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Re: Transforms and z-index (Was: [CSSWG] Minutes and Resolutions 2011-04-20)

From: Alan Gresley <alan@css-class.com>
Date: Sat, 23 Apr 2011 00:35:49 +1000
Message-ID: <4DB19245.7020803@css-class.com>
To: Boris Zbarsky <bzbarsky@MIT.EDU>
CC: www-style@w3.org, Simon Fraser <smfr@me.com>
On 22/04/2011 2:07 PM, Alan Gresley wrote:

> It is correct that transforms behave like opacity. I can confirm that
> all browsers currently layer a transformed element as if it had
> 'position: relative' and 'z-index: 1'.

I'm wrong. That is z-index: 0.

> This means that these transformed
> elements behave as if they have been positioned and have established a
> 'new stacking context'.

I'm wrong. It's in the current stacking context. A new test.

http://css-class.com/test/css/3/transform/transform-z-index.htm


I get what you mean in your other email now. A statically positioned 
transformed element is statically positioned but for any positioned 
child elements, it is as if it was relatively positioned (creates a new 
containing block). The only affect of giving a transformed element 
position: relative is for it's own offset.

This also means that transform has a special type of behavior since you 
can not reset it's position to static and unlike opacity, it changes 
layers with different z-index.



-- 
Alan Gresley
http://css-3d.org/
http://css-class.com/
Received on Friday, 22 April 2011 14:36:18 GMT

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