On Sat, Oct 3, 2015 at 1:14 AM, Anne van Kesteren <ann...@annevk.nl> wrote: > On Thu, Oct 1, 2015 at 4:23 AM, Brian Birtles <bbirt...@mozilla.com> wrote: >> I'd like to change this API, probably to one of the following (listed >> roughly in order of preference). I wonder if anyone else has an opinion >> on this? > > I'm curious as to what this maps to closer to the metal. That can help > inform a reasonable low-level API. The other thing I'm wondering about > is whether it's still reasonably to introduce new synchronous layout > getters/setters. I was hoping we'd move away from that at some point.
The timing part is conceptually equivalent to doing something like elem.style.animationDuration = '3s' with the difference that we update the internal value of the duration immediately, rather than waiting for a style flush. It doesn't trigger synchronous layout however. It simply queues a style update. Fetching computedTiming will flush any pending style updates if it's called on an Animation that corresponds to a CSS animation or transition (i.e. not a script-generated animation) in much the same way that calling getComputedStyle(elem).animationDuration does. It doesn't invalidate style in anyway, however.