- From: Simon Fraser <smfr@me.com>
- Date: Thu, 08 Apr 2010 14:06:07 -0700
- To: "Tab Atkins Jr." <jackalmage@gmail.com>
- Cc: Brad Kemper <brad.kemper@gmail.com>, Håkon Wium Lie <howcome@opera.com>, Perry Smith <pedzsan@gmail.com>, "www-style@w3.org list" <www-style@w3.org>
On Apr 8, 2010, at 12:38 PM, Tab Atkins Jr. wrote: > I've seen a few sites (can't find a URL right now, sorry) that have a > very cool animation on their main navigation using javascript. The > text of the nav link is naturally at the top of the block, but when > you hover over it it drops the bottom quickly, bounces, and settles > down. When you unhover, it flies up and bounces the same way. > > Without any fanciness, this is just a change in positioning. With > transitions, we can trivially make this a smooth slide from being > positioned at the top to being at the bottom. Actually, you can't transition from "top: 0" to "bottom: 0", just as you can't transition between "height: auto" to "height: 50px". The reason is that the user agent would have to do a layout in order to compute the final state before starting the transition, and then, if some other state changes while the transition is running, that final state becomes invalid. > But to do the "fly and > bounce" thing, you need an animation. I want to use this idea of > attaching an animation to a transition, as it generally *works* the > way I want, but I want to override the default transition slide with > my own keyframe path. You could do the bounce effect with a more elaborate timing function. > I think this sort of thing will be reasonably common, and so I believe > that transition-animations should override the transition they're > attached to, if they manipulate the same property. I think we have > reasonable freedom to later add an ability for the > transition-animation to combine with the transition, rather than > straight overriding it, but I don't think that's necessary *right now* > to get it working. If we end up attaching animations to transitions, then I agree that the animation should override the transition. As I said in another email, let's deal with additivity separately. Simon
Received on Thursday, 8 April 2010 21:06:44 UTC