Restoring Fragment inside compose [312895363]

Fixed

Feature Request

Status Update

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Description

ju...@veepee.com

created issue #1

Nov 23, 2023 02:58PM

What is the correct strategy to restoring a fragment commited inside a compose AndroidView? I would expect that something like the example below to be enough to handle the fragment state restoration in an orientation change, but when rotating the screen the fragment is no longer drawn.

                   val containerId = rememberSaveable {
                        ViewCompat.generateViewId()
                    }
                    val fragmentTag = rememberSaveable {
                        "FragmentTag$containerId"
                    }
                    AndroidView(factory = { context ->
                        FragmentContainerView(context).apply {
                            id = containerId
                        }
                    }, update = { containerView ->
                        if (containerView.getFragment<Fragment?>() == null) {
                            supportFragmentManager.commit {
                                replace(containerId, SomeFragment(), fragmentTag)
                            }
                        }
                    })

StackOverflow proposes a solution using reflection, but as that is not a public API I would like to avoid using it and instead having a proper support from androidx team.

It would be nice to have a composable version of FragmentContainerView that could handle Fragment state restoration properly.

FragmentStateRestorationInsideCompose.zip

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Comments

jb...@google.com <jb...@google.com> #2Nov 27, 2023 04:12PM

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

commit c60f33e229e31ab328ef6b59dab63b264954831c
Author: Alexandre Elias <aelias@google.com>
Date: Fri Jul 10 16:23:09 2020

Semantics no-op cleanups

Partly in response to lmr's broad code review, I did a pass of
superficial API/implementation cleanup. The main changes are:

- I changed each Boolean SemanticsProperty where false is equivalent to
not being present to take "Unit" instead. This is conceptually
clearer: it avoids questions like "can I cancel out a semantics from a
merged child by setting it to false?" Because "property = Unit" looks
weird, I also changed the style of these to "property()".

- I moved the Semantics id generator closer to where it's used, in
SemanticsModifierCore. I made it internal and an AtomicInt.
(Note that integer ids are heavily used in the Android
AccessibilityNodeInfo APIs so I can't simply remove them entirely.)

- I deleted dead code. Some examples include SemanticsHintOverrides,
a public API not connected to anything, and SemanticsPropertyKey
merge() open method which is never called. (In both cases I have
a different plan in mind for accessibility.)

Fixes: 145951226
Fixes: 145955412
Test: existing tests
Relnote: "Single-value semantics properties now use a calling style.
For example, 'semantics { hidden = true }' is now written as:
'semantics { hidden() }'."

Change-Id: Ic1afd12ea22c926babc9662f1804d80b33aa0cfc

M ui/integration-tests/benchmark/src/androidTest/java/androidx/ui/benchmark/test/LayoutNodeModifierBenchmark.kt
M ui/ui-core/api/0.1.0-dev15.txt
M ui/ui-core/api/current.txt
M ui/ui-core/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-core/api/public_plus_experimental_current.txt
M ui/ui-core/api/restricted_0.1.0-dev15.txt
M ui/ui-core/api/restricted_current.txt
M ui/ui-core/src/androidAndroidTest/kotlin/androidx/ui/graphics/vector/VectorTest.kt
M ui/ui-core/src/androidAndroidTest/kotlin/androidx/ui/semantics/SemanticsTests.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidActuals.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidComposeView.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidComposeViewAccessibilityDelegateCompat.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidPopup.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/Expect.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsConfiguration.kt
D ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsHintOverrides.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsModifier.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsNode.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsOwner.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsWrapper.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/semantics/SemanticsProperties.kt
M ui/ui-foundation/api/0.1.0-dev15.txt
M ui/ui-foundation/api/current.txt
M ui/ui-foundation/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-foundation/api/public_plus_experimental_current.txt
M ui/ui-foundation/api/restricted_0.1.0-dev15.txt
M ui/ui-foundation/api/restricted_current.txt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Clickable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Dialog.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Scroller.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/selection/Selectable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/selection/Toggleable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/semantics/FoundationSemanticsProperties.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ButtonTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/CardTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/CheckboxScreenshotTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/RadioButtonScreenshotTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ScaffoldTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/SnackbarTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/SurfaceTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ripple/RippleIndicationTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/textfield/TextFieldScreenshotTest.kt
M ui/ui-material/src/main/java/androidx/ui/material/AppBar.kt
M ui/ui-material/src/main/java/androidx/ui/material/TextFieldImpl.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/AssertsTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/CallSemanticsActionTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/ErrorMessagesTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/FindersTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/PrintToStringTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/ScrollToTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/TextActionsTest.kt
M ui/ui-test/src/main/java/androidx/ui/test/Actions.kt
M ui/ui-test/src/main/java/androidx/ui/test/Filters.kt
M ui/ui-text/api/0.1.0-dev15.txt
M ui/ui-text/api/current.txt
M ui/ui-text/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-text/api/public_plus_experimental_current.txt
M ui/ui-text/api/restricted_0.1.0-dev15.txt
M ui/ui-text/api/restricted_current.txt
M ui/ui-text/src/commonMain/kotlin/androidx/ui/text/CoreTextField.kt
M ui/ui-text/src/commonMain/kotlin/androidx/ui/text/TextSemanticsProperties.kt

