1785134 - In-content tabs have too large font size

Status: RESOLVED FIXED

(Thunderbird :: Upstream Synchronization, defect)

Description

[Alessandro Castellani [:aleca]]

The font size in our in-content sections is now bloated.
Maybe regressed by bug 1773342

This seems to happen on GTK with increased font sizing.
I'm on elementary OS 6 and I'm using their built-in accessibility feature to upscale the font to 1.25

This is mostly due to our own implementation of the uiFontSize.jsm, in which we implemented a default body font size of 1rem to normalize all sizes and respect the OS scaling.

My setup

• My OS font size is 12px. This is what Thunderbird detects and assigns here: https://searchfox.org/comm-central/rev/a5c77525a528bc679d9f9c82e2d02846e6006933/mail/modules/UIFontSize.jsm#156-165
• My OS font scaling factor is set to 1.25.

If I manually set font-size: 12px on the HTML element of a content tab, the UI normalizes correctly.
We don't set the font-size style on those elements if it matches the default size of the OS, because up to this point the UI always scaled correctly.

Something has changed that it seems to interfere with those changes and making only the content font size larger.
These are uneducated guesses, so I might be completely wrong.

Comment 1

[Alessandro Castellani [:aleca]]

Attachment: chrome-content.png

Comment 2

[Alessandro Castellani [:aleca]]

Gentle ping to emilio to see if he has any idea.

Comment 3

[Alessandro Castellani [:aleca]]

Remove bug 1773342 as the cause for the regression since 2 days ago i reviewed a patch changing some icons in the account setup tab and the font sizing looked correct.
So, this might be a very recent regression.

Comment 4

[Emilio Cobos Álvarez [:emilio]]

Okay, let me know if I have something to do with the regression and happy to poke :)

Comment 5

[Alessandro Castellani [:aleca]]

Found the culprit: https://hg.mozilla.org/mozilla-central/diff/b2bdddc979f368917b07162504961bc5690fff8a/toolkit/themes/shared/in-content/common-shared.css#l1.18

Comment 6

[Richard Marti (:Paenglab)]

On Windows the font is smaller than before.

Comment 7

[Alessandro Castellani [:aleca]]

Yeah, that created some unexpected and inconsistent outcomes depending on the platform and OS font size.

Comment 8

[Alessandro Castellani [:aleca]]

Bug 1784891 might be helpful for us since it introduces a class that will exclude applying that root font sizing.
Not sure if it makes sense, or if at this point it's easier to override the whole common-shared.css and start applying our style, since we're drastically diverging from m-c toolkit style and our UI needs to be less brittle and prone to breakages due to toolkit changes.

Comment 9

[Dão Gottwald [:dao]]

(In reply to Alessandro Castellani [:aleca] from comment #8)

Bug 1784891 might be helpful for us since it introduces a class that will exclude applying that root font sizing.

Yep, that should come handy.

I think you'll also want to stop doing that:

(In reply to Alessandro Castellani [:aleca] from comment #0)

This is mostly due to our own implementation of the uiFontSize.jsm, in which we implemented a default body font size of 1rem to normalize all sizes and respect the OS scaling.

Comment 10

[Richard Marti (:Paenglab)]

Attachment: Bug 1785134 - Override the toolkit :root font size in in-content pages. r=aleca

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/b54c090e0816
Override the toolkit :root font size in in-content pages. r=aleca