- From: Dael Jackson <daelcss@gmail.com>
- Date: Wed, 20 Jan 2021 19:10:31 -0500
- To: www-style@w3.org
=========================================
These are the official CSSWG minutes.
Unless you're correcting the minutes,
Please respond by starting a new thread
with an appropriate subject line.
=========================================
Color 4
-------
- RESOLVED: All new color functions serialize to themselves (Issue
#5825: What serialization should be used when using color
(lab ...) syntax to specify a lab color?)
- RESOLVED: Make the first parameter in the color function, the
color space, required (Issue #5825)
- RESOLVED: Have the minimum precision raised to 10 bits (Issue
#5825)
CSS Pseudo
----------
- RESOLVED: Add a warning to the section and close this issue but
continue work (Issue #4619: Who is currently using
CSSPseudoElement and what events can target them?)
- RESOLVED: Use the existing parent function in css pseudo element
as returning first element ancestor and add an immediate
parent that could possibly return a pseudo element
(Issue #3836: Should CSSPseudoElement have a pseudo()
method? Would it be worth considering having two
separate properties, Element element and
Element|CSSPseudoElement parent)
Cascade & CSSOM
---------------
- RESOLVED: Fix the draft of cssom so it points to color 4 and then
publish (Issue #3827: Link "Applies to", "Canonical
order" in propdef tables)
- RESOLVED: Publish cascade after resolution of issue #4838 (Issue
#3827)
CSS Overflow 3
--------------
- florian will edit the spec to clarify that overflow:clip extends
paint containment (Issue #5800: Clarify when
overflow-clip-margin has an effect)
CSS Sizing
----------
- RESOLVED: Take TabAtkins's last comment in GitHub (Issue #5721:
Expected size of replaced element with aspect-ratio but
width/height auto)
- Comment from GH:
1. No explicit sizes means it uses the automatic sizes of the
element.
2. For replaced elements the automatic sizes are the natural
sizes.
3. When 'aspect-ratio' is in play the automatic size in the
ratio-dependent axis is instead calculated from the size
in the ratio-determining axis + aspect-ratio
4. Since both 'width' and 'height' are using automatic sizes,
the ratio-dependent axis is the block axis by default.
===== FULL MINUTES BELOW ======
Agenda: https://lists.w3.org/Archives/Public/www-style/2021Jan/0008.html
Present:
Rachel Andrew
Adam Argyle
Tab Atkins-Bittner
Christian Biesinger
Oriol Brufau
Elika Etemad
Simon Fraser
Daniel Holbert
Dael Jackson
Sanket Joshi
Brian Kardell
Johnathan Kew
Una Kravets
Vladimir Levin
Daniel Libby
Chris Lilley
Ting-Yu Lin
Peter Linss
Alison Maher
François Remy
Morgan Reschenberg
Florian Rivoal
Devin Rousso
Alan Stearns
Miriam Suzanne
Greg Whitworth
Lea Verou
Regrets:
Tantek Çelik
Scribe: dael
astearns: Thanks to everyone for calling in on time. We'll wait a
couple more minutes to get the list of people online to
fill out
astearns: Let's start. Any changes to the agenda?
Color 4
=======
What serialization should be used when using color(lab ...) syntax to
specify a lab color?
---------------------------------------------------------------------
github: https://github.com/w3c/csswg-drafts/issues/5825
chris: I added some comments before the call to clarify the options.
Two questions, what to do for lab and lch and what do for
extended precision. Start with lab and lch.
chris: Spec says if you use lab and lch, lch serializes to lab. But
if you do color (lab) it serializes to color. Suggested is
all three serialize to lab. I'm willing but wanted feedback
to if it's an improvement
leaverou: On one hand, we have the rule values serialize to shortest
form. Might be helpful for authors if number of formats
returned is fewer than ones spec.
