[css-regions] Add " Reordering and Accessibility" section just like Flexbox

Hi all,

I would like to propose adding "Reordering and Accessibility" section to
CSS Regions spec.

CSS Regions Module Level 1
http://dev.w3.org/csswg/css-regions/

As CSS Regions just controls visual order (flow), the semantics of content
should not be changed.
Especially, the order of content should not be changed by CSS Regions,
as many web developers expect "separate structure and presentation".

However, current Blink implementation of CSS Regions changes order of
accessibility tree objects by CSS Regions. Accessibility tree objects are
exposed assistive technologies such as screen readers though Accessibility APIs.

Yet the Blink's bug is not the spec's bug, I believe the spec should mention
relationship of reordering content and accessibility to avoid similar bugs
in other UAs and incorrect use of CSS Regions.

The Flexbox spec has "Reordering and Accessibility" section and I think we can
reuse this section like:

> The CSS Regions does not affect ordering in non-visual media (such as speech).
> Likewise, CSS Regions does not affect the default traversal order of
> sequential navigation modes (such as cycling through links, see e.g.
> ‘nav-index’ [CSS3UI] or tabindex [HTML40]). Authors must use CSS Regions only
> for visual, not logical, reordering of content; style sheets that use CSS
> Regions to perform logical reordering are non-conforming.

5.4.1. Reordering and Accessibility
http://www.w3.org/TR/css3-flexbox/#order-accessibility

FYI. I reported this issue on Chromium Issue Tracker.

Issue 293023: Order of Accessibility Objects is broken by CSS Regions
http://code.google.com/p/chromium/issues/detail?id=293023

Wishes,

Takeshi
-- 
Takeshi Kurosawa <taken.spc@gmail.com>

Received on Sunday, 27 October 2013 08:55:58 UTC