HTML Accessibility Task Force Teleconference

07 Mar 2011


See also: IRC log


Gregory_Rosmaita, Rich, Chuck_Pritchard


<trackbot> Date: 07 March 2011

<scribe> scribe: Gregory_Rosmaita

<scribe> scribenick: oedipus

<scribe> Meeting: Canvas Subgroup of HTML Accessibility Task Force Teleconference

<richardschwerdtfe> http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/0075.html

<Downchuck> http://blog.codinginparadise.org/2010/12/tricks-for-aria-on-ipadios.html

<Downchuck> helpful article for me as I work with ios



<richardschwerdtfe> http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/0075.html

Strategy for positioning fallback content relative to corresponding canvas UI drawing counterparts


RS: looked at Chuck's path in SVG thing

CP: just talking about PATH element

RS: suggesting what? PATH for drawing?

CP: have to do manually in CANVAS
... can convert SVG path to series of canvas path commands or reverse -- example of what is available -- first thing IMAGEMAP, if not available can generate PATH -- just an example

RS: bind an object to something being drawn on screen -- how would 1 set dimensions for object on screen -- how to say "here are bounds of this object"
... want to say this area i am drawing to is associated with this element, and here is bounding element/clipping rectangle
... device context and clipping rectangle, you are done

CP: for arbitrary paths, don't want to lose ability to represent arbitrary path -- curve that only takes op portion of bounding rectangle becomes less useful
... keep going back to SVG because in terms of usability, very similar
... have example of drawFocusRing
... 1 touch event short -- in canvas, if get mouse event, doesn't require pre-binding elements in DOM -- could change title, draw a focus event
... with iPhone and iPad 1 more layer of touch events that haven't been exposed

RS: fit testing within a region?

CP: yes

RS: how establish region?

CP: arbitrary -- 2 diff ways: paint to bitmap image and color of fill is mapped over and associated with function call -- quick and dirty to make clickable canvas area
... other: keep object with x,y bounding boxes
... event elegance -- this is a bounding box i am listening to and will now run through program
... point of standards is to give flexibility while having a standard

RS: can't limit to just path?

CP: drawFocusRing works, but is hit-testing based -- don't want to force to redefine every path -- could reuse drawFocusRing with diff name, but requires setting region for each clickable element

RS: would that work for touch devices?

CP: hit-testing and methods are passed -- would work with touch device if events available
... canvas on iOS -- click on canvas, thinks is image -- will expose title of image -- have to perform awkward steps -- don't want to pass touch events into canvas DOM until user affirms this is element the user wants
... slide finger over link -- give name of link -- set virtual focus on link -- double-tap to activate

RS: if move finger over can tell if in clickable area?

CP: only when activated -- before, just a canvas blob
... once double-tap element, starts processing events

RS: bound to corresponding element, but what are you using as parameters -- how to glean bounding rectangle

CP: with clicakable use same semantics as drawFocusRing and bind current path to element -- run for each element

RS: seems like a reasonable approach

CP: requires that all clickable areas defined ahead of time rather than after an event -- text clickability can get weird
... double-tap on a word, but don't want ot send extra word boundaries if don't have to
... if receive events, ARIA handles with activedescendant
... awkward on iOS getting events to fire -- brought up on www-dom list fact that what apple introduced is "innovative" and unique -- like a touch hover event
... did same thing -- touch hover event not bound or standardized -- if was, could have bounded into hit testing
... setClickableArea falls apart if lot of complexity (lots of text)
... if dealing with complex app, not as desireable

RS: want to say "take current path to calculate"

<Downchuck> setClickArea(element) ; clearClickableAreas();

<Downchuck> [sic] setClickableAreas

RS: diff btw text and objects -- text has font info so can compute bounding rectangle for text
... might be able to deal with that

CP: more innovative user interfaces as touch and canvas implemented more broadly and robustly

RS: apply to text? such as word processor -- do on each piece of text?

CP: if apply ClickableArea apply to shape -- circle with text make outer circle clickable

RS: but not on each piece of text in circle?

CP: possibility -- a11y and ARIA standardizes things for UI -- use of it will depend on application
... might want to allow someone to double-tap to start reading with "you are currently over this word" -- how to do quickly?
... circular text box moseOver first thing to tell is word currently over, then speak text block

RS: know in document area, but do hit-testing at word and character level?

CP: when click on RTE, need to know where to put caret

RS: does application rather than system do all the work

CP: depends on application
... hit testing is going to be less memory intense -- asynchronous based model works better

RS: would be good if could bind hit testing to an element
... more than a11y impact

CP: make things easier to program

RS: need to float this concept to WG -- setClickableRegion

CP: RS float that, i will float "touch hover" concept


Chuck Pritchard update on working modification to simulator caret tracking


CP: hasn't progressed -- still at 1 character right now -- grabbing focus for ZoomText

Outstanding Bugs and Issues Being Monitored

RS: nothing moved on any?

CP: no -- nearly got WebKit to consider resolution of pixels





Issue 131: http://www.w3.org/html/wg/tracker/issues/131

RS: submitted as editorial issue

CP: should be addressed; just a bit of pushback from webkit community about shadow DOM, but not too hard a pushback

RS: thought webkit ok with response we gave them

CP: need to let it get into codebase

RS: if not moving, need to ping apple people to find out why

CP: give it 2 days -- webkit collective discussed as group last week

RS: regular meetings?

CP: no -- converse over bug reports

RS: conncected to WHATWG?

CP: no directly with webkit bug tracker

RS: travelling to CSUN -- could discuss canvas a11y at satruday/sunday f2f

CP: not yet gotten tickets

RS: face2face meeting in San Diego
... first time i can host a canvas call will be 28 March 2011

CP: apple is 1 developer who have made the leap so far -- only full screen touch interface widely available

RS: will float by maciej


Summary of Action Items

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Guessing input format: RRSAgent_Text_Format (score 1.00)

Succeeded: s/double-tab/double-tap/G
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Found Scribe: Gregory_Rosmaita
Found ScribeNick: oedipus
Default Present: Gregory_Rosmaita, Rich, Chuck_Pritchard
Present: Gregory_Rosmaita Rich Chuck_Pritchard
Agenda: http://lists.w3.org/Archives/Public/public-canvas-api/2011JanMar/0078.html
Found Date: 07 Mar 2011
Guessing minutes URL: http://www.w3.org/2011/03/07-html-a11y-minutes.html
People with action items: 

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