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fred-wang opened this issue May 16, 2019 · 11 comments
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Make display:contents map to display:none #90

fred-wang opened this issue May 16, 2019 · 11 comments
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css / html5 Issues related to CSS or HTML5 interoperability MathML Core Issues affecting the MathML Core specification

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@fred-wang
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cc @rwlbuis @bkardell @mrego @emilio

From https://drafts.csswg.org/css-display/#unbox-mathml

For all MathML elements, display: contents computes to display: none.

TODO: check the implementation status in webkit/firefox and write tests for these.
Rob did https://github.com/Igalia/chromium-dev/commit/177eb951392219339c47526c65c1789439a1d6b0
@fred-wang fred-wang added css / html5 Issues related to CSS or HTML5 interoperability MathML Core Issues affecting the MathML Core specification need implementation update need specification update Issues requiring specification changes need tests Issues related to writing WPT tests labels May 16, 2019
@fred-wang
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Probably we can also add a note in the core spec, pointing to https://drafts.csswg.org/css-display/#unbox-mathml

@emilio
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emilio commented May 16, 2019

It should be working in Gecko AFAICT: https://searchfox.org/mozilla-central/rev/11cfa0462a6b5d8c5e2111b8cfddcf78098f0141/servo/components/style/style_adjuster.rs#127

@fred-wang
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Thanks @emilio , yes I think I saw this code recently :-)
Adding the rules in WebKit/Chromium and writing a WPT test should be easy.

@fred-wang
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Spec update: w3c/mathml-core@d4bb13a

@fred-wang fred-wang removed the need specification update Issues requiring specification changes label Jun 3, 2019
@Jamesernator
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Jamesernator commented Aug 23, 2019 •
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Any chance of getting a dedicated mathml element that functions like display: contents;? Currently there's no way to group elements (e.g. within a <mrow>).

e.g.:

<mrow>
  <!-- Would have styles effectively like display: contents -->
  <mgroup id="energyTerm">
    <mi>E</mi>
  </mgroup>
  <mo>=</mo>
  <mgroup id="resultTerm">
    <mi>m</mi>
    <mo>&InvisibleTimes;</mo>
    <msup>
      <mi>c</mi>
      <mn>2</mn>
    </msup>
  </mgroup>
</mrow>

@fred-wang
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@Jamesernator In the short term, I personally don't think we are going to introduce new MathML elements in MathML Core since the goal is to try to find a core subset to implement in browsers. We are doing more css compat work, so maybe we could reopen the discussion in the future about display: contents (w3c/csswg-drafts#2167) if there are concrete/important use cases for it. It's not obvious to why it's needed in your example, using an explicit mrow is a better grouping (resultTerm) or equivalent to the element alone (energyTerm).

@Jamesernator
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The example isn't very good I just wanted to be short, this is a better example:

<!doctype html>

<style>
  #container {
    border: 1px solid grey;
    width: 100px;
  }

  #firstTerm:hover {
    color: green;
  }

  #restOfSeries:hover {
    color: blue;
  }
</style>

<div id="container">
  <math>
    <mn id="firstTerm">1</mn>
    <mo>+</mo>
    <mgroup id="restOfSeries">
      <mi>A</mi>
      <mo>+</mo>
      <msup>
        <mi>A</mi>
        <mi>2</mi>
      </msup>
      <mo>+</mo>
      <msup>
        <mi>A</mi>
        <mi>3</mi>
      </msup>
      <mo>+</mo>
      <msup>
        <mi>A</mi>
        <mi>4</mi>
      </msup>
      <mo>+</mo>
      <mi>...</mi>
    </mgroup>
  </math>
</div>

This can't be replaced with <mrow> because <mrow> does not break when there's insufficient space.

e.g. With an <mgroup> suggested element or display: contents on something it'd look like:

Screen Shot 2019-08-26 at 6 19 45 pm

But trying to use <mrow> for this doesn't work because it doesn't break:

Screen Shot 2019-08-26 at 6 21 41 pm

fred-wang added a commit to w3c/mathml-core that referenced this issue Aug 26, 2019
@fred-wang
Add reference to CSS spec regarding display: none
53e08d8 
w3c/mathml#90
@fred-wang
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@Jamesernator OK, I guess you are testing in Gecko? Ideally linebreaking should be improved and supported in any mrow, so you won't need such an mgroup element ( w3c/mathml-core#127 ). But defining a full linebreaking is going to be tricky so it's also postponed for later until we sort out the other issues...

@Jamesernator
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OK, I guess you are testing in Gecko?

