Fragment ViewModel's onCleared not called [74139250]

Fixed

Bug

[AOSP] assigned

Status Update

No update yet.

Description

bo...@gmail.com

created issue #1

Mar 3, 2018 10:11AM

Library used (support-v4, appcompat-v7, ...):

implementation 'com.android.support:appcompat-v7:27.1.0'

implementation "android.arch.lifecycle:runtime:1.1.0"
implementation "android.arch.lifecycle:extensions:1.1.0"
implementation "android.arch.lifecycle:common-java8:1.1.0"

Version used: 27.1.0
Theme used: N/A
Devices/Android versions reproduced on: Emulator 24

- Relevant code to trigger the issue.

Make an Activity that contains a Fragment.
Make the Activity use a ViewModel, and make the Fragment also use a ViewModel.
Start the Activity and press back.
The Activity's ViewModel's onCleared method is called.
With AppCompat 27.0.2, the Fragment's ViewModel's onCleared method is called (as it should)
With AppCompat 27.1.0, the Fragment's ViewModel's onCleared method is not called (incorrect).

See the attached project that shows the issue.

With 27.0.2, the logs read:
---------------------------

org.jraf.android.viewmodelproblem.MainActivity: onCreate
org.jraf.android.viewmodelproblem.MainActivityViewModel: constructor
org.jraf.android.viewmodelproblem.MainFragment: onCreate
org.jraf.android.viewmodelproblem.MainFragmentViewModel: constructor

[back is pressed]

org.jraf.android.viewmodelproblem.MainActivity: onDestroy
org.jraf.android.viewmodelproblem.MainActivityViewModel: onCleared
org.jraf.android.viewmodelproblem.MainFragmentViewModel: onCleared
org.jraf.android.viewmodelproblem.MainFragment: onDestroy

With 27.1.0, the logs read:
---------------------------
org.jraf.android.viewmodelproblem.MainActivity: onCreate
org.jraf.android.viewmodelproblem.MainActivityViewModel: constructor
org.jraf.android.viewmodelproblem.MainFragment: onCreate
org.jraf.android.viewmodelproblem.MainFragmentViewModel: constructor

[back is pressed]

org.jraf.android.viewmodelproblem.MainActivity: onDestroy
org.jraf.android.viewmodelproblem.MainActivityViewModel: onCleared
org.jraf.android.viewmodelproblem.MainFragment: onDestroy

This seems to happen because of line 1645 of Fragment, this test:
if (mViewModelStore != null && !mHost.mFragmentManager.isStateSaved()) {
is always false because mHost.mFragmentManager.isStateSaved() is true.

ViewModelProblem.zip

144 KB

Download

Comments

il...@google.com <il...@google.com> Mar 3, 2018 03:58PM

Accepted by il...@google.com.

il...@google.com <il...@google.com> #2Mar 3, 2018 05:15PM

The problem is very serious.
Currently html5 clearRect isn't working within any android 4 devices.
Please, solve this problem as soon as possible.

il...@google.com <il...@google.com> Mar 5, 2018 09:55PM

Marked as fixed.

lo...@gmail.com <lo...@gmail.com> #3Mar 6, 2018 08:58AM

we have the same problem

We are waiting for a patch since November because none of the workaround we have tried is stable.

We hope that the patch will come before the launching of our app and if not...well, sadly, we will launch the app on iOS and windows only

ja...@gmail.com <ja...@gmail.com> #4Mar 8, 2018 07:06AM

[Comment deleted]

b9...@gmail.com <b9...@gmail.com> #5Mar 8, 2018 07:13AM

Still appears to be an issue as I'm getting quirky results when trying clearRect in a loop. #3 solution is good but too heavy to work in a loop.

ka...@gmail.com <ka...@gmail.com> #6Mar 8, 2018 12:51PM

What about using requestAnimationFrame for loop rather than using a timer loop ?

b9...@gmail.com <b9...@gmail.com> #7Mar 14, 2018 05:01PM

Hey, this is a serious issue that is affecting our production components, could someone please look into this???

yc...@gmail.com <yc...@gmail.com> #8Mar 16, 2018 09:45AM

is there any solvtion for that issue ?

il...@google.com <il...@google.com> #9Mar 16, 2018 04:48PM

Something like that works for me:

function bug_workaround() {
$(canvas).hide();
setTimeout(function() {
$(canvas).show();
}, 1);
}

I call this function after clear.

[Deleted User] <[Deleted User]> #10Mar 19, 2018 03:28AM

Opacity trick is better because will not initiate page reflow and hide /
show will.

kk...@google.com <kk...@google.com> #11Apr 10, 2018 04:14AM

which trick would that be? modify the opacity?

[Deleted User] <[Deleted User]> #12Apr 16, 2018 03:15PM

Yes,

function bug_workaround() {
canvas.style.opacity = 0.99;
setTimeout(function() {
canvas.style.opacity = 1;
}, 1);
}

an...@gmail.com <an...@gmail.com> #13Jun 8, 2018 10:54AM

[Comment deleted]

il...@google.com <il...@google.com> #14Jun 8, 2018 02:33PM

Hi,

I'm having the same problem but the workaround doesn't seem to help. Was wondering if this issue is somehow fixed by now?

Thank You.

al...@gmail.com <al...@gmail.com> #15Jun 15, 2018 09:18PM

This opacity hack works for me. I've had this issue on 4.1.1 and 4.1.2, both Galaxy S3 and the S3 mini.

Calling this function between clearing the canvas and the next draw call seems to have fixed the problem.

function bug_workaround() {
canvas.style.opacity = 0.99;
setTimeout(function() {
canvas.style.opacity = 1;
}, 1);
}

Thanks, dennis.ra!

al...@gmail.com <al...@gmail.com> #16Jun 15, 2018 09:21PM

The opacity trick doesn't seem to work for me (Android 4.3).
Hide & show causes a lot of nasty flicker.

This solution works form me:

https://medium.com/@dhashvir/android-4-1-x-stock-browser-canvas-solution-ffcb939af758
But only the second one:
canvas.clearRect(0, 0, w, h);
canvas.style.display = 'none';// Detach from DOM
canvas.offsetHeight; // Force the detach
canvas.style.display = 'inherit'; // Reattach to DOM

Performance hit seems to be minimal for my app (game with multiple canvas one over another).

lb...@gmail.com <lb...@gmail.com> #17Jun 15, 2018 09:26PM

seems android 4.1/4.2/4.3 both have this problem?

al...@gmail.com <al...@gmail.com> #18Jun 16, 2018 04:43PM

@17, thanks for the suggestion. I have reported the issue here:

https://issuetracker.google.com/issues/110285295

m....@gmail.com <m....@gmail.com> #19Dec 27, 2018 08:16PM

https://drive.google.com/file/d/1zBwQSAHyw8aoyggjjYoG6Bo4NQz3l45T/view?usp=drive_web (-Docs--1.docx)

3g...@gmail.com <3g...@gmail.com> #20Mar 27, 2021 06:55AM

file sdcard encrypt....

[Deleted User] <[Deleted User]> #21Mar 2, 2022 06:20AM

Common