Fragments which use postponeEnterTransition() never receive onStart/onResume [129035555]

Fixed

Bug

Status Update

No update yet.

Description

ch...@google.com

created issue #1

Mar 21, 2019 07:31AM

Component used: Navigation
Version used: 2.0.0

The fragment I use as my startDestination uses postponeEnterTransition() and startPostponedEnterTransition() for transition purposes. When my app is opened though, that fragment is never actually visible.

This is because the Fragment does *not* receive onStart() or onResume(), so my data source is never setup, so I do not call scheduleStartPostponedTransitions(). The last lifecycle callback I get is onViewCreated().

If I remove the call to postponeEnterTransition() then everything works as normal, except my transitions.

Comments

il...@google.com <il...@google.com> #2Mar 21, 2019 04:08PM

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

commit e36c65f67e49ddbfa0080542295f4a4850ae17da
Author: Sumir Kataria <sumir@google.com>
Date: Tue Aug 07 13:04:03 2018

Enforce ConstraintTracker#setState is on the main thread.

- setState now asserts that we are on the main thread
- Moved assert*Thread methods into their own utils
- Annotated several tests manually calling onBroadcastReceive
as @UiThreadTest as our broadcast receivers only operate on
the main thread (they use the default registerReceiver
method)
- NetworkCallbacks are invoked on non-main threads by default;
in this case, we re-post them to the main thread

This is part of the solution to a concurrency exception in
ConstraintTracker.

Bug: 112272753
Test: Updated and ran tests
Change-Id: I7011e5993b814f4fcafe861e283a827cd1edee12

M work/workmanager/build.gradle
M work/workmanager/src/androidTest/java/androidx/work/impl/constraints/trackers/BatteryChargingTrackerTest.java
M work/workmanager/src/androidTest/java/androidx/work/impl/constraints/trackers/BatteryNotLowTrackerTest.java
M work/workmanager/src/androidTest/java/androidx/work/impl/constraints/trackers/ConstraintTrackerTest.java
M work/workmanager/src/androidTest/java/androidx/work/impl/constraints/trackers/StorageNotLowTrackerTest.java
M work/workmanager/src/androidTest/java/androidx/work/impl/workers/ConstraintTrackingWorkerTest.java
M work/workmanager/src/main/java/androidx/work/impl/WorkManagerImpl.java
M work/workmanager/src/main/java/androidx/work/impl/background/systemalarm/SystemAlarmDispatcher.java
M work/workmanager/src/main/java/androidx/work/impl/constraints/trackers/ConstraintTracker.java
M work/workmanager/src/main/java/androidx/work/impl/constraints/trackers/NetworkStateTracker.java
A work/workmanager/src/main/java/androidx/work/impl/utils/ThreadUtils.java

https://android-review.googlesource.com/727429

https://goto.google.com/android-sha1/e36c65f67e49ddbfa0080542295f4a4850ae17da

ch...@google.com <ch...@google.com> #3Mar 21, 2019 08:25PM

Fixed in

https://android-review.googlesource.com/c/platform/frameworks/support/+/728180 (not sure why the automated message isn't being shown here). This should be available in alpha07.

ch...@google.com <ch...@google.com> #4Mar 21, 2019 08:33PM

Full sample:

https://github.com/chrisbanes/navigation-postpone-sample

il...@google.com <il...@google.com> #5Mar 21, 2019 08:43PM

Moving this to the Fragment component since this is not related to Navigation - the same thing occurs when using fragment transactions directly when using setReorderingAllowed(true).

il...@google.com <il...@google.com> Mar 28, 2019 09:48PM

Assigned to jb...@google.com.

an...@gmail.com <an...@gmail.com> #6Sep 19, 2019 06:49PM

Is there any update on this issue? It's been reported in March.

jb...@google.com <jb...@google.com> Jan 24, 2020 10:42PM

Reassigned to il...@google.com.

li...@gmail.com <li...@gmail.com> #7Feb 23, 2020 10:48AM

Is there any progress or workaround? This issue may trigger many chain reactions, e.g. LiveData observer's onChange never be called.

il...@google.com <il...@google.com> #8Feb 24, 2020 05:59AM

Re #7 - this is being actively worked on in the blocked by issue.

il...@google.com <il...@google.com> #9Aug 17, 2020 11:53PM

Marked as fixed.

A postponed fragment will never reach onResume() (part of the contract of a postponed fragment is that it can only go up to STARTED), so the example project needed to be changed to use onStart().

That being said, this has been fixed internally and will be avilable in Fragment 1.3.0-alpha08.

Note: this fix relies on using the new state manager and will not function if it is manually disabled.