https://android-review.googlesource.com/1360099

ju...@gmail.com <ju...@gmail.com> #3Nov 28, 2023 02:02PM

Yes, I am familiar with AndroidViewBinding, however, as far as I know it has some limitations, like, I can't decide at runtime what fragment to commit.

ju...@gmail.com <ju...@gmail.com> #4Nov 28, 2023 02:03PM

I also can't give parameters to the fragment being inflated.

ap...@google.com <ap...@google.com> #5Mar 27, 2024 11:07PM

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

commit ffe9335a155bf0dea9c3558e50da01d526579040
Author: Jeremy Woods <jbwoods@google.com>
Date: Tue Mar 26 20:24:54 2024

Create AndroidFragment to allow adding fragments in Compose

Adding new AndroidFragment API that creates the given Fragment class and
adds it to the enclosing FragmentManager, within Compose.

It handles setting the ViewCompositionStrategy and saving the state of
the fragment across recompositions.

RelNote: "The new AndroidFragment Composable allows adding fragments
into the Compose hierarchy via the fragment class name."
Test: added AndroidFragmentTest
Bug: 230126482
Bug: 312895363

Change-Id: Icf84199bbe487b2a2b6a95d2b6e09415f810e77a

M docs-tip-of-tree/build.gradle
M fragment/fragment-compose/api/current.txt
M fragment/fragment-compose/api/restricted_current.txt
M fragment/fragment-compose/build.gradle
A fragment/fragment-compose/samples/build.gradle
A fragment/fragment-compose/samples/src/main/java/androidx/fragment/compose/samples/FragmentComposeSamples.kt
M fragment/fragment-compose/src/androidTest/AndroidManifest.xml
A fragment/fragment-compose/src/androidTest/java/androidx/fragment/compose/AndroidFragmentTest.kt
A fragment/fragment-compose/src/androidTest/java/androidx/fragment/compose/FragmentRecreateTest.kt
A fragment/fragment-compose/src/androidTest/java/androidx/fragment/compose/FragmentRemoveTest.kt
A fragment/fragment-compose/src/androidTest/java/androidx/fragment/compose/SimpleEditTextFragment.kt
A fragment/fragment-compose/src/androidTest/java/androidx/fragment/compose/test/EmptyTestActivity.kt
A fragment/fragment-compose/src/androidTest/res/layout/content.xml
A fragment/fragment-compose/src/androidTest/res/layout/sample_edit_test_layout.xml
A fragment/fragment-compose/src/main/java/androidx/fragment/compose/AndroidFragment.kt
A fragment/fragment-compose/src/main/java/androidx/fragment/compose/FragmentState.kt
M fragment/fragment/api/current.txt
M fragment/fragment/api/restricted_current.txt
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentTransaction.java
M settings.gradle

https://android-review.googlesource.com/2989182

ju...@veepee.com <ju...@veepee.com> #6Mar 28, 2024 10:02AM

Hey, Thanks to checking this out, I just checked this sample in the the repository, but this does not solve my issue.

I don't have access to the actual fragment class, we use an abstraction that just returns me a instance of Fragment with the arguments set, so this won't solve the issue for me, would it be possible to allow passing the Fragment instance ?

il...@google.com <il...@google.com> #7Mar 28, 2024 04:59PM

Re comment#6 - no. AndroidFragment uses the FragmentFactory you've set on your FragmentManager to instantiate fragment instances, ensuring that every construction of the fragment, from the initial one to the one after process death and recreation all go through the same route.

This aligns with other fragment based APIs like FragmentScenario and NavHostFragment. You'll want to adjust your own abstraction to use those APIs and separate the creation of the fragment instance from the arguments.

il...@google.com <il...@google.com> #8Mar 28, 2024 05:01PM

I'll note that FragmentFactory does allow you to request an AbstractBaseFragment and redirect it to a specific subclass of that class without exposing that subclass itself if you do need that level of indirection.

ju...@veepee.com <ju...@veepee.com> #9Mar 29, 2024 07:18AM

We were always allowed to create a new Fragment and to commit a Fragment instance in FragmentManager, could you align with that as well? My abstraction returns a Fragment instance because this allows us to avoid directly depending on the gradle module that provides the Fragment and this strategy improves compilation time by making the gradle dependency graph flatter.