leaverou: I can see arguments for serializing anything that doesn't
need backwards compat as color
<TabAtkins> We shouldn't change the specified function like this -
color() should remain color()
astearns: TabAtkins mentioned something on IRC. I believe color
remains color and it's only when serialized with a bare
lch or lab
chris: correct
<chris> Tab, not a proposal
astearns: I can see argument for shortest that if your color happens
to have a lab we could serialize to that
TabAtkins: I'm confused. First post on thread asks for that. Color
with lab color space to serialize to lab function
TabAtkins: My assumption is lab should be used when refer to color
of lab space
chris: I hadn't read it as meaning that. I read as unclear and said
spec says what to do. Then it drifted to should we harmonize
TabAtkins: We shouldn't change function in a major way. They should
get back out what they put in. Color function has a lot
more functionality than individual color functions. Would
be strange to lose that. In TypedOM it would serialize to
form without fallbacks
chris: Agree. If you look at my A and B options I don't propose do
away. A is continue as is. B is serialize as color(lab)
chris: Clearer?
TabAtkins: Yes.
TabAtkins: Taking that opinion we shouldn't do B because it's
unexpected. I think maybe not A because I find it weird
chris: When discussed previously seems to be what people want.
TabAtkins: That's true
leaverou: hsl() also serializes as rgb(), so lch serializing as lab
is the same
plinss: I agree with TabAtkins it's strange if functions changed. If
we get to world with TypedOM where it serializes as the same
function the author created. Will make a world of hurt if
functions change, esp if inconsistent
<argyle> i like option B as well
astearns: argyle you mentioned you like changing in IRC?
argyle: I like it. I am acknowledging hsl serializes to rgb. It is
the common space. Most common is where tried to serialize. I
like in option b you can write in either syntax and get the
superset. You get the higher order. It seems like it
upgrades colors not downgrade or transfer.
<bkardell> of the two I like B better too, I think - but it's really
hard to say without actually using it and living with it
for a while :-p
<TabAtkins> Note that the TypedOM will give trivial conversions to
whatever function form you want.
chris: I see a comment the TypedOM gives color conversion functions.
That's not clear to me. I thought that was case but I think I
see it gives a null string. Discussion on twitter it should
be separate spec.
chris: I believe in future there will be color conversion functions,
though.
chris: That's broader. I could type hsl and get lab. That's much
broader.
<TabAtkins> That Twitter discussion is not reflective of the current
spec or my continued intention, fwiw.
leaverou: Even though TypedOM helps because authors don't parse
manually, they still have to handle different formats
because closely tied. If lab serializes as color(lab) it's
unclear to me what TypedOM class will correspond.
serialization or specified?
TabAtkins: TypedOM reifies to the class function it would serialize
to. Specified you get what you put in and computed it's
rules for conversion
TabAtkins: Another reason not to change into color is class
correspondent to color is more difficult to work with
than lab or lch class. If people using anything else
would prefer to give easiest to work with.
<fremy> What TabAtkins just said makes a lot of sense to me
leaverou: The more different classes and author could expect they
need to handle. If they don't know color they have to
handle it
TabAtkins: Can convert to any form they want
astearns: And if they return color they would still need to deal
with first param with all the variations
chris: Hearing arguments on both sides but no clear consensus.
smfr: Can you summarize?
<astearns> options:
https://github.com/w3c/csswg-drafts/issues/5825#issuecomment-763722847
chris: The ones in GitHub. Option A is serialize lab and lch with
shortest form which is lab.
chris: Option B is lab and lch as color(lab)
chris: TabAtkins was worried about an option c that serializes
color(lab) as lab. I only see objections to that.
<TabAtkins> I was worried about that because Sam proposed it in the
original post. ^_^
smfr: Have to consider along with serialization of rgba and srgb. If
you look at comment from 3 days ago from Sam he suggests
[reads] and lab is odd one out
smfr: One of the considerations is if you used color for srgb you
want to round trip precision.
chris: Agree in general. color 3 required round to 8 bits. Currently
min is 8 bits on both. Happy to increase for color which
might make sense. I don't know how much existing code exists
elsewhere but none for color form.
chris: It's always been 0 to 1 so you had precision
leaverou: If this is higher precision we could consider opt in to
other handling
smfr: One approach would be consider rgb/hsl as legacy and all newer
colors serialize with color function
chris: I can see that as clear
<TabAtkins> My preferred option: serialize lab() to lab(), lch() to
lch(), and color(anything) to color(). I'd accept
serializing lch() to lab() if necessary, but would
prefer to avoid that.
leaverou: TabAtkins would you argue for changing how hsl serializes?
