[whatwg] hit regions: limited set of elements for fallback content

[Rik Cabanier]

On Mon, Feb 17, 2014 at 8:20 PM, Ian Hickson <ian at hixie.ch> wrote:

> On Mon, 17 Feb 2014, Rik Cabanier wrote:
> >
> > The current spec for hit regions restricts what elements can be used as
> > fallback content [1]:
> >
> > [...]
> >
> > Why is there this limitation?
>
> It supports the content model restrictions, which are there to avoid
> authors making mistakes that harm accessibility (amongst other things).
> Reasons for content model restrictions are discussed in more detail in the
> introduction to the spec:
>
>
> http://whatwg.org/html#restrictions-on-content-models-and-on-attribute-values
>
> If there are specific use cases that can't be done given the current
> restrictions, please let me know; we can definitely consider relaxing some
> of the restrictions. (It's very hard to tighten restrictions, but
> comparatively easy to relax them, which is why we start them on the strict
> side rather than on the relaxed side.) So far, all the use cases that
> people have brought up for things that can't be done within the current
> restrictions also happen to be things that canvas is actually really bad
> at doing at all.


Thanks.
Were those use cases posted to this list?

So, you wouldn't want the same limitations as for regular HTML elements?
http://www.whatwg.org/specs/web-apps/current-work/#wai-aria
The canvas fallback content could be what is exposed to the user so it
might be painful for the author to match it up with hit regions.

I agree that relaxing it to any element could allow non-sense. Is there a
clear definition of what is disallowed or allowed in HTML? I couldn't find
it in the spec.


> There's another non-normative section that goes into more
> detail about these kinds of things:
>
>    http://whatwg.org/html#best-practices
>