[csswg-drafts] [cssom] Resolved value for font-size should perhaps take user's minimum font-size into account (#10479)

dholbert has just created a new issue for https://github.com/w3c/csswg-drafts:

== [cssom] Resolved value for font-size should perhaps take user's minimum font-size into account ==
[CSSOM section 9 on resolved values](https://drafts.csswg.org/cssom/#resolved-values) (i.e. the value returned by `getComputedStyle`) doesn't have any special case for the `font-size` property right now.

However: users can configure a minimum font-size to enforce in their browser settings; and in Safari and Chrome, this clamping does seem to be reflected in the values that `getComputedStyle(elem).fontSize` returns.  In Firefox, the clamping doesn't take effect in `getComputedStyle` and we got a bug report on Firefox differing from other browsers in this respect: https://bugzilla.mozilla.org/show_bug.cgi?id=1903360

Perhaps we should spec this clamping behavior as part of the resolved value for `font-size`? (and explicitly apply the clamping in the getComputedStyle implementation)  e.g. just specify that the resolved value of `font-size` is the used value, or something along those lines? (I'm not sure if that would bring in any additional complexity...)

Additional notes:
- I've got a testcase to poke at some edge cases here: https://bugzilla.mozilla.org/attachment.cgi?id=9408768
- Safari behaves a bit differently from Chrome/Firefox in that they seem to let the `font-size` impact the resolved value of `1em`, not just the size of rendered text. That's probably a Safari bug (CC @heycam / @nt1m ).
- https://bugzilla.mozilla.org/show_bug.cgi?id=1903360 includes instructions for how to find the relevant preferences UI in [Firefox](https://bugzilla.mozilla.org/show_bug.cgi?id=1903360#c0), [Chrome](https://bugzilla.mozilla.org/show_bug.cgi?id=1903360#c1), and [Safari](https://bugzilla.mozilla.org/show_bug.cgi?id=1903360#c4).

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/10479 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Thursday, 20 June 2024 23:58:29 UTC