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Re: html5 editor responds to Canvas accessibility related bugs

From: Charles Pritchard <chuck@jumis.com>
Date: Fri, 08 Oct 2010 15:34:26 -0700
Message-ID: <4CAF9C72.9020107@jumis.com>
To: Benjamin Hawkes-Lewis <bhawkeslewis@googlemail.com>
CC: Ian Hickson <ian@hixie.ch>, "public-canvas-api@w3.org" <public-canvas-api@w3.org>
  On 10/7/2010 11:44 PM, Benjamin Hawkes-Lewis wrote:
> Does anyone have any specific API proposals to put on the table to resolve Bugs 10248 and 10249?

Apart from my canvas + css based proposal, there's this proposal from 
the following URL:
http://lists.w3.org/Archives/Public/www-dom/2010JulSep/att-0106/UserInterfaceIndependence.html

My take on it:
selectionPolygon is not nearly as useful as is the drawFocusRing-style 
option of passing the current canvas path.
'poly' is useful for describing a custom caret, but it's not flexible 
enough to describe a selected area. It seems selectionPolygon is
only enough for a magnifier, not for actual display of selected content.




Here's a copy / paste of the relevant bits of the proposal:

[Supplemental, NoInterfaceObject]
interface MagnifierNotifications {
   // Editorial Note: I'm not partial to the method name focusPosition. 
Any other suggestions?
   void focusPosition(
          in DOMElement element,
          in optional array cursorRect,
          in optional array selectionPolygon
        );
};

[bool] window.navigator.accessibility.magnifier.active
window.navigator.accessibility.magnifier.focusPosition ( element, 
cursorRect, selectionPolygon )

Returns void. Allows the web author to send an explicit notification 
informing the screen magnifier to update its cache of the cursor 
location. Web authors should call this method when updating the display 
or cursor position of custom views.

Parameters for Magnifier.focusPosition
1. DOMElement element
Required reference to the element (e.g. canvas) that has focus.
2. optional array cursorRect
Optional array representing the rectangular cursor location relative to 
the [0,0] position of focused element. [ x1, y1, x2, y2 ]
3. optional array selectionPolygon
Optional array representing the selection polygon relative to the [0,0] 
position of focused element. [ x1, y1, x2, y2, ... xn, yn ]
Editorial Note: It may be better if the optional params are shape 
objects with a coords array and a type string like 'rect' or 'poly'. 
That would allow the author to decide if they wanted to provide the 
extra polygon coords, or just use a simple shape.
Received on Friday, 8 October 2010 22:34:56 GMT

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