machine-generated version

Author: howcome

css-multicol/Overview.html

@@ -10,10 +10,10 @@
    rel=dcterms.rights>
   <meta content="CSS Multi-column Layout Module" name=dcterms.title>
   <meta content=text name=dcterms.type>
-  <meta content=2013-02-07 name=dcterms.issued>
+  <meta content=2013-05-10 name=dcterms.date>
   <meta content="Håkon Wium Lie" name=dcterms.creator>
   <meta content=W3C name=dcterms.publisher>
-  <meta content="http://www.w3.org/TR/2013/ED-css3-multicol-20130207/"
+  <meta content="http://dev.w3.org/csswg/css3-multicol/"
    name=dcterms.identifier>
   <link href="../default.css" rel=stylesheet type="text/css">
   <link href="http://www.w3.org/StyleSheets/TR/W3C-ED.css" rel=stylesheet
@@ -38,13 +38,13 @@
 
    <h1>CSS Multi-column Layout Module</h1>
 
-   <h2 class="no-num no-toc" id=w3c-working>Editor's Draft 7 February 2013</h2>
+   <h2 class="no-num no-toc" id=w3c-working>Editor's Draft 10 May 2013</h2>
 
    <dl>
     <dt>This version:
 
     <dd>
-     <!--<a href="http://www.w3.org/TR/2013/CR-css3-multicol-20130207">http://www.w3.org/TR/2013/ED-css3-multicol-20130207/</a>-->
+     <!--<a href="http://www.w3.org/TR/2013/CR-css3-multicol-20130510">http://dev.w3.org/csswg/css3-multicol/</a>-->
      <a
      href="http://dev.w3.org/csswg/css3-multicol/">http://dev.w3.org/csswg/css3-multicol/</a>
 
@@ -58,13 +58,14 @@ <h2 class="no-num no-toc" id=w3c-working>Editor's Draft 7 February 2013</h2>
     <dd><a
      href="http://www.w3.org/TR/2009/CR-css3-multicol-20091217/">http://www.w3.org/TR/2009/CR-css3-multicol-20091217/</a>
 
-  <dt>Feedback:</dt>
-    <dd><a href="mailto:www-style@w3.org?subject=%5Bcss-multicol%5D%20feedback"
-         >www-style@w3.org</a> 
-         with subject line &ldquo;<kbd>[css-multicol] 
-         <var>&hellip; message topic &hellip;</var></kbd>&rdquo;
-         (<a rel="discussion" href="http://lists.w3.org/Archives/Public/www-style/"
-           >archives</a>)
+    <dt>Feedback:
+
+    <dd><a
+     href="mailto:www-style@w3.org?subject=%5Bcss-multicol%5D%20feedback">www-style@w3.org</a>
+     with subject line “<kbd>[css-multicol] <var>… message topic
+     …</var></kbd>” (<a
+     href="http://lists.w3.org/Archives/Public/www-style/"
+     rel=discussion>archives</a>)
 
     <dt>Editors:
 
@@ -117,20 +118,22 @@ <h2 class="no-num no-toc" id=status-of-this-document>Status of this
    “css3-multicol” in the subject, preferably like this:
    “[<!---->css3-multicol<!---->] <em>…summary of comment…</em>”
 
-  <p>This document was produced by the <a href="/Style/CSS/members">CSS
-   Working Group</a> (part of the <a href="/Style/">Style Activity</a>).
+  <p>This document was produced by the <a
+   href="http://www.w3.org/Style/CSS/members">CSS Working Group</a> (part of
+   the <a href="http://www.w3.org/Style/">Style Activity</a>).
 
   <p>This document was produced by a group operating under the <a
-   href="/Consortium/Patent-Policy-20040205/">5 February 2004 W3C Patent
-   Policy</a>. W3C maintains a <a href="/2004/01/pp-impl/32061/status"
+   href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February
+   2004 W3C Patent Policy</a>. W3C maintains a <a
+   href="http://www.w3.org/2004/01/pp-impl/32061/status"
    rel=disclosure>public list of any patent disclosures</a> made in
    connection with the deliverables of the group; that page also includes
    instructions for disclosing a patent. An individual who has actual
    knowledge of a patent which the individual believes contains <a
-   href="/Consortium/Patent-Policy-20040205/#def-essential">Essential
+   href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential
    Claim(s)</a> must disclose the information in accordance with <a
-   href="/Consortium/Patent-Policy-20040205/#sec-Disclosure">section 6 of the
-   W3C Patent Policy</a>.</p>
+   href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section
+   6 of the W3C Patent Policy</a>.</p>
   <!--end-status-->
 
