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Re: canvas example

From: Jonathan Mcdougall <jonathanmcdougall@gmail.com>
Date: Thu, 22 Dec 2011 19:00:17 -0500
Message-ID: <CAP_q9LxEKeRLOJLFSY2u5ujs7rt52e4sraAYGD0TN21DCyPbPw@mail.gmail.com>
To: Charles Pritchard <chuck@jumis.com>
Cc: public-canvas-api@w3.org
On Thu, Dec 22, 2011 at 6:00 PM, Charles Pritchard <chuck@jumis.com>
> On 12/22/11 2:44 PM, Jonathan Mcdougall wrote:
>> On Thu, Dec 22, 2011 at 2:32 PM, Charles Pritchard<chuck@jumis.com>
>> wrote:
>>> So for example, with your application, it makes the most sense to
>>> have a combobox look like: <canvas role="combobox" tabindex="0"
>>> aria-label="select an item"></canvas>
>> Although every control can live in its own<canvas>, I never thought
>> of using it this way. I was expecting the various controls to be
>> part of a larger canvas. One of the difficulties is with floating
>> elements such as menus or comboboxes, where the canvas needs to
>> extend past the bounds of the control while in a normal state,
>> giving trouble with the flow around it.
> This is a place where ARIA markup is a big help. You might have
> aria-haspopup in addition to role="combobox", and create another
> canvas layer for that popup.

True, but aria has nothing to do with it. I don't like using any kind
of device that breaks or interferes with the normal flow of a page and
wouldn't agree that a combobox implemented as one or more layers of
<canvas> is good idea. Although I'm not sure if that's what you're

>> I'm also not sure what we're talking about here. I'm reading on
>> this mailing list about how <canvas> shouldn't be used to replace
>> native controls (which I mostly agree with), but you seem to
>> suggest otherwise.
> ARIA was designed in response to developers creating form controls
> by using <div>, <ul> and the like. The same applies for Canvas.
> [...]
> There is no <spreadsheet> tag, in HTML, for instance. So we have to
> glue a bunch of primitives together.  ARIA is the language of those
> low level primitives.

Okay, are we talking about aria or <canvas>? I was not prepared to
discuss accessibility concerns and I don't know much about aria,
except that it is metadata about semantics. Honestly, this is not a
subject that interests me much, unfortunately.

I jumped into this discussion without reading old threads, although I
did look at the ones from October to December. I have never
contributed or read the w3c mailing lists, so I apologize if this is
an ongoing discussion about aria, which would make me off-topic here.

Concerning <spreadsheet>, I'm not sure whether you are suggesting that
implementing one in a canvas would be better than using html elements.
If you are, then I disagree. Canvas ignores any kind of user settings
about colors, fonts, themes or images. Using it for graphical
applications works fine, but not for office applications.

But again, you might be talking about aria, in which case, I'm not
sure what to respond.

> For what it's worth, I also agree with section Best
> Practices as published by the WHATWG.

I don't. Most of it is feasible (some is implemented on canui, more
would be if I had the interest), some is candy (spell checking) and
a few are currently impossible (ime, d&d, etc.) None of them is a
show-stopper though, as long as the goal is not to reproduce native

All of these caveats also apply to games running on the desktop that
don't use the windowing system's native controls, but it never stopped
games from being made.

Jonathan McDougall
Received on Friday, 23 December 2011 00:01:13 UTC

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