Re: ACTION-1474 Rewrite text alternative computation.

Thanks for taking this on! It's great to have the accessible name and
description calculation in the form of an algorithm.

Here's some initial feedback:

(1) F.iii: You shouldn't always append spaces when concatenating the text
alternatives of children. As an example:

<label>
  <input type="checkbox">
  Make this the <em>top</em>most element
</label>

The correct accessible text is "Make this the topmost element", not "Make
this the top most element". Similarly for the :before and :after
pseudoclasses - they're appended with no whitespace.

I'm not sure how to resolve this, but as a first stab, how about: do not
add extra whitespace when the previous and next elements are both inline
and their text both comes from contents.

(2) In the mapping table for aria-labelledby: should talk about "referenced
objects", not a single "referenced object". Should explain what to do if
some of the referenced objects are visible and others are not.

(3) The algorithm is incomplete for AXAPI. The text alternative algorithm
gives explicit instructions on how to construct a string, and then the
mapping table says to map that to AXTitle or AXDescription. The current
behavior of Safari is to expose the visible text in AXTitle and ALSO the
alternative text in AXDescription, so for example <button
aria-label="Bar">Foo</button> would get an AXTitle of "Foo" and
AXDescription of "Bar". The algorithm should handle that case, unless the
Apple folks specifically want to change it.

(4) I'm not sure it does the right thing for a link with a tooltip.
Consider:

You can read more about <a href="http://en.wikipedia.org/wiki/Russia"
title="Russia">his home country</a> on Wikipedia.

Firefox currently exposes "his home country" as the name, and "Russia" as
the description. Both NVDA and JAWS read out the name first, but also read
out the description when it has focus. The algorithm needs to handle this
case. It needs to handle both the case where other text and the tooltip are
present, and the case where the tooltip is the only provided text.

- Dominic

On Fri, Oct 31, 2014 at 6:59 AM, Joseph Scheuhammer <clown@alum.mit.edu>
wrote:

> All,
>
> Rewrite completed.  See:
> http://rawgit.com/w3c/aria/master/accname-aam/accname-
> aam.html#mapping_additional_nd_te
>
> --
> ;;;;joseph.
>
> 'Array(16).join("wat" - 1) + " Batman!"'
>            - G. Bernhardt -
>
>
>