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

Ian Hickson ian at hixie.ch
Mon Feb 17 22:49:43 PST 2014

On Mon, 17 Feb 2014, Rik Cabanier wrote:
> Were those use cases posted to this list?

I'm sure some were. Your typical use case would be something like a graph, 
a game menu, a fractal explorer, and so on.

> So, you wouldn't want the same limitations as for regular HTML elements?

Not sure what you mean. The rules for addHitRegion() match the regular 
<canvas> content model.

> http://www.whatwg.org/specs/web-apps/current-work/#wai-aria

This seems orthogonal to the issue of addHitRegion()... I'm not sure I 
follow the relevance here.

> 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.

Not sure what you mean here. Can you elaborate? Maybe an example would 

> 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.

Allowed or disallowed in what sense? If you mean the content models, the 
specification has elaborate text describing the rules; you can find the 
introduction to content models here:


Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
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