[CSS21] @page margins and constant page area width

We had a discussion earlier about what the sentence
   # To simplify implementations, user agents may use a single page
   # area width on left, right, and first pages. In this case, the
   # page area width of the first page should be used.
in
   http://www.w3.org/TR/CSS21/page.html#page-selectors
really means. We proposed either changing the wording to

   # To simplify implementations, in this case user agents may adjust
   # the margins to effect a constant page area width on left, right,
   # and first pages.

or dropping the exception altogether, thus requiring UAs to format
content for different widths on different pages.

Mozilla's pagination model is well-suited to handling pages of
different widths, but after talking with Robert O'Callahan about how
some other implementations do pagination, I conclude that it is
unrealistic to expect those implementations to be able to do this.
Thus we need to keep the exception for CSS2.1.

I propose clarifying the text as described above and also requiring
the adjustment not result in negative page margins (unless the
necessary page width is greater than the width of the page sheet) so
that this adjustment does not unexpectedly result in clipped content.

~fantasai

Received on Wednesday, 15 August 2007 03:58:00 UTC