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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

>  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

> 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
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 UTC

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