Re: hit regions and a11y geometrics

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?

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?