Re: [css-regions] Comments

On Mar 9, 2011, at 9:58 PM, Robert O'Callahan wrote:

> On Thu, Mar 10, 2011 at 12:30 PM, Jacob Refstrup <jrefstrup@apple.com> wrote:
> When an box is determining it's text-wrap path it will use it's interior wrap path but also consider any exterior wrap path for boxes that are in front of it in Z-order (within the current stacking context).
> 
> Currently in CSS z-order does not affect layout, and in Gecko we don't determine z-order until paint time, so I would prefer not to see any new requirement that z-order affect layout. Maybe you could use document order instead?

We were attempting to avoid introducing new properties for stacking and ordering, but if z-index can't be used, it may be unavoidable.

There are two features that we wanted to support here.  The first is the ability to choke the propagation of the exterior wrap paths outwards.  We had the thought that using stacking contexts might be a convenient way to do this.  The second feature was an easy way of determining whether you are affected by an exterior wrap.  We thought z-order would be convenient.

I do think document order might be an acceptable solution, but we'd still need a solution for not propagating wraps out through ancestors.  This could be done with a new CSS property if stacking contexts are not considered acceptable, but I'd love to have a heuristic for doing this (in the same way we just have default rules for margins propagating out for collapse).  We might be able to do something simple like state that if you have any normal flow content that exterior wrap paths don't propagate outwards.  This allows positioned images with wraps to be grouped inside another positioned containing block while still propagating the wraps outwards.

dave
(hyatt@apple.com)