TabAtkins: Long past impossible at this point
TabAtkins: In an ideal world yes, but the compat is out of our hands
chris: I quite like smfr's suggestion. Color rgb serializes as
itself. Therefore lab serializes as color(lab).
smfr: That falls out. Can see it's annoying for authors
chris: That's the case in both suggestions. We could change that
TabAtkins: Only reason lch serializes to lab is analogy?
chris: Yes
smfr: My thought was color function is used to describe the color
space and therefore lab and lch are lumped together. Maybe not
great for serialization
chris: There's little legacy code, but ongoing implementations. Time
to change it is now. In 6 months it's too late to change
TabAtkins: smfr, because you came in later, I'm moderately against
normalizing to color function because TypedOM form is a
lot more complicated than individual color functions. I
would prefer to give the simpler forms if they put them
in.
smfr: Reasonable
<TabAtkins> Omitting the srgb keyword is standard "shortest form
serialization" stuff, I'm fine with that.
chris: Since talking about sRGB. The first param is the color space
and it defaults to srgb. Two ways to default it. If code is
looking at this in serialized forms maybe it's cleaner if it
always has an explicit color space. I can argue either way.
Shortest serializeable or explicit color space
smfr: Question, if you spec rgba with % which means >8 bit. If that
serializes do you maintain precision?
chris: Currently, in color 4 they are no longer int. You can do
137.5 and it's supposed to go to highest possible with a min
of 8 bits. Most implementations seems to truncate
smfr: In WebKit we use color function to trigger higher precision
storage.
chris: Lots of int precision on the web. I've read people worry
about blowing up dom if it's bigger
<TabAtkins> Proposal: the sRGB functions all serialize to rgb() (
partially legacy, and partially consistency). All other
functions serialize to themselves.
<leaverou> TabAtkins: hwb() too?
<leaverou> TabAtkins: it's an sRGB function, but no legacy
implications
<TabAtkins> leaverou: Yes, that's the "partially consistency" I
mentioned. ^_^
astearns: TabAtkins has a proposal to have all legacy rgb serialize
to rgb and all new serialize to themselves. Sounds like
people are okay with new functions serialize to themselves
chris: That would amount to option A.
astearns: Option A except lch serializes to lch
chris: Okay
<TabAtkins> But I'm also fine with just "the current legacy
functions serialize to rgb(), everything else to itself"
leaverou: If we do srgb to itself it also makes sense to keep lab as
itself. It's same thing, really
chris: Right
astearns: One person I haven't heard from in a bit is plinss. Would
you be okay with this?
plinss: That's what I argued for. I don't believe functions should
change to other functions
<argyle> 👍🏻
astearns: Proposal: All new color functions serialize to themselves
RESOLVED: All new color functions serialize to themselves
<TabAtkins> color(srgb 1 0 0) should serialize to color(1 0 0), per
shortest-serialization
chris: Follow up on that. If I say color(srgb) it's same as
color(rgb) if I just give rgb. Should they both go to the
same form and if so which?
astearns: TabAtkins says shortest omitting defaults
leaverou: Not sure it's good to have this form without a color space
<bkardell> +1 lea
<fantasai> +1 lea
<argyle> +1 lea
smfr: I would prefer srgb as explicit
<TabAtkins> I'd be fine with removing the optionality of the keyword
plinss: We're talking about the color function optionally losing
srgb?
