W3C home > Mailing lists > Public > www-style@w3.org > January 2008

Re: CSS2.1: computed value of z-index

From: Robert O'Callahan <robert@ocallahan.org>
Date: Thu, 3 Jan 2008 11:31:58 +1300
Message-ID: <11e306600801021431g54697e1av8a09e395d58ea4bb@mail.gmail.com>
To: "Maciej Stachowiak" <mjs@apple.com>
Cc: www-style@w3.org
On Jan 3, 2008 9:54 AM, Maciej Stachowiak <mjs@apple.com> wrote:

> http://www.w3.org/TR/CSS21/visuren.html#z-index
>
> z-index only applies to positioned elements, however, its computed
> value is "as specified". Since the computed value can be exposed to
> script via getComputedStyle(), I suggest that it would be more useful
> if the computed value is "as specified for positioned elements,
> otherwise auto" so that scripts get the value actually used.


Sounds reasonable.


> [Side note: the spec also says "In future levels of CSS, other
> properties may introduce stacking contexts, for example 'opacity'."
> Does that mean z-index should apply to non-positioned elements
> affected by such properties? Hyatt tells me this is already an open
> question for CSS3.]
>

Why don't we just make z-index applicable to everything, with a non-auto
z-index inducing a stacking context? That would be really easy for us to
implement. Right now we actually have to have code to explicitly disable
z-index for non-positioned elements.

I guess there could be compatibility issues, but who would add z-index to
non-positioned elements where they expect it to be ignored?

Rob
-- 
"He was pierced for our transgressions, he was crushed for our iniquities;
the punishment that brought us peace was upon him, and by his wounds we are
healed. We all, like sheep, have gone astray, each of us has turned to his
own way; and the LORD has laid on him the iniquity of us all." [Isaiah
53:5-6]
Received on Wednesday, 2 January 2008 22:32:03 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 27 April 2009 13:54:57 GMT