Re: hit testing and retained graphics

On 7/1/2011 11:10 AM, Tab Atkins Jr. wrote:
> On Fri, Jul 1, 2011 at 7:41 AM, Charles McCathieNevile<chaals@opera.com>  wrote:
>> On Thu, 30 Jun 2011 03:16:18 +0200, Cameron McCormack<cam@mcc.id.au>
>> wrote:
>>> Matt May:
>>>> Flash uses retained-mode graphics.
>>> If Flash doesn’t support immediate mode graphics, then I’m not sure how
>>> it would be that the “Bespin/Skywriter canvas-as-UI problem … would have
Flash supports path objects which can be rendered in retained-mode, overlaid
as children in the object model, and/or composited onto a bitmap.

It very much supports the Canvas 2d API as it is written, and as it works
with CSS. I've checked, I've written it, it works just fine.

I've taken canvas based apps, I've run them in the browser as-is,
and then compiled them with the flex compiler, to have the run
on a flash implementation of Canvas 2d.

>> Demanding perfection is great if you only care about accessing what is
>> perfect, but history bears out the fact that people want the stuff that is
>>
>> The only way to do good accessibility is to sneak it in so that the
>> author accidentally makes things accessible while making it work well
>> for themself or their majority userbase.  It's almost impossible to do
Tab, this is very much the reason why Richard has proposed that Canvas 
handle
marshaling of pointer events into the subdom. We don't need event marshaling
to accomplish what we need to accomplish in populating the accessibility 
tree.

Richard asked me to go out and talk to canvas developers. I did.
They all want event marshaling. They do not have a particular attitude
about accessibility, but they all want to set  a  setElementPath(element)
method in canvas working with the subdom.

Richard and I need to see that for HTML5, so that subdom elements
have sufficient accessibility metadata for ATs.

How would you like me to mark that up, in the document I'm preparing?
Is it a "use case", or something else? Ian Hickson has called this 
methodology
a "stalking horse".

Am I wrong in my conclusion here? As I understand it, setElementPath 
precisely
fits the criteria you're describing.

And as far as things go, developers are all interested in having 
setElementPath,
drawFocusRing, and a subdom which responds to pointer and keyboard events.
Not because they're looking to support particular ATs, but because those 
methods
make things easier on them, to get the results they want to see in their 
work.


-Charles

Received on Friday, 1 July 2011 19:01:32 UTC