Thanks David and Martin for the feedback on this proposal. I'll try to address the various questions and concerns below:
To that end, is there a plan for making this capability uniformly available? > We don't have any plans to implement backdrop-filter on other graphics backends. This property has been sitting behind a pref while we have waited for a larger WebRender rollout. It may be worth noting that WebRender is now at 73.9% of Nightly and 85% of Windows 10 on Nightly. When we last investigated, the effort to support this feature on the other backends was significant. Generally, I don't believe we should be devoting engineering time to supporting new CSS features on the legacy backends unless the cost is low. In addition to the initial development, we have to concern ourselves with the maintenance cost until these backends are fully deprecated. It's worth calling out here that shipping platform features for only some > of our graphics backends is something new for us. (It's possible we've > done it in the past, but I'm not aware of us doing it *intentionally*.) > This is new, and we should evaluate it on a case-by-case basis. I don't think shipping backdrop-filter this way should set precedent for other new CSS features. Because it's primarily for cosmetic enhancement, and not generally used in a way where lack of support breaks the functionality or layout of a site, the nature of backdrop-filter lends itself better to shipping to a subset of users. A counter-example might be conic-gradient, which might be used for some critical part of site UI, such as a color picker. I don't think we should ship something like this to a subset of users. We risk creating Web compatibility problems for our own users. While > shipping the feature to some of our users will probably reduce web > compatibility problems for that subset of users, it will also probably > *increase* Web compatibility problems for the remaining users, since many > developers who *do* care about testing on Firefox may produce content > that's broken for those users. > Usage across the web is still relatively low, but it is growing. (Chrome stats [1] show 1.83% usage, but it's hard to know how much of that is meaningful in a way that sites look broken without the feature.) Non-WR users won't see anything different on sites that use backdrop-filter than they do now. Content that uses backdrop-filter now is already "broken" for all our users in that respect. The biggest compat risk likely stems from sites that place text on a blurred background image, which may render the text less readable without the effect, and again is already what all Firefox users see. I suppose it's a question of how much this risk will increase until we have WR everywhere. It makes the idea of targeting and testing on Firefox more complicated for > Web developers. We're at risk of being ignored by Web developers; being a > more complicated and fragmented target increases that risk, especially for > the smaller fragment(s), and also makes Web developers dislike us for > creating more complexity for them. > This is a risk I'm concerned about. It may be upsetting for developers who test in Firefox on a WR-supported machine and incorrectly assumes that backdrop-filter will look the same for all users. It's unlikely that they will create a "broken" experience for users, but the site will look different. We can and do plan to mitigate this through blog posts and outreach (use @supports), but the risk will still be there. One path forward is to gate this feature in Nightly and early beta to collect more feedback and data on our implementation. I'd prefer this slower rollout to none at all. As of now the pref is off for everyone. Cheers, Sean [1] https://www.chromestatus.com/metrics/css/timeline/popularity/508 On Tue, Jun 9, 2020 at 6:18 PM Martin Thomson <m...@mozilla.com> wrote: > On Wed, Jun 10, 2020 at 8:01 AM L. David Baron <dba...@dbaron.org> wrote: > > It's also something that I think we shouldn't be doing, at least not > > without a clear and relatively short timeline for having the feature > > available across all graphics backends (whether by implementing it > > for more backends or by no longer shipping those backends). > > I agree with David's reasoning here about this being potentially > harmful, but I do recognize the value of prototyping or experimenting. > This doesn't seem to be either of those though. > > To that end, is there a plan for making this capability uniformly > available? > _______________________________________________ > dev-platform mailing list > dev-platform@lists.mozilla.org > https://lists.mozilla.org/listinfo/dev-platform > _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
