1561546 - prefers-color-scheme is not updated immediately after changing ui.systemUsesDarkTheme

Status: VERIFIED FIXED

(Core :: Widget, defect, P2)

Description

[eight04]

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0

Steps to reproduce:

1. Visit bugzilla.mozilla.org
2. Verify the site is displayed in light theme
3. Open a new tab about:config, set ui.systemUsesDarkTheme to 1
4. Switch back to the bugzilla tab

Actual results:

Bugzilla is still displayed in light theme. If you resize the window, dark theme applies immediately.

Expected results:

Changing theme should not require a resize. Also, I think this issue may prevent background page from detecting changes of prefers-color-scheme.

Comment 1

[Hani Yacoub, Desktop QA]

Managed to reproduce this issue on Firefox Nightly 69.0a1, Firefox 68.0b14 and Firefox 67.0.4 on Windows 10 x 64, Mac OS X 10.14 and on Ubuntu 18.04 x64.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Widget code is what tracks these prefs. This should not be too hard to fix.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The component has been changed since the backlog priority was decided, so we're resetting it.
For more information, please visit auto_nag documentation.

Comment 4

[BugBot [:suhaib / :marco/ :calixte]]

The priority flag is not set for this bug.
:jimm, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 5

[Jim Mathies [:jimm]]

Something to poke at when you need a break from update work.

Comment 6

[Adam Gashlin (he/him) [:agashlin] (ex-moco)]

Attachment: Bug 1561546 - Update theme on ui.systemUsesDarkTheme change. r?Ehsan

Mostly this just needs to run RefreshSystemMetrics(), but to ensure
that runs after the preference change has affected the LookAndFeel,
I'm calling ThemeChanged(), which should do the work after all
other preference callbacks have run.

Comment 7

[Adam Gashlin (he/him) [:agashlin] (ex-moco)]

Attachment: Bug 1561546 Part 2 - Update theme when nsXPLookAndFeel prefs change.

Also causes removing a pref to take effect immediately, and prevents
losing all color pref overrides when the theme changes.

Comment 8

[Emilio Cobos Álvarez (:emilio)]

That looks good to me, thanks!

Maybe instead of the observer service we should use something like what the android code does for device changes, putting it in a common place?

Basically what that (fairly ugly) piece of code is doing is just going through all windows and call ThemeChanged on each.

In any case either way looks ok to me.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9ef1dd77e6b2
Update theme when nsXPLookAndFeel prefs change. r=dholbert,jmathies

Comment 10

[Stefan Hindli [:stefan_hindli]]

Backed out changeset 9ef1dd77e6b2 (Bug 1561546) for causing frequent failures in dom/animation/test/mozilla/test_restyles.html CLOSED TREE

https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception&classifiedState=unclassified&fromchange=8e5c9493f893354485c602377ffc4913ed9f39c2&selectedJob=266173162

https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=266173162&repo=autoland&lineNumber=4271

Comment 11

[Pulsebot]

Backout by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/235856e26f56
Backed out changeset 9ef1dd77e6b2 for causing frequent failures in dom/animation/test/mozilla/test_restyles.html CLOSED TREE

Comment 12

[Adam Gashlin (he/him) [:agashlin] (ex-moco)]

Attachment: Bug 1561546 Part 1 - Change scrollbar pref early. r?hiro

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e452ba381a62
Part 1 - Change scrollbar pref early. r=hiro

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/29b8270e326c
Part 2 - Update theme when nsXPLookAndFeel prefs change. r=dholbert,jmathies

Comment 15

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/e452ba381a62
https://hg.mozilla.org/mozilla-central/rev/29b8270e326c

Comment 16

[BugBot [:suhaib / :marco/ :calixte]]

Since the status are different for nightly and release, what's the status for beta?
For more information, please visit auto_nag documentation.

Comment 17

[Julien Cristau [:jcristau]]

I'm assuming this can ride the trains, feel free to reset status and request uplift if not.

Comment 18

[Dahan Gong]

During my tests on Win 10 v1903 x64 (build 18362.387, Pro & Education) , both Firefox 71.0a1 (win64 exe, 2019-10-05) nightly and the firefox-71.0a1.en-US.win64.zip downloaded from https://archive.mozilla.org/pub/firefox/nightly/2019/09/2019-09-20-09-49-18-mozilla-central/ can not make extensions respond on dark theme changes.

Comment 19

[Adam Gashlin (he/him) [:agashlin] (ex-moco)]

Hello Dahan,
Did this previously work on Firefox 70? If so, please file a new regression bug, and fill in the "regressed by" field with this bug number (1561546).

If not, it is still a good idea to file a new bug, and you might leave that bug number in the "see also" field of this bug so interested parties will know to look at it.

In either case, please provide some more information about how to reproduce the bug, such as a particular extension that doesn't respond, what it was supposed to do, and what specific "dark theme changes" you mean.

Comment 20

[Dahan Gong]

(In reply to Adam Gashlin (he/him) [:agashlin] from comment #19)

Hello Dahan,
Did this previously work on Firefox 70? If so, please file a new regression bug, and fill in the "regressed by" field with this bug number (1561546).

If not, it is still a good idea to file a new bug, and you might leave that bug number in the "see also" field of this bug so interested parties will know to look at it.

In either case, please provide some more information about how to reproduce the bug, such as a particular extension that doesn't respond, what it was supposed to do, and what specific "dark theme changes" you mean.

Then it seems not a "regression bug", so I've created https://bugzilla.mozilla.org/show_bug.cgi?id=1587723 .

Comment 21

[Cristian Fogel [:cfogel]]

Confirmed with 69.0a1(2019-06-26).
Verfiied fix with 71.0b5.

Comment 22

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug is a regression, but please revert this change in case of error.