chris: Making it mandatory
plinss: When it serializes out you don't have it
chris: That's one option. We're talking if you want srgb you have to
say so
leaverou: And I see agreement for that in irc
<florian> +1
plinss: Gotcha. No strong opinion
chris: I think it's consistent with your argument plinss
plinss: It's fine. If color space is optional in function I'm fine
if it serializes without, but also fine with it not optional
leaverou: Can make optional in the future. If we start optional we
can't change
chris: I'm fine removing the optionality
astearns: Proposal: Make the first param in the color funciton, the
color space, required
RESOLVED: Make the first parameter in the color function, the color
space, required
<TabAtkins> Just clarifying - does the first resolution apply to
hwb() serializing as itself?
chris: I can edit this in
astearns: Something about precision?
chris: Yes, if you use srgb you expect higher precision. Min is 8
bits right now. I'd like to increase. P3 min is 10 bits per
component. Could make same
astearns: Proposal: Have the minimum precision raised to 10 bits
RESOLVED: Have the minimum precision raised to 10 bits
chris: hwb is same as hsl where it comes out as rgb or rgba
<TabAtkins> I'm fine either way fwiw
<TabAtkins> non-sRGB functions
astearns: Resolution about all color functions is amended to
different way of expressing rgb?
chris: I see hwb as similar to hsl
astearns: Amended resolution is now non-rgb color functions
serialize to themselves
chris: Yes
astearns: Is that first part of issue or all covered?
chris: Covered that. I think I'm good
leaverou: If color srgb has higher precision and difference between
that and srgb is maintained can the colors opt into better
interpolation? Right now we have backwards compat but
doing it in lch is far better. If they don't have
backwards compat concerns maybe they can opt into better
<argyle> well said Lea!
astearns: leaverou can I ask you to open a separate issue? That way
people can weigh in on GH
CSS Pseudo
==========
Who is currently using CSSPseudoElement and what events can
target them?
-----------------------------------------------------------
github: https://github.com/w3c/csswg-drafts/issues/4619
florian: This is more of a request for information. CSS Pseudo
Element class exists and is an event target, but it's not
clear what API uses and what events it receives. When the
issue was raised I think intent was figure out who should
we talk to when we refine events on Pseudos
florian: This has been sitting in GH for a while without feedback.
This is a louder call to figure out who is the crowd
interested
emilio: I think main consumer is web animations. Like css animations
that target css pseudo elements. Not aware of other
consumers.
florian: I'm a little fuzzy on this because decision to stop using
pseudo elements as a class on animation, but pointed out
there still is. But that would be for the group
astearns: One of the reasons we pushed to have css pseudo element
historically is we thought regions could be made out of
pseudo elements but that's moot at this point
florian: I see reasons why it's useful, but before drafting new
things it would be good to know what's done
gregwhitworth: Are you saying you can't animation pseudo elements?
florian: No, but I believe API shape of animations has changed and
it's no longer done through pseudo element class set up in
pseudos 4. I could be wrong. A bit out of my area
astearns: Anyone else with a known dependency or use case for css
pseudo element as an event target?
astearns: So it may be down to whatever use case web animations
might have?
florian: Plus what sanketj and I want to add
sanketj: Does anyone use pseudo element not as an event target? Web
animations is only thing I could tell which has since been
dropped. I didn't find any users of pseudo element at all
florian: I have use cases, but not existing usage
iank: I think this has been one of the things that's an obvious gap
on api side. Nice to get target if it's exposed but not high
priority so hasn't been impl
sanketj: Should we try to remove css pseudo element and come at it
again in a different way? Not sure the process
astearns: If there are no consumers and little implementor interest
it's plausible to remove it and retain intent of fixing
the hole in the API. Need motivating use cases to spur
implementation interest
florian: I don't know. If we suspect API shape is wrong maybe
remove. But I believe there are use cases that we're slowly
getting to. Having a place where we accumulate our way to
useful thing it would be good. If we start by deleting it
doesn't speed up getting there
astearns: Fair point
astearns: sanketj do you have an argument for deletion?
sanketj: Not specifically. Originally looked around highlight api
and there are not highlight events. Pseudo element being an
event target prompted us to look. I don't think I have a
way to have it useful in highlight, but I don't have a
strong reason to delete or keep
florian: I have other use cases to look into in the near future. I'd
like to keep working. For now it's hear so no rush to delete
iank: One thing to keep in mind is only before and after pseudo
elements make sense with this API. Perhaps merging in that
this might change is a path
sanketj: Yes, only tree abiding was designed originally I think. I
don't believe it works for range based
iank: Yeah, for example doesn't make sense for ::first-line
fantasai: Would work for any, but only defined for tree abiding.
