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Re: hit testing and retained graphics

From: Charles Pritchard <chuck@jumis.com>
Date: Sat, 18 Jun 2011 11:26:48 -0700
Message-ID: <4DFCEDE8.9090002@jumis.com>
To: Richard Schwerdtfeger <schwer@us.ibm.com>
CC: franko@microsoft.com, Mike@w3.org, david.bolter@gmail.com, cyns@exchange.microsoft.com, public-canvas-api@w3.org, public-html-a11y@w3.org, public-html@w3.org
Rich,

I've looked at supporting SVG in the Canvas shadow DOM.
Unfortunately, SVG and HTML forms are not tightly integrated.

These two markup examples were seen as undesirable by SVG developers:
Example 1:
<svg><path d="M...z" aria-owns="input" /><foreignObject 
id="input"><input /></foreignObject></svg>
Example 2:
<input aria-path="M...z" />

There are three audiences for this API:
1. Canvas developers -want- an API for managed mouse events.
2. Existing accessibility APIs, mainly, -need- a means to run 
ObjectFromPoint. They -may- want a list of bounding rectangles as well.
3. Some AT devices -need- path information for all interactive objects.

I've tried to find an acceptable solution for vendors, svg developers 
and canvas developers.
No luck so far.

-Charles

On 6/17/2011 11:41 AM, Richard Schwerdtfeger wrote:
>
> Charles, Frank, Mike,
>
> I am back from vacation. How far do we need to go with hit testing? 
> Right now I am looking at associating a closed draw path with a DOM 
> object in the canvas subtree. We would then need to address the 
> routing of pointing device input events to the DOM object. The drawing 
> path can be used to provide bound information to platform 
> accessibility API.
>
> Do we need to bind any other drawing properties to the canvas object - 
> similar to the way device context's are handled on graphic subsystems 
> like Windows?
>
> Mike, I am including you as before I went on vacation you indicated 
> that a number of developers desired this feature and wanted to be 
> involved.
>
> Rich
>
>
> Rich Schwerdtfeger
> CTO Accessibility Software Group
>
Received on Saturday, 18 June 2011 18:27:46 GMT

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