I'd say if having a relation means either we don't have good assumptions of the hierarchy or it's more performant way than tree traversal. In either case we want to have opposite relation expect the case when related accessible is a child (not performant to run through children but performant to get a parent).
IA2 says about member_of relation (http://accessibility.linuxfoundation.org/a11yspecs/ia2/docs/html/group__grp_relations.html#gb0213d9d1193fb6e6f50e1f2115aa911): It is also possible that each member has multiple additional targets, e.g. one for every other member in the group. That makes me think you can't do a good guess about hierarchies. And either we need to have opposite relation or fix a spec. Btw, Firefox exposes member_of on child accessibles from subtree of ARIA atomic regions only. I don't think opposite relation is applicable here. I think I agree with Peter Korn that we shouldn't expose relations in every case so if AT has a good idea about hierarchies then relations should be used as fallback when hierarchies fail. That's what we do for node_child_of relation for example. Thanks. Alex. On Sat, Feb 25, 2012 at 8:06 AM, James Teh <[email protected]> wrote: > On 25/02/2012 1:28 AM, Peter Korn wrote: >> >> It has been a LONG time since I wrote any screen reader code on Windows, >> but I recall clearly that the old Win32 radio button group box control >> was always a peer of the buttons it was grouping, not the parent. > > Correct. However, if you're using something that implements IA2, someone has > obviously already gone to the trouble of implementing their own > accessibility objects, so they may as well sanitise the hierarchy as well > (i.e. make the grouping a parent). If anyone can come up with use cases > contradicting this, there's a good case for the new relation. Otherwise, > probably not. > > Jamie > > -- > James Teh > Director, NV Access Limited > Email: [email protected] > Web site: http://www.nvaccess.org/ > Phone: +61 7 5667 8372 > > _______________________________________________ > Accessibility-ia2 mailing list > [email protected] > https://lists.linuxfoundation.org/mailman/listinfo/accessibility-ia2 _______________________________________________ Accessibility-ia2 mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/accessibility-ia2
