IssueTracker

Using the Jetpack navigation library, when performing a shared element transition from a Fragment that is shown inside a androidx.viewpager2.widget.ViewPager2 into another Fragment, the following exception is thrown:

java.lang.IllegalArgumentException: Only TabItem instances can be added to TabLayout
        at com.google.android.material.tabs.TabLayout.addViewInternal(TabLayout.java:1606)
        at com.google.android.material.tabs.TabLayout.addView(TabLayout.java:1589)
        at androidx.transition.TransitionUtils.createViewBitmap(TransitionUtils.java:138)
        at androidx.transition.TransitionUtils.copyViewImage(TransitionUtils.java:64)
        at androidx.transition.Visibility.onDisappear(Visibility.java:404)
        at androidx.transition.Visibility.createAnimator(Visibility.java:257)
        at androidx.transition.Transition.createAnimators(Transition.java:744)
        at androidx.transition.TransitionSet.createAnimators(TransitionSet.java:480)
        at androidx.transition.Transition.playTransition(Transition.java:1808)
        at androidx.transition.TransitionManager$MultiListener.onPreDraw(TransitionManager.java:300)
        at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:1119)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:3333)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:2222)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:9123)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:999)
        at android.view.Choreographer.doCallbacks(Choreographer.java:797)
        at android.view.Choreographer.doFrame(Choreographer.java:732)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:984)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:237)
        at android.app.ActivityThread.main(ActivityThread.java:8167)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1100)

The viewpager is used with a Tablayout. The transition is used to navigate from a screen that shows a tab and below that a list of items, into a detail fragment (showing the details for the selected item fullscreen, not under a tab)

The exception only happens when a shared element is provided and when the ChangeBounds transition is set in the target fragment (Fade() does not trigger the Exception)

When removing the FragmentNavigatorExtras from the navigate call, or when removing the sharedElementEnterTransition = ChangeBounds() call from the target fragment; the exception is not thrown (but there is no transition either)

It seems to me that the com.google.android.material.tabs.TabLayout does not support the addView(View child, int index) call, which the androidx.transition.TransitionUtils class uses as part of the createViewBitmap(View view, Matrix matrix, RectF bounds, ViewGroup sceneRoot) method:

if (HAS_OVERLAY && addToOverlay) {
   sceneRoot.getOverlay().remove(view);
   parent.addView(view, indexInParent);
}

Relevant dependency versions:

implementation 'androidx.transition:transition:1.4.1'
implementation 'com.google.android.material:material:1.4.0'
implementation 'androidx.fragment:fragment-ktx:1.3.6'