On 17/04/2010 5:28 PM, Rob Gallo wrote:
> This issue is a tough one. I would like to suggest yet another approach
> where embed characters would have their own ranges, and those ranges should
> basically return an empty attribute string, or a string that would amount to
> plain text.
In principle, I totally agree with you. However, the problem is that 
this requires clients to make many more calls to 
IAccessibleText::get_attributes() than they would with the other 
approach. This isn't such an issue for in-process clients, but it most 
definitely a performance penalty for out-of-process clients. This will 
affect NVDA to some extent (we have a sort of hybrid of in-proc and 
out-proc stuff). However, if I'm not mistaken, this change will also 
affect ATK clients (all out-of-process), as the cross-platform layer 
implementation will be the same. Alex, am I correct here?

Having said that, if I understand correctly, Firefox is already exposing 
these as separate ranges (even descending to get the formatting), so 
maybe this isn't such an issue. However, on a big block of text with 
lots of embedded objects, it could get a bit nasty.

> Here's why: embed characters aren't, strictly speaking,  text. They
> represent objects which contain their own text. And the text of the target
> objects should have their own attributes. If the object that contains the
> embed character and the target object have differing sets of attributes,
> that leads to confusion.
The idea that Aaron Leventhal proposed was that ATs should just ignore 
the formatting for the embedded object characters, as it has to descend 
to get the formatting anyway. It is done for the purpose of optimisation 
only; as I said, I totally agree with you in principle. This 
*definitely* needs to be very well documented if it is going to happen.

Alex, if this is going to affect ATK as well, we should probably pull 
Joanie and maybe others into the discussion.

Jamie

-- 
James Teh
Vice President
NV Access Inc, ABN 61773362390
Email: [email protected]
Web site: http://www.nvaccess.org/
_______________________________________________
Accessibility-ia2 mailing list
[email protected]
https://lists.linux-foundation.org/mailman/listinfo/accessibility-ia2

Reply via email to