Re: [css3-page] Idea for simplier page-margin boxes

On Mon, Mar 25, 2013 at 12:13 PM, Håkon Wium Lie <howcome@opera.com> wrote:

> How would one achieve the same in Julian's proposal [2]? I guess you
> would write something like this -- let's call it example 2:
>
>   @page { margin: 8% }
>   div.title { position: pagebox;
>      left: 12%; right: 12%; top: 3%;
>      content: string(chapter) }
>   @page :left { position: pagebox:
>      left: 8%; right: 88%; top: 3%;
>      text-align: left;
>      content: counter(page) }
>
  @page :right { position: pagebox:
>      left: 88%; right: 8%; top: 3%;
>      text-align: right;
>      content: counter(page) }
>

I believe this would be more like
@page :left div.pagenum { position: pagebox:
     left: 8%; top: 3%;
     content: counter(page) }
@page :right div.pagenum { position: pagebox:
     right: 8%; top: 3%;
     content: counter(page) }
Using positioning, you can get rid of the need to set text-align.

Using abspos also creates some dependencies. In the code above, I'm
> guessing that the page number will fit in a box with a with of 4%
> (100-88-8). For page numbers, that's a reasonable guess. For other
> types of content, using abspos may cause overflow/overlap.
>

CSS3 Paged Media solves this by introducing what is really a new layout
model just for margin boxes. That is not simple. We propose to render
actual elements in the margin boxes, so one could use flexbox to position
the page number and chapter title instead of the pseudo-flexbox features in
CSS3 Paged Media.

I'm not against adding abspos margin boxes for marginalia. However,
> I've used the current css3-page model to publish real-world books [3]
> and I find it simple & powerful -- not over-complicated & inadequate.
>

It's simple and powerful from the point of view of authors who want to do
exactly what the feature was designed to do. Since you designed the
feature, I'm not surprised it's a good fit for your needs :-). But 16 new
pseudo-elements and a lot of spec text defining positioning and sizing for
the margin-box layout model is not simple for implementors, or people
trying to write tests for the feature, or authors trying to understand the
behavior they're getting, or authors trying to understand how to get the
behavior they want. And it will get more complex if/when we add features
for the use-cases Julian introduced at the start of this thread.

Rob
-- 
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