LGTM3 On Thu, Sep 16, 2021 at 8:35 AM Mike West <[email protected]> wrote:
> LGTM2. > > I agree with Mike Taylor that we should generally be giving developers > insight into changes via devtools when practical, and helping them through > shifts in behavior so they're not surprised. That said, for this particular > change, I agree with Rego that the risk is quite low, and assuming Firefox > will follow along, developers will quickly regain a consistent story. > > Please keep an eye on feedback through dev and beta channels, but I'm > comfortable with y'all trying this change. > > -mike > > > On Wed, Sep 15, 2021 at 10:23 PM Rune Lillesveen <[email protected]> > wrote: > >> On Wed, Sep 15, 2021 at 2:55 PM Mike Taylor <[email protected]> >> wrote: >> >>> Hey Rune, >>> >>> Is there any way for developers to know behavior has changed on their >>> sites when this ships? (Or alternatively, any clues for folks triaging >>> bugs, besides bisecting?). >>> >>> I'm wondering about sites where breakage is pretty bad. Would it be >>> useful to ship a devtools issue (probably overkill given the use counter >>> data, especially if they're over-counting problematic cases...)? >>> >> >> You mean adding a devtools warning if the propagated values would have >> been different without containment? >> >> I think the background and overflow scrollbar propagation would have >> pretty obvious effects. If the body direction/writing-mode is orthogonal to >> the root html direction/writing-mode, such effects would be more subtle and >> harder to spot. We have changed how body/html/viewport propagation for >> orthogonal writing-modes have been done before without any such >> signals/warnings (not sure if we even have done intent-to-ship for that). >> >> (Also, I asked dholbert if he thinks it's something Gecko would want to >>> ship in https://bugzilla.mozilla.org/show_bug.cgi?id=1730763#c2) >>> >> >> Thanks! Positive response from dholbert. >> >> On 9/14/21 6:12 PM, Rune Lillesveen wrote: >>> >>> Contact emails [email protected] >>> >>> Specification http://drafts.csswg.org/css-contain-1/#c3 >>> >>> Summary >>> >>> Used values for contain different from none on the root or body elements >>> will disable propagation of CSS properties from body as per >>> specification[1]. [1] https://drafts.csswg.org/css-contain-1/#c3 >>> >>> This change was brought to the CSSWG because the unconditionally >>> propagating body styles to the viewport would create circular dependencies >>> for CSS Container Queries. For instance, a propagated writing-mode from >>> body to the viewport, when orthogonal to the outer, could change the size >>> of root element which in turn could affect style resolution for body via >>> container queries, which again could result in a different computed >>> writing-mode for body. See the github issue for details: >>> https://github.com/w3c/csswg-drafts/issues/5913. It should be noted >>> that the CSSWG has regretted introducing propagation from body and have >>> resolved >>> <https://github.com/w3c/csswg-drafts/issues/6079#issuecomment-816307011> >>> on not introducing new properties to be propagated from body. >>> >>> The implementation was added to M93 behind a flag along with use >>> counters for used contain values different from none on html root and body: >>> >>> https://chromestatus.com/metrics/feature/timeline/popularity/3936 >>> https://chromestatus.com/metrics/feature/timeline/popularity/3937 >>> >>> These use counters cover more cases than potentially problematic ones, >>> as they do not detect if the styles are different on body and root and >>> would make any differences. Still the use counters are low - 0.0004% and >>> 0.0008% respectively. >>> >>> Blink component Blink>CSS >>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3ECSS> >>> >>> TAG review None. Change to a W3C Recommendation in the CSSWG. >>> >>> TAG review status Not applicable >>> >>> Risks >>> Interoperability and Compatibility >>> >>> - Not shipping this change would block shipping CSS Container >>> Queries, or cause stateful style/layout issues. >>> - Low use counters for containment on body and root. >>> - There is an interop risk if the other engines do not change their >>> implementations. The use counters indicate that, at least at the moment, >>> applying containment to root and body is rare. >>> >>> I have not filed a standards position for Gecko. This seems like a >>> rather small change compared to APIs typically filed as a >>> standards position. I got a quick reply on the webkit-thread. >>> Issues are filed for both browsers and I have triaged the failing tests >>> on wpt.fyi accordingly. >>> >>> Gecko: No signals https://bugzilla.mozilla.org/show_bug.cgi?id=1730763 >>> >>> WebKit: No objection: >>> https://lists.webkit.org/pipermail/webkit-dev/2021-September/031982.html >>> >>> Web developers: No signals >>> >>> >>> >> >> -- >> Rune Lillesveen >> >> -- >> 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 [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACuPfeSk22%3D%2Bn%3DSuG%2BK8p%2BYKA%3DLE4AoZ7516LkddzARZp7_yhA%40mail.gmail.com >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACuPfeSk22%3D%2Bn%3DSuG%2BK8p%2BYKA%3DLE4AoZ7516LkddzARZp7_yhA%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- > 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 [email protected]. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAKXHy%3De43pQBXdxbi%2BjjdTfO2SeH1%3Dieqvw8fkaSDXdoUR-8Vw%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAKXHy%3De43pQBXdxbi%2BjjdTfO2SeH1%3Dieqvw8fkaSDXdoUR-8Vw%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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