Flexbox Tab Order for Keyboard Users Proposal

The following proposal is a result of meetings between Scientific American,
Mozilla, and IBM.

For the keyboard user, the suggestion is to have the experience be
consistent with the visual layout created using the Flexbox order rather
than sticking with the DOM order. Coincidentally, this is the current
default behavior of Firefox though it is listed as a bug.

Current wording:

The order property does not affect ordering in non-visual media (such as
speech). Likewise, order 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 order only for
visual, not logical, reordering of content; style sheets that use order to
perform logical reordering are non-conforming.


This is so that non-visual media and non-CSS UAs, which typically present
content linearly, can rely on a logical source order, while order is used
to tailor the visual order. (Since visual perception is two-dimensional and
non-linear, the desired visual order is not always logical.)

Suggested wording:

The order property does not affect ordering in non-visual media (such as
speech). However, order does affect the default traversal order of
sequential navigation modes (such as cycling through links, see e.g.
nav-index [CSS3UI] or tabindex [HTML40]).


Consequently, the suggestion for the screen reader is to inform the
accessibility tree so that mouse, keyboard, and screen reader users all get
the same experience.


Regards,
Bo



Bo J Campbell | +1-805-453-0028 | bcampbell@us.ibm.com
Accessibility & User Experience Consultant | IBM Accessibiity | IBM
Research