W3C home > Mailing lists > Public > www-style@w3.org > December 1999

some confusion with the 'all' medium

From: Bill dehOra <Wdehora@cromwellmedia.co.uk>
Date: Wed, 15 Dec 1999 14:54:53 -0000
Message-ID: <AA4C152BA2F9D211B9DD0008C79F760A5CA3E3@odin.cromwellmedia.co.uk>
To: "'www-style'" <www-style@w3.org>
[this message is crossposted to www-style and w3c-dom, as I'm not sure where
this mail belongs...my apologies]

Hi,

I'm having some difficulty getting my head around the medium 'all' (I'm not
sure that the CSS spec didn't mean to say 'any'). Does a sheet that does not
have targeted media implicitly have '@media all{...}' wrapped around the
sheet? If so why does it need to exist? It seems that 'all' is redundant. 

The problem with such a redundancy crops up in the DOM. In the context of
the DOM the stylesheets.MediaList interface states:

    "An empty list is the same as a list that contains the medium  'all' ". 

This sounds like one must add the keyword 'all' to an empty list. Otherwise
it actually isn't the same.  Problems with this are:

1: suppose there exists a media list with one element. If that element is
removed, using the stylesheets.delete() method, does the now empty list
automatically revert to one containing 'all'? 

2: if an empty list is given the medium 'tty', using the  does this imply
that 'all' is to be removed? 

3: if not, what are the semantics of 'all' AND 'tty'?

4: if no media are mentioned in the stylesheet, this implies an empty media
list. Which implies a list that contains the medium 'all'. Which isn't
explicit in the stylesheet.

5: Note that 'all' is a CSS word, yet it appears in the stylesheet's
interface. How do we know that a different, future, stylesheet spec will
have the keyword 'all'?

It seems easier to just eliminate 'all' from both the DOM and the CSS specs,
and assume that any CSS/stylesheet rule that is not media targeted is
applicable to <any> available end-media. I appreciate peoples thoughts on
this.

Regards,

Bill de hOra 
Received on Wednesday, 15 December 1999 09:55:55 GMT

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