Every pseudo element has originating element. If you
highlight it will cross multiple pseudo elements as you
cross multiple elements
iank: In related to geometry apis and event propagation the tree
abiding ones are much simpler
florian: I'd suggest slap a warning across this area of the spec
saying don't rush to impl but if you have use cases or
problems bring forward
astearns: As a way forward put a warning on this part of the spec
that this is early and needs fleshing out. Do we close
this issue with a resolution to have a warning or do we
need to dive into web animations usage more
florian: Since we're not resolving to delete it I don't think we
need the explanation urgently
astearns: Proposal: Add a warning to the section and close this issue
astearns: Objections?
RESOLVED: Add a warning to the section and close this issue but
continue work
Should CSSPseudoElement have a pseudo() method? Would it be worth
considering having two separate properties, Element element
and Element|CSSPseudoElement parent
-----------------------------------------------------------------
github: https://github.com/w3c/csswg-drafts/issues/3836#issuecomment-502344378
florian: This is because it is now possible to have pseudos attached
to pseudos. In addition to element class having pseudo,
pseudo element class has a pseudo.
florian: Another question, pseudo element class has an element
method that returns originating element. Pseudo on a pseudo
do you want originating or parent pseudo?
florian: Original thought is return the parent. Later proposed we
should have both. Element returns originating element, but
also have a parent method that returns parent pseudo if
there is one and if there isn't returns originating
florian: Got thumbs up so proposal is accept
astearns: If it's not nested parent returns nothing?
florian: Returns same as element
astearns: First is element ancestor and second is immediate parent
florian: Yes
fantasai: One thought, if we extend to non-tree-abiding, parent is
not quite the right word. If you select first-letter
element parent is the first line or some weird nesting. We
could call it parent and say these things are special
florian: It would be walking up hierarchy step by step. Just need to
define weird cases
fantasai: As long as people say it can be re-purposed to not quite a
parent it's fine to me. Just wanted to point out it's
going to be a bit weird
astearns: Other opinions?
astearns: Hearing people in favor
astearns: Proposal: Use the existing parent function in css pseudo
element as returning first element ancestor and add an
immediate parent that could poss return a pseudo element
RESOLVED: Use the existing parent function in css pseudo element as
returning first element ancestor and add an immediate
parent that could possibly return a pseudo element
Cascade & CSSOM
===============
Link "Applies to", "Canonical order" in propdef tables
------------------------------------------------------
github: https://github.com/w3c/csswg-drafts/issues/3827#issuecomment-759849067
<fantasai> https://drafts.csswg.org/css-cascade-4/#changes
fantasai: Have some text we can link to. Cascade 4 has a nice
section of it. Needs to be republished as a WD. Changes
here ^. One issue still being discussed so may not be able
to publish today
fantasai: Other major changes we did is define processing of
elements not in tree and define term property.
fantasai: Other problem is that canonical order is only defined in
cssom editors draft. That's far ahead of /tr and it is
behind on edits.
fantasai: In order to crosslink we need to republish cssom. But I
don't know state of draft and if it should be published or
needs more edits.
fantasai: We can't make fix to propdef tables as long as spec is out
of date
astearns: emilio do you have an idea of if we could publish cssom
draft as is?
emilio: I think we could publish. A few fixes I'd like but they
interact with HTML
astearns: Could resolve to publish a new WD of cssom as-is?
TabAtkins: One edit that might be good to pull in which is remove
color serialization so we can defer to color 4
chris: I have removed it. But there's a related issue where it keeps
linking to color 3 and I want to stop it. But the edits are in
astearns: Proposal: Fix the draft of cssom so it points to color 4
and then publish
astearns: Objections?
