| commit | 4eb26e6225ed30a6cfc73eb743eaf9f59086521c | [log] [tgz] |
|---|---|---|
| author | Delan Azabani <dazabani@igalia.com> | Wed Sep 22 00:10:23 2021 |
| committer | Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> | Wed Sep 22 00:21:51 2021 |
| tree | d41f5bbd6f61e254eae4fba3c04425ea2e5744bc | |
| parent | 4f50940a6a8864ef73232048f7d41892216cb080 [diff] |
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}
The web-platform-tests Project is a cross-browser test suite for the Web-platform stack. Writing tests in a way that allows them to be run in all browsers gives browser projects confidence that they are shipping software that is compatible with other implementations, and that later implementations will be compatible with their implementations. This in turn gives Web authors/developers confidence that they can actually rely on the Web platform to deliver on the promise of working across browsers and devices without needing extra layers of abstraction to paper over the gaps left by specification editors and implementors.
The most important sources of information and activity are:
wpt:matrix.org matrix channel; includes participants located around the world, but busiest during the European working day.If you'd like clarification about anything, don't hesitate to ask in the chat room or on the mailing list.
Clone or otherwise get https://github.com/web-platform-tests/wpt.
Note: because of the frequent creation and deletion of branches in this repo, it is recommended to “prune” stale branches when fetching updates, i.e. use git pull --prune (or git fetch -p && git merge).
See the documentation website and in particular the system setup for running tests locally.
The wpt command provides a frontend to a variety of tools for working with and running web-platform-tests. Some of the most useful commands are:
wpt serve - For starting the wpt http serverwpt run - For running tests in a browserwpt lint - For running the lint against all testswpt manifest - For updating or generating a MANIFEST.json test manifestwpt install - For installing the latest release of a browser or webdriver server on the local machine.wpt serve-wave - For starting the wpt http server and the WAVE test runner. For more details on how to use the WAVE test runner see the documentation.On Windows wpt commands must be prefixed with python or the path to the python binary (if python is not in your %PATH%).
python wpt [command]
Alternatively, you may also use Bash on Ubuntu on Windows in the Windows 10 Anniversary Update build, then access your windows partition from there to launch wpt commands.
Please make sure git and your text editor do not automatically convert line endings, as it will cause lint errors. For git, please set git config core.autocrlf false in your working tree.
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Save the Web, Write Some Tests!
Absolutely everyone is welcome to contribute to test development. No test is too small or too simple, especially if it corresponds to something for which you've noted an interoperability bug in a browser.
The way to contribute is just as usual:
git checkout -b topic../wpt lint as described above.If you spot an issue with a test and are not comfortable providing a pull request per above to fix it, please file a new issue. Thank you!