Hi David, On 11/15/2017 02:27 AM, L. David Baron wrote: > On Sunday 2017-11-12 16:11 +0100, Emilio Cobos Álvarez wrote: >> Hi, >> >> In bug 1416564 I intend to remove the mozmm CSS unit. >> >> This unit is Mozilla-only, has no spec, and is unused in all our >> codebase (except for two tests, one of those which tests the unit itself). >> >> This unit was introduced experimentally in bug 537890, our browser >> chrome code used it in bug 588464, and all that is gone since then. >> >> Given there's no spec, and no usage in the wild as far as I can tell, I >> think we should try to remove it. >> >> Thoughts? > > So I think this unit had a pretty strong use case: designing of > touch user interfaces, where touch targets need to be at least a > certain physical size in order to work well with human fingertips. > > There's also a risk from having physical units in CSS that we > learned the last time CSS had them: designs that work with some > ratios of physical units to other units and break with other ratios. > > I've been meaning to dig up the minutes from the time we tried to > get the CSS working group to add these units, but I haven't had a > chance over the last few days. I think if those minutes suggest > that the working group was receptive to adding such units to the > spec (or perhaps even agreed to do so, but then they were never > actually added by the editor), I'd tend to think we should leave our > implementation, whereas if the minutes suggest that the balance of > working group opinion was against them, then we should remove it. > Would you be able to try searching for those minutes? I know > there's been an in-person discussion (and I think it was at a > meeting at a TPAC a few yeas ago).
So, I've looked through and I haven't found any related minutes (I've looked for minutes that mentioned "physical", of which they were many, but all related to physical properties and scroll snapping, and for minutes that mentioned mozmm, of which they were none). I've found two threads in the w3c mailing list that look related, one which is basically the discussion that lead to all units being changed to be relative to the density of the display: https://lists.w3.org/Archives/Public/www-style/2010Jan/0058.html And someone interjecting on a thread about adding the Q unit: https://lists.w3.org/Archives/Public/www-style/2013Nov/0302.html Then there's a relevant, more recent, csswg-drafts issue: https://github.com/w3c/csswg-drafts/issues/614 But from the comments in there it doesn't seem to be a strong sense about it being useful, but mostly the opposite (and actually [1] may be a legit bug we should look into if we keep it in tree, or behavior we should document). Also, some other alternatives for that use case that work in all browsers are mentioned, like resolution-dependent media queries. What do you think David? I landed the patch this morning, and I'd really prefer it to stick. Given the recent cssswg-drafts issue where the CSSWG members were not really excited about it, I think it's ok to remove it, but happy to back the patch out if you think it's not. -- Emilio [1]: https://github.com/w3c/csswg-drafts/issues/614#issuecomment-254679777 > > -David > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
