Would a method that returns a Promise be more in line with what this is doing?
On Wed, Jan 22, 2020, 1:49 PM Simon Fraser <simon.fra...@apple.com> wrote: > > On Jan 21, 2020, at 5:27 PM, Thomas Guilbert <tguilb...@google.com> wrote: > > The idea was to reuse an API name that developers are already > familiar with, in a similar context. The name is also being used in > XRSession ( > https://developer.mozilla.org/en-US/docs/Web/API/XRSession/requestAnimationFrame), > and in OffscreenCanvas (or technically DedicatedWorkerGlobalScope). The > AnimationFrameProvider > mixin > <https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html#animationframeprovider> > could > also be updated so HTMLVideoElement can extend it. > > Yes, this isn't formally spec'ed out, but it will be. For now, they are > added to the task queue and run like any other task. So, going off the spec > you linked, I think this would be "5) Perform oldestTask's step" and not > "10) Rendering: [...] 11. Foreach document run animation frame callbacks > for that Document". > > > I would expect something that's called "requestAnimationFrame" to only > fire in the "update the rendering" steps; requestAnimationFrame is a > "before rendering" callback. So firing a callback with the same name at > other times seems like it will lead to author confusion. > > The author's expectation should be that any content/style changes they > make inside a requestAnimationFrame callback will appear on-screen in the > same frame as other changes in the same event loop cycle, and that > requestAnimationFrame won't be called more often than is necessary to > update the screen at the appropriate frame rate. > > Simon > > > On Tue, Jan 21, 2020 at 1:01 PM Simon Fraser <simon.fra...@apple.com> > wrote: > >> On Jan 21, 2020, at 12:37 PM, Thomas Guilbert <tguilb...@google.com> >> wrote: >> >> Hello, >> >> I'm reaching out to see if webkit would like to weigh in on the following >> proposal:https://discourse.wicg.io/t/proposal-video-requestanimationframe/3691 >> >> The HTMLVideoElement.requestAnimationFrame() API allows web developers to be >> notified when a video frame has been presented for composition, and provides >> metadata for that frame. >> >> If you want to try it out, a prototype is available in Chromium Dev, >> behind the enable-experimental-web-platform-features flag. >> >> >> This is not official feedback, but I have some issues with the proposal. >> >> First, the name is confusing. It sounds like you're requesting a frame >> from the video, but it's really a "frame available" callback. Why not call >> it onFrameAvailable()? >> >> Second, its interaction with normal requestAnimationFrame() and the HTML >> event loop needs to be better defined. Where in in the >> https://html.spec.whatwg.org/multipage/webappapis.html#event-loop-processing-model >> do >> these callbacks fire? >> >> Simon >> >> >> > _______________________________________________ > webkit-dev mailing list > webkit-dev@lists.webkit.org > https://lists.webkit.org/mailman/listinfo/webkit-dev >
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