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Re: [css3-regions] regions forming stacking contexts

From: David Hyatt <hyatt@apple.com>
Date: Wed, 01 Feb 2012 16:46:06 -0600
Cc: Alex Mogilevsky <alexmog@microsoft.com>, "www-style@w3.org Style" <www-style@w3.org>
Message-id: <4F6CC361-58B0-47BB-9384-8590112E44CE@apple.com>
To: robert@ocallahan.org
It seems to me that the "region generator" should dictate how the regions are painted. In the case of explicitly specified regions that can be anywhere in the DOM tree, it seems preferable to simply have regions make stacking contexts and render separately as units.

However if the "region generator" (e.g., multi-column layout) acts as the container for all the regions that are generated, then obviously optimizations are possible, i.e., you know the regions are all together, direct children of the multi-column block, and so you can change the painting rules accordingly.

So basically I think the default behavior should be stacking contexts and if regions happen to be the implementation building block for other systems like multi-column, then those other systems can specify their own painting rules and behind the scenes we could still use regions and get the paint order that is desired by that particular generator.

dave
(hyatt@apple.com)

On Feb 1, 2012, at 3:48 PM, Robert O'Callahan wrote:

> On Wed, Feb 1, 2012 at 10:27 PM, Alex Mogilevsky <alexmog@microsoft.com> wrote:
> I probably don't know about opacity and filters...
> 
> Can you elaborate on what other things are not going to be possible with fragmented content? For example, if somebody wants to create 3d page turning effects (with transforms and shadows applied to pages separately), will it also be problematic for the reasons you are describing?
> 
> It might be possible to address the problem by somehow saying that each region renders an independent copy of the content flowed into the region. Then an element that's a stack context but split across regions would split into stacking contexts within each region. Or something like that.
> 
> Also, region formatting allows setting different background on same element in different regions. Is that also problematic if an element has to be rendered as a unit?
> 
> How's that? Are we allowing per-region styling of the flowed content now? That has all kinds of issues of its own :-).
> 
> Rob
> -- 
> "If we claim to be without sin, we deceive ourselves and the truth is not in us. If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness. If we claim we have not sinned, we make him out to be a liar and his word is not in us." [1 John 1:8-10]
Received on Wednesday, 1 February 2012 22:46:36 GMT

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