<chris> +1
RESOLVED: Fix the draft of cssom so it points to color 4 and then
publish
astearns: What do we want to do on cascade?
<fantasai> https://drafts.csswg.org/css-cascade-4/#changes
fantasai: Cascade has an open issue on same-origin check for the
quirks mode. After that we should be ready to publish.
That should be most of the outstanding edits. Changes list
is here^
fantasai: We made 5 or 6 changes
astearns: Resolving that one issue will take what?
fantasai: TabAtkins would know
TabAtkins: I'd have to review to see if Anne responded
fantasai: He did
TabAtkins: Is he saying I'm right? If yes it's easy
<fantasai> https://github.com/w3c/csswg-drafts/issues/4838#issuecomment-762052244
fantasai: I don't know. There's the comment ^
fantasai: Do we want to take a resolution to publish once you and
Anne decide wording
astearns: Prop: Publish cascade after resolution of 4838
RESOLVED: Publish cascade after resolution of 4838
astearns: Anything else on this?
CSS Overflow 3
==============
Clarify when overflow-clip-margin has an effect
-----------------------------------------------
github: https://github.com/w3c/csswg-drafts/issues/5800
vmpstr: Clarifying a sentence in overflow that says "If the element
does not have overflow: clip (or another property defined to
respect this property), this property has no effect."
Clarifying what "this property" refers to
vmpstr: Paint containment clips, would like overflow:clip to extend
paint containment
florian: Yes, contain:paint applies. Poorly worded, editor will make
it better
astearns: Will handle by making it explicit contain:paint applies?
florian: Not sure how I'll rephrase but the answer is it applies and
we'll fix the sentence
vmpstr: Maybe remove the sentence?
florian: Possibly. It's 3am so I'm not awake enough to draft the
sentence on the fly.
fantasai: Can't remove the sentence because it doesn't apply to most
elements. Some clipping effects it applies and some where
it doesn't
CSS Sizing
==========
Expected size of replaced element with aspect-ratio but width/height
auto
--------------------------------------------------------------------
github: https://github.com/w3c/csswg-drafts/issues/5721
fantasai: cbiesinger brought up case of image with intrinsic size.
Set aspect-ratio that's not that of the image. Previously
not possible. Question is what is this supposed to do?
Have a jpeg that's 200x100, set aspect-ratio as 1-1. What
does it render
fantasai: No clear answers. leaverou made a poll with inconclusive
results. We need an answer. Looking for opinions and ideas
about why it should be an answer
TabAtkins: I have a preferred answer here. The aspect-ratio property
by virtue of it being explicit it should be honored and
then we round sizing as normal. Use ratio determining,
take natural size, process through spec aspect-ratio and
use it. Added a comment on GH
TabAtkins: In the jpeg example of 1x1 aspect-ratio we set width to
natural width and then we make it square. You asked for
it to be square so I think people would expect that
iank: I agree with TabAtkins' analysis
<fremy> LGTM too
<fantasai> wfm
astearns: Some consensus. Might be easiest to get a good answer by
declaring an answer and use the get an answer by saying
something wrong and getting people to say why wrong
astearns: Proposal: Take TabAtkins's last comment in GH and resolve
on that
cbiesinger: Takes writing mode into account?
TabAtkins: Yeah, ratio determining for axis takes writing mode into
account
RESOLVED: Take TabAtkins's last comment in GH
[Comment from GH
1. No explicit sizes means it uses the automatic sizes of the
element.
2. For replaced elements the automatic sizes are the natural sizes.
3. When 'aspect-ratio' is in play the automatic size in the
ratio-dependent axis is instead calculated from the size in
the ratio-determining axis + aspect-ratio
4. Since both 'width' and 'height' are using automatic sizes, the
ratio-dependent axis is the block axis by default.
]
astearns: Thank you everybody
Received on Thursday, 21 January 2021 00:11:13 UTC