androidx.navigation.NavGraphNavigator.navigate(NavGraphNavigator.kt:49)
        at androidx.navigation.NavController.navigateInternal(NavController.kt:188)
        at androidx.navigation.NavController.navigate(NavController.kt:1435)
        at androidx.navigation.NavController.navigate(NavController.kt:1221)
        at androidx.navigation.NavController.navigate(NavController.kt:1149)
        at androidx.navigation.NavController.navigate(NavController.kt:1575)
        at my.app.features.login.login.LoginUIKt$LoginScreen$2.invoke(LoginUI.kt:65)
        at my.app.features.login.login.LoginUIKt$LoginScreen$2.invoke(LoginUI.kt:64)
        at my.app.features.login.LoginResultHandlerKt$LoginResultHandler$1.invoke(LoginResultHandler.kt:38)
        at my.app.features.login.LoginResultHandlerKt$LoginResultHandler$1.invoke(LoginResultHandler.kt:34)
        at androidx.compose.runtime.CompositionImpl$RememberEventDispatcher.dispatchSideEffects(Composition.kt:789)
        at androidx.compose.runtime.CompositionImpl.applyChanges(Composition.kt:640)
        at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$2.invoke(Recomposer.kt:478)
        at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$2.invoke(Recomposer.kt:415)
        at androidx.compose.ui.platform.AndroidUiFrameClock$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:1003)
        at android.view.Choreographer.doCallbacks(Choreographer.java:826)
        at android.view.Choreographer.doFrame(Choreographer.java:757)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:990)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loopOnce(Looper.java:201)
        at android.os.Looper.loop(Looper.java:288)
        at android.app.ActivityThread.main(ActivityThread.java:7727)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)

Comments

il...@google.com <il...@google.com> #2Jun 7, 2021 05:16PM

Nested scrolling works partially (as per

http://b/122818889). Let's discuss if we need full support and if so make sure it works.

jo...@olavstoppen.no <jo...@olavstoppen.no> #3Jun 8, 2021 09:37AM

Hi!

What is 'partially' exactly?
How do I see it?
Thanks!

jo...@olavstoppen.no <jo...@olavstoppen.no> #4Jun 8, 2021 09:39AM

As of now:
- Nesting scroll views with a scroll direction perpendicular to the ViewPager2's orientation inside ViewPager2 works
- Nesting scroll views with a scroll direction parallel to the ViewPager2's orientation inside ViewPager2 does not work

jo...@gmail.com <jo...@gmail.com> #5Jun 8, 2021 02:51PM

Horizontal ViewPager2 not correctly working into a vertical RecyclerView
Set a setNestedScrollingEnabled to the RecyclerView into the ViewPager2 (across reflection) resolves the problem

an...@gmail.com <an...@gmail.com> #6Jun 8, 2021 08:07PM

ageevvalentin@gmail.com, could you provide a sample app? I'd like to learn more about the circumstances that cause the problem; putting a clean ViewPager2 inside a clean RecyclerView seems to work fine, so there must be other factors involved.

il...@google.com <il...@google.com> #7Jun 9, 2021 12:44AM

Assigned to il...@google.com.

Added a patch for androidx-master-dev that demos a horizontal ViewPager2 inside a vertical RecyclerView.

Verified that it works correctly on a:
- Nexus 4 emulator with API 17
- Nexus 5X emulator with API 28
- Pixel 2 device with API 29

To reproduce:
- Check out the Android Jetpack source (at commit 256899f482ff85cddfb050f37550be7b5ec927ef) (see steps in [1])
- Apply the patch (`git apply 0001-Add-sample-where-a-horizontal-ViewPager2-is-nested-i.patch`)
- Build and install viewpager2's integration-tests app: `./gradlew viewpager2:integration-tests:testapp:installDebug`
- Run it

Closing the issue for now, but please reopen if you have a minimal reproduction app

[1]

https://android.googlesource.com/platform/frameworks/support/+/256899f482ff85cddfb050f37550be7b5ec927ef

il...@google.com <il...@google.com> Jun 9, 2021 03:40AM

Accepted by il...@google.com.

ap...@google.com <ap...@google.com> #8Jun 9, 2021 05:21PM

Re-opening as requested by a few users. Narrowed down the focus to nested scrolling elements with the same scroll direction.

il...@google.com <il...@google.com> #9Jun 9, 2021 05:26PM

Marked as fixed.

Any progress on this? (only talking about the "same scroll direction" issue)

I searched a lot for workarounds on Google and SO, but it seems no one really found a suitable solution yet.
The thing is that all other VerticalViewPagers out there have other problems that are similarly annoying. Most of them revolve around touch issues like "What's a click and what's a swipe" or "what's the fling threshold to snap to the next page".

So if someone knows of a working sample of VerticalViewPagers, I'd be happy to see a link :)