Re: a:hover and a:active and named anchors

[Wed, 31 Jul 2002 08:01:32 -0400] Stuart Ballard:
>Nice, except for one small problem...
>
>a {dynamic: hover; background-color: blue}
>a:hover {dynamic: not hover; background-color: red}

There should have been a statement in my explanation that the "dynamic"
property cannot be changed by a dynamic pseudo-class.

>(The general principle that's being violated here was stated by Hixie, I 
>believe[1], as "selectors can't depend on values of CSS properties".

I'm going to guess that what that principle means (I don't recall the
original statement, if I ever heard it) is that the determination of which
*elements* may be matched by a given a selector cannot depend on the CSS
properties of (any) elements.

This does not apply to pseudo-classes and pseudo-elements, though.  For
example, in CSS2, the ":first-line" pseudo-element can apply only to a
block-level element; but whether an element is block-level or inline-level
is dependent on the "display" property.

While it is a technical distinction, the suggested "dynamic" property
doesn't change which *elements* a selector might match: it changes which
dynamic pseudo-classes can actually be triggered by external changes.
There is precedent for this in an existing  CSS3 working draft; see:
     http://www.w3.org/TR/2000/WD-css3-userint-20000216#user-input
(the "user-input" property determines whether an element can take
the :active state).  An analogous infinite loop is noted and disallowed.
-- 
Randall Joseph Fellmy aka Randy@Coises.com

Received on Wednesday, 31 July 2002 15:08:01 UTC