   <p>This document has been a Working Draft in the CSS Working Group for
@@ -949,25 +952,20 @@ <h3 id=pseudo-algorithm><span class=secno>3.4. </span>Pseudo-algorithm</h3>
   <p>The pseudo-algorithm below determines the used values for ‘<a
    href="#column-count"><code class=property>column-count</code></a>’ (N)
    and ‘<a href="#column-width"><code
-   class=property>column-width</code></a>’ (W). There are two other
-   variables in the pseudo-algorithm:
-
-  <ul>
-   <li><code>available-width</code>: if the used width of the multi-column
-    element has not been determined when the ‘<a href="#column-count"><code
-    class=property>column-count</code></a>’ and ‘<a
-    href="#column-width"><code class=property>column-width</code></a>’ must
-    be determined (e.g., if it is floating with a ‘<code
-    class=property>width</code>’ of ‘<code class=property>auto</code>’
-    as per CSS 2.1 section 10.3.5) this variable is <code>unknown</code>,
-    otherwise it is the same as the used width of the multi-column element.
-    In vertical text, the used height replaces used width in this
-    calculation.
-
-   <li><code>shrink-to-fit</code>: this variable represents the result of a
-    <em>shrink-to-fit</em> computation. CSS does not define the exact
-    algorithm.
-  </ul>
+   class=property>column-width</code></a>’ (W). There is one other variable
+   in the pseudo-algorithm: U is the used width of the multi-column element.
+
+  <p class=note>The used width U of the multi-column element can depend on
+   the element's contents, in which case it also depends on the computed
+   values of the ‘<a href="#column-count"><code
+   class=property>column-count</code></a>’ and ‘<a
+   href="#column-width"><code class=property>column-width</code></a>’
+   properties. This specification does not define how U is calculated.
+   Another module (probably the Basic Box Model <a href="#CSS3BOX"
+   rel=biblioentry>[CSS3BOX]<!--{{CSS3BOX}}--></a> or the Intrinsic &
+   Extrinsic Sizing Module <a href="#CSS3-SIZING"
+   rel=biblioentry>[CSS3-SIZING]<!--{{CSS3-SIZING}}--></a>) is expected to
+   define this.
 
   <p>Two assumptions are being made by the pseudo-algorithm:
 
@@ -977,51 +975,13 @@ <h3 id=pseudo-algorithm><span class=secno>3.4. </span>Pseudo-algorithm</h3>
    <li>that no column breaks are added through style sheets
   </ul>
 
-  <p>The <code>floor()</code> function rounds a number to the next smaller
-   integer. <!--
-<pre>
-(01)  if ((column-width = auto) and (column-count = auto)) or
-(02)     ((available-width = unknown) and (column-count = auto)) then
-(03)    exit; /* no columns */
-(04)  fi
-(05)  
-(06)  if (available-width = unknown) and (column-count != auto) and (column-width != auto) then
-(07)    N := column-count;  
-(08)    W := column-width;
-(09)    exit;
-(10)  fi
-(11)  
-(12)  if (available-width = unknown) then
-(13)    available-width := shrink-to-fit;
-(14)  fi
-(15)  
-(16)  if (column-width = auto) then
-(18)    N := column-count;
-(19)    W := max(0, (available-width - ((N - 1) * column-gap))/N);
-(27)  elsif (column-count = auto) then
-(28)    if (column-width >= available-width) then
-(29)      N := 1
-(30)      W := available-width;
-(31)    else
-(32)      N := floor((available-width + column-gap) / (column-width + column-gap));
-(33)      W := ((available-width + column-gap) / N) - column-gap;
-(34)    fi
-(35)  elsif (column-width >= available-width) then
-(36)    N := 1
-(37)    W := available-width;
-(38)  else
-(39)    N := min(column-count, floor((available-width + column-gap) / (column-width + column-gap)))
-(40)    W := ((available-width + column-gap) / N) - column-gap;
-(41)  fi
-</pre>
-
-<p><span class=issue>Alternative encoding of pseudo-algorithm:
--->
+  <p>The <code>floor(X)</code> function returns the largest integer Y ≤ X.
 
