IssueTracker

> The Transition Kotlin extensions target the Framework Transition class which is a bit confusing

All extensions in 'core-ktx' target either 'core' or the framework types. This is working as expected. It sounds like this is a feature request for a transition-ktx with equivalent extensions for the androidx.transition types.

> as most framework classes are being deprecated in favor of their AndroidX counterparts, Fragments for example.

"Most"? This *dramatically* overstates what is actually happening. Fragments (and loaders) were added to the framework in a time where the Android team did not have external libraries for shipping features. Transition was added 5 years later.

Pardon my misunderstanding, I was under the belief that where possible, new features that could be developed outside the framework, would be under Androidx. Also it's a common refrain to use the Androidx libraries over the framework libraries where possible, as those ship update independently of platform releases. I wasn't attempting to be dramatic.

If the Transition api is unlikely to change, there is no need for a transition-ktx for androidx.transition types. If developers should use Androidx transitions over framework transitions where possible however, then it would be much appreciated.

I am well aware of the limitations that existed when Fragments and Loaders were created, and when the Transition api was introduced.

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

commit ae42e311ecfbac18cedc90e489d1fdde956a4557
Author: Jake Wharton <jakew@google.com>
Date:   Fri Nov 22 11:13:30 2019

    Introduce transition-ktx for standalone transition library
   
    These extensions are the same as androidx.core.transition for the platform types, just adapted to the standalone library.
   
    Bug: 138870873
    Test: gw :transition:transition-ktx:build :transition:transition-ktx:connectedCheck
    Change-Id: Ie80022cc60ed1f482b7593db5ef1ac1c5ea33d8d

M       buildSrc/src/main/kotlin/androidx/build/PublishDocsRules.kt
M       jetifier/jetifier/migration.config
M       settings.gradle
A       transition/transition-ktx/OWNERS
A       transition/transition-ktx/api/1.4.0-alpha01.txt
A       transition/transition-ktx/api/current.txt
A       transition/transition-ktx/api/public_plus_experimental_1.4.0-alpha01.txt
A       transition/transition-ktx/api/public_plus_experimental_current.txt
A       transition/transition-ktx/api/res-1.4.0-alpha01.txt
A       transition/transition-ktx/api/restricted_1.4.0-alpha01.txt
A       transition/transition-ktx/api/restricted_current.txt
A       transition/transition-ktx/build.gradle
A       transition/transition-ktx/src/androidTest/AndroidManifest.xml
A       transition/transition-ktx/src/androidTest/java/androidx/transition/TestActivity.kt
A       transition/transition-ktx/src/androidTest/java/androidx/transition/TransitionTest.kt
A       transition/transition-ktx/src/androidTest/res/layout/test_activity.xml
A       transition/transition-ktx/src/main/AndroidManifest.xml
A       transition/transition-ktx/src/main/java/androidx/transition/Transition.kt

https://android-review.googlesource.com/1172715

Hi! I have successfully created a demo project which can reproduce this issue. Please check the following repo and I hope it helps to resolve the issue.

https://github.com/h6ah4i/FragmentStateAdapterOnFailedToRecyclerViewFailure

[UPDATE]
This issue still exists on ViewPager2 v1.0.0-alpha06 with RecyclerView v1.1.0-beta01.

I can confirm I can repro this and will try to provide a workaround / fix soon.
Big thanks for the sample app, repro steps and research info. Super appreciated!

The easiest workaround would involve copying FragmentStateAdapter and FragmentViewHolder into your project, and in FragmentStateAdapter adding ensureFragment(holder.getAdapterPosition()) as the first line of placeFragmentInViewHolder method. Attached as a patch to your sample app.

We'll work on a proper fix. Might unblock you in the meantime though. Thanks again for reporting and a sample app.

