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Re: quick questions

From: Glenn Adams <glenn@skynav.com>
Date: Sat, 18 Aug 2012 10:56:06 +0800
Message-ID: <CACQ=j+cqpFBq2QsuaNmkpAfOZ6hSzw2OVuL=TF6j+u=9XqwdBg@mail.gmail.com>
To: Kouichi Uchimura <Kouichi.Uchimura@jp.sony.com>
Cc: public-tt@w3.org
On Fri, Aug 17, 2012 at 2:24 PM, Kouichi Uchimura <
Kouichi.Uchimura@jp.sony.com> wrote:

> Hi
>
> I have 2 more questions. Sorry for send many questions...
>
> (a) tts:visibility
>  tts:visibility specifies visibility of the elemnet.
>  What is expected if visibility is set to hidden to region elemet?
>   (1) the region and its descendant elements are hidden

  (2) the region is hidden but decendant elements are visible if any
>  I guess (1) is correct understanding but this takes me another question.
>

(1) is correct, in the sense that any content targeted to the region is no
displayed


>
>  What is expected in next case
>   <region xml:id="r1" and set it to visible!>
>   ...
>   <p region="r1" tts:visibility="hidden" begin="0s" "1s">
>     textA
>     <span tts:visibility="visible">
>       textB
>     </span>
>   </p>
>
> In first question, my expectation is
>  if an element is invisible then its descendant elements are invisible.
>

none of <p> or its descendants are visible


> If this is true, textB above is also invisibile???
>

children of a hidden element are hidden regardless of their visibility
setting


> If not, it means (2) is correct but
>  where content is drawn if region is hidden?
>
> (b) "em" relative unit of length
> How can I specify the region extent and origin to use "em" unit?
> What fontSize is applied to compute the relative value?
>

font size is always well defined in the sense that if it is not specified
on region or otherwise referenced then the initial value '1c' applies; if
ttp:cellResolution is not specified, then 32 15 applies, so fontSize (in
vertical dimension) would be heightOfRootContainer/32


> I guess "em" can be used to specify fontSize property only and
> not for extent/origin.
>

the only place where the value of <length> is restricted, is when
tts:extent is specified on the root element tt:tt, in which case it must be
pixels; see the text under [1]

If tts:extent is specified on the ttelement, then the width and height must
be expressed in terms of two
<length><http://www.w3.org/TR/ttaf1-dfxp/#style-value-length>
specifications,
and these specifications must be expressed as non-percentage, definite
lengths using pixel units.

[1] http://www.w3.org/TR/ttaf1-dfxp/#style-attribute-extent


>
> best regards,
> Uchimura
>
> --
> Consumer Products & Services Group
> Home Entertainment Business Group
> Home Entertainment Development Div.
> Section1 Dept.7
> Sony Corp.(Japan)
> Kouichi Uchimura <Kouichi.Uchimura@jp.sony.com>
>
>
>
>
Received on Saturday, 18 August 2012 02:56:55 GMT

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