Hi Emlio, Thanks for your patience with these fixes and taking the time to outline your concerns. Hope things are better now, and as always, if not just say so. :)
Chris On Thu, Feb 20, 2020 at 7:39 AM Emilio Cobos Álvarez <emi...@mozilla.com> wrote: > A quick status update here: > > I landed some heuristics to disable scroll anchoring in pathological > cases in Firefox a long while ago. This stopped virtually all compat > issues, though it's obviously not great. > > Chris and other Chromium folks have been doing work to fix Chromium > issues that were causing these interop problems, and improving the > scroll anchoring spec. > > So I'm going to try and peek up those spec changes in Firefox and then > try to remove those heuristics on Nightly, and see how it goes. > > -- Emilio > > On 11/7/19 12:07 AM, Chris Harrelson wrote: > > HI Emilio, > > > > I'll follow up on crbug.com/920289 <http://crbug.com/920289>. Let's > > discuss there. > > > > On Tue, Oct 29, 2019 at 3:03 PM Emilio Cobos Álvarez <emi...@mozilla.com > > <mailto:emi...@mozilla.com>> wrote: > > > > Hi all, > > > > 10/18/19 7:19 PM, Chris Harrelson wrote: > > > Hi, > > > > > > Another quick update: Emilio, Navid, Nick, Stefan and I met today > and > > > discussed which issues are important to fix and why. We now have > > a list of > > > spec issues, and WPT tests to fix that are Chromium bugs, that > should > > > substantially improve interop. Nick and Stefan will take on the > > work to fix > > > them, with the review and feedback support of Emilio. > > > > So, today another scroll-anchoring bug crossed my radar, and this one > > I'm not sure at all how to fix it, because there's no obvious answer > > here as far as I can tell. > > > > My diagnosis (for one of the pages, the one I could repro and > > reduce) is > > in here[1], but basically my current explanation is that the page > > should > > be broken per spec, and that when it works it's hitting a bug in both > > Chromium[2] which we have an equivalent of but are just not hitting > > because in Firefox changing `overflow` does more/different layout > work > > than in Chrome. > > > > The test-case may as well work if we change our scroll event or timer > > scheduling (see there), but that is obviously pretty flaky. > > > > I honestly don't have many better ideas for more fancy heursitics > about > > how to unbreak that kind of site. From the point of view of the > > anchoring code, the page is just toggling height somewhere above the > > anchor, which is the case where scroll anchoring _should_ work, > usually. > > > > I can, of course (and may as a short-term band-aid, not sure yet) add > > `overflow` to the magic list of properties like `position` that > > suppress > > scroll anchoring everywhere in the scroller, but that'd be just > kicking > > the can down the road and waiting for the next difference in layout > > performance optimizations between Blink and Gecko to hit us. > > > > I think (about to go on PTO for the next of the week) I'll add > > telemetry > > for pages that have scroll event listeners, and see if disabling > scroll > > anchoring on a node when there are scroll event listeners attached > > to it > > is something reasonable (plus adding an explicit opt-in of course). > > > > I'm not terribly hopeful that the percentage of such documents is > going > > to be terribly big, to be honest, but providing an opt-in and doing > > outreach may be a reasonable alternative. > > > > Another idea would be to restrict the number of consecutive scrolls > > made > > by scroll anchoring to a given number at most. That would made the > > experience in such broken websites somewhat less annoying, but it'll > > also show flickering until that happens, which would make the browser > > still look broken :/. > > > > Thoughts / ideas I may not have thought of/be aware of? > > > > Thanks, > > > > -- Emilio > > > > [1]: https://bugzilla.mozilla.org/show_bug.cgi?id=1592094#c15 > > <https://bugzilla.mozilla.org/show_bug.cgi?id=1592094#c15> > > [2]: https://bugs.chromium.org/p/chromium/issues/detail?id=920289 > > <https://bugs.chromium.org/p/chromium/issues/detail?id=920289> > > > > > Thanks all, > > > Chris > > > > > > > > > On Thu, Oct 10, 2019 at 2:13 PM Rick Byers <rby...