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

commit 07cadad5116ff71ab161a8ef3433679d89530405
Author: Jakub Gielzak <jgielzak@google.com>
Date:   Mon Jul 29 15:17:08 2019

    Fix for FragmentStateAdapter transient state issue
   
    Fixes a crash when a ViewHolder which has gone through
    onFailedToRecycleView is shown again violating Adapter's design
    assumptions.
   
    Bug: 134246546
    Test: TransientStateFragmentTest
    Test: ./gradlew viewpager2:connectedCheck
   
    Change-Id: Ieb166c6fb48907cbb7aa46ab87a3ae4cc29591a6

A       viewpager2/src/androidTest/java/androidx/viewpager2/widget/TransientStateFragmentTest.kt
M       viewpager2/src/main/java/androidx/viewpager2/adapter/FragmentStateAdapter.java

https://android-review.googlesource.com/1092796
https://goto.google.com/android-sha1/07cadad5116ff71ab161a8ef3433679d89530405

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

commit a35a5180df0b98c4af4a4e119388f7d70d27ade4
Author: Jakub Gielzak <jgielzak@google.com>
Date:   Tue Jul 30 17:27:14 2019

    FragmentStateAdapter transient state fix follow-up
   
    Follow-up to Ieb166c6fb48907cbb7aa46ab87a3ae4cc29591a6:
    * Disabled tests on API < 16
    * Updated a comment
   
    Bug: 134246546
    Test: TransientStateFragmentTest
    Test: ./gradlew viewpager2:connectedCheck
   
    Change-Id: Id27c1267d4fc75c41849291322952fc1ea0e8d0d

M       viewpager2/src/androidTest/java/androidx/viewpager2/widget/TransientStateFragmentTest.kt
M       viewpager2/src/main/java/androidx/viewpager2/adapter/FragmentStateAdapter.java

https://android-review.googlesource.com/1093437
https://goto.google.com/android-sha1/a35a5180df0b98c4af4a4e119388f7d70d27ade4

The fix is now in place and should come out in the next release.

Fixed in now released beta03 - https://developer.android.com/jetpack/androidx/releases/viewpager2#1.0.0-beta03

I can't reproduce this myself but I get this issue in production on Xiaomi running Android 10 with ViewPager2 1.0.0 stable release. Any idea what could cause it now?

Hi, could you share the stack trace?

Here's an issue I created since this was marked as fixed: https://issuetracker.google.com/issues/147688910

