RE: [css3-page] "odd/even" for "page-break-before|after"?

Thank you for your prompt reply.

Technically speaking, ltr/rtl/vertical doesn't matter. What matters is how it's bound. Usually ltr document is left-binding, where page 1 is right. Books in vertical text, for example, are usually right-binding and thus page 1 is left.

> Is there a common pattern for which side page 1 starts on?

Yes. Usually, chapters start on right pages in left-binding books, right? In the right-binding books, chapters start on left pages. That is why MS Word has an option to page break to even/odd for sections. I couldn't find similar option in OpenOffice but I have to admit that I'm not very familiar with it.

> Are you expecting that authors (or perhaps publishing houses) will use a single common stylesheet for both directions of books?

I agree with you on that stylesheets will be modified and optimized per books or per publishers. But "page break on new chapter" is a very common pattern that I think it's worth to try to abstract. I wish it be a logical intention rather than physical specification. It's like whether to use <b> or <em>. <b> is direct and specifies exactly how it looks. <em> is a little more abstracted, it only states that "it should be emphasized" and does not specify how. As you said, <b> is more intuitive , but I hope you'd agree that both has their own benefits.

"left/right" and "even/odd" are similar I think. "left/right" is more intuitive, but for someone who wants to switch "how", abstraction is useful. Switching binding direction happens in some languages, and for them, I think abstracted specification is useful.

Actually, as I write this, I noticed that the spec could be difficult to implement. There's no property to specify bindings in current CSS as far as I know, right? Then, how could browsers know which page is left and right? Browsers know the page number, so they can distinguish even and odd pages. But without binding information, you can't map pages to left and right, can you?


-----Original Message-----
From: Tab Atkins Jr. [mailto:jackalmage@gmail.com] 
Sent: Saturday, August 28, 2010 10:29 AM
To: Ishii Koji
Cc: www-style@w3.org
Subject: Re: [css3-page] "odd/even" for "page-break-before|after"?

On Fri, Aug 27, 2010 at 12:46 AM, Ishii Koji <kojiishi@gluesoft.co.jp> wrote:
> I was reading CSS Paged Media Module Level 3 
> http://dev.w3.org/csswg/css3-page/

> and am wondering, is it possible to add "even" and "odd" to the values for "page-break-after" and "page-break-before"?
>
> Maybe this has been discussed before, I'm sorry in advance in that case, but as I understand, when author specifies "page-break-after:right" for example, the original intention is likely to make the next page at the same side of the cover page.
>
> It is "right" for the left-binding books, but it is opposite for the right-binding books.
>
> I think "even/odd" has a few benefits.
> * It can represent the author's original intention better in most cases.
> * It has better abstractions when CSS has properties for binding method in future.
>
> We could have both values allowed in case where the author wants to specify left or right regardless of the how the book is bound.

I don't think I agree.  I've never published a book, but were I to do so, I think it would be more intuitive to think of the pages in terms of left/right rather than even/odd.  The latter requires me to remember exactly which side page 1 starts on - in other words, I'd just have to use some extra knowledge to map the even/odd back to left/right!

Is there a common pattern for which side page 1 starts on?  I've read thousands of books in my life and never really noticed which side was even and which was odd.  Is this pattern the same for ltr books and rtl books?

Are you expecting that authors (or perhaps publishing houses) will use a single common stylesheet for both directions of books?  If there was a common pattern, and it was shared between both book directionalities, this still wouldn't help any individual book, as books are always published with a particular directionality.  You'd only realize a minor benefit if you're publishing multiple books in both directions, and have a common base stylesheet that you use for all of them.

~TJ

Received on Saturday, 28 August 2010 05:04:33 UTC