W3C home > Mailing lists > Public > www-style@w3.org > August 2004

Re: [CSS21] Media types

From: csant <csant@csant.info>
Date: Sun, 01 Aug 2004 12:16:27 +0200
To: "David Woolley" <david@djwhome.demon.co.uk>, www-style@w3.org
Message-ID: <opsb1thpkad84skq@csant.info>

On Mon, 26 Jul 2004 21:45:06 +0100 (BST), David Woolley  
<david@djwhome.demon.co.uk> wrote:

>> However the statement "user agents may have different modes which  
>> support
>> different media types" can be open to interpretation - no definition of
>> 'mode' is given.
> I think, basically, it means that a user can choose the media type for
> which the user agent renders, and it is even possible, as for example
> with Amaya's GUI, structure tree and text mode display.

A user can choose different displays - but they occur in different windows  
of one application. Opera, e.g., can display 'screen', 'handheld',  
'projection' and 'print' in different instances running simultaneously, or  
even in different pages (or tabs) of one instance.

This means that I can switch between the different displays, and I could  
maybe even tile them and see them next to each other.

However, 'speech' and 'braille' introduce a new dimension to this  
scenario: the document is displayed *simultaneously* in more, different  
media types that the user is experiencing at the same moment, just through  
different senses: the visual, the aural and the tactile one.

> However, from what you said in a response to an off list comment, I
> think your real problem here is with document object models, in that
> parallel rendering in different media types could result in different
> values in each rendering and if the document is perverse enough to
> actually manipulate the object model based on these different values,
> one could get some very strange interactions, or would have to have
> completely separate scripting contexts (which would prevent the user
> hopping between the different renderings).

Yes and No. I think the document object model could be one for all, but  
there will be the need for different and parallel formatting structures,  
one for each 'mode' - and this is the strength of media types. I could  
want to display some content on screen, and some other content in  
'speech', using the 'content' property for this. And in a similar way I  
could want or need different scripting for different media types, but this  
does not directly belong to this list.

The media types belonging to one 'mode' (visual, aural or tactile) do  
exclude each other - I cannot experience 'handheld' and 'screen' *at the  
same time*, but I can quickly switch from one to the other; but different  
'modes' can be displayed (display is here a little bit misleading, as  
being too tightly associated with the visual experience) and experienced  
simultaneously, and allowing different formatting structures for each of  
them is the basic concept of media types: certain media types are not  
'mutually exclusive', but on the contrary 'go in concert'. This is not  
explicitly mentioned in the spec.


"He is old". But she is wrong. It is not age; it is that a drop has  
fallen; another drop.
~~~ Virginia Woolf
Received on Sunday, 1 August 2004 06:19:18 UTC

This archive was generated by hypermail 2.3.1 : Monday, 2 May 2016 14:27:14 UTC