RE: [css3-animations] display:none, visibility:hidden and animations

I assume you expect the same for an animation on the parent itself, correct ?

From: Rik Cabanier [mailto:cabanier@gmail.com]
Sent: Monday, October 03, 2011 9:36 AM
To: Sylvain Galineau
Cc: Boris Zbarsky; www-style@w3.org
Subject: Re: [css3-animations] display:none, visibility:hidden and animations

Hi Sylvain,

If a parent's style goes to 'none', I would expect that nested animation would stop and no longer be animated by the browser.
Once the parent goes to non-'none', the children's animation should start over.

Rik

On Sat, Oct 1, 2011 at 5:47 PM, Sylvain Galineau <sylvaing@microsoft.com<mailto:sylvaing@microsoft.com>> wrote:

[Boris Zbarsky:]
>
> On 9/29/11 5:12 PM, Tab Atkins Jr. wrote:
> > I don't believe there are any issues.  This is clearly the correct
> > model.  There is no reason whatsoever for 'display' to have an effect
> > on what animations run.
>
> That requires UAs to always compute the value of animation properties on
> all elements, including in display:none subtrees.
>
> In particular, this requires performing selector matching and so forth on
> those elements, which is something UAs commonly optimize out now.
>
> I don't believe that this is desirable.  Unless I'm missing something
> here?
>
> -Boris
I would agree that from an implementation standpoint, this is not optimal.
We should start with what behavior makes sense for authors, though. What do
you want display:none to do to an element's animation, or one running on a child
of that element ? Should it pause the animation ? Stop it ? Same question for
visibility:hidden.