380915 - replace separate font size prefs for monospace fonts with font-size-adjust

Status: NEW

(Core :: CSS Parsing and Computation, defect)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Now that we have font-size-adjust implemented on all platforms, we should replace the code involving having separate font size preferences for monospace fonts with a default value of font-size-adjust (-moz-auto) that means:
 * for unicameral scripts, 'none'
 * for bicameral scripts, to use the font-size-adjust from the default font.
However, any author specified font in absolute length units or pixels should cause an inherited font-size-adjust: -moz-auto to become none.  (Although maybe we should give authors a way to override that.)

We don't need the separate preference anymore because having the font backend provide the relevant metrics allows us to compute the right ratio (generally better than the user can).

Comment 2

[Stanimir Stamenkov]

It would be nice if Bug 429605 gets fixed first.

Comment 3

[Jonathan Watt [:jwatt]]

Even though the Firefox preferences UI only has font size fields for Proportional vs Monospace, the implementation will actually look for font.size.[generic].[langGroup] for all generic fonts.

https://hg.mozilla.org/mozilla-central/file/550779e6bab4/layout/base/nsPresContext.cpp#l575

Presumably we should change that so we only ever look for the one font.size.[langGroup] pref. (It seems very unlikely that a significant number of users are setting the prefs for these other generic fonts anyway.)