Add a skeleton implementation of FontFaceSet interface with support
for resolving the `document.fonts.ready` Promise when the loading of
web fonts is completed.
This change exposes new failures in the web platform tests.
These were ERROR before the change because `document.fonts.ready` caused
a `ReferenceError` causing the tests to be aborted and they now FAIL:
- /css/CSS2/linebox/vertical-align-top-bottom-001.html
- /css/css-flexbox/flex-one-sets-flex-basis-to-zero-px.html
- /css/css-fonts/generic-family-keywords-001.html
- /css/css-fonts/math-script-level-and-math-style/math-script-level-004.tentative.html
- /css/css-fonts/math-script-level-and-math-style/math-script-level-002.tentative.html
- /css/css-text/text-autospace/text-autospace-ligature-001.html
- /css/css-values/calc-size/calc-size-width.tentative.html
These were TIMEOUT before the change because `document.fonts.ready` was
a ReferenceError and the tests were asynchronous (reftest-wait). These now
FAIL because the assertions are now executed after fonts are loaded:
- /css/css-fonts/matching/fixed-stretch-style-over-weight.html
- /css/css-fonts/matching/range-descriptor-reversed.html
- /css/css-fonts/matching/stretch-distance-over-weight-distance.html
- /css/css-fonts/matching/style-ranges-over-weight-direction.html
- /css/css-fonts/variations/variable-box-font.html
- /css/css-fonts/variations/variable-gpos-m2b.html
- /css/css-fonts/variations/variable-gsub.html
- /css/css-fonts/variations/variable-opsz-size-adjust.html
- /css/css-position/sticky/position-sticky-change-top.html
- /css/css-position/sticky/position-sticky-fixed-ancestor.html
- /css/css-position/sticky/position-sticky-flexbox.html
- /css/css-position/sticky/position-sticky-grid.html
- /css/css-position/sticky/position-sticky-inline.html
- /css/css-position/sticky/position-sticky-rendering.html
- /css/css-position/sticky/position-sticky-stacking-context.html
- /css/css-position/sticky/position-sticky-table-td-left.html
- /css/css-position/sticky/position-sticky-table-td-right.html
- /css/css-position/sticky/position-sticky-table-tfoot-bottom.html
- /css/css-position/sticky/position-sticky-table-th-right.html
- /css/css-position/sticky/position-sticky-table-thead-top.html
- /css/css-position/sticky/position-sticky-table-tr-bottom.html
- /css/css-position/sticky/position-sticky-table-tr-top.html
- /css/css-position/sticky/position-sticky-writing-modes.html
- /css/css-pseudo/marker-intrinsic-contribution-001.html
- /css/css-text/hyphens/hyphens-character.html
These tests now PASS due to this patch:
* FAIL -> PASS
- /html/canvas/element/text/2d.text.draw.fill.maxWidth.fontface.html
- /html/canvas/element/text/2d.text.measure.width.empty.html
* TIMEOUT -> PASS
- /css/css-fonts/variations/font-descriptor-range-reversed.html
- /css/css-fonts/variations/variable-opsz.html
- /css/css-position/sticky/position-sticky-table-th-left.html
* ERROR -> PASS
- /css/css-fonts/generic-family-keywords-002.html
- /css/css-fonts/generic-family-keywords-003.html
* These two tests only PASS in Layout 2020:
- /css/CSS2/positioning/inline-static-position-001.html
- /css/cssom-view/getBoundingClientRect-empty-inline.html
These two tests have subtests that PASS intermittenttly:
- /fetch/metadata/generated/css-font-face.sub.tentative.html
- /css/css-fonts/generic-family-keywords-001.html
These tests are new TIMEOUTS that used to FAIL because
`documents.fonts.ready` was undefined:
- /resource-timing/TAO-match.html
- /resource-timing/content-type.html
- /resource-timing/nextHopProtocol-is-tao-protected.https.html
The failure in `/resize-observer/change-layout-in-error.html` could be
due to an issue in the ResizeObserver implementation that is now exposed
with this change, but this needs more investigation.
Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>
* feat: Support font-relative `ch` and `ic` units
After #31966, which made it possible for the first time to resolve
font-relative CSS units, this change adds support for the `ch` and
`ic` units.
One difference with the `ex` unit that was added in that PR is that
these units must reflect the advance width of a character (the zero
digit in the case of `ch`, and the CJK water radical for `ic`) as it
would be rendered by the current font group. This means that the size
of these units don't only depend on the first available font, in the
case where that font does not contain a glyph for that character.
This is implemented by adding the advance width for these two
characters as optional fields of `FontMetrics`, so the advance width
computation happens in advance. Then, when the font metrics are
queried as part of unit resolution, the font group is searched for the
first font containing that character.
This change only implements support for these units in upright
typesetting modes, since Servo does not yet have support for vertical
writing modes. This means that many of the WPT tests that test for the
behavior of these units with vertical writing modes do not pass.
This change also makes a number of WPT tests pass, which relied on the
`ch` and `ic` units. It, however, also makes the test
`/css/css-text/white-space/text-wrap-balance-overflow-002.html` fail,
since it tests `text-wrap: balance`, which Servo does not yet
implement, and it was only previously passing by chance due to the
previous behavior of these units.
* Revert Python 3.10-related changes to wss
* Fix formatting
* Remove test expectation
This adds an initial implementation of font fallback, on part with the
one used in legacy layout. There are still issues. For instance, font
matching is done per unicode character rather than based on graphemes or
the shape first approach of Chrome. The idea is that these changes can
be made later.
Most tests were only being run for layout-2013, not for layout-2020.
This wasn't great since layout-2020 is now the default.
So this patch unifies the lists of included tests for both layouts.
For layout-2013 this implies adding css/css-content/, css/css-logical/
and css/css-masking/clip/.
For layout-2020 this implies adding several additional css tests, and
also tests like dom/, js/, html/, etc.
