Re: hit testing and retained graphics

Hi Richard,

Yes I get your purpose,except one part :

* You control the drawing * ?!


in this sentence:
If you wanted to create a canvas rendering of a checkbox in the fallback
content, on the canvas that was 70X70 you can do it. You control the drawing

and some thing else if a developer doesn't use sub-tree in shadow DOM? what
does happen?


Thanks


On Thu, Jul 7, 2011 at 6:25 PM, Richard Schwerdtfeger <schwer@us.ibm.com>wrote:

> Hi Paniz,
>
> I am not sure if I am answering your question but you could create these
> objects on canvas and create equivalents in the canvas subtree whereby the
> canvas is a rendering of the HTML element in the canvas subtree and you can
> give it any size and dimension you want. All the elements in canvas subtree
> could be placed in the keyboard navigation order. If you wanted to create a
> canvas rendering of a checkbox in the fallback content, on the canvas that
> was 70X70 you can do it. You control the drawing. Accessibility wise I don't
> yet have a way to communicate those bounds to the accessibility API. This is
> what we have been discussing. We have been discussing creating a drawing
> path on canvas that represents the bounds of the object, binding it to the
> canvas subtree element (which is in the keyboard navigation order). In doing
> so we would have the user agent to do hit testing on the drawing objects in
> canvas and pass the pointing event to the corresponding object in the
> accessibility subtree. The bounds of the object used for hit testing would
> be passed to the corresponding accessible object (corresponding the to the
> DOM element in the subtree). Now a magnifier would know how to zoom to the
> corresponding 70x70 checkbox on the canvas.
>
> To be honest, this is not new. This is how desktops like Windows work. You
> have a graphic on the screen bound to a COM object which supports MSAA. The
> MSAA bounding rectangle is retrieved from the retained mode graphic.
> We are arguing for putting this capability into canvas.
>
> Rich
>
>
> Rich Schwerdtfeger
> CTO Accessibility Software Group
>
> [image: Inactive hide details for paniz alipour ---07/07/2011 08:42:16
> AM---Hi Richard, I mean for example I have an interaction UI on]paniz
> alipour ---07/07/2011 08:42:16 AM---Hi Richard, I mean for example I have an
> interaction UI on canvas as like web pages,
>
>
> From: paniz alipour <alipourpaniz@gmail.com>
> To: Richard Schwerdtfeger/Austin/IBM@IBMUS
> Cc: chuck@jumis.com, cyns@exchange.microsoft.com, david.bolter@gmail.com,
> franko@microsoft.com, Mike@w3.org, public-canvas-api@w3.org,
> public-html@w3.org, public-html-a11y@w3.org
> Date: 07/07/2011 08:42 AM
>
> Subject: Re: hit testing and retained graphics
> Sent by: public-canvas-api-request@w3.org
> ------------------------------
>
>
>
> Hi Richard,
>
> I mean for example I have an interaction UI on canvas as like web pages,
>
> textbox,radiobutton ,checkbox,.... .I want to know these elements that are
> drawn or are images on canvas
>
> could be incredible,Of course they can but in your opinion how many percent
> it is possible(forexample checkbox with height 70 and width 70)
>
> Best Regards
>
> On Thu, Jul 7, 2011 at 6:02 PM, Richard Schwerdtfeger <*schwer@us.ibm.com*<schwer@us.ibm.com>>
> wrote:
>
>    Hi Paniz,
>
>    I am not quite following you. Could you please provide more detail?
>
>    Thanks,
>
>
>    Rich
>
>
>    Rich Schwerdtfeger
>    CTO Accessibility Software Group
>
>    [image: Inactive hide details for paniz alipour ---07/07/2011 06:32:18
>    AM---Hello to all, Maybe you think that this question is not rel]paniz
>    alipour ---07/07/2011 06:32:18 AM---Hello to all, Maybe you think that this
>    question is not related to this discussion,
>
>    From: paniz alipour <*alipourpaniz@gmail.com* <alipourpaniz@gmail.com>>
>    To: Richard Schwerdtfeger/Austin/IBM@IBMUS
>    Cc: *chuck@jumis.com* <chuck@jumis.com>, *franko@microsoft.com*<franko@microsoft.com>,
>    *Mike@w3.org* <Mike@w3.org>, *david.bolter@gmail.com*<david.bolter@gmail.com>,
>    *cyns@exchange.microsoft.com* <cyns@exchange.microsoft.com>, *
>    public-canvas-api@w3.org* <public-canvas-api@w3.org>, *
>    public-html-a11y@w3.org* <public-html-a11y@w3.org>, *public-html@w3.org
>    * <public-html@w3.org>
>    Date: 07/07/2011 06:32 AM
>
>    Subject: Re: hit testing and retained graphics
>    ------------------------------
>
>
>
>
>    Hello to all,
>
>    Maybe you think that this question is not related to this discussion,
>
>    But I want to know whether the web widget that are located on canvas,
>
>    are they incredible .I mean a check box with height 70,weight 70,
>
>    or no it will design as the common web widget on websites?
>
>    Thanks
>
>    On Fri, Jun 17, 2011 at 11:11 PM, Richard Schwerdtfeger <*
>    schwer@us.ibm.com* <schwer@us.ibm.com>> 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
>
>
>
>
>    --
>    Paniz Alipour
>
>
>
>
>
>
> --
> Paniz Alipour
>
>


-- 
Paniz Alipour