Re: hit regions and a11y geometrics

On Thu, Jan 30, 2014 at 10:46 AM, Dominic Mazzoni <dmazzoni@google.com>wrote:

> On Wed, Jan 29, 2014 at 5:03 PM, Alexander Surkov <
> surkov.alexander@gmail.com> wrote:
>
>> A first thesis I would make is the web author can do CSS to define
>> geometry of DOM elements underneath the canvas and in most cases it should
>> work well.
>>
>
> I think the problem with this is that it adds an enormous burden to the
> developer, to convert from transformed canvas pixel coordinates, back to
> CSS coordinates. I can draw a nice animated UI with a combination of
> rotations, translations, and scales, plus complex curved paths. Why should
> I need to reverse all of that math in order to specify the accessible
> bounding box of a focusable element within that UI?
>

Yes, it's some work but it's just a built-in option the web author can do.


> I think there's a lot of support behind the idea of (1) using canvas
> drawing routines to draw a focus ring, and (2) specifying the accessible
> bounding box of an element, using canvas coordinate space. The
> disagreements seem to be about the exact semantics of a drawFocus*
> function, and how much it should do with accessible bounding boxes vs
> having a different API for that.
>
> Hit regions could solve many of these problems in theory, but I keep
> hearing that there's no consensus on those. Who exactly doesn't want to
> implement hit regions?
>
>