Media Queries Issues

This page is only preserved for historical interest. Current issues for Media Queries are tracked here:

http://www.w3.org/Style/CSS/Tracker/products/7

Issue 1

RESOLVED. The draft addresses all of this now. You can use CSS escapes, however.

The syntax for media queries needs some clarification:

It should be made clear that media queries are split on “,” and then parsed.
It should be made clear that media=“ ” is valid and that media=“all, ” is not.
It should be made clear where whitespace is required and where it is optional.
It should be made clear what case-insensitive means.
It should be made clear that you can not use CSS escapes. (No IDENTS!)

Came up in discussion: HTML, CSS, and XML differ in their definition of whitespace. XML has U+0020, U+0009, U+000D, and U+000A. CSS adds U+000C to that list. HTML adds U+000B on top of the CSS list. Is the notion of whitespace languages dependent? @media uses CSS and media=“” uses HTML? (The current proposal seems to be that HTML adds a pre-processing steps that replaces U+000B with U+0020. In that case the notion of whitespace can remain what CSS says.)

Issue 2

What to do with the ‘resolution’ feature? See e-mail thread: http://lists.w3.org/Archives/Public/www-style/2007Jan/thread.html#msg63 Use cases, what if horizontal and vertical resolution differ, et cetera.

Issue 3

RESOLVED http://lists.w3.org/Archives/Public/www-style/2007Dec/0038.html

whitespace is as defined by CSS
where whitespace is required and optional is clear in the syntax
EOF handling is handled by “malformed media query” (we don’t want style sheet EOF handling as you might get style sheets applying to the wrong device)
HTML needs to deal with media=“” and media=“ ” etc.

Issue 4

http://lists.w3.org/Archives/Public/www-style/2007Nov/0209.html

Can you use a media feature with a media type for which it is not applicable? I vote yes. (I being Anne.)

More Issues

RESOLVED http://lists.w3.org/Archives/Public/www-style/2007Dec/0005.html (we now reference CSS 2.1)
RESOLVED http://lists.w3.org/Archives/Public/www-style/2007Nov/0212.html (grid no longer applies to aural)

Media Queries Syntax

RESOLVED - syntax is now part of the draft.

An idea based on the CSS 2.1 grammar:

media_query_list
 : S* media_query [ COMMA S* media_query]*
 ;
media_query
 : [[ONLY | NOT] S+ media_type [S+ AND S+ expression ]*] | expression [ S+ AND S+ expression ]*
 ;
media_type
 : IDENT
 ;
expression
 : media_feature [':' S* term]?
 ;
media_feature
 : IDENT S*
 ;