W3C home > Mailing lists > Public > www-style@w3.org > February 2012

Re: [css3-animations] What does animation-fill-mode do when animation-iteration-count is zero?

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Fri, 3 Feb 2012 06:49:34 -0800
Message-ID: <CAAWBYDBh+CrgfUuKeREbKP9=5kJxKeNUgGC-9USQBfaLkf-U=A@mail.gmail.com>
To: Sylvain Galineau <sylvaing@microsoft.com>
Cc: Øyvind Stenhaug <oyvinds@opera.com>, "www-style@w3.org" <www-style@w3.org>
On Thu, Feb 2, 2012 at 8:10 PM, Sylvain Galineau <sylvaing@microsoft.com> wrote:
> [Tab Atkins Jr.:]
>> On Thu, Feb 2, 2012 at 5:30 AM, Øyvind Stenhaug <oyvinds@opera.com> wrote:
>> > On Thu, 02 Feb 2012 01:58:33 +0100, Sylvain Galineau
>> > <sylvaing@microsoft.com> wrote:
>> >> I assume animation-iteration-count:0 means no animation occurs and no
>> >> animation events are thrown regardless of duration and delay.
>> >>
>> >> Does animation-fill-mode have any effect in this case?
>> >
>> > When I raised this back in
>> > <http://lists.w3.org/Archives/Public/www-style/2011Oct/0107.html>,
>> > David argued that it would make sense to avoid a discontinuity at 0.
>> > With that reasoning,
>> >
>> > - start event and end event should dispatch at the end of the delay
>> > - fill mode 'backwards'/'both' should have an effect during the delay
>> > phase
>> > - fill mode 'forwards'/'both' should have an effect after the delay
>> > phase
>>
>> I agree with dbaron that this is the ideal behavior.
>>
> Why is it ideal?

For the reason dbaron gives - it avoids a discontinuity at 0, which we
try to avoid in CSS (as it causes surprises).

One could argue that someone setting animation-iteration-count to 0 is
trying to "turn off" the animation, but there's already a simple way
to turn off an animation - either change animation-name to 'none', or
remove it from the animation declarations directly.  There's no need
to add an additional way.

~TJ
Received on Friday, 3 February 2012 14:50:26 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 17:20:50 GMT