Another abandoned server code base... this is kind of an ancestor of taskrambler.
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">
<html lang=en>
<head profile="http://www.w3.org/2006/03/hcard"><meta
content="text/html; charset=utf-8" http-equiv=Content-Type>
<title>CSS Regions Module Level 3</title>
<link href=default.css rel=stylesheet type="text/css">
<style type="text/css">
/* Alternate stylesheet fonts are here because in some browsers (Opera 11.5) */
/* The fonts are not applied if only loaded from the alternate stylesheet */
/* License font the following two fonts: fonts/Droid-Serif-fontfacekit/Google Android License.txt */
@import url(fonts/Droid-Serif-fontfacekit/stylesheet.css);
@import url(fonts/Droid-Sans-Mono-fontfacekit/stylesheet.css);
/*
@import url(http://fonts.googleapis.com/css?family=Droid+Serif:700,400,400italic,700italic);
@import url(http://fonts.googleapis.com/css?family=Droid+Sans+Mono);
*/
a.toggle {
position: fixed;
top: 0.5em;
right: 0.5em;
font-size: smaller;
color: gray;
opacity: 0.2;
}
a.toggle:hover {
opacity: 1;
color: #46A4E9;
}
.issue.resolved, .issue.stale, .issue.moved {
display: none;
}
#region-style-example p, #region-style-example pre {
clear: both;
}
#region_styling_illustration {
margin: 0px auto;
width: 70ex;
}
.big.note {
font-size: 1.2em;
line-height: 1.3em;
color: #2f2f2f;
}
.big.note:before {
content: "NOTE";
display: block;
color: rgba(0, 0, 0, 0.15);
font-weight: bold;
margin-bottom: 0.5em;
}
</style>
<link href="http://www.w3.org/StyleSheets/TR/W3C-WD.css" rel=stylesheet
type="text/css">
<link href=alternate-spec-style.css id=st rel=stylesheet
title="additional spec styles" type="text/css">
<body>
<div class=head id=div-head> <!--begin-logo-->
<p><a href="http://www.w3.org/"><img alt=W3C height=48
src="http://www.w3.org/Icons/w3c_home" width=72></a> <!--end-logo--></p>
<h1 id=css-regions-module>CSS Regions Module Level 3</h1>
<h2 class="no-num no-toc" id=longstatus-date>W3C Working Draft 29 November
2011</h2>
<dl>
<dt>This version:
<dd><a
href="http://www.w3.org/TR/2011/WD-css3-regions-20111129/">http://www.w3.org/TR/2011/WD-css3-regions-20111129/</a>
<dt>Latest version:
<dd><a
href="http://www.w3.org/TR/css3-regions/">http://www.w3.org/TR/css3-regions/</a>
<dt>Previous version:
<dd><a
href="http://www.w3.org/TR/2011/WD-css3-regions-20110609/">http://www.w3.org/TR/2011/WD-css3-regions-20110609/</a>
<dt>Editors:
<dd class=vcard><span class=fn>Vincent Hardy</span>, <span
class=org>Adobe Systems, Inc.</span>, <span
class=email>vhardy@adobe.com</span>
<dd class=vcard><span class=fn>Alex Mogilevsky</span>, <span
class=org>Microsoft</span>, <span
class=email>alexmog@microsoft.com</span>
</dl>
<!--begin-copyright-->
<p class=copyright><a
href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright"
rel=license>Copyright</a> &copy; 2011 <a
href="http://www.w3.org/"><acronym
title="World Wide Web Consortium">W3C</acronym></a><sup>&reg;</sup> (<a
href="http://www.csail.mit.edu/"><acronym
title="Massachusetts Institute of Technology">MIT</acronym></a>, <a
href="http://www.ercim.eu/"><acronym
title="European Research Consortium for Informatics and Mathematics">ERCIM</acronym></a>,
<a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C <a
href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
<a
href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a>
and <a
href="http://www.w3.org/Consortium/Legal/copyright-documents">document
use</a> rules apply.</p>
<!--end-copyright-->
<hr title="Separator for header">
</div>
<h2 class="no-num no-toc" id=abstract>Abstract</h2>
<p>The CSS regions module allows content to flow across multiple areas
called regions. The regions are not necessarily contiguous in the document
order. The CSS regions module provides an advanced content flow mechanism,
which can be combined with positioning schemes as defined by other CSS
modules such as the Multi-Column Module <a href="#CSS3COL"
rel=biblioentry>[CSS3COL]<!--{{CSS3COL}}--></a> or the Grid Layout Module
<a href="#CSS3-GRID-LAYOUT"
rel=biblioentry>[CSS3-GRID-LAYOUT]<!--{{CSS3-GRID-LAYOUT}}--></a> to
position the regions where content flows.
<h2 class="no-num no-toc" id=status-of-this-document>Status of this
document</h2>
<p class="big note">This document uses an experimental style sheet. We
welcome your feedback on the styles at <a
href="mailto:site-comments@w3.org">site-comments@w3.org</a>.</p>
<!--begin-status-->
<p><em>This section describes the status of this document at the time of
its publication. Other documents may supersede this document. A list of
current W3C publications and the latest revision of this technical report
can be found in the <a href="http://www.w3.org/TR/">W3C technical reports
index at http://www.w3.org/TR/.</a></em>
<p>Publication as a Working Draft does not imply endorsement by the W3C
Membership. This is a draft document and may be updated, replaced or
obsoleted by other documents at any time. It is inappropriate to cite this
document as other than work in progress.
