- From: Tab Atkins Jr. <jackalmage@gmail.com>
- Date: Tue, 9 Sep 2014 09:04:04 -0700
- To: www-style list <www-style@w3.org>
Currently, the animations spec requires "snapshotting" all the animation-affecting properties when the animation starts. We previously discussed allowing some things to be updated on the fly, and in today's f2f discussion, we clarified more. Here's the proposal: just let everything be adjustable. The start time of the animation (when the animation starts applying; when value is adjusted (in the animation-* properties, or in the @keyframes rule), just recompute what value the animation would be at if it had always had those values, and start applying that instead. Event-handling needs to be dealt with here; we propose that start and end events are fired once, and are guaranteed to fire, even if an adjustment caused the actual start/end time to never be instantiated. Iteration events just fire whenever the animation plays through an iteration boundary; adjusting an animation to "skip" a bunch of iterations does *not* fire a bunch at once, and if you adjust an animation to return to an earlier point, the iteration event for a particular index will fire again. (More discussion today showed that this idea of how to handle events appears to generalize well; we can use this as a general rule for how to resolve "when do events fire in case X".) ~TJ
Received on Tuesday, 9 September 2014 16:04:51 UTC