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Re: Thoughts towards an accessible <canvas>

From: Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com>
Date: Mon, 23 Mar 2009 19:43:20 +0000
Message-ID: <49C7E658.40906@googlemail.com>
To: joshue.oconnor@cfit.ie
CC: "John Foliot - WATS.ca" <foliot@wats.ca>, joshue.oconnor@ncbi.ie, mjs@apple.com, Henri Sivonen <hsivonen@iki.fi>, 'Charles McCathieNevile' <chaals@opera.com>, 'Wai-Ig' <w3c-wai-ig@w3.org>, wai-xtech@w3.org, 'HTMLWG' <public-html@w3.org>
On 23/3/09 12:56, Joshue O Connor wrote:
> whatever the accessibility
> solution is , it should support where possible, the existing ways that
> users interact with web content such as being able to give focus to HTML
> items using UA keystrokes etc, so the /new/ solution isn't such a huge
> departure from how existing content is navigated and understood.
>
>In short, I am concerned about the
> maintaining the consistency of interaction models that the AT user has
> to deal with, as one platform may render or present content differently
> to the end user from another.

I agree this is a worrying problem, which I guess boils down to the fact 
that an effective graphical user interface is not just a "scripted 
image" (http://tinyurl.com/c9onzg).

I can see how a nested DOM tree could provide access to effectively 
blind users interacting with speech or braille. It's less obvious what 
this implies for people who typically interact with visible controls, 
e.g. people with motor disabilities using switch access, people with bad 
eyesight using screen magnification, people with reading difficulties 
using text-to-speech, people who use symbol browsers that convert 
on-screen text to symbols, people who speak the names of controls into 
speech recognition programs, people with colorblindness who want to 
customise interface colors, people with learning disabilities - or, um, 
ordinary users for that matter, who will struggle to learn interface 
patterns that diverge from platform or web norms.

Maybe the answer is that the nested tree should cater to these users too 
and the browser should offer an easy way to disable "canvas" 
specifically in favour of that DOM tree. Alternatively, efforts like 
http://dev.aol.com/dhtml_style_guide may help somewhat in terms of 
enforcing consistency between apps.

--
Benjamin Hawkes-Lewis
Received on Monday, 23 March 2009 19:44:06 GMT

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