Build an infrastructure for Fragment Strict Mode [153737341]

Fixed

Feature Request

androidx-bug-bounty

Status Update

No update yet.

Description

il...@google.com

created issue #1

Apr 10, 2020 05:55PM

Component used: Fragment

StrictMode is an Android system level feature for enabling the detection of potential problematic behavior and penalizing issues found (i.e., by enabling logging, throwing exceptions, etc.).

We should build the same type of infrastructure for Fragments so that developers can enable runtime checking for bad behaviors and validate that they (or libraries they depend on) aren't using deprecated APIs or known potential problematic behaviors.

Importantly, this should only be as a second line of defense behind deprecation warnings or Lint warnings to catch these issues at build time or to handle cases where third party libraries / dependencies are triggering these behaviors so that bugs can be filed against them.

We should support at least penaltyLog(), penaltyDeath(), and penaltyListener().

Given that we should maintain behavior compatibility, we should not add any enableDefaults() or detectAll() methods and instead have developers opt into exactly the detect***() methods they want. This should also remove the need for permit***() methods since they'll all default to off.

Ideally, this is something that developers can either:

Set globally via FragmentStrictMode.setDefaultPolicy(FragmentStrictMode.Policy)
Set on a specific FragmentManager (and its children FragmentManagers) via fragmentManager.setStrictModePolicy(FragmentStrictMode.Policy) (this would override the default policy)

This API shouldn't be made public until there is at least two detect***() calls added. These will be filed as separate issues.

Comments

ap...@google.com <ap...@google.com> #2Feb 18, 2021 09:42PM

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> #3Feb 18, 2021 09:42PM

Marked as fixed.

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> #4Mar 2, 2021 06:27PM

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

ap...@google.com <ap...@google.com> #5Mar 10, 2021 08:31PM

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

Issue 153737341

Description

Issue summary

Comments

ap...@google.com <ap...@google.com> #2Feb 18, 2021 09:42PM

ap...@google.com <ap...@google.com> #3Feb 18, 2021 09:42PM

ap...@google.com <ap...@google.com> #4Mar 2, 2021 06:27PM

ap...@google.com <ap...@google.com> #5Mar 10, 2021 08:31PM

Add comment

Issue metadata