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Re: SMIL and style sheet cascading

From: Al Gilman <asgilman@access.digex.net>
Date: Sun, 25 Oct 1998 09:49:19 -0500 (EST)
Message-Id: <199810251449.JAA07430@access5.digex.net>
To: marja@w3.org (Marja-Riitta Koivunen)
Cc: w3c-wai-ua@w3.org, howcome@w3.org, lauren@sqwest.bc.ca (Lauren Wood)
to follow up on what Marja-Riitta Koivunen said:

> I just want to make sure that I have understood this right:
> 
> The user should be able to change the font size and colors etc. of a
> document if she or he needs it. And I this should be done easily in one
> place in a user agent. User may even create her own style sheet to change
> the important attribute values.
> 
> A SMIL document can have many different media objects some of which have a
> style sheet attached and some of which do not. Is it then possible to have
> one general style sheet or user agent attribute values that can change e.g.
> the font size or colors of all the media objects included in the SMIL
> document?

I don't think that this works.

At least, if the user agent does the minimum to implement the
respective W3C recommendations piecewise, and few are up to CSS2
yet, that there is not currently support for central management
of sub-object styling from a hierarchical cascade rooted in 
the super-object.

We need to get a reading from a style expert better than myself,
but if I remember correctly, the cascading in CSS2 is done once
for "the whole document" and does not comprehend sub-objects
which add layers to the cascade or stack of stylesheets.

This is the display-side dual of the problems of conflicting
event-trapping philosophies between SMIL and DHTML.

IIRC in DHTML the innermost scope has the right of first refusal
to handle an event occurring within it, and in SMIL the outermost
scope has this power.

Integrating the hierarchy models of SMIL and HTML is something I
view as a problem; I have been asking the DOM group for help in
this area because I think the reconciliation should be designed
from an object oriented framework.  However, this strategy may
require new charter for the DOM group or an explicitly chartered
planning activity working in a suitable OO medium.  So the
problem is outstanding; there are not known to be plans on the
books that can be expected to solve it.

Hakon, please check me (or get someone to answer this) in my
remarks about "to the cascade, the document is an atom, not part
of a hierarchy."

Lauren, please give me some reading on my remarks re: blending
HTML and SMIL hierarchy models vs. DOM workscope.

Marja, please keep at it.  We may find that this turns into
WAI-PF guidelines on how to use stylesheets in HTML/SMIL
combinations.

> 
> Marja
> 
Received on Sunday, 25 October 1998 09:49:35 GMT

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