Firefox Mint-Y-Dark and dark themes in general Bug + Fix

[smurphos]

Describe the bug Longstanding readability issues with firefox content widget display in using Mint-Y-Dark and any other dark theme

To Reproduce Steps to reproduce the behavior: Set Mint-Y-Dark as GTK / Controls theme - experience text readability issues in various Firefox content widgets - particularly entries.

Expected behavior No readability issues.

Frequency Does the issue happen:

• [x ] Always
• [ ] Randomly

Edition (Desktop environment): In which edition is this happening?

• [ x] Cinnamon Edition
• [ x] MATE Edition
• [ x] Xfce Edition

Live or post-install: Indicate if this is happening after the installation, or during the live session:

• [x] Post-install
• [x] Live session

The Fix

Ship the Mint Firefox build with an override in /usr/lib/firefox/distribution/distribution.ini to create and set this key in about:config

widget.content.gtk-theme-override with a value of Mint-Y

[JosephMcc]

Personally I'm not sure this is a great idea. It would be unclear to most users why Firefox isn't adapting to their theme changes.

[smurphos]

It doesn't effect the application of the GTK theme to the firefox header bar / menus etc only to the elements of website content that firefox partially themes.

[JosephMcc]

Hmm... I didn't realize that. I'd have to play with it a bit. It would raise bug reports from people who choose say the blue version and get stuck with green highlights, correct?

[smurphos]

Possibly or you could just go with Adwaita and be done with it. I don't really understand why users would want website content to be themed by the GTK theme anyway. Chromium based browsers don't do it.

[gm10]

Personally I have it set to

user_pref("widget.content.gtk-theme-override", "#");

That (or any other invalid but not empty name) makes it fall back to its default, un-themed controls (at least on MATE). Seems preferable to me to using a specific theme.

Or just wait for Mozilla to fix this, the bug report on this has only been open for 18 years now. :100:

[smurphos]

user_pref("widget.content.gtk-theme-override", "#"); works well...

[NikoKrause]

So, do I get it right, that if you choose a Dark variant for Firefox, e.g. Adwaita-Dark or Mint-Y-Dark-Red, you want Firefox to use/gtk-theme-override to Adwaita or Mint-Y-Red.

At least in Cinnamon it's possible to do this on theme change. We would just need to create or change the file /home/USER/.mozilla/firefox/***.default/user.js with the content:

user_pref("widget.content.gtk-theme-override", "My-Theme-without-Darkl");

[gm10]

@NikoKrause that doesn't seem a reliable solution. Not all dark themes have a convenient -Dark suffix. The global override seems far more reliable, and also you're not taking the decision away from the user that way by simply modifying their local profile.

[smurphos]

Agreed with @gm10 - I think users would be happiest to have their web content delivered in a consistent readable fashion as intended by the web site designer without interference from their choice of system theme.

[clefebvre]

Fixed in ubuntu-system-adjustments 2018.12.12.