On Wed, Sep 14, 2022 at 5:56 PM Yoav Weiss <yoavwe...@chromium.org> wrote:
> > > On Sunday, September 11, 2022 at 7:20:45 AM UTC+2 fbea...@google.com > wrote: > >> 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 >> > > Thanks, but that doesn't define that the hint is a high entropy one. > Talking to Mike Taylor, it seems we can improve the CH Infra spec to make > it clearer that any hint that's not low-entropy is a high entropy hint. > Then your spec can get that definition for free. > Thanks to https://github.com/WICG/client-hints-infrastructure/pull/127, we've just updated our spec with https://github.com/WICG/user-preference-media-features-headers/pull/8 > > >> >> >>> >>> >>>> >>>> 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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