[css3-color] Re: Errata (was: Re: [CSSWG] Minutes and Resolutions 2011-07-06)

> <nimbu> http://lists.w3.org/Archives/Public/www-style/2011Jul/0025.html

Regarding Comment 3:

> ChrisL: Need to clarify 3.2 that 'treated' doesn't affect the computed value
> dbaron: I think his proposed wording isn't quite sufficient because
> "treated as though it has the index: 0" also has an effect on the
> painting level of descendents, which this doesn't mention

Well, that's precisely the issue. ;-)  What _does_ "treated" mean?  Is 
the sentence merely describing painting layer position (as assumed in my 
proposal) or is it describing something more (which would indeed affect 
descendants)?

> ChrisL: do you have better proposed wording?
> dbaron: I think what's there already might be OK
> smfr: What's there already is certainly better than his suggestion.

Really?  What's there already is vague and convoluted, whereas my 
suggestion uses the new language of CSS21 to express the same thing 
accurately and concisely (but, of course, it necessarily makes an 
assumption about what the spec is trying to say, an assumption which may 
or may not be correct).

> <dbaron> just change "except that 'auto' is treated" to "except that a
> computed value of 'auto' is treated" to make it clear that it
> doesn't change the computed value
> smfr: Maybe "behaves as if its z-index were zero"?
> fantasai: Could work. Subjunctive implies that it is not true.

How about:

   | If an element with opacity less than 1 is not positioned
   | then it is painted on the same layer, within its parent stacking
   | context, as positioned elements with stack level 0. Otherwise,
   | if its computed value of 'z-index' is auto then it behaves exactly
   | as if its actual value of 'z-index' were 0.

Are we *sure* that this behaviour — that child stacking contexts become 
the responsibility of this opacity-induced stacking context rather than 
the closest ancestor non–opacity-induced stacking context — is what we 
want though?

Either way, I believe the first sentence of my proposal to be better 
than the one in the spec!

Cheers,
Anton Prowse
http://dev.moonhenge.net

Received on Thursday, 7 July 2011 17:30:28 UTC