Re: [css-flexbox] Accessibility of Order

"Tab Atkins Jr." <jackalmage@gmail.com> wrote on 01/09/2015 05:01:38 PM:

> From: "Tab Atkins Jr." <jackalmage@gmail.com>
> To: Bo J Campbell/Los Angeles/IBM@IBMUS
> Cc: www-style list <www-style@w3.org>
> Date: 01/09/2015 05:03 PM
> Subject: Re: [css-flexbox] Accessibility of Order
>
> On Fri, Jan 9, 2015 at 4:12 PM, Bo J Campbell <bcampbell@us.ibm.com>
wrote:
> > I have added a general example of the reason why the tab order needs to
be
> > updated to match the visual order when it is changed via Flexbox Order.
In
> > turn, the accessibility API should also get the same visual flow.
> >
> > https://wiki.csswg.org/spec/css3-flexbox/accessibility
> >
> > I would like to continue understanding any further arguments stopping
this
> > proposal since PF is asking for this, IBM and Freedom Scientific agree
this
> > is what needs to happen, and I believe I have addressed the arguments
made
> > so far in the wiki document.
>
> Your examples are all trivial, and don't illustrate one of the primary
> use-cases for 'order', such as Example 7 in the spec, where the
> *intended behavior* is to put the main content first in the markup
> *precisely so that* it will show up first in tabbing order, and then
> visually arrange the sidebars relative to the main content in some
> arbitrary style-dependent way.
>
> We continue to bring this up as a counter-example every time, and it's
> somewhat frustrating to see it continually brushed aside in favor of
> trivial examples that don't provide compelling reasons to preserve
> source order.
>
> ~TJ
>

The "Holy Grail" layout is fine according to WCAG 1.3.2 as it almost
specifically talks about these sections of information. Since the order of
the sections is "meaningless" then the sections (boxes) can be arranged
however one likes. I would add here, though, that if the tab must start in
a particular place in those sections, that the author is giving the
sequence meaning. If the sequence does, in fact, have meaning, then it
should follow the WCAG traversal order.

What we are hearing and seeing from our developers is that Flexbox is an
extremely valuable, powerful tool but is currently very restricted in use
because the tab order easily breaks WCAG Meaningful Sequence rules, causing
their apps to be inaccessible.

They key for them would be to build a switch into CSS that allows the
author to tell the UA whether a particular Flexbox has a meaningful
sequence.

-Bo