I am facing this issue in 1.0.0 release

Fatal Exception: java.lang.IllegalStateException
Design assumption violated.
androidx.viewpager2.adapter.FragmentStateAdapter.placeFragmentInViewHolder + 287 (FragmentStateAdapter.java:287)
androidx.viewpager2.adapter.FragmentStateAdapter$1.onLayoutChange + 190 (FragmentStateAdapter.java:190)
android.view.View.layout + 21131 (View.java:21131)
android.view.ViewGroup.layout + 6400 (ViewGroup.java:6400)
androidx.recyclerview.widget.RecyclerView$LayoutManager.layoutDecoratedWithMargins + 9587 (RecyclerView.java:9587)
androidx.recyclerview.widget.LinearLayoutManager.layoutChunk + 1685 (LinearLayoutManager.java:1685)
androidx.recyclerview.widget.LinearLayoutManager.fill + 1587 (LinearLayoutManager.java:1587)
androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren + 665 (LinearLayoutManager.java:665)
androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2 + 4134 (RecyclerView.java:4134)
androidx.recyclerview.widget.RecyclerView.dispatchLayout + 3851 (RecyclerView.java:3851)
androidx.recyclerview.widget.RecyclerView.onLayout + 4404 (RecyclerView.java:4404)
android.view.View.layout + 21112 (View.java:21112)
android.view.ViewGroup.layout + 6400 (ViewGroup.java:6400)
androidx.viewpager2.widget.ViewPager2.onLayout + 527 (ViewPager2.java:527)
android.view.View.layout + 21112 (View.java:21112)
android.view.ViewGroup.layout + 6400 (ViewGroup.java:6400)
androidx.constraintlayout.widget.ConstraintLayout.onLayout + 1915 (ConstraintLayout.java:1915)
android.view.View.layout + 21112 (View.java:21112)
android.view.ViewGroup.layout + 6400 (ViewGroup.java:6400)
android.widget.FrameLayout.layoutChildren + 323 (FrameLayout.java:323)
android.widget.FrameLayout.onLayout + 261 (FrameLayout.java:261)
android.view.View.layout + 21112 (View.java:21112)
android.view.ViewGroup.layout + 6400 (ViewGroup.java:6400)
android.widget.LinearLayout.setChildFrame + 1828 (LinearLayout.java:1828)
android.widget.LinearLayout.layoutVertical + 1656 (LinearLayout.java:1656)
android.widget.LinearLayout.onLayout + 1565 (LinearLayout.java:1565)
android.view.View.layout + 21112 (View.java:21112)
android.view.ViewGroup.layout + 6400 (ViewGroup.java:6400)
android.widget.FrameLayout.layoutChildren + 323 (FrameLayout.java:323)
android.widget.FrameLayout.onLayout + 261 (FrameLayout.java:261)
android.view.View.layout + 21112 (View.java:21112)
android.view.ViewGroup.layout + 6400 (ViewGroup.java:6400)
android.widget.LinearLayout.setChildFrame + 1828 (LinearLayout.java:1828)
android.widget.LinearLayout.layoutVertical + 1656 (LinearLayout.java:1656)
android.widget.LinearLayout.onLayout + 1565 (LinearLayout.java:1565)
android.view.View.layout + 21112 (View.java:21112)
android.view.ViewGroup.layout + 6400 (ViewGroup.java:6400)
android.widget.FrameLayout.layoutChildren + 323 (FrameLayout.java:323)
android.widget.FrameLayout.onLayout + 261 (FrameLayout.java:261)
com.android.internal.policy.DecorView.onLayout + 883 (DecorView.java:883)
android.view.View.layout + 21112 (View.java:21112)
android.view.ViewGroup.layout + 6400 (ViewGroup.java:6400)
android.view.ViewRootImpl.performLayout + 3368 (ViewRootImpl.java:3368)
android.view.ViewRootImpl.performTraversals + 2809 (ViewRootImpl.java:2809)
android.view.ViewRootImpl.doTraversal + 1815 (ViewRootImpl.java:1815)
android.view.ViewRootImpl$TraversalRunnable.run + 8228 (ViewRootImpl.java:8228)
android.view.Choreographer$CallbackRecord.run + 995 (Choreographer.java:995)
android.view.Choreographer.doCallbacks + 807 (Choreographer.java:807)
android.view.Choreographer.doFrame + 739 (Choreographer.java:739)
android.view.Choreographer$FrameDisplayEventReceiver.run + 981 (Choreographer.java:981)
android.os.Handler.handleCallback + 873 (Handler.java:873)
android.os.Handler.dispatchMessage + 99 (Handler.java:99)
android.os.Looper.loop + 226 (Looper.java:226)
android.app.ActivityThread.main + 7212 (ActivityThread.java:7212)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run + 576 (RuntimeInit.java:576)
com.android.internal.os.ZygoteInit.main + 956 (ZygoteInit.java:956)

I also facing this issue in 1.0.0 release

finally I do can reproduce this bugs, please check this! https://stackoverflow.com/a/63114195/8868638.

