On Thursday 2019-07-11 10:59 -0400, Jeff Muizelaar wrote: > On Thu, Jul 11, 2019 at 10:46 AM Emilio Cobos Álvarez <emi...@crisal.io> > wrote: > > On 7/10/19 11:01 PM, Connor Brewster wrote: > > > Hi David, > > > > > >> It's not clear to me what this option means in terms of what you're > > >> proposing to implement and ship. @supports is a feature that web > > >> developers can use -- and it should clearly match whether the > > >> feature is supported. However, I think what you're suggesting here > > >> is that you might ship the feature only when WebRender is enabled -- > > >> I think that's something that requires further discussion, given the > > >> confusion it would cause in the web development world. It also > > >> seems (?) like you're suggesting something else about limiting which > > >> filters are usable to only those that have a GPU implementation in > > >> WebRender -- but it's not clear to me if that's for backdrop-filter > > >> only, or also for the filter property -- when WebRender is enabled. > > > > > > The idea here is that @supports would reflect whether or not > > > backdrop-filter and WebRender are enabled. This would allow web > > > authors to add a fallback style if needed. I do agree that this would > > > cause some confusion and needs more discussion. > > > > This seems pretty hard to do right / pretty awkward. @supports must > > reflect whether the property parses. Not enabling the property if > > webrender is not enabled seems hacky, but doable. > > > > But if you have WebRender enabled and your GPU process crashes, going > > all the way back to the style system to invalidate everything doesn't > > seem trivial / worth the effort. It seems pretty hard actually. > > I feel like having the wrong results from @supports in this case is > probably acceptable. > I suspect background-filter is rarely used in ways that lying in > @supports causes a website to become unusable. > > I see disabling it in @supports as sort a best effort kind of thing as > opposed to needing to be perfect.
I don't think having a CSS feature that stops working if the GPU process crashes is acceptable. It's not a coherent story to web developers, and it means that once sites start relying on the feature (which they'll think they can do because it looks like it works), pages will be broken for some portion of our users. -David -- 𝄞 L. David Baron http://dbaron.org/ 𝄂 𝄢 Mozilla https://www.mozilla.org/ 𝄂 Before I built a wall I'd ask to know What I was walling in or walling out, And to whom I was like to give offense. - Robert Frost, Mending Wall (1914) _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
