W3C home > Mailing lists > Public > www-style@w3.org > January 2009

Re: [css3-mediaqueries] Width/Height Clarifications

From: fantasai <fantasai.lists@inkedblade.net>
Date: Tue, 13 Jan 2009 18:30:22 -0800
Message-ID: <496D4E3E.9050700@inkedblade.net>
To: "L. David Baron" <dbaron@dbaron.org>
CC: "Grant, Melinda" <melinda.grant@hp.com>, Anne van Kesteren <annevk@opera.com>, "www-style@w3.org" <www-style@w3.org>

L. David Baron wrote:
>
> So this is what the spec now says, and I'm currently trying to
> understand what it means.  (What it says is that for paged media,
> 'width', 'height', and 'aspect-ratio' are based on the "page box"
> and 'device-width', 'device-height', and 'device-aspect-ratio' are
> based on the "page sheet size".)
> 
> After reading CSS 2.1, sections 13.1 and 13.2
> ( http://www.w3.org/TR/CSS21/page.html#page-intro ), the only cases
> where these seem to differ are things like 2-up printing where two
> pages are printed on a single sheet or tiling where a page is spread
> over multiple sheets, and printing to a file which in turn is
> printed to sheets of a different paper size (or somehow getting
> confused about what the actual paper size is, in which case we're
> not going to suddenly get it right for media queries).
> 
> I'm not entirely sure how to implement this distinction in a
> browser, because when we're printing to a file or doing print
> preview, we don't necessarily know anything about the sheet size,
> only the page box size.  (The spec also perhaps even implies that
> for print preview, we should be using the screen dimensions, which I
> think is wrong.)

I think, actually, that zooming effects like 2up printing shouldn't
affect which media queries match (i.e. they should be handled at
the graphics buffer to screen display level, not the layout level)

But, anyway, your original question: the page box is always equal
to the page sheet in CSS2.1. This is not always true in CSS3. See
   http://www.w3.org/TR/css3-page/#page-size-prop
   http://dev.w3.org/csswg/css3-page/#page-size

~fantasai
Received on Wednesday, 14 January 2009 02:31:23 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 17:20:15 GMT