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RE: HTML 5 Canvas Accessibility Call on January 10

From: Richard Schwerdtfeger <schwer@us.ibm.com>
Date: Fri, 14 Jan 2011 11:37:03 -0600
To: Frank Olivier <Frank.Olivier@microsoft.com>
Cc: "chuck@jumis.com" <chuck@jumis.com>, Cynthia Shelly <cyns@microsoft.com>, "david.bolter@gmail.com" <david.bolter@gmail.com>, "janina@rednote.net" <janina@rednote.net>, "oedipus@hicom.net" <oedipus@hicom.net>, "public-canvas-api@w3.org" <public-canvas-api@w3.org>, public-canvas-api-request@w3.org, "public-html-a11y@w3.org" <public-html-a11y@w3.org>, Shawn Warren <swarren@aisquared.com>, Tim Lalor <tlalor@aisquared.com>
Message-ID: <OF2B8F6505.2D883F13-ON86257818.005CD091-86257818.0060C701@us.ibm.com>

I think the IE team needs to look at the following:

GTK client on HTML5 canvas:

noVNC - VNC client using HTML5 Canvas:

A colleague of mine, Artur Ortega from Yahoo, was kind enough to point me
to these implementations of canvas. As I said, time and again, now that
canvas has been been put into HTML we are going to find rich applications
making extensive use of it and not basic HTML. With canvas HTML 5 has given
the developer the keys to the store. I have seen a general trend by people
in WhatWG (just going to lay it out there) that by inhibiting the efforts
to make things like rich text editing and canvas (in the broader sense)
accessible that this is going to somehow stop developers from doing things
that they would prefer only be done in straight HTML. In fact, Chuck, told
us on the last call that Google was working on an IME for canvas. I have
been working in accessibility for over 20 years and work in Emerging
Technologies at IBM and accessibility has never been an inhibitor in people
pushing the envelope. In fact, if we do not address this we may put
accessibility back to where it was prior to Windows 3.0.

I will say that the web standards community took a similar approach to
JavaScript. In the early examples JavaScript was used for neat little
advertisements on web pages. So, because people did not know how to solve
the problem and there were not enough use cases for it at the time web
accessibility basically degraded to say "if you use it you must provide an
alternative as it is inaccessible". All the example I have been pointed to
as the reasons for not addressing canvas accessibility are much like these
advertisements. That led to new legislation that took years to extract. We
did that using ARIA.

All the reall applications like those linked to above and Bespin that have
proven to actually provide use to people we are being asked to ignore. Now
this may mean we need to create an accessibility API for the web which we
can do and I have heard people from Microsoft and Mozilla in favor of that
but let's go through the engineering process to get this right.

I can't make the browser vendors address accessibility for canvas but we
have an AT vendor here willing to work with us on this problem. I would ask
that we get our first proposals through and move forward on RTE and these
other use cases.

Rich Schwerdtfeger
CTO Accessibility Software Group

From:	Frank Olivier <Frank.Olivier@microsoft.com>
To:	Richard Schwerdtfeger/Austin/IBM@IBMUS, Shawn Warren
            <swarren@aisquared.com>, Tim Lalor <tlalor@aisquared.com>
Cc:	"chuck@jumis.com" <chuck@jumis.com>, "janina@rednote.net"
            <janina@rednote.net>, "public-canvas-api@w3.org"
            <public-canvas-api@w3.org>, "david.bolter@gmail.com"
            <david.bolter@gmail.com>, Cynthia Shelly <cyns@microsoft.com>,
            "public-html-a11y@w3.org" <public-html-a11y@w3.org>,
            "oedipus@hicom.net" <oedipus@hicom.net>
Date:	01/10/2011 09:18 AM
Subject:	RE: HTML 5 Canvas Accessibility Call on January 10
Sent by:	public-canvas-api-request@w3.org

My apologies; I won’t be able to attend the meeting on Monday (Traveling)

At this point, the IE team does not think that text editing via canvas is a
problem that we should tackle for HTML5 due to the inherent complexities of
the problem and limited options to solve this correctly. The best solution
for HTML5 (via tooling, education, author guidance) is to not fake text
entry via canvas elements – much better native mechanisms for text editing
already exist in HTML5.


From: Richard Schwerdtfeger [mailto:schwer@us.ibm.com]
Sent: Friday, January 07, 2011 7:36 PM
To: Shawn Warren; Tim Lalor
Cc: chuck@jumis.com; janina@rednote.net; public-canvas-api@w3.org; Frank
Olivier; david.bolter@gmail.com; Cynthia Shelly; public-html-a11y@w3.org;
Subject: RE: HTML 5 Canvas Accessibility Call on January 10

Shawn, Tim,

That is excellent. We are pleased AI Squared is able to attend the call.

The call-in information and agenda are here:


You will note that we also run an IRC channel where people will be taking
minutes. You can use use the free chatzilla plug-in to Firefox to

The W3C IRC server is:


The chat room is #html-a11y

As an FYI you will see at the bottom of the page above an attached file
called canvaseditor.html This file shows how we are using a shadow DOM to
populate platform accessibility APIs for user drawn check boxes. A problem
is the lack of accurate positioning information. Some of which is addressed
in the change proposal (caret and focus ring) to the Canvas 2D Context API
calls. The proposed changes to the Canvas 2D API specification are marked
between <zzz> and </zzz> sections. Currently the DOM Accessibility API
mapping of the shadow DOM (this is all the elements that are children of
the <canvas> element in HTML) only is done in Beta versions of the IE 9
browser. The shadow DOM is also participates in the keyboard navigation of
HTML in the IE 9 implementation.

Frank and David it will be very helpful if you are able to attend the call
on Monday.

Best Regards,

Rich Schwerdtfeger
CTO Accessibility Software Group

Inactive hide details for "Shawn Warren" ---01/07/2011 10:57:26 AM---Well I
don't know much...about a lot of things really ;).."Shawn Warren"
---01/07/2011 10:57:26 AM---Well I don't know much...about a lot of things
really ;)...but I usually do know who to ask. I secur

From: "Shawn Warren" <swarren@aisquared.com>
To: Richard Schwerdtfeger/Austin/IBM@IBMUS
Cc: <janina@rednote.net>, <chuck@jumis.com>, <public-canvas-api@w3.org>,
"Tim Lalor" <tlalor@aisquared.com>
Date: 01/07/2011 10:57 AM
Subject: RE: Canvas Accessibility

Well I don’t know much…about a lot of things really ;)…but I usually do
know who to ask. I secured time from a senior engineer, Tim Lalor (CC), for
your next Monday meeting (1/10).


From: Richard Schwerdtfeger [mailto:schwer@us.ibm.com]
Sent: Thursday, January 06, 2011 7:48 PM
To: Shawn Warren
Cc: janina@rednote.net; chuck@jumis.com; public-canvas-api@w3.org
Subject: Canvas Accessibility

Hi Shawn,

I am not sure how much you know about HTML 5 <canvas> but requiring authors
to provide positioning information for all the content found in canvas is a
very expensive proposition. I am not sure we are going to be able to get
that to fly with authors. Would you be willing to discuss options on how we
can get you what you need for a Monday HTML Canvas Accessibility Meeting?

This is response to your email response to my question in December:

The canvas accessibility meeting runs at 2pm CST on Mondays for an hour.

Best Regards,


Rich Schwerdtfeger
CTO Accessibility Software Group

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Received on Friday, 14 January 2011 17:39:22 UTC

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