[css-ui] Consider removing slider-horizontal from <compat-auto>

[emilio]

Firefox doesn't support it and we've never seen a compat issue due to this. I noticed this while looking at Firefox-specific test failures for appearance.

cc @frivoal, do you have the context of why was it needed?

[emilio]

Same for square-button and push-button

[SebastianZ]

While implemented across browsers, I also wonder whether searchfield is actually needed.

I'm not sure how to interpret the drastic drop in usage. Though currently only 0.000309% of pages seem to use it.

Sebastian

[SebastianZ]

For what it's worth, the values mentioned by @emilio have also very low usage numbers.

square-button
push-button
slider-horizontal

Sebastian

[emilio]

cc @chrishtr, @smfr, does it seem sensible to drop them?

[chrishtr]

Removing them from Chromium sounds good to me, given those use counters. @mfreed7 and team are going to look into it.

[chrishtr]

@dizhang168

[nt1m]

cc @chrishtr, @smfr, does it seem sensible to drop them?

@pxlcoder, what do you think?

[zcorpan]

The reason push-button and square-button were included was that they were being used somewhat frequently:

• -moz-appearance values
• -webkit-appearance values
• both -moz-appearance and -webkit-appearance with different values

However, the impact of dropping them is likely minimal since they only have an effect on elements that are buttons, and also aren't styled in a way that makes appearance act like none (e.g., a border is specified). That is, it would only affect a situation like:

input { appearance: none; /* basically no other styles */ }
input[type=button] { appearance: push-button; }

For slider-horizontal and slider-vertical, IIRC that was kept in as a way to not regress horizontal/vertical rendering of sliders until a better mechanism was specified for that purpose. It has an effect in Chromium and WebKit (but not in Gecko): https://software.hixie.ch/utilities/js/live-dom-viewer/saved/11364

[zcorpan]

Looks like slider-vertical was already dropped: https://drafts.csswg.org/css-ui-4/#issue-27993a83

[css-meeting-bot]

The CSS Working Group just discussed [css-ui] Consider removing slider-horizontal from <compat-auto>, and agreed to the following:

• RESOLVED: remove slider-horizontal, square-button, and push-button from <compat-auto>; PaulG will open an issue about ARIA roles and concerns about slider-vertical and push-button

The full IRC log of that discussion

<emeyer> emilio: Firefox never supported this
<emeyer> …Recently, I found three keywords where there are problems in WPT
<emeyer> …Usage is pretty low
<emeyer> …We also have no compat issues about this
<masonf> q?
<masonf> q+
<astearns> ack masonf
<emeyer> masonf: We don’t object to this
<emeyer> astearns: What are we resolving?
<emeyer> emilio: Drop slider-horizontal, square-button, and push-button
<PaulG> q+
<astearns> ack PaulG
<emeyer> PaulG: slider-vertical has native semantics around orientation
<emeyer> …If there is usage, we should communicate that ARIA values need to be used
<masonf> q?
<emeyer> emilio: Right now, the spec says it does nothing special
<emeyer> dbaron: I don’t think there a history of appearance changing accessibility rules, is there?
<emeyer> PaulG: In Chromium, (scribe got lost)
<emeyer> dbaron: I don’t think the CSS `appearance` property affect accessibility
<emeyer> PaulG: I’m looking at the demo in the issue, in Chromium, the vertical slider renders with orientation: vertical that nothing else set
<emeyer> dbaron: That’s surprising to me
<dbaron> masonf: me too (but confirm it)
<bkardell_> Is it bad? Seems good?
<emeyer> PaulG: Concern is if it’s dropped, anyone depending on that orientation needs to know they need to replace that with ARIA
<dbaron> s/rules/roles/
<emeyer> astearns: Given that usage is very low, is this a big concern?
<emeyer> PaulG: This is in no way a reason to stop, but this is a concern APA will probably voice
<masonf> q?
<emeyer> …I’m guessing where this is used, understanding of accessibility is low
<emeyer> …I’ll help smooth that over with APA, I’d just like numbers
<emeyer> masonf: We’re speaking just about slider-horizontal, yes? Not slider-vertical
<emeyer> …Is it an accessibility problem for horizontal?
<emeyer> PaulG: No, only concerned with vertical and that semantic meanings are conveyed in other ways
<emeyer> masonf: We should open an issue about vertical
<emeyer> …I think we’re okay horizontal, but need to discuss more about vertical
<emeyer> astearns: So proposed resolution is to remove slider-horizontal, square-button, and push-button
<emeyer> PaulG: I might need to check push-button
<emeyer> …Does ARIA pressed get added?
<emeyer> astearns: What if we resolve to do the removal, then Paul, can you open an issue on slider-vertical and push-button on possible ARIA concerns?
<emeyer> PaulG: Yes
<dbaron> https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/modules/accessibility/ax_slider.cc;l=47-83;drc=5a252fef36aced8857912a7eba43dad5590cb54d
<emeyer> RESOLVED: remove slider-horizontal, square-button, and push-button from <compat-auto>; PaulG will open an issue about ARIA roles and concerns about slider-vertical and push-button

[foolip]

@frivoal is this something you'll do the spec edits for? I'm asking for web-platform-tests/interop#295, but perhaps we can update the tests separately from the spec change?

[frivoal]

Sorry for being slow catching up here. The PR from @zcorpan looks great, so I went ahead and merged it.

[zcorpan]

Thanks @frivoal! Tests for this are at web-platform-tests/wpt#40233