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Re: [css3-transitions] starting and reversing animations

From: Simon Fraser <smfr@me.com>
Date: Fri, 29 Jan 2010 09:58:46 -0800
Cc: www-style <www-style@w3.org>
Message-id: <CD328A55-3322-4D58-8405-A3D17EAE0085@me.com>
To: "L. David Baron" <dbaron@dbaron.org>
On Jan 29, 2010, at 9:51 AM, L. David Baron wrote:

> On Friday 2010-01-29 10:05 -0600, Tab Atkins Jr. wrote:
>> On Fri, Jan 29, 2010 at 9:55 AM, Simon Fraser <smfr@me.com> wrote:
>>> No, the transition properties are taken from the destination style.
>> 
>> Wow, that's *completely* unclear, and also different from what I had
>> gathered from examples used on the mailing list.  Yeah, in that case
>> examples are *absolutely required*, since there's no mention of that
>> anywhere in the spec and it runs contrary to what I would have
>> thought.
> 
> Hmmm.  I attempted to explain that in the spec when I wrote:
>  # When the value of an animatable property changes,
>  # implementations must decide what transitions to start based on
>  # the values of the ‘transition-property’, ‘transition-duration’,
>  # ‘transition-timing-function’, and ‘transition-delay’ properties
>  # at the time of the change. Since this specification does not
>  # define what property changes are considered simultaneous,
>  # authors should be aware that changing any of the transition
>  # properties a small amount of time after making a change that
>  # might transition can result in behavior that varies between
>  # implementations, since the changes might be considered
>  # simultaneous in some implementations but not others. 
> In the new "Starting of Transitions" section.
> 
> However, rereading it, I now realize that "at the time of the
> change" is not clear at all.  What I meant to say is probably "at
> the time that would be immediately after the change if no
> transitions had been specified".  Does that make it clearer?

I don't think this really captures the issue that will most affect
authors, which is whether the transition properties themselves
should be considered to come from the current style, or the
"destination" style.

Perhaps an example in the spec would make this clearer.

Simon
Received on Friday, 29 January 2010 17:59:22 GMT

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