RE: Timed tracks

The original context of this was applying CSS styling to the captions. I don’t want the page CSS to apply to the captions (given that they may share similar elements like <p> and <div> this could get confusing and is generally inappropriate). The text track display should be in a nested browsing context like that of an iframe. So that content in an nested browsing context is not styled by the host page CSS, and access to the caption text should be limited in exactly the same way that access to the DOM of a document in a nested browsing context is limited.

In same domain scenarios there may be reasons to allow some interaction between the contexts, I’m not aware of any explicit mechanism for authors being able to apply style to elements within a nested browsing context, but I wouldn’t necessarily be opposed to a proposal, the mechanism should apply both for both iframes and text tracks – perhaps an new kind of CSS combinator that could drill into a nested browsing context.

From: rocallahan@gmail.com [mailto:rocallahan@gmail.com] On Behalf Of Robert O'Callahan
Sent: Friday, April 23, 2010 11:29 AM
To: Sean Hayes
Cc: John Foliot; Philippe Le Hegaret; Ian Hickson; public-html@w3.org
Subject: Re: Timed tracks

On Fri, Apr 23, 2010 at 8:52 PM, Sean Hayes <Sean.Hayes@microsoft.com<mailto:Sean.Hayes@microsoft.com>> wrote:
Given that the page author will have access to the video timeline, they will of course be able to superimpose anything they like; and turning on and off the caption stream is fine. What I want to avoid is inadvertent leakage, especially when they come from different source to the HTML.

OK, then I have no idea what you meant by "there will need to be a strong barrier between the HTML and the timed text environments ... in order that the video/caption author's intention is not undermined by the HTML page author."

I totally agree that we need to prevent caption information from one origin leaking to the a containing page with a different origin. That would have interesting implications for certain kinds of solutions based on HTML and CSS ... for example, you wouldn't want the page author to be able to apply selectors that match on attribute values, because then captions with sensitive data in attribute values could leak that data to the page. It's not completely dissimilar to the :visited problem.

Rob
--
"He was pierced for our transgressions, he was crushed for our iniquities; the punishment that brought us peace was upon him, and by his wounds we are healed. We all, like sheep, have gone astray, each of us has turned to his own way; and the LORD has laid on him the iniquity of us all." [Isaiah 53:5-6]