1880563 - theming issues with `/org/x/apps/portal/color-scheme` set to `prefer-dark`

Status: RESOLVED INVALID

(Core :: Widget: Gtk, defect)

Description

[binarynoise]

Attachment: attachments.zip

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:122.0) Gecko/20100101 Firefox/122.0

Steps to reproduce:

• fresh Arch Linux vm with cinnamon. Install Firefox, mint-l-theme
• apply light theme, set color-scheme to default
• start fresh Firefox instance
• apply dark theme, set color-scheme to prefer-dark (theme does fallback)
• apply light theme, set color-scheme to default
• set color-scheme to prefer-dark, apply dark theme (theme does not fallback)

Actual results:

The falls back to internal dark theme when color-scheme is set after applying dark theme

Expected results:

It should apply the dark gtk theme both times without falling back

Comment 1

[Emilio Cobos Álvarez [:emilio]]

Ok, so this is a theme bug. The log has this:

[Parent 3979: Main Thread]: D/LookAndFeel toggling gtk-application-prefer-dark-theme
[Parent 3979: Main Thread]: D/LookAndFeel didn't work, falling back to default theme

This means that the Mint-L-Theme doesn't respect gtk-application-prefer-dark-theme. So we don't find a dark theme and fall back to Adwaita. For dark themes we try to guess the light theme name. But for light themes is pretty hard (most themes just have a -dark variant, but this one doesn't, the dark is in the middle of the name).

The right fix is making the theme properly react to that gtk setting.

Comment 2

[binarynoise]

Ok, thanks.
I'll open an issue over at Mint-L-Theme tomorrow

Comment 3

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

The Bugbug bot thinks this bug should belong to the 'Firefox::Theme' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 4

[binarynoise]

One question though,
when setting the correct dark gtk-theme right after changing the color-scheme, why does the new theme not get applied and the fallback to adwaita removed?

Comment 5

[Emilio Cobos Álvarez [:emilio]]

That is a limitation of the way we apply the adwaita fallback. It prevents us from getting further theme name change notifications.