W3C home > Mailing lists > Public > www-svg@w3.org > April 2005

Re: SVG12: seeking requirements

From: Craig Northway <craign@cisra.canon.com.au>
Date: Tue, 26 Apr 2005 14:56:50 +1000
Message-ID: <426DCA12.6040909@cisra.canon.com.au>
To: Bjoern Hoehrmann <derhoermi@gmx.net>
Cc: www-svg@w3.org

Hi Bjoern,

Bjoern Hoehrmann wrote:

>Dear Scalable Vector Graphics Working Group,
>
>  From http://www.w3.org/TR/2005/WD-SVGMobile12-20050413/struct.html 
>
>[...]
>  When the 'discard' element is used, the end user may see unexpected
>  results when seeking backward because the seek will not re-insert
>  the discarded elements.
>[...]
>
>This suggests that implementations are required to not re-insert those
>elements which does not seem to be required. Please either change the
>document to link to this requirement or rephrase this part to not
>suggest such a requirement.
>  
>
Please explain what you mean? I'm a bit confused by your comment.

Here's my understanding of the discard elements behaviour:

The UA is required to discard the target element and all ancestors when 
the begin time of the discard element is reached. The discard element is 
also discarded after processing. Seeking backward will not reinsert 
elements that have been discarded.

The UA cannot store the discarded elements for reinsertion, this would 
defeat the purpose of discarding them! I can't see how there can be any 
behaviour other than not reinserting the elements in the document seeks 
backwards.

And here's a draft suggestion for clarifying this section:

When the 'discard' element is used, the end user may see unexpected results when seeking backwards in the timeline and replaying content. Elements that have been targeted by a 'discard' element and removed will not be reinserted when seeking backwards past the begin time of the targeting 'discard' element.

Regards,
Craig
Received on Tuesday, 26 April 2005 04:57:00 GMT

This archive was generated by hypermail 2.3.1 : Friday, 8 March 2013 15:54:30 GMT