Yes. I had looked for overflow: linebreak in the mathml core spec but couldn't find it so I supposed it had been removed, didn't notice the "Define MathML line breaking?" boxes.

fred-wang added a commit to web-platform-tests/wpt that referenced this issue Aug 26, 2019
@fred-wang
Add tests for display: contents on MathML elements
26b0525 
w3c/mathml#90
@fred-wang fred-wang mentioned this issue Aug 26, 2019
Merged
fred-wang added a commit to web-platform-tests/wpt that referenced this issue Aug 26, 2019
@fred-wang
Add tests for display: contents on MathML elements (#18668)
94a0b42 
w3c/mathml#90
@NSoiffer
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The MathML 3 spec has a section on linebreaking: https://www.w3.org/TR/MathML3/chapter3.html#presm.linebreaking. As @fred-wang said, it is not well supported in Gecko and other places. I suspect we will revisit linebreaking for core to see what can be done to make it easier to implement, but that's a lower priority item.

moz-v2v-gh pushed a commit to mozilla/gecko-dev that referenced this issue Aug 29, 2019
@fred-wang @moz-wptsync-bot
Bug 1576581 [wpt PR 18668] - Add tests for display: contents on MathM…
e2973c5 
…L elements, a=testonly

Automatic update from web-platform-tests
Add tests for display: contents on MathML elements (#18668)

w3c/mathml#90
--

wpt-commits: 94a0b420301fc9d7da16097083ecdce927e22343
wpt-pr: 18668
xeonchen pushed a commit to xeonchen/gecko that referenced this issue Aug 30, 2019
@fred-wang @moz-wptsync-bot
Bug 1576581 [wpt PR 18668] - Add tests for display: contents on MathM…
785fa70 
…L elements, a=testonly

Automatic update from web-platform-tests
Add tests for display: contents on MathML elements (#18668)

w3c/mathml#90
--

wpt-commits: 94a0b420301fc9d7da16097083ecdce927e22343
wpt-pr: 18668
@fred-wang
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Tests:

https://w3c-test.org/mathml/relations/css-styling/display-contents.html
https://w3c-test.org/mathml/relations/css-styling/not-participating-to-parent-layout.html

@fred-wang fred-wang removed the need tests Issues related to writing WPT tests label Sep 16, 2019
gecko-dev-updater pushed a commit to marco-c/gecko-dev-comments-removed that referenced this issue Oct 4, 2019
@marco-c
Bug 1576581 [wpt PR 18668] - Add tests for display: contents on MathM…
e327704 
…L elements, a=testonly

Automatic update from web-platform-tests
Add tests for display: contents on MathML elements (#18668)

w3c/mathml#90
--

wpt-commits: 94a0b420301fc9d7da16097083ecdce927e22343
wpt-pr: 18668

UltraBlame original commit: 518f1d58aca0f6172291259876cedb195550e53f
gecko-dev-updater pushed a commit to marco-c/gecko-dev-wordified that referenced this issue Oct 4, 2019
@marco-c
Bug 1576581 [wpt PR 18668] - Add tests for display: contents on MathM…
33fe308 
…L elements, a=testonly

Automatic update from web-platform-tests
Add tests for display: contents on MathML elements (#18668)

w3c/mathml#90
--

wpt-commits: 94a0b420301fc9d7da16097083ecdce927e22343
wpt-pr: 18668

UltraBlame original commit: 518f1d58aca0f6172291259876cedb195550e53f
gecko-dev-updater pushed a commit to marco-c/gecko-dev-wordified-and-comments-removed that referenced this issue Oct 4, 2019
@marco-c
Bug 1576581 [wpt PR 18668] - Add tests for display: contents on MathM…
360b2f9 
…L elements, a=testonly

Automatic update from web-platform-tests
Add tests for display: contents on MathML elements (#18668)

w3c/mathml#90
--

wpt-commits: 94a0b420301fc9d7da16097083ecdce927e22343
wpt-pr: 18668

UltraBlame original commit: 518f1d58aca0f6172291259876cedb195550e53f
bhearsum pushed a commit to mozilla-releng/staging-firefox that referenced this issue May 1, 2025
@fred-wang @moz-wptsync-bot
Bug 1576581 [wpt PR 18668] - Add tests for display: contents on MathM…
aadc3bb 
…L elements, a=testonly

Automatic update from web-platform-tests
Add tests for display: contents on MathML elements (#18668)

w3c/mathml#90
--

wpt-commits: 94a0b420301fc9d7da16097083ecdce927e22343
wpt-pr: 18668
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@fred-wang @emilio @NSoiffer @Jamesernator