forked from mirrors/gecko-dev
1a8e47e878
Automatic update from web-platform-tests CSS highlight processing model This patch implements the inheritance-based propagation for highlight pseudo-elements, as described in css-pseudo’s #highlight-cascade and introduced in w3c/csswg-drafts#2474. Highlight pseudos like ::selection were historically implemented such that only the ::selection selector (*::selection) worked intuitively. The spec’s processing model essentially makes it possible to define both general ::selection styles and more specific ::selection styles. We add a feature (HighlightInheritance) and a new computed style extra field of type scoped_refptr<StyleHighlightData>, which in turn points to four refcounted ComputedStyle instances, one for each highlight. Only a handful of properties are applicable, but reusing ComputedStyle like this simplifies the applying code, and allows us to share many of the field groups between instances anyway. We update the initial style singleton to point to a set of four empty highlight styles, which we only use when the feature is enabled. When the feature is disabled (or resolving custom ::highlight styles), there is no functional change. Highlight styles are lazily computed on paint’s demand, inherit only from the originating element styles, and we store the result in the Element’s pseudo cache (StyleCachedData). When the feature is enabled, we compute highlight styles during the originating element’s recalc (RecalcOwnStyle), skipping any highlight pseudos that the element had no matching rules for (a question that can already be answered thanks to pseudo bits). Style resolution is largely unchanged: we start with default styles, then use output of the cascade to change those styles. But defaulting is much easier for highlight styles: all properties are inherited, so we can simply clone the whole ComputedStyle. Relevant test page and screenshots: • https://bucket.daz.cat/work/igalia/0/8.html • https://bucket.daz.cat/4f37833aa15299a5.png (before) • https://bucket.daz.cat/67d2abdd9bcda17c.png (after) WPT already has some tests (css/css-pseudo/cascade-highlight-*), but more thorough test coverage will land in these patches: • https://github.com/web-platform-tests/wpt/pull/30688 • https://github.com/web-platform-tests/wpt/pull/30692 Bug: 1024156 Change-Id: I1f54f36ef2ac80165261a3f80d3a21cdf359c199 Cq-Do-Not-Cancel-Tryjobs: true Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2850068 Reviewed-by: Anders Hartvoll Ruud <andruud@chromium.org> Reviewed-by: Mason Freed <masonf@chromium.org> Commit-Queue: Delan Azabani <dazabani@igalia.com> Cr-Commit-Position: refs/heads/main@{#923485} -- wpt-commits: 4eb26e6225ed30a6cfc73eb743eaf9f59086521c wpt-pr: 30813
18 lines
545 B
HTML
18 lines
545 B
HTML
<!doctype html>
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<meta charset="utf-8">
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<link rel="author" title="Delan Azabani" href="mailto:dazabani@igalia.com">
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<script src="support/selections.js"></script>
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<link rel="stylesheet" href="support/highlights.css">
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<style>
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main {
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font-size: 7em;
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margin: 0.5em;
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}
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main::selection {
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color: white;
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background-color: green;
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}
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</style>
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<p>Test passes if the text below is white on green.
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<main class="highlight_reftest">quick</main>
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<script>selectNodeContents(document.querySelector("main"));</script>
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