Re: Final changes to Hit Regions before return to Last Call

Jay, we also agreed to add a note RE: our approach to MouseEvents, so I will be
sending you some draft text for that.

Mark

On 4/17/14, 12:47 PM, Jay Munro wrote:
> Thanks. Do you have a link to the build you’re looking at, as my source has no
> set of pixels at the beginning of the section.
> 
> I’m working on the source from html5_canvas_CR in github.
> 
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> 
> *From:*Rik Cabanier [mailto:cabanier@gmail.com]
> *Sent:* Thursday, April 17, 2014 8:36 AM
> *To:* Jay Munro
> *Cc:* Mark Sadecki; public-canvas-api@w3.org
> *Subject:* Re: Final changes to Hit Regions before return to Last Call
> 
>  
> 
> Hi Jay,
> 
>  
> 
> 1. "set of pixels" is still in the spec. It needs to refer to the path in the
> beginning of the section
> 
> 2. the steps for addHitRegion don't cover what should happen if there is no
> control or ID. We need an extra step that checks this and throws an exception
> 
>  
> 
> Rik
> 
>  
> 
> On Wed, Apr 16, 2014 at 11:38 AM, Jay Munro <jaymunro@microsoft.com
> <mailto:jaymunro@microsoft.com>> wrote:
> 
> Mark,
> 
> Sanity check before I submit changes.
> 
> --Jay
> 
> 
> -----Original Message-----
> From: Mark Sadecki [mailto:mark@w3.org <mailto:mark@w3.org>]
> Sent: Tuesday, April 15, 2014 12:54 PM
> To: public-canvas-api@w3.org <mailto:public-canvas-api@w3.org>; Jay Munro
> Subject: Final changes to Hit Regions before return to Last Call
> 
> The following changes were discussed during the canvas accessibility sub group
> call on 14 APR 2014
> 
> <http://www.w3.org/2014/04/14-html-a11y-minutes.html>
> 
> ## The region representing the control
> 
> * Add a step that handles a null value for control, similar to the one that is
> defined for ID, just before the existing step 1.
> 
>> "If control is null, return nothing and abort these steps."
> 
> ## The region for a pixel
> 
> * Change "set of pixels" to "path" in step 2 and link "path" to
> <http://www.w3.org/html/wg/drafts/2dcontext/html5_canvas_CR/#hit-region%27s-path>
> 
> ## addHitRegion()
> 
> * add the following step after step 3 (Let specified pixels be the pixels
> contained in source path.)
> 
>> "Remove from specified pixels any pixels not contained within the
>> clipping
> region."
> 
> ## clearHitRegions()
> 
> * Remove Step 2 RE: Garbage Collection
> 
> ## MouseEvent
> 
> We agreed that we would eliminate event retargeting altogether and just pass the
> event.region to the canvas element.  This would require the following changes:
> 
> * Revert order of steps and add step for handling a canvas element with no hit
> region list.  The first 4 steps should read as follows:
> 
>    1. If the pointing device is not indicating a pixel on the canvas, act as
> normal and abort these steps.
> -> 2. If the canvas element has no hit region list, act as normal and
> 
> -> abort
> 
> these steps.
>    3. Let pixel be the pixel indicated by the pointing device.
>    4. Let region be the hit region that is the region for the pixel pixel on
> this canvas element's bitmap, if any.
> 
> * The following steps are no longer required (the numbers will be shifted by one
> if the above steps have been followed) and should be removed:
> 
> 7. Let control be the region's control, if any.
> 8. Let the canvas element be the target of the event object, unless there is a
> control, then target the control instead.
> 9. Continue dispatching the event, but with the updated event object and target
> as given in the above steps.
> 
> --
> Mark Sadecki
> Web Accessibility Engineer
> World Wide Web Consortium, Web Accessibility Initiative
> Telephone: +1.617.715.4017 <tel:%2B1.617.715.4017>
> Email: mark@w3.org <mailto:mark@w3.org>
> Web: http://w3.org/People/mark
> 
>  
> 


-- 
Mark Sadecki
Web Accessibility Engineer
World Wide Web Consortium, Web Accessibility Initiative
Telephone: +1.617.715.4017
Email: mark@w3.org
Web: http://w3.org/People/mark

Received on Thursday, 17 April 2014 17:44:47 UTC