[css3-animations] Change to currentColor means it's no longer animatable?

[A w3c-style discussion accidentally turned technical. I'm moving it
to www-style.]

For a few reasons, we're changing the definition of currentColor to
resolve to a definite color at used-value time rather than
computed-value time.
<http://lists.w3.org/Archives/Public/www-style/2012Jan/0521.html>
<http://lists.w3.org/Archives/Public/www-style/2012Jan/0936.html>

This changes the behavior of currentColor and Transitions.
Previously, if you had a set up like:

p {
  color: red;
  border-color: currentColor;
  transition: 1s border-color;
}
p:hover {
  color: blue;
}

...you would transition the border-color when you hover the element,
since at computed-value time (the point that transitions look at) it
was "red" or "blue", not "currentColor".

With this change, though, this would no longer occur, since the
border-color's computed value would be "currentColor" regardless.

Is this acceptable?  Or should we make an exception for currentColor
and transition it?  Conceptually, currentColor is still a
computed-time value - it doesn't require any layout information to
figure out.  We're only moving it to used-time so that it has better
inheritance behavior in some situations.

~TJ

Received on Monday, 30 April 2012 19:38:04 UTC