Re: DFXP LC Comments - Issue 14 Response; Erik Hodge

Dear Erick,
If you require any further follow-up please do so, and if you are 
satisfied with the TTWG response, please acknowledge it by replying to 
this mail and copying the TTWG public mailing list:
public-tt@w3.org
Regards,
Thierry Michel

Glenn A. Adams a écrit :

>Dear Erik,
>	
>Thank you for your comments, [1], on the DFXP Last Call Working Draft
>[2].  The TT WG has concluded its review of your comments and has
>agreed upon the following responses.
>
>If you require any further follow-up, then please do so no later than
>September 1, and please forward your follow-up to <public-tt@w3.org>.
>
>Regards,
>Glenn Adams
>Chair, Timed Text Working Group
>
>************************************************************************
>
>Citations:
>
>[1] http://lists.w3.org/Archives/Public/public-tt/2005Apr/0044.html
>[2] http://www.w3.org/TR/2005/WD-ttaf1-dfxp-20050321/
>
>************************************************************************
>
>Comment - Issue #14 [1]; 26 Apr 2005 10:10:15 -0700
>
>It has been said on other threads that introduction of the timing
>model into the layout was due to the following:
>
>  
>
>>>(1) we wanted regions to be temporally activated/deactivated;
>>>(2) we want to animate certain region styles, such as background color
>>>(which is independent of background colors deriving from content
>>>elements) and position;
>>>
>>>In order to provide these temporally sensitive features, we need to
>>>      
>>>
>make
>  
>
>>>regions timed elements, which implies a timing context, which in turn
>>>indicated a need for having the root container element <tt/> be a
>>>      
>>>
>timed
>  
>
>>>container.
>>>      
>>>
>
>The use of timing inside layout elements (and, in turn, in
>the root container element <tt/>) is not necessary if certain
>other attributes are allowed.  I feel that adding timing to
>these elements is adding unneeded complexity; if left as is,
>I fear a lot more investigation and documentation will need
>to be done to cover the non-obvious edge cases.
>
>You can do both of the things you described, above, in
>SMIL 2.0 without the existence of region timing attributes.
>
>(1) To temporally activate/deactivate regions:
>You could add the "showBackground" region attribute to TT
>and allow the value of "whenActive".  See:
>
>   http://www.w3.org/TR/SMIL2/layout.html#adef-showBackground
>
>When "whenActive" is active, "...the background color will
>not be shown in the region when no media object is rendering
>into that region". Also, you could allow animation of that
>attribute by using a <set> or <animate> element in the body
>that targets the region and its showBackground attribute.
>The latter option would allow you to turn the region's display
>on and off when no text was displayed in it.  When text is
>displayed in the region and you want it to be hidden, you can
>move it behind other regions, resize it to 0x0, move it off
>screen, ...etc.  The second two are contrived, I admit, but
>moving a region behind another is not, IMHO.
>
>(2) To animate region styles, you could use the <set> and/or
><animate> element in the body, with the region's id as the
>targetElement value.  For instance, the following SMIL2
>Language-profile presentation animates the region's color
>from blue to red to yellow then back to red then back to
>blue at one-second intervals:
>
>
><smil xmlns="http://www.w3.org/2001/SMIL20/Language">
>   <head>
>     <layout>
>       <root-layout width="340px" height="280px" />
>
>       <region id="r1" regionName="foo"
>               top="10px" left="10px"
>               height="240px" width="320px"
>
>               backgroundColor="blue" />
>     </layout>
>   </head>
>   <body>
>     <par>
>
>       <img src="data:text/plain,Hello" width="50px" height="50px"
>             region="r1" dur="5s" />
>
>         <set targetElement="r1" attributeName="backgroundColor"
>             to="red" begin="1s" dur="3s" />
>
>         <set targetElement="r1" attributeName="backgroundColor"
>             to="yellow" begin="2s" dur="1s" />
>
>     </par>
>   </body>
></smil>
>
>Note: In SMIL 2.0 you can smoothly animate from one value to
>another if the value is numerical, e.g., from="#0000FF" (blue)
>to="#FF0000" (red).  SMIL 2.0 also has a shortcut for smoothly
>animating color called (naturally) "animateColor".
>
>Response:
>
>The TT WG believes the intended usage is implementable, but may need
>additional clarifying language in section 10.4 that establishes the
>time interval context for /tt/head/layout/region elements based on a
>time intervals resolvable on /tt, /tt/head, and /tt/head/layout,
>respectively, all three of which are identical.
>
>If during the Call for Implementation (CR) phase of DFXP it is found
>that the present syntax and/or semantics is unimplementable or in need
>of further clarification, then the TT WG has an option to exclude this
>feature from a subsequent Proposed REC (PR).
>
>************************************************************************
>
>
>
>  
>

Received on Friday, 12 August 2005 22:30:50 UTC