   <pre>
 (01)  if ((column-width = auto) and (column-count = auto)) then
 (02)        exit; /* not a multicol element */
 
+<!--
 (03)  if ((available-width = unknown) and (column-count = auto)) then
 (04)    exit; /* no columns */
 
@@ -1032,22 +992,23 @@ <h3 id=pseudo-algorithm><span class=secno>3.4. </span>Pseudo-algorithm</h3>
 
 (09)  if (available-width = unknown) then
 (10)    available-width := shrink-to-fit;
+-->
 
-(11)  if (column-width = auto) and (column-count != auto) then
-(12)    N := column-count;
-(13)    W := max(0, (available-width - ((N - 1) * column-gap)) / N);
-(14)  exit;
-
-(15)  if (column-width != auto) and (column-count = auto) then
-(16)    N := max(1, floor((available-width + column-gap) / (column-width + column-gap)));
-(17)    W := ((available-width + column-gap) / N) - column-gap;
-(18)  exit;
-
-(19)  if (column-width != auto) and (column-count != auto) then
-(20)    N := min(column-count, floor((available-width + column-gap) / (column-width + column-gap)))
-(21)    N := max(1, N); 
-(22)    W := ((available-width + column-gap) / N) - column-gap;
-(23)  exit
+(03)  if (column-width = auto) and (column-count != auto) then
+(04)    N := column-count;
+(05)    W := max(0, (U - ((N - 1) * column-gap)) / N);
+(06)  exit;
+
+(07)  if (column-width != auto) and (column-count = auto) then
+(08)    N := max(1, floor((U + column-gap) / (column-width + column-gap)));
+(09)    W := ((U + column-gap) / N) - column-gap;
+(10)  exit;
+
+(11)  if (column-width != auto) and (column-count != auto) then
+(12)    N := min(column-count, floor((U + column-gap) / (column-width + column-gap)))
+(13)    N := max(1, N); 
+(14)    W := ((U + column-gap) / N) - column-gap;
+(15)  exit
 </pre>
 
   <p>In paged media, user agents may perform this calculation on a per-page
@@ -1063,7 +1024,7 @@ <h3 id=pseudo-algorithm><span class=secno>3.4. </span>Pseudo-algorithm</h3>
    columns. However, both ‘<a href="#column-width"><code
    class=property>column-width</code></a>’ and ‘<a
    href="#column-count"><code class=property>column-count</code></a>’ are
-   honored when the width of the element has not been determined. This can,
+   honored when the width of the element depends on its contents. This can,
    e.g., be the case for table cells and floats.
 
   <h3 id=stacking-context><span class=secno>3.5. </span>Stacking context</h3>
@@ -1087,8 +1048,9 @@ <h2 id=column-gaps-and-rules><span class=secno>4. </span>Column gaps and
    will not alter the placement of anything else. If a column rule is wider
    than its gap, the adjacent column boxes will overlap the rule, and the
    rule may possibly extend outside the box of the multicol element. Column
-   rules are painted just above the background of the multicol element.
-   Column rules are only drawn between two columns that both have content.
+   rules are painted in the inline content layer, but below all inline
+   content inside the multicol element. Column rules are only drawn between
+   two columns that both have content.
 
   <h3 id=column-gap><span class=secno>4.1. </span>‘<a
    href="#column-gap0"><code class=property>column-gap</code></a>’</h3>
@@ -2005,14 +1967,14 @@ <h3 id=column-span><span class=secno>6.1. </span>‘<a
   <h2 id=filling-columns><span class=secno>7. </span>Filling columns</h2>
 
   <p>There are two strategies for filling columns: columns can either be
-   balanced, or not. If columns are balanced, user agents should try to fill
-   all columns in a row so that the columns appear to have the same amount of
-   content, while also trying to minimize the overflow content. If columns
-   are not balanced, they are filled sequentially; some columns may end up
-   partially filled, or with no content at all. In any case, user agents must
-   honor forced page breaks and should try to honor ‘<code
-   class=property>widows</code>’, ‘<code class=property>orphans</code>’
-   and other properties that may affect column lengths.
+   balanced, or not. If columns are balanced, user agents should try to
+   minimize the variation in content between columns, while also trying to
+   minimize the overflow content. If columns are not balanced, they are
+   filled sequentially; some columns may end up partially filled, or with no
+   content at all. In any case, user agents must honor forced page breaks and
+   should try to honor ‘<code class=property>widows</code>’, ‘<code
+   class=property>orphans</code>’ and other properties that may affect
+   column lengths.
 
