Re: Rough draft of some success criteria for a extension guideline "Touch accessible"

On 18/08/2015 14:50, David MacDonald wrote:
> Thanks for your input Patrick. I've always very much appreciated your
> comments to WCAG over the years, especially the last draft of WCAG 2...
>
> I'll try summarize your concern to ensure I understand it: You feel
> system screen readers don't have the ability to map an alternative
> gesture in the case where the author created a custom gesture that
> collides with the screen reader's core gesture functioning.

Even further than that. At least when it comes to HTML/CSS/JS web 
content, ANY gesture interface that the author (through the use of JS 
that listens to touch events or pointer events with pointerType of 
touch) may have added to their page/web app will simply not work 
(barring the special case of iOS and its pass-through gesture).

If the author has specified behavior that happens on, say, scrolling, 
that's a different matter (I seem to remember this was brought up in 
this thread before as an example of gesture and how touch-AT provides an 
alternative gesture). As an author, I've not implemented any "gesture" 
here, I simply hooked myself into the scroll event. So that's a 
different matter altogether - but once again, something outside of the 
author's control anyway (I as an author listen for scroll events; users 
on touch devices scroll by using swipe gestures on their phone; touch-AT 
users can scroll with an alternative gesture...but essentially, as an 
author, I don't feel I've implemented a "gesture" as such).



> Given that
> the screen reader gesture will override it, you think as far as we can
> go to ensure this application is accessible is to require redundant
> functionality to custom gestures in buttons etc... Do I have that right?
> If so, perhaps we can require that authors do not choose custom gestures
> that collide with system screen reader gestures???.

More drastically, that once touch-AT is in operation, it's not safe to 
use *any* gestures, as they will all (barring iOS/pass-through 
situation) be intercepted by the AT and never reach the JS.

P
-- 
Patrick H. Lauke

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Received on Tuesday, 18 August 2015 14:44:55 UTC