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Re: hit testing and retained graphics

From: Edward O'Connor <eoconnor@apple.com>
Date: Fri, 24 Jun 2011 11:18:18 -0700
To: public-html@w3.org
Cc: public-canvas-api@w3.org, public-html-a11y@w3.org
Message-id: <m239iz2ivp.fsf@eoconnor.apple.com>

I've talked with several WebKit engineers here at Apple, including those
who invented <canvas>, and the consensus is that adding retained-mode
features to the Canvas API is not something we're interested in.

The Canvas API is an immediate-mode graphics API. Essentially, it's a
programmable <img>. If you want to do hit testing you have to implement
it yourself, by tracking what you draw. Grafting random pieces of a
retained-mode API into it is bad design. Like folk from Google[1] and
Microsoft[2] have pointed out, the Web's retained-mode graphics feature
is SVG.

> I have a very large IBM application in development and given the state
> of SVG accessibility and how the application is constructed it is not
> a good fit.

If there are accessibility problems with SVG, we should let the SVG WG
know about the problems so that they can be fixed. If existing SVG
implementations aren't performant enough for your use cases, please file
bugs on those implementations.


1. http://lists.w3.org/Archives/Public/public-html/2011Jun/0339.html
2. http://lists.w3.org/Archives/Public/public-html/2011Jun/0351.html
Received on Friday, 24 June 2011 18:18:57 UTC

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