1509746 - Ensure animationiteration event is fired

Status: NEW

(Core :: CSS Transitions and Animations, enhancement, P3)

Description

[Hiroyuki Ikezoe (:hiro)]

Attachment: animationiteration.html

If the main-thread is busy in the initial frame where the animation is painted and if the busyness persists until animation iteration change happens we don't fire animationiteration event.

On Chrome the event is fired.

Comment 1

[Brian Birtles (:birtles)]

I believe that's per spec. Iteration events are only fired when we have main thread animation frames within the active interval. There's no guarantee that any will be fired. Chrome also drops them in many cases.

Comment 2

[Hiroyuki Ikezoe (:hiro)]

From web developers perspective it's not intuitive because the animation iteration change actually can be visible on the content.

Comment 3

[Brian Birtles (:birtles)]

I'm not sure exactly what you're proposing. I don't think we want to solve this in the general case since you can have an animation with a 1ms interval (or much less) and we don't expect UAs to dispatch all the animationiteration events. All the spec requires is that you get the latest one for the current frame.