[css3-animations] can inserting a @keyframes rule start an animation?

• From: Ralph Thomas <ralpht@gmail.com>
• Date: Mon, 7 Oct 2013 16:24:22 -0700
• To: www-style@w3.org
• Message-ID: <CAAYQYDR3SncV5_khntjsCxLGGwEJn_kzqZ6kqOC7t0TWd=a=8Q@mail.gmail.com>

Hi www-style,

  I recently added an optimization to WebKit to not perform a full
style recalc when inserting a @keyframes rule[1], which raised the
question from Simon Fraser:

"If an element has: -webkit-animation-name: foo and you insert
@-webkit-keyframes foo {...}, does the animation start?"

WebKit does not start an animation in this case (and didn't prior to
my change), but Firefox does. The CSS 3 Animations spec doesn't
directly address the issue, but does say:

"If the name does not match any keyframe at-rule, there are no
properties to be animated and the animation will not execute."

So which is the correct behavior, and can we amend the spec to make
this explicit?

Thanks,
 Ralph

[1]: https://bugs.webkit.org/show_bug.cgi?id=119479

Received on Monday, 7 October 2013 23:24:51 UTC