Message last modified on Mar 29, 2024 07:43AM

il...@google.com <il...@google.com> #10Mar 29, 2024 05:01PM

You'll want your abstraction to be implemented in terms of a FragmentFactory.

ju...@veepee.com <ju...@veepee.com> #11Apr 2, 2024 08:20AM

My abstraction does not use fragmentFactory, and don't need to. How is that related to this issue? Devs have always been able to instantiate a fragment using default fragment constructor, I am not exposing which Fragment subclass is being instantiated in the calling site or using the className as key to find which fragment to instantiate, to add a fragment to FragmentManager we just need the base class Fragment.

ba...@gmail.com <ba...@gmail.com> #12Apr 4, 2024 09:10AM

Hi. Would it be possible to update an existing fragment when the args given to it change? I've a PageFragment in my app that load an url received as argument. When I navigate using my bottom bar, a PageFragment is loaded with different url for each. Right now it won't work with AndroidFragment as the clazz is the same and it won't recompose based on arguments alone.

il...@google.com <il...@google.com> #13Apr 8, 2024 05:55PM

Re comment#12 - you can surround the AndroidFragment with key(url) to reset that subtree whenever url changes.

ba...@gmail.com <ba...@gmail.com> #14Apr 8, 2024 07:52PM

Thanks, using key(url) works like a charm. I thought this function was only available for LazyList|Column...

ba...@gmail.com <ba...@gmail.com> #15Apr 25, 2024 12:23PM

For your information we have the following crash using AndroidView:

Exception java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState at androidx.fragment.app.FragmentManager.checkStateLoss (FragmentManager.java:1) at androidx.fragment.app.FragmentManager.ensureExecReady (FragmentManager.java:1) at androidx.fragment.app.FragmentManager.execSingleAction (FragmentManager.java:1) at androidx.fragment.app.BackStackRecord.commitNow (BackStackRecord.java:1) at androidx.fragment.compose.AndroidFragmentKt$AndroidFragment$4.invoke (AndroidFragment.kt:110) at androidx.fragment.compose.AndroidFragmentKt$AndroidFragment$4.invoke (AndroidFragment.kt:3) at androidx.compose.runtime.DisposableEffectImpl.onRemembered (Effects.kt:7) at androidx.compose.runtime.CompositionImpl$RememberEventDispatcher.dispatchRememberObservers (Composition.kt:144) at androidx.compose.runtime.CompositionImpl.applyChangesInLocked (Composition.kt:1) at androidx.compose.runtime.CompositionImpl.applyChanges (Composition.kt:6) at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$1.invoke (Recomposer.kt:1) at androidx.compose.runtime.Recomposer$runRecomposeAndApplyChanges$2$1.invoke (Recomposer.kt:7) at androidx.compose.ui.platform.AndroidUiFrameClock$withFrameNanos$2$callback$1.doFrame (AndroidUiFrameClock.android.kt:11) at androidx.compose.ui.platform.AndroidUiDispatcher.performFrameDispatch (AndroidUiDispatcher.android.kt:34) at androidx.compose.ui.platform.AndroidUiDispatcher.access$performFrameDispatch (AndroidUiDispatcher.android.kt:1) at androidx.compose.ui.platform.AndroidUiDispatcher$dispatchCallback$1.doFrame (AndroidUiDispatcher.android.kt:17) at android.view.Choreographer$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:7918) at java.lang.reflect.Method.invoke at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run (RuntimeInit.java:548) at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:936)

lo...@gmail.com <lo...@gmail.com> #16Apr 25, 2024 03:18PM

Will there also be an overload in which we can directly pass in an already created fragment instance? Like:

fun <T : Fragment> AndroidFragment(
    fragment: T,
    modifier: Modifier = Modifier,
    fragmentState: FragmentState = rememberFragmentState(),
    arguments: Bundle = Bundle.EMPTY,
    onUpdate: (T) -> Unit = { },
) { ... }

il...@google.com <il...@google.com> #17Apr 25, 2024 07:59PM

Re comment#15 - please file a separate issue so we can track that crash.

il...@google.com <il...@google.com> #18Apr 25, 2024 08:00PM

Marked as fixed, reassigned to jb...@google.com.

Re comment#16 - no, as explained in comment#7.