1461589 - implement font-variant-emoji

Status: RESOLVED FIXED

(Core :: Graphics: Text, enhancement, P3)

Comment 1

[Jonathan Kew [:jfkthame]]

See https://github.com/googlefonts/noto-emoji/issues/391 for an example of a situation where this is wanted.

Comment 2

[Jonathan Kew [:jfkthame]]

And see https://github.com/w3c/csswg-drafts/issues/7315 for a spec question that we should get clarified before shipping this.

Comment 3

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1461589 - Add support for the CSS font-variant-emoji property to the style system. r=#firefox-style-system-reviewers

Comment 4

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1461589 - Handle font-variant-emoji during font matching. r=#layout-reviewers

Depends on D147494

Comment 5

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1461589 - Add/update CSS parsing tests to cover font-variant-emoji. r=#layout-reviewers

Depends on D147495

Comment 6

[Jonathan Kew [:jfkthame]]

I have some WIP here, but I'd like to get a response to #7315 before moving forward as that may require changes to the behavior currently implemented by these patches.

Comment 7

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1461589 - Add a WPT reftest for text/emoji-style presentation controls. r=#layout-reviewers

These tests assume the system has both text- and emoji-style glyphs available for U+263A, the old WHITE SMILING FACE
symbol that has long existed in legacy fonts, and now also supports an emoji-style rendering. If two distinct
presentations are not available, the first (mismatch) test will fail.

The spec says:

Even when font-variant-emoji is used, the presence of Variation Selector 15 (U+FE0E) or Variation Selector 16 (U+FE0F)
in the contents of an element override the rendering specified in font-variant-emoji.
Therefore, font-variant-emoji sets a default presentation which the text being rendered can opt out of.

So the second test checks that U+263A responds to the property as expected, and that the variation selectors
can still override it.

Depends on D147496

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/39eda9a47424
Add support for the CSS font-variant-emoji property to the style system. r=emilio
https://hg.mozilla.org/integration/autoland/rev/c44d30da26ef
Handle font-variant-emoji during font matching. r=emilio
https://hg.mozilla.org/integration/autoland/rev/98090ae94c2f
Add/update CSS parsing tests to cover font-variant-emoji. r=layout-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/c1a7287807c1
Add a WPT reftest for text/emoji-style presentation controls. r=emilio

Comment 9

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/36611 for changes under testing/web-platform/tests

Comment 10

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/39eda9a47424
https://hg.mozilla.org/mozilla-central/rev/c44d30da26ef
https://hg.mozilla.org/mozilla-central/rev/98090ae94c2f
https://hg.mozilla.org/mozilla-central/rev/c1a7287807c1

Comment 11

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot

Comment 12

[Hamish Willee]

FF108 MDN docs work for this can be tracked in https://github.com/mdn/content/issues/22118

Comment 13

[Dave Letorey]

Completed documenting this property.

Related Pull Requests:

• content PR
• BCD PR
• Firefox Release PR