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Re: another example of HTMl 5 canvas with interactive UI elements.

From: Joshue O Connor <joshue.oconnor@cfit.ie>
Date: Fri, 10 Jul 2009 08:14:30 +0100
Message-ID: <4A56EA56.6050904@cfit.ie>
To: Lachlan Hunt <lachlan.hunt@lachy.id.au>
Cc: Steven Faulkner <faulkner.steve@gmail.com>, HTMLWG WG <public-html@w3.org>, W3C WAI-XTECH <wai-xtech@w3.org>
Lachlan Hunt wrote:
> Joshue O Connor wrote:
>> This kind of thing seems to me a ridiculous level of complexity and a
>> retrograde step in web development.
> Rather than simply rejecting the idea outright, could you elaborate on
> specifically what was wrong with the techniques I described? 

Its clever, in that - yes it /could/ work and fair play for you having
the smarts for coming up with it. However, its just (and no slight on
you) very complicated. In particular if you look at this through the
lens of an author who would have to do the /extra/ steps you describe to
make stuff accessible. They just won't bother. When a declarative markup
language is used it has inherent properties that are recognised by AT.
<canvas> etc is just a drawing API with no such properties - any
solution will be a hack really.

>Or, better
> yet, could you suggest a simpler approach that provides for such a wide
> range of accessibility issues, including keybaord navigation and various
> forms of assistive technoloy, while still working seamlessly alongside
> the existing mouse based interaction and providing a reasonable level of
> backwards compatibility?

Yes, the WG could strongly advocate the use of <canvas> for nothing
other than eye candy or pretty pictures. In fact the spec already pretty
much states that it shouldn't be used when there is a better solution -
not that many will listen as the genie is already out.

> Ignoring the fact that this particular example is, as Maciej pointed
> out, probably better implemented using alternative techniques that don't
> involve canvas, the challenge I attempted to address was to make that
> particular use of canvas accessible in a way that retained the same
> functionality and support for the existing user interaction, using a
> backwards compatible technique that could conceivably be applied to
> other interactive uses of canvas as well.  If there is something else
> that can achieve this, I would be very interested to know what.

And me. So keep coming up with them!


Received on Friday, 10 July 2009 07:15:22 UTC

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