   <h3 id=cf><span class=secno>7.1. </span>‘<a href="#column-fill"><code
    class=property>column-fill</code></a>’</h3>
@@ -2093,7 +2055,7 @@ <h2 id=overflow><span class=secno>8. </span>Overflow</h2>
   <h3 id=overflow-inside-multicol-elements><span class=secno>8.1.
    </span>Overflow inside multicol elements</h3>
 
-  <p>Content in the normal flow that extends into column gaps (e.g., long
+  <p>Floated or in-flow content that extends into column gaps (e.g., long
    words or images) is clipped in the middle of the column gap.
 
   <div class=example>
@@ -2459,7 +2421,7 @@ <h3 id=cr-exit-criteria><span class=secno>9.1. </span>CR exit criteria</h3>
   <h2 class=no-num id=acknowledgments>Acknowledgments</h2>
 
   <p>This document is based on several older proposals and comments on older
-   proposals. Contributors include Øyvind Stenhaug, Sylvain Galineau,
+   proposals. Contributors include Øyvind Stenhaug, Sylvain Galineau,
    Giovanni Campagna, David Hyatt, David Singer, David Woolley, Elika Etemad,
    Björn Höhrmann, Joost de Valk, Peter-Paul Koch, Shelby Moore, Till
    Halbach, Cédric Savarese, Andy Clarke, Robert O'Callahan, Markus Mielke,
@@ -2475,16 +2437,16 @@ <h3 class=no-num id=normative-references>Normative references</h3>
   <!-- Sorted by label -->
 
   <dl class=bibliography>
-   <dt style="display: none"><!-- keeps the doc valid if the DL is empty -->
+   <dd style="display: none"><!-- keeps the doc valid if the DL is empty -->
     <!---->
 
    <dt id=CSS21>[CSS21]
 
    <dd>Bert Bos; et al. <a
-    href="http://www.w3.org/TR/2011/REC-CSS2-20110607/"><cite>Cascading Style
+    href="http://www.w3.org/TR/2011/REC-CSS2-20110607"><cite>Cascading Style
     Sheets Level 2 Revision 1 (CSS 2.1) Specification.</cite></a> 7 June
     2011. W3C Recommendation. URL: <a
-    href="http://www.w3.org/TR/2011/REC-CSS2-20110607/">http://www.w3.org/TR/2011/REC-CSS2-20110607/</a>
+    href="http://www.w3.org/TR/2011/REC-CSS2-20110607">http://www.w3.org/TR/2011/REC-CSS2-20110607</a>
    </dd>
    <!---->
 
@@ -2504,8 +2466,28 @@ <h3 class=no-num id=other-references>Other references</h3>
   <!-- Sorted by label -->
 
   <dl class=bibliography>
-   <dt style="display: none"><!-- keeps the doc valid if the DL is empty -->
+   <dd style="display: none"><!-- keeps the doc valid if the DL is empty -->
     <!---->
+
+   <dt id=CSS3-SIZING>[CSS3-SIZING]
+
+   <dd>Tab Atkins Jr.; Elika J. Etemad. <a
+    href="http://www.w3.org/TR/2012/WD-css3-sizing-20120927/"><cite>CSS
+    Intrinsic &amp; Extrinsic Sizing Module Level 3.</cite></a> 27 September
+    2012. W3C Working Draft. (Work in progress.) URL: <a
+    href="http://www.w3.org/TR/2012/WD-css3-sizing-20120927/">http://www.w3.org/TR/2012/WD-css3-sizing-20120927/</a>
+   </dd>
+   <!---->
+
+   <dt id=CSS3BOX>[CSS3BOX]
+
+   <dd>Bert Bos. <a
+    href="http://www.w3.org/TR/2007/WD-css3-box-20070809"><cite>CSS basic box
+    model.</cite></a> 9 August 2007. W3C Working Draft. (Work in progress.)
+    URL: <a
+    href="http://www.w3.org/TR/2007/WD-css3-box-20070809">http://www.w3.org/TR/2007/WD-css3-box-20070809</a>
+   </dd>
+   <!---->
   </dl>
   <!--end-informative-->