Improve Compose in Fragment experience [258046948]

Fixed

Feature Request

Status Update

No update yet.

Description

ch...@google.com

created issue #1

Nov 7, 2022 09:53PM

Using Compose within Fragments require setting a different ViewCompositionStrategy (DisposeOnViewTreeLifecycleDestroyed) so that the composition follows the fragment's view lifecycle. While we do document this behavior in https://developer.android.com/jetpack/compose/interop/interop-apis#composition-strategy it is still a common 'gotcha' that developers frequently run into as per feedback we've received from partners (b/229427938).

To prevent developers from making this mistake, we can improve the DevEx by either:

providing a lint warning when using ComposeView in a fragment (preferred - works for existing implementations)
create a subclass ComposeFragment (less preferred - requires awareness of this new component, also can be confused with fragment-in-compose use case)

Comments

il...@google.com <il...@google.com> #2May 31, 2023 11:32PM

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

commit 92bd7222fcfd7523e8fa80b7f72e967b8bbf4750
Author: Ian Lake <ilake@google.com>
Date: Tue Aug 27 10:07:52 2019

Split LifecycleCallbacks from FragmentManager

Create a separate FragmentLifecycleCallbacksDispatcher
object that is responsible for dispatching
FragmentLifecycleCallbacks events.

Test: existing FragmentLifecycleTest pass
BUG: 139536619
Change-Id: I64cc2b364af65760b0008efb317a742df2c0718d

A fragment/fragment/src/main/java/androidx/fragment/app/FragmentLifecycleCallbacksDispatcher.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java

https://android-review.googlesource.com/1110155

https://goto.google.com/android-sha1/92bd7222fcfd7523e8fa80b7f72e967b8bbf4750

ap...@google.com <ap...@google.com> #3Jan 16, 2024 11:55PM

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

commit 092d14cd22c174405221b930665869f7c9fc8b65
Author: Ian Lake <ilake@google.com>
Date: Tue Aug 27 14:46:02 2019

Remove FragmentState mInstance

Make FragmentState a simple Parcelable by removing
its mInstance field and its instantiate() method.

This required we change the order of restoring:
instead of reconnecting retained Fragments with their
FragmentState instances, we first iterate through
all FragmentState instances and do one of two things:
1) Reconnect the retained fragment if it exists
2) Create a new fragment from the FragmentState

This allows us to do just one pass through our
FragmentState objects and run the edge case of
detecting retained fragments created after the
state was saved after creating the set of active
fragments.

Test: all existing tests pass
BUG: 139536619
Change-Id: Iba7cc300c127bc05127d122fa5acc1ccc871a76b

M fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentManagerViewModel.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentState.java

https://android-review.googlesource.com/1108716

https://goto.google.com/android-sha1/092d14cd22c174405221b930665869f7c9fc8b65

ap...@google.com <ap...@google.com> #4Jan 17, 2024 08:27PM

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

commit 66d98b470d8887fdd16461c2da0df69ec62dd8d8
Author: Ian Lake <ilake@google.com>
Date: Fri Aug 16 13:22:20 2019

Add skeleton for FragmentStateManager

Store a HashMap of mWho to FragmentStateManager
instances. This serves as the minimal starting
point for moving logic that interacts with a
single Fragment from FragmentManager into
FragmentStateManager.

Test: existing tests pass, new FragmentStateManagerTest
BUG: 139536619
Change-Id: Ifaea272a3202e918143f65245fb98157ad971827

A fragment/fragment/src/androidTest/java/androidx/fragment/app/FragmentStateManagerTest.kt
M fragment/fragment/src/main/java/androidx/fragment/app/BackStackState.java
M fragment/fragment/src/main/java/androidx/fragment/app/Fragment.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java
A fragment/fragment/src/main/java/androidx/fragment/app/FragmentStateManager.java

https://android-review.googlesource.com/1109796

https://goto.google.com/android-sha1/66d98b470d8887fdd16461c2da0df69ec62dd8d8

jb...@google.com <jb...@google.com> #5Jan 17, 2024 08:47PM

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

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

commit 92d322f39a3436da8ce0e59f55194c70abe1fb8e
Author: Ian Lake <ilake@google.com>
Date: Tue Aug 27 16:46:05 2019

Move saving/restore Fragment state to FragmentStateManager

Separate the saving and restoring of Fragment
instances from FragmentManager, allowing
FragmentStateManager to fully manage the
restoration of Fragments.

Test: new FragmentStateManagerTest, existing tests
BUG: 139536619
Change-Id: Iba0df8f617d7805995612eaad52e26f5f2e99707

M fragment/fragment/src/androidTest/java/androidx/fragment/app/FragmentStateManagerTest.kt
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentStateManager.java

https://android-review.googlesource.com/1109797

https://goto.google.com/android-sha1/92d322f39a3436da8ce0e59f55194c70abe1fb8e

na...@google.com <na...@google.com> #6Jan 24, 2024 07:53PM

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

commit 5318d9bfea4baae7190875673fd087b9526c30c5
Author: Ian Lake <ilake@google.com>
Date: Wed Sep 04 13:40:58 2019

Move ensureInflatedFragmentView to FragmentStateManager

Move this logic into FragmentStateManager.

Test: all existing tests pass
BUG: 139536619
Change-Id: I1f8fafba5e35fda592bbe13954eed2ff355aae55

M fragment/fragment/src/main/java/androidx/fragment/app/FragmentManager.java
M fragment/fragment/src/main/java/androidx/fragment/app/FragmentStateManager.java

https://android-review.googlesource.com/1113752

https://goto.google.com/android-sha1/5318d9bfea4baae7190875673fd087b9526c30c5

Issue 258046948