Re: [css3-transitions] transitions and rendering objects vs. DOM nodes

On Jun 28, 2009, at 11:12 PM, Robert O'Callahan wrote:

> On Sat, Jun 27, 2009 at 11:44 AM, L. David Baron <dbaron@dbaron.org>  
> wrote:
> I have another question about transitions that I think ought to be
> addressed in the spec ( http://dev.w3.org/csswg/css3-transitions/ ),
> though in this case I'm not exactly sure how it should be addressed
> in the spec.
>
> This is the question of whether transition should be associated with
> a change in style on a content node, or a change in style on a
> rendering object (a box).  Either solution poses a bunch of
> problems.
>
> If transitions are associated with the style on an element (DOM
> node), then we have problems in any case where a content node has
> more than one style.  The main case of this I can think of is
> pseudo-elements.  For example, I think it's hard to do something
> sensible with:
>  p { color: gray; }
>  p::first-line { color: black; }
>  p:hover { color: blue; }
>  p:hover::first-line { color: aqua; }
>  a { transition: 3s color; }
> then it's really not clear what the transition on the anchor should
> be when the p goes into the :hover state (either when the anchor is
> split between the first line and the second, or when the anchor is
> entirely in the first line).
>
> How about: if an element has a first-line or first-letter rule  
> setting a property on it, then transitions on that property are  
> disabled for the element and all its descendants.

I'm not understanding why transitions can't be made to work on first- 
line and first-letter?

dave
(hyatt@apple.com)