Occurred in 1.0.0

java.lang.IllegalStateException: Design assumption violated.
        at androidx.viewpager2.adapter.FragmentStateAdapter.placeFragmentInViewHolder(FragmentStateAdapter.java:287)
        at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:276)
        at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:67)
        at androidx.recyclerview.widget.RecyclerView.dispatchChildAttached(RecyclerView.java:7556)
        at androidx.recyclerview.widget.RecyclerView$5.addView(RecyclerView.java:860)
        at androidx.recyclerview.widget.ChildHelper.addView(ChildHelper.java:107)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:8601)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8559)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8547)
        at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1641)
        at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1587)
        at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:665)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4134)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3851)
        at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4404)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at androidx.viewpager2.widget.ViewPager2.onLayout(ViewPager2.java:527)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at com.google.android.material.appbar.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:148)
        at com.google.android.material.appbar.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:43)
        at com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior.onLayoutChild(AppBarLayout.java:1892)
        at androidx.coordinatorlayout.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:918)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at androidx.constraintlayout.widget.ConstraintLayout.onLayout(ConstraintLayout.java:1915)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at androidx.drawerlayout.widget.DrawerLayout.onLayout(DrawerLayout.java:1231)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
        at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
        at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
        at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1557)
        at android.widget.LinearLayout.onLayout(LinearLayout.java:1466)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:573)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:508)
        at android.view.View.layout(View.java:15596)
        at android.view.ViewGroup.layout(ViewGroup.java:4966)
        at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:

version 1.0.0-beta03


java.lang.IllegalStateException: Design assumption violated.
        at androidx.viewpager2.adapter.FragmentStateAdapter.placeFragmentInViewHolder(FragmentStateAdapter.java:287)
        at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:276)
        at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:67)
        at androidx.recyclerview.widget.RecyclerView.dispatchChildAttached(RecyclerView.java:7867)
        at androidx.recyclerview.widget.RecyclerView$5.addView(RecyclerView.java:893)
        at androidx.recyclerview.widget.ChildHelper.addView(ChildHelper.java:107)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:8902)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8860)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8848)
        at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1645)
        at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1591)
        at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:668)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep1(RecyclerView.java:4255)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:4010)
        at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4578)
        at android.view.View.layout(View.java:23219)
        at android.view.ViewGroup.layout(ViewGroup.java:6532)
        at androidx.viewpager2.widget.ViewPager2.onLayout(ViewPager2.java:527)
        at android.view.View.layout(View.java:23219)
        at android.view.ViewGroup.layout(ViewGroup.java:6532)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
        at android.view.View.layout(View.java:23219)
        at android.view.ViewGroup.layout(ViewGroup.java:6532)
        at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1829)
        at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1673)
        at android.widget.LinearLayout.onLayout(LinearLayout.java:1582)
        at android.view.View.layout(View.java:23219)
        at android.view.ViewGroup.layout(ViewGroup.java:6532)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
        at android.view.View.layout(View.java:23219)
        at android.view.ViewGroup.layout(ViewGroup.java:6532)
        at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1829)
        at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1673)
        at android.widget.LinearLayout.onLayout(LinearLayout.java:1582)
        at android.view.View.layout(View.java:23219)
        at android.view.ViewGroup.layout(ViewGroup.java:6532)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
        at android.view.View.layout(View.java:23219)
        at android.view.ViewGroup.layout(ViewGroup.java:6532)
        at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1829)
        at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1673)
        at android.widget.LinearLayout.onLayout(LinearLayout.java:1582)
        at android.view.View.layout(View.java:23219)
        at android.view.ViewGroup.layout(ViewGroup.java:6532)
        at android.widget.FrameLayout.layoutChildren(FrameLayout.java:332)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:270)
        at com.android.internal.policy.DecorView.onLayout(DecorView.java:804)
        at android.view.View.layout(View.java:23219)
        at android.view.ViewGroup.layout(ViewGroup.java:6532)
        at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:3686)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:3144)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:2115)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:8582)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:975)
        at android.view.Choreographer.doCallbacks(Choreographer.java:799)
        at android.view.Choreographer.doFrame(Choreographer.java:734)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:960)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:236)
        at android.app.ActivityThread.main(ActivityThread.java:7864)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:620)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1011)

The cause is getItemId return the  duplicate id.
I find self test stable reproduction.