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Re: Please vote on the canvas accessibility proposal

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Wed, 24 Feb 2010 01:59:13 +1100
Message-ID: <2c0e02831002230659n3c92cad4w7c3e479d4b6b07a2@mail.gmail.com>
To: Steven Faulkner <faulkner.steve@gmail.com>
Cc: Frank Olivier <franko@microsoft.com>, Richard Schwerdtfeger <schwer@us.ibm.com>, Cynthia Shelly <cyns@exchange.microsoft.com>, Andi Snow-Weaver <andisnow@us.ibm.com>, "janina@rednote.net" <janina@rednote.net>, "jongund@uiuc.edu" <jongund@uiuc.edu>, "cooper@w3.org" <cooper@w3.org>, David Bolter <david.bolter@gmail.com>, "public-html-a11y@w3.org" <public-html-a11y@w3.org>
On Wed, Feb 24, 2010 at 12:41 AM, Steven Faulkner
<faulkner.steve@gmail.com> wrote:
> Hi Sylvia,
>>  - ATs will read content like 'please upgrade your browser' instead of
>> useful text.
>
>>Where does that come from? Wouldn't they just see the canvas element
>>and try to do something useful with it?
>
> This is an example of the sort of content  developers are already including
> inside the canvas element. I looked at www.canvasdemos.com I could not
> find ANY with fallback (most provided zero fallback) that would be useful
> for AT users:
>
>
> http://concentriclivers.com/slippymap.html
> <canvas id="map" width="500" height="500"  onmousedown="mouseDown(event);"
> onmousemove="mouseMove(event);"   onmouseup="mouseUp();"
> onmouseout="mouseOut();">Your  browser doesn't support canvas
> elements.</canvas>
> http://labs.jam3.ca/wp-content/uploads/2010/02/canvasVoxels.html
>
> <canvas id="myCanvas" width="100" height="100">
> 		Your browser does not support the canvas
> 	</canvas>
>       <audio src="houseofcards.mp3" autoplay="autoplay" loop="2000">
> 		Your browser does not support the audio element.
> 	</audio>  		
>
> http://www.snappymaria.com/canvas/FunctionPlotter.html
> <canvas onmouseout="releaseCanvas();" onmouseup="releaseCanvas();"
> onmousemove="slideCanvas(event);" onmousedown="clickCanvas(event);"
> height="480" width="640" id="mainCanvas">
> It looks like your browser does not support Canvas.
> Try FireFox, Chrome, Opera, or Safari instead.
> </canvas>
>
> regards
> stevef
>

OK, but that is fallback content for browsers who do not support the
elements at all. There is no need to create accessibility information
for data that the browser cannot display anyway. The text inside is
the same text for anyone running an old or unsupported browser and it
would be part of the normal text on a page, so read out by AT,
wouldn't it?

Regards,
Silvia.
Received on Tuesday, 23 February 2010 15:00:13 GMT

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