Comments on HTML5 Image Description Extension (longdesc)

While Igalia shares many of the concerns raised by Apple [1] and has
similar doubts about the benefits of longdesc, we will not formally
object to advancing the HTML Image Description document along the REC
track. However, if longdesc does continue to advance, we have a number
of concerns, many of which I identified whilst implementing support for
longdesc in the Orca screen reader for GNU/Linux desktop environments.
Below please find text Igalia would like you to consider incorporating
into the specification.

=====================================
Proposed Additions to "3.0.2 Authors"
=====================================

*  Authors MUST NOT rely solely on longdesc as the means to provide
   access to information which is essential for the user.

*  When the description is part of the target document, authors SHOULD
   NOT rely upon assistive technologies to constrain presentation of the
   description to that fragment. If such restriction is essential,
   authors MUST take additional means to mark surrounding content as
   hidden.

=======================================
Proposed Changes to "3.0.3 User Agents"
=======================================

Current:

    If the longdesc value is valid, User agents must make the link
    available to all users through the regular user interface(s).

Issue:

    One way to achieve the above is via the right-click menu. Firefox
    does this. It works well for sighted users who can use a mouse.
    It works well with the Orca screen reader which makes it possible
    for the user to move to the image and then synthesize a right
    click. But the image with a longdesc is likely not going to be
    focusable, so keyboard-only users cannot navigate to it, which
    is necessary prior to bringing up the context menu via the keyboard.

Proposed modification to the above:

    ... including users who cannot use a mouse and do not use any
    assistive technologies.

Other additions:

    If the longdesc value is valid, user agents MUST make activation
    of the link possible via the platform's accessible action interface
    on platforms where such an interface is present.

    When the description is only part of the target document, user
    agents MUST provide a means to return to the image being described
    via the platform's accessibility API.

============

Thank you in advance for your time and consideration of these issues.
--Joanmarie Diggs and Alejandro Piņeiro


[1] http://lists.w3.org/Archives/Public/public-html-admin/2014Aug/0028.html

Received on Thursday, 21 August 2014 15:13:59 UTC