Re: [ttml2] condition attribute

From: Glenn Adams <glenn@skynav.com<mailto:glenn@skynav.com>> Date: Wednesday, 26 November 2014 14:08


On Wed, Nov 26, 2014 at 2:02 AM, Nigel Megitt <nigel.megitt@bbc.co.uk<mailto:nigel.megitt@bbc.co.uk>> wrote:
Hi Glenn,

Is there any difference between setting the condition attribute of a body, div, p, region or span to "false" and setting the tts:display style attribute to "none"?

yes, for one thing, tts:display is animatable, while condition isn't;


Thanks, that's clear. I hadn't gone through all the permitted <condition>s so I hadn't realised that there's no temporal query allowed within a condition, meaning that the same condition always evaluates to the same value for a given related media object and document processing context.


If not, perhaps we should consider deprecating tts:display.

Kind regards,

Nigel



From: Glenn Adams <glenn@skynav.com<mailto:glenn@skynav.com>>
Date: Wednesday, 26 November 2014 02:03
To: TTWG <public-tt@w3.org<mailto:public-tt@w3.org>>
Subject: [ttml2] condition attribute
Resent-From: <public-tt@w3.org<mailto:public-tt@w3.org>>
Resent-Date: Wednesday, 26 November 2014 02:04

I've added support for a generic 'condition' attribute [1][2], available for use with any element type except profile matter vocabulary.

While the primary syntax is now drafted, additional details regarding semantics of condition expression processing semantics will be needed. But that can be safely done after FPWD.

[1] https://dvcs.w3.org/hg/ttml/raw-file/tip/ttml2/spec/ttml2.html#content-attribute-condition

[2] https://dvcs.w3.org/hg/ttml/rev/0933a6108611