W3C home > Mailing lists > Public > www-style@w3.org > June 2013

Re: [css3-multicol] updated editor's draft

From: Håkon Wium Lie <howcome@opera.com>
Date: Tue, 4 Jun 2013 01:16:25 +0200
Message-ID: <20909.9161.418487.999432@gargle.gargle.HOWL>
To: Morten Stenshorne <mstensho@opera.com>
Cc: Bert Bos <bert@w3.org>, Simon Sapin <simon.sapin@exyr.org>, www-style@w3.org
Morten Stenshorne wrote:
 
 >  > Bert Bos <bert@w3.org> writes:

 > > Apart from this max(), the W is indeed the same in all three cases, so 
 > > how about showing just the three cases for N, like in your version, but 
 > > purely declaratively, and then the W separately:
 > >
 > >     if column-width = auto then
 > >       N := column-count
 > >     else if column-count = auto then
 > >       N := max(1, floor((U + column-gap)/(column-width + column-gap)))
 > >     else
 > >       N := min(column-count, max(1, 
 > >         floor((U + column-gap)/(column-width + column-gap))))
 > >
 > >   And:
 > >
 > >     W := max(0, ((U + column-gap)/N - column-gap)
 > 
 > Looks good.

Done. 

  http://dev.w3.org/csswg/css-multicol/#pseudo-algorithm

 > >> >   - these assumptions:
 > >> >       -- that the block direction is unconstrained
 > >> >       -- that no column breaks are added through style sheets
 > >> 
 > >> The used value of column-width isn't affected by breaks or block
 > >> direction restrictions, but used column-count may be, but that
 > >> depends on what "used" means in this case. The column-count property
 > >> has the following phases:
 > >> 
 > >> - Specified/computed (whatever the stylesheet or style attributes
 > >> says)
 > >> 
 > >> - After running the pseudo algorithm
 > >> 
 > >> - Actual layout
 > >> 
 > >> Consider this example:
 > >> 
 > >> <body style="width:600px;">
 > >>   <div style="column-width:200px; column-gap:0; height:2em;
 > >> line-height:1em;"> line<br>
 > >>      line<br>
 > >>      line<br>
 > >>      line<br>
 > >>      line<br>
 > >>      line<br>
 > >>      line<br>
 > >>    </div>
 > >> </body>
 > >> 
 > >> The computed value of column-count is auto.
 > >> The pseudo algorithm resolves column-count to 3.
 > >> Layout ends up with 4 columns, due to restricted height.
 > >> 
 > >> What if we define it so that *used* column-count in the example above
 > >> is 3, while *actual* column-count is 4 [1]? If we do that, you can
 > >> remove the assumptions.
 > >> 
 > >> [1] http://www.w3.org/TR/CSS21/cascade.html#value-stages
 > >
 > > That sounds attractive. Does it influence anything else apart from the 
 > > terminology in the spec?
 > 
 > No, it shouldn't.

I'd like to get rid of the assumptions, too, but I'm unsure if the
replaced text is simple.

Perhaps it could be expressed with something like:

  "The /used value/ for for /column-count/ is calculated without
  regard for explicit column breaks or constrained column lengths,
  while the /actual value/ takes these into consideration."

And then proceed with the example?

-h&kon
              Håkon Wium Lie                          CTO °þe®ª
howcome@opera.com                  http://people.opera.com/howcome
Received on Monday, 3 June 2013 23:17:09 UTC

This archive was generated by hypermail 2.3.1 : Monday, 2 May 2016 14:39:12 UTC