- From: Bert Bos <bert@w3.org>
- Date: Tue, 29 Nov 2011 20:24:27 +0100
- To: www-style@w3.org, List WAI Liaison <wai-liaison@w3.org>
Hello Michael and others, I was checking if the CSS Template Layout module was ready for our webmaster and suddenly saw that I still had two very old messages in my mailbox that I apparently planned to answer but never did. I'm very sorry. :-( It's too late for today's publication, but luckily it is only a WD; there will be another version later. Meanwhile, I put some text in the editor's draft. This was your comment: On Wednesday 16 June 2010 21:10:50 Michael Cooper wrote: > The following is comment one of two from the Protocols and Formats > Working Group on the CSS Template Layout Module draft of 29 April > 2010 <http://www.w3.org/TR/2010/WD-css3-layout-20100429/>. Approval > to send this as formal WG comments is recorded at > http://www.w3.org/2010/06/16-pf-minutes.html#item08. Thanks to Léonie > Watson for preparing these comments. > > Current CSS techniques make it possible to separate the visual > presentation of a page from the source order. This can have both > positive and negative connotations for accessibility, and the CSS3 > template layout module increases the potential for both. > > The attached zip file contains a page with three examples: > > 1. Content priority source order, where the source order is content, > related content, navigation. > 2. Visual priority source order, where the source order is > navigation, content, related content. > 3. Complete mess source order, where the source order is related > content, navigation, content. > > In each case, the visual presentation follows a typical layout for > sighted users. Navigation on the left, content in the middle, and > related content on the right. > > Examples 1 and 3 use a source order that differs from the visual > presentation. This causes the tab order through the page to jump > around, particularly in example 3. Sighted people who only use a > keyboard may find this movement confusing. > > On the other hand, example 1 uses a source order that is helpful to > screen reader users. The content is placed first in the source order, > without disrupting the visual presentation. > > This isn't a new conundrum, but we're in a good position to encourage > best practice for accessibility amongst developers. We'd suggest > adding a short informative section to the template layout module > that references the following WCAG 2.0 success criteria: > > 1.3.2 Meaningful Sequence: When the sequence in which content is > presented affects its meaning, a correct reading sequence can be > programmatically determined. (Level A) > 2.4.3 Focus Order: If a Web page can be navigated sequentially and > the navigation sequences affect meaning or operation, focusable > components receive focus in an order that preserves meaning and > operability. (Level A) [Attachment omitted] Maybe you want to check the text that I wrote to see if I understood the point correctly? See http://dev.w3.org/csswg/css3-layout/#accessibility Bert -- Bert Bos ( W 3 C ) http://www.w3.org/ http://www.w3.org/people/bos W3C/ERCIM bert@w3.org 2004 Rt des Lucioles / BP 93 +33 (0)4 92 38 76 92 06902 Sophia Antipolis Cedex, France
Received on Tuesday, 29 November 2011 19:24:56 UTC