[css3-multicol] new editor's draft

A new editor's draft is of css3-multicol is available:

  http://dev.w3.org/csswg/css3-multicol/

Here are the changes:

1) It has been clarified that all column heights in a row are the same
height. This is clearly stated in section 2, but this text (in
section 7) can be misleading and uses the wrong term ("lengths"):

  Otherwise, columns are filled sequentially and will therefore end up
  having different lengths.

It has been changed to:

  Otherwise, columns are filled sequentially and some columns may end
  up partially filled, or with no content at all.

2) To clarify that constrained column heights result in extra column
boxes in the inline direction even in paged media, section 8.2 now
starts with:

  Content that extend outside column boxes at the edges of the
  multi-column element is clipped according to the 'overflow'
  property. A multicol element can have more columns than it has room
  for due to:

   - a declaration that constrains the column height (e.g., using
     'height' or 'max-height'). In this case, additional column boxes
     are created in the inline direction

   - the size of the page. In this case, additional column boxes are
     moved to the next page(s).

   - explicit column breaks. In this case, additional column boxes are
     created in the inline direction for continous media, and
     additional column boxes are moved to the next page(s) for paged
     media.

These lines have been removed:

  In continuous media, columns that do not fit within the multicol
  element are added in the inline direction.

  In paged media, columns that do not fit within the page are moved to
  the next page.


3) An implementor has pointed out that the current text may be
interpreted as saying that all columns of a paginated element should
have the same width. This is incorrect -- we must allow columns to
adapt to the avilable width for each page, like we do for other content.
This text in section 2:

   All column boxes in a multi-column element have the same column
   width, and all column boxes in a row have the same column height.

has therefore been changed to:

   All column boxes in a row have the same column width, and all
   column boxes in a row have the same column height.

4) It bas been clarified that column rules may extend outside the
multicol box, and -- if so -- they obey the 'overflow' property:

This text:

  If a column rule is wider than its gap, the column rule will overlap
  adjacent column boxes.

has been changed to:

  If a column rule is wider than its gap, the column rule will overlap
  adjacent column boxes, and possibly extend outside the box of the
  multicol element.

And, In section 8.2, this text:

   Content that extend outside column boxes at the edges of the
   multi-column element is clipped according to the ‘overflow’
   property.

has been changed to:

   Content and column rules that extend outside column boxes at the
   edges of the multi-column element is clipped according to the
   ‘overflow’ property.

5) As per Alex's proposal, this text has been added to the description
of the 'column-span' element:

   This property has no effect on elements that no not fit entirely
   within the multicol element. Also, if a setting on this property pushes the
   element outside a multicol element, this property will have no effect.

6) The break-* properties have been given their own h3 element.

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Some other notes, mostly to myself:

---

I've been tempted to introduce the term "multicol box" to mean "the
content box(es) of a multicol element". That would be slightly more
accurate. However, I think the current text works.

---

The figures should use images instead of elements that rely on certain
fonts etc.

---

At the F2F meeting in Oslo, we agreed that column balancing applies to
multicol boxes with specified height. However, I don't see that this
needs clarifiction. Section 7 states that 'colum-fill' applies to
'multicol elements' and:

  In continuous media, this property will only be consulted if the
  length of columns has been constrained.

So, no change there.

---

-h&kon
              Håkon Wium Lie                          CTO °þe®ª
howcome@opera.com                  http://people.opera.com/howcome

Received on Thursday, 21 October 2010 22:29:53 UTC