On Fri, Sep 9, 2022 at 5:49 PM Yoav Weiss <yoavwe...@chromium.org> wrote:
> > > On Fri, Sep 9, 2022 at 4:21 PM 'Thomas Steiner' via blink-dev < > blink-dev@chromium.org> wrote: > >> Contact emails >> >> fbeauf...@chromium.org, to...@chromium.org >> >> Explainer >> >> >> https://github.com/wicg/user-preference-media-features-headers/blob/main/README.md >> >> Specification >> >> >> https://wicg.github.io/user-preference-media-features-headers/#sec-ch-prefers-reduced-motion >> > > It seems worthwhile to properly specify that the hints in question are > high-entropy hints that are not sent without an opt-in. > Based on https://github.com/WebKit/standards-positions/issues/15, it > doesn't seem like that is clear. > Thank you! I've updated the spec to make it clear. See https://github.com/WICG/user-preference-media-features-headers/pull/7 > > >> >> API spec >> >> Yes >> >> Summary >> >> The Sec-CH-Prefers-Reduced-Motion client hint is modeled after the >> prefers-reduced-motion user preference media feature as defined in Media >> Queries Level 5. This headers follows Sec-CH-Prefers-Color-Scheme, which >> was described in >> https://groups.google.com/a/chromium.org/g/blink-dev/c/tEZ4RVsP1ms. >> >> Blink component >> >> Blink>CSS >> >> Motivation >> >> CSS media queries, and specifically user preference media features like >> prefers-reduced-motion, have a potentially significant impact on the >> amount of CSS that needs to be delivered by a page, and on the experience >> the user is going to have when the page loads. >> >> It is a best practice to not load CSS responsible for animations in the >> critical rendering path if the user prefers reduced motion, but to instead >> only load said CSS if the user doesn't mind motion. One way of doing so is >> via <link media>. However, high-traffic sites like Google Search that >> wish to honor user preference media features like prefers-reduced-motion >> and that inline CSS for performance reasons, need to know about the motion >> preferences (or other user preference media features respectively) ideally >> at request time, so that the initial HTML payload already has the right CSS >> inlined. >> >> TAG review >> >> https://github.com/w3ctag/design-reviews/issues/632 >> >> TAG review status >> >> Unsatisfied >> >> Demo link >> >> https://sec-ch-prefers-reduced-motion.glitch.me/ >> >> Debuggability >> >> Developers can change the Sec-CH-Prefers-Reduced-Motion client hint >> header value by emulating motion preferences via DevTools in the Rendering >> panel like they can do with the Sec-CH-Prefers-Color-Scheme client hint >> header today. >> >> Measurement >> >> The kClientHintsPrefersReducedMotion WebFeature tracks >> Sec-CH-Prefers-Reduced-Motion client hint usage. >> >> Risks >> >> >> Interoperability and Compatibility >> There are no particular compatibility risks. >> >> Interoperability is still pending on other browser vendors replying. >> Support for Client Hints in general is not enthusiastic though. >> >> >> Signals from other implementations (Gecko, WebKit): >> >> Gecko: Pending (https://github.com/mozilla/standards-positions/issues/526 >> ) >> >> WebKit: Pending ( >> https://lists.webkit.org/pipermail/webkit-dev/2021-May/031856.html, now >> migrated to https://github.com/WebKit/standards-positions/issues/15) >> >> Web / Framework developers: Positive (WICG proposal Issue: >> https://github.com/WICG/proposals/issues/30 with feedback from >> developers working for Facebook >> <https://github.com/WICG/proposals/issues/30#issuecomment-854962840> and >> Magento >> <https://github.com/WICG/proposals/issues/30#issuecomment-850873790>. >> Twitter: https://twitter.com/kilianvalkhof/status/1392404416335056896. >> The proposal was initially discussed in >> https://github.com/w3c/csswg-drafts/issues/4162 and received positive >> feedback via 16 Likes and 3 supportive comments: >> https://github.com/w3c/csswg-drafts/issues/4162#issuecomment-621047333, >> https://github.com/w3c/csswg-drafts/issues/4162#issuecomment-631400330, >> and >> https://github.com/w3c/csswg-drafts/issues/4162#issuecomment-645742958). >> Google Search is interested in this header, too. >> >> Ergonomics: >> >> N/A >> >> Activation: >> >> Developers will include Sec-CH-Prefers-Reduced-Motion in the response >> headers Accept-CH and Critical-CH to let the browser know that they’re >> interested in the motion preferences. If supported, the request header >> Sec-CH-Prefers-Reduced-Motion will be populated with the appropriate >> value. >> >> Is this feature fully tested by web-platform-tests? >> >> Yes. https://wpt.fyi/results/client-hints. >> >> Tracking bug >> >> https://crbug.com/1361871 >> >> Link to entry on the Chrome Platform Status >> >> https://chromestatus.com/feature/5141804190531584 >> >> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to blink-dev+unsubscr...@chromium.org. >> To view this discussion on the web visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CALgRrL%3DgTkCO%3DmZErYjf1BCyQAPFNNMv3KJFPpFEFV3Ev6%3DrtA%40mail.gmail.com >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CALgRrL%3DgTkCO%3DmZErYjf1BCyQAPFNNMv3KJFPpFEFV3Ev6%3DrtA%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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