Percentage offsets for relatively positioned elements in auto-height containers (was Re: [CSSWG] Minutes and Resolutions 2009-08-05)

On Wednesday 2009-08-05 11:06 -0700, fantasai wrote:
>   - RESOLVED: CSS2.1 Issue 134 (percentage offsets for relpos in
>               auto-height containers) closed No Change.
>       http://wiki.csswg.org/spec/css2.1#issue-134

Just for the record (since I couldn't really remember the deal with
this while we were discussing it), implementing this resolution
(i.e., leaving the spec changed for relatively positioned elements
as well) isn't trivial.

It basically requires that relative positioning, or at least this
case of it, happen in an additional pass after an element computes
the positions and sizes of all its children (which is needed to
compute its own content-box height).  (However, for elements with
'overflow' not 'visible', it needs to happen before computing the
scrollable area, and thus before computing its own border-box size.)

The Mozilla bug on the topic is
https://bugzilla.mozilla.org/show_bug.cgi?id=391528

-David

-- 
L. David Baron                                 http://dbaron.org/
Mozilla Corporation                       http://www.mozilla.com/

Received on Wednesday, 5 August 2009 22:06:28 UTC