1722886 - System theme is incorrect when ui.systemUsesDarkTheme is set differently

Status: RESOLVED FIXED

(Core :: Widget: Gtk, defect)

Description

[Kestrel]

Attachment: Adwaita-dark with ui.systemUsesDarkTheme = 0

STR:

1. Select a dark GTK theme like Adwaita-dark.
2. Enable the System theme.
3. Set ui.systemUsesDarkTheme = 0.

Expected:

Browser uses system theme colors and web content uses light theme like before.

Actual:

Browser uses light theme colors but with some dark colors that result in low contrast. Some widgets are dark with dark text. Same kind of problem with light GTK theme and ui.systemUsesDarkTheme = 1.

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=365bfc91ddd5d9be1a5d5bee72377c025b099321&tochange=a57a18bd5034b718955a35fecea22727d556e35f

Regressed by Bug 1707957.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

This is because this function is getting the pref value, which is lying, rather than the underlying system value...

I guess we could support this without much trouble, but I'd rather add an explicit way of overriding prefers-color-scheme for content, wdyt?

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1722886 - Add a way to override prefers-color-scheme for content without messing with widget values. r=stransky

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/399441fe2466
Add a way to override prefers-color-scheme for content without messing with widget values. r=stransky

Comment 5

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/399441fe2466

Comment 6

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

The patch landed in nightly and beta is affected.
:emilio, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Comment 7

[Emilio Cobos Álvarez (:emilio)]

Karl do you think this is worth uplifting? (Since you filed bug 1725917)

Comment 8

[Karl Tomlinson (:karlt)]

I think this was a good thing to do, but would be of limited value for an uplift because the user would still need to discover and change preferences.

widget.gtk.alt-theme.dark already exists for a workaround in the meantime. Even though there may be a small advantage in the user having the option of changing the newer pref now rather than changing an existing intermediate pref, the regression has already shipped and so the existing workaround would already be needed.

https://phabricator.services.mozilla.com/D122807 proposes a solution that does not require pref discovery and change.