@chromium.org > > <mailto:rby...@chromium.org>> wrote: > > > > > >> Sorry for the delay. > > >> > > >> We agree that scroll anchoring has unrealized potential to be > > valuable for > > >> the web at large, and to make that happen we should be investing > > a lot more > > >> working with y'all (and if we can't succeed, probably removing > > it from > > >> chromium). Concretely +Chris Harrelson who leads rendering for > > Chrome (and > > >> likely someone else from his team), as well as +Nick Burris from > > the Chrome > > >> input team will start digging in ASAP. In addition to just the > > normal > > >> high-bandwidth engineer-to-engineer collaboration between > > chromium and > > >> gecko I propose the following high-level goals for our work: > > >> > > >> - Ensure that there are no known deviations in behavior > between > > >> chromium and the spec (one way or the other). > > >> - Ensure all the (non-ua-specific) site compat constraints > > folks are > > >> hitting are captured in web-platform-tests. I.e. if Gecko > > passes the tests > > >> and serves a chromium UA string it should work as well as in > > Chrome (modulo > > >> other unrelated UA compat issues of course). > > >> - Look for any reasonable opportunity to help deal with > > UA-specific > > >> compat issues (i.e. those that show up on sites that are > > explicitly looking > > >> for a Gecko UA string or other engine-specific feature). > > This may include > > >> making changes in the spec / chromium implementation. This > > is probably the > > >> toughest one, but I'm optimistic that if we nail the first > > two, we can find > > >> some reasonable tradeoff for the hard parts that are left > > here. Philip (our > > >> overall interop lead) has volunteered to help out here as > well. > > >> > > >> Does that sound about right? Any suggestions on the best forum > > for tight > > >> engineering collaboration? GitHub good enough, or maybe get on > > an IRC / > > >> slack channel together somewhere? > > >> > > >> Rick > > >> > > >> On Mon, Oct 7, 2019 at 2:11 PM Mike Taylor <mi...@mozilla.com > > <mailto:mi...@mozilla.com>> wrote: > > >> > > >>> Hi Rick, > > >>> > > >>> On 9/28/19 10:07 PM, Rick Byers wrote: > > >>>> Can you give us a week or so to chat about this within the > > Chrome team > > >>>> and get back to you? > > >>> > > >>> Any updates here? > > >>> > > >>> Thanks. > > >>> > > >>> -- > > >>> Mike Taylor > > >>> Web Compat, Mozilla > > >>> > > >> -- > > >> 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 > > <mailto:blink-dev%2bunsubscr...@chromium.org>. > > >> To view this discussion on the web visit > > >> > > > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAFUtAY-DPW4tXA_R-c0WAj76Qtj4TYdjwHai3odyNdWYVfJhZA%40mail.gmail.com > > < > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAFUtAY-DPW4tXA_R-c0WAj76Qtj4TYdjwHai3odyNdWYVfJhZA%40mail.gmail.com > > > > >> > > < > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAFUtAY-DPW4tXA_R-c0WAj76Qtj4TYdjwHai3odyNdWYVfJhZA%40mail.gmail.com?utm_medium=email&utm_source=footer > > < > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAFUtAY-DPW4tXA_R-c0WAj76Qtj4TYdjwHai3odyNdWYVfJhZA%40mail.gmail.com?utm_medium=email&utm_source=footer > >> > > >> . > > >> > > > _______________________________________________ > > > dev-platform mailing list > > > dev-platf...@lists.mozilla.org > > <mailto:dev-platf...@lists.mozilla.org> > > > https://lists.mozilla.org/listinfo/dev-platform > > <https://lists.mozilla.org/listinfo/dev-platform> > > > > > > > -- > > 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 > > <mailto:blink-dev%2bunsubscr...@chromium.org>. > > To view this discussion on the web visit > > > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/8b44aa83-914f-344a-6da2-a56917230156%40mozilla.com > > < > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/8b44aa83-914f-344a-6da2-a56917230156%40mozilla.com > >. > > > > -- > 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/7baea287-a45e-ed96-9f24-40916da92770%40mozilla.com > . >
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