[Accessibility-ia2] Relations to move to previous/next paragraphs

Peter Korn Peter.Korn at Sun.COM
Wed Dec 17 11:44:46 PST 2008


Malte, Pete,

Another issue here is a cost-benefit tradeoff.  I was an early proponent 
of implementing flows-from/to relations for all paragraphs in OOo 
Writer, but then later became convinced that the cost to do this (in RAM 
and processor) wasn't worth the gain (somewhat less code complexity in 
the AT).  This is what led to the situation we have now - providing it 
across page boundaries where it is more clearly important for AT (which 
might otherwise first see a footer and then a header paragraph going 
down in sequential/boundary order).

I'm open to having my mind changed again - and in particular, it really 
isn't my mind that needs changing (this is a matter for the OOo 
engineers & AT engineers) - but my general feeling is that it is better 
to not introduce what may be a significant increase in the number of 
objects created/lifecycled/tracked in OOo Writer for something that 
should be pretty straightforward for AT to handle.


Regards,

Peter Korn
Accessibility Architect & Principal Engineer,
Sun Microsystems, Inc.

> The question "How much of a burden would it be" is for Oliver, because
> he would have to do it ;)
>
> But I see one issue with this:
>
> Right now, we use this relation only when one paragraph is split to
> multiple pages.
>
> So the relation (also) tells you that it's basically the same paragraph,
> even if multiple objects for it exist..
>
> When we would use flows from/to for every paragraph, you wouldn't be
> able to figure out the difference between the normal case and the
> special case.
>
> On the other hand, I don't know if any AT makes use of this information,
> and/or if it's really needed.
>
> Also cc-ing Peter and Will, because we defined this behavior ages ago
> with Peter, and Will knows best how Orca would handle it.
>
> Any ideas/comments on this?
>
> Malte.
>
> Pete Brunet wrote, On 12/16/08 02:08:
>   
>> Malte, How much of a burden would it be to provide flows from/to
>> relation between all the objects.  Today the AT has to go out to the
>> document object to make the connection between paragraphs.  Please see
>> Mick's comment in item 8 of the minutes for the prior IA2 meeting at
>> http://www.linuxfoundation.org/en/Accessibility/IAccessible2/Minutes/20081202
>>
>>  
>> *Pete Brunet*
>>                                                                          
>> IBM Accessibility Architecture and Development
>> 11501 Burnet Road, MS 9022E004, Austin, TX 78758
>> Voice: (512) 286-5485, Cell: (512) 689-4155
>> Ionosphere: WS4G
>>
>>
>>
>> From: 	Malte Timmermann <Malte.Timmermann at Sun.COM>
>> To: 	Pete Brunet/Austin/IBM at IBMUS
>> Cc: 	Accessibility-ia2 at lists.freestandards.org
>> Date: 	11/19/2008 11:05 AM
>> Subject: 	Re: [Accessibility-ia2] Relations to move to previous/next
>> paragraphs
>> Sent by: 	Malte.Timmermann at Sun.COM
>>
>>
>> ------------------------------------------------------------------------
>>
>>
>>
>> When I suggested the "prev/next" stuff in that CSUN meeting, I was not
>> sure about the concrete name, but "flows from/to" was exactly what I
>> meant. I didn't want to define an additional one.
>>
>> For the implementation:
>> IIRC, our (OOo Accessibility API) intention was to help AT to follow the
>> text flow correctly, when ONE paragraph flows to multiple pages,
>> optionally divided by some header/footer:
>>
>> <PARAGRAPH-XY - only some part of it on page n>
>> <optional: page footer>
>> <optional: page header>
>> <PARAGRAPH-XY - on page n+1, rest of the SAME paragraph on prev page...>
>>
>> The intention was to then connect the two paragraphs via flows from/to.
>>
>> There was no intention to connect all paragraphs this way in reading
>> oder, and also not to do anything special in the table scenario
>> described below...
>>
>> Malte.
>>
>>
>>
>>
>>
>> Pete Brunet wrote, On 11/19/08 03:01 AM:
>>     
>>> At the CSUN F2F earlier this year we discussed the issue of an AT easily
>>> getting access to the previous and next paragraphs.  Today the AT has to
>>> go to the parent and then to the previous or next child.  It was
>>> suggested that maybe IA2 needs new "preceeded by" and "followed by"
>>> relations.  There are already the flows from/to relations.  Is there any
>>> reason why flows from/to can't be used to link all paragraphs?
>>>
>>> Xing Li (Syphony a11y development) provided the following scenario where
>>> a table is inserted between two paragraphs
>>>     Paragraph A
>>>     Table T
>>>     Paragraph B
>>> and asked what the relations would be in that scenario and if
>>> flow-from/to is a must for all paragraphs.
>>>
>>> *Pete Brunet*
>>>                                                                          
>>> IBM Accessibility Architecture and Development
>>> 11501 Burnet Road, MS 9022E004, Austin, TX 78758
>>> Voice: (512) 286-5485, Cell: (512) 689-4155
>>> Ionosphere: WS4G
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>> _______________________________________________
>>> Accessibility-ia2 mailing list
>>> Accessibility-ia2 at lists.linux-foundation.org
>>> https://lists.linux-foundation.org/mailman/listinfo/accessibility-ia2
>>>       
>>     
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