W3C home > Mailing lists > Public > www-style@w3.org > April 2010

Re: transitions vs. animations

From: Brad Kemper <brad.kemper@gmail.com>
Date: Thu, 8 Apr 2010 12:24:28 -0700
Message-Id: <2AF9832A-E033-42BF-BEB4-46FC6A5CC1F7@gmail.com>
To: "Tab Atkins Jr." <jackalmage@gmail.com>
Cc: HÃ¥kon Wium Lie <howcome@opera.com>, Perry Smith <pedzsan@gmail.com>, "www-style@w3.org list" <www-style@w3.org>


On Apr 8, 2010, at 11:45 AM, "Tab Atkins Jr." <jackalmage@gmail.com>  
wrote:

> As far as I can tell, this is identical to my proposal, just with a
> slightly differing syntax, right?  You use /s to separate the
> animations, rather than wrapping them in a function?

That's the basic idea. I'm pretty sure was using play(<complete- 
animation-shorthand>) before you were, but if you want to think of it  
as changing your syntax, that's fine. I won't argue. This also allows  
the use of individual transition-animation-* properties after the  
slash, instead of always using the shorthand. I think that's a pretty  
big deal, and a motivation for doing it this way.

This is separate from whether or not I think 'end-play' etc. are good  
ideas, as I haven't bought into your whole proposal in toto.

>
>> The difference is that the "transition-animation" only plays during  
>> the time that the transition is playing, and is time-clipped to  
>> that duration. Thus, you can have infinite iterations in the  
>> transition-animation part, but they would only last while the  
>> property was transitioning (would not play during the transition- 
>> delay either).
>
> I think this is a good idea.
>
>> Another difference is that if the keyframes are animating the same  
>> property as the transition, then the effect is additive. This way,  
>> you can have, e.g., a horizontal move that was not smooth, but  
>> staggered, surged, or spurted from left to write, due to the  
>> effects of the transition-animation.
>
> You haven't specified how this is supposed to work.  Does this mean
> that if I am transitioning 'left' and the animation has a 'left:20px;'
> rule in one of the keyframe-declarations, that point in time will have
> left equal to (whatever the transition would set it to) + (20px)?

Yes, exactly. Or if the keyframe was a negative number, it would  
subtract (naturally).

> If so, how does a % work?

TBD. I haven't pondered it much. I was thinking multiply instead of  
add, but I need to consider that more.

> How do colors work?  How do keyword
> properties work?

I'm not sure. Maybe only lengths and numbers make sense. I'll give it  
some thought.

> How do I say "ignore the transition, instead use
> this cool animation function I've defined here" (the "fling and
> bounce" transition I mentioned earlier).

Sorry, I'm not familiar with that use case. I'll look it up when I get  
home tonight (or you could forward me the quoted part of what you're  
talking about there). 
Received on Thursday, 8 April 2010 19:25:13 GMT

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