Re: PFWG preliminary review of Web Animation 1.0

Dear Michael,

Thank you very much for your review. We had been doing some guesswork 
about the requirements in this area so we very much appreciate your input.

I have read the mails you referenced added some initial comments below.

We will discuss this in one of our upcoming meetings and if there is 
anything further to add I will send it along.

(2013/07/19 0:53), Michael Cooper wrote:
> The core requirement to point out is that it is critical to
> accessibility for the user to have the ability to stop, pause and
> optionally restart, and prevent animation. This can be enabled via the
> user agent or via author-controlled features, but needs to be something
> that can be used in all cases of animation. There are references to
> these states in the spec, but it is not clear at the moment that the
> spec prescribes that these functions must be available, and how.

With the Web Animations model, all animations--whether they are defined 
in CSS, SVG, or via the script API--have an associated "player".

This player can be used to pause, seek, restart, and change the playback 
rate of animation.

It is possible to get the list of all active players in a document using 
the script API.

Using this API, it is possible to create a tool that periodically polls 
for all active animations (whether SVG, CSS, or created using the API) 
and pauses them. If necessary, we could add an observer interface to 
simplify this.

There is no global kill-switch for all animations since that would 
interfere with "essential" animations.

Authors can use the API to provide playback control for all animations 
in their content. For SVG, we anticipate exposing an additional timeline 
that provides playback control for all animations in a given SVG fragment.

User agents are expected to implement CSS and SVG in terms of an 
underlying Web Animations model, and hence it should be possible for 
user agents to easily provide global settings that apply to all 
animations (except RAF or setTimeout-scripted animations).

Are there other features or references that you think would be useful to 
include in this specification? Perhaps specific conformance criteria or 
explicit reference to the necessity of these features?

Thank you once again for your help!

Best regards,


Received on Friday, 19 July 2013 04:27:52 UTC