<p>The (<a
href="http://lists.w3.org/Archives/Public/www-style/">archived</a>) public
mailing list <a href="mailto:www-style@w3.org">www-style@w3.org</a> (see
<a href="http://www.w3.org/Mail/Request">instructions</a>) is preferred
for discussion of this specification. When sending e-mail, please put the
text &#8220;css3-regions&#8221; in the subject, preferably like this:
&#8220;[<!---->css3-regions<!---->] <em>&hellip;summary of
comment&hellip;</em>&#8221;
<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="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="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential
Claim(s)</a> must disclose the information in accordance with <a
href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section
6 of the W3C Patent Policy</a>.</p>
<!--end-status-->
<p>This draft is related to the drafts about Multi-column Layout <a
href="#CSS3COL" rel=biblioentry>[CSS3COL]<!--{{CSS3COL}}--></a>, Grid
Layout <a href="#CSS3GRID"
rel=biblioentry>[CSS3GRID]<!--{{CSS3GRID}}--></a>, Flexible Box Layout <a
href="#CSS3-FLEXBOX"
rel=biblioentry>[CSS3-FLEXBOX]<!--{{CSS3-FLEXBOX}}--></a>, and Template
Layout <a href="#CSS3LAYOUT"
rel=biblioentry>[CSS3LAYOUT]<!--{{CSS3LAYOUT}}--></a>.
<h2 class="no-num no-toc" id=table-of-contents>Table of contents</h2>
<!--begin-toc-->
<ul class=toc>
<li><a href="#introduction"><span class=secno>1. </span>Introduction</a>
<ul class=toc>
<li><a href="#named-flows-and-regions"><span class=secno>1.1.
</span>Named flows and regions</a>
<li><a href="#region-styling"><span class=secno>1.2. </span>Regions
styling</a>
</ul>
<li><a href="#css-regions-concepts"><span class=secno>2. </span>CSS
regions concepts</a>
<ul class=toc>
<li><a href="#regions"><span class=secno>2.1. </span>Regions</a>
<li><a href="#named-flow"><span class=secno>2.2. </span>Named flow</a>
<li><a href="#regions-flow-breaking-rules"><span class=secno>2.3.
</span>Regions flow breaking rules</a>
</ul>
<li><a href="#relation-to-document-events"><span class=secno>3.
</span>Relation to document events</a>
<li><a href="#properties-and-rules"><span class=secno>4. </span>Properties
and rules</a>
<ul class=toc>
<li><a href="#the-flow-into-property"><span class=secno>4.1. </span>The
&lsquo;<code class=property>flow-into</code>&rsquo; property</a>
<li><a href="#the-flow-from-property"><span class=secno>4.2. </span>The
&lsquo;<code class=property>flow-from</code>&rsquo; property</a>
<ul class=toc>
<li><a href="#auto-width-on-regions"><span class=secno>4.2.1.
</span>Auto width on regions</a>
<li><a href="#auto-height-on-regions"><span class=secno>4.2.2.
</span>Auto height on regions</a>
</ul>
<li><a href="#region-flow-break"><span class=secno>4.3. </span>Region
flow break properties: &lsquo;<code
class=property>break-before</code>&rsquo;, &lsquo;<code
class=property>break-after</code>&rsquo;, &lsquo;<code
class=property>break-inside</code>&rsquo;</a>
<li><a href="#the-region-overflow-property"><span class=secno>4.4.
</span>The region-overflow property</a>
<li><a href="#the-at-region-style-rule"><span class=secno>4.5.
</span>The @region rule</a>
</ul>
<li><a href="#pseudo_elements"><span class=secno>5.
</span>Pseudo-elements</a>
<ul class=toc>
<li><a href="#processing-model"><span class=secno>5.1. </span>Processing
model</a>
</ul>
<li><a href="#cssom_view_and_css_regions"><span class=secno>6.
</span>CSSOM view and CSS regions</a>
<ul class=toc>
<li><a href="#the-namedflow-interface"><span class=secno>6.1. </span>The
NamedFlow interface</a>
<li><a href="#extension-to-the-element-interface"><span class=secno>6.2.
</span>Extension to the Element interface</a>
<li><a href="#region-flow-layout-events"><span class=secno>6.3.
</span>Region flow layout events</a>
</ul>
<li><a href="#relation-to-other-specifications"><span class=secno>7.
</span>Relation to other specifications</a>
<li><a href="#usecases"><span class=secno>8. </span>Use Cases</a>
<li><a href="#conformance"><span class=secno>9. </span>Conformance</a>
<li><a href="#changes"><span class=secno>10. </span>Changes</a>
<ul class=toc>
<li><a href="#changes_from_June_09_2011"><span class=secno>10.1.
</span>Changes from June 09<sup>th</sup> 2011 version</a>
</ul>
<li class=no-num><a href="#acknowledgments">Acknowledgments</a>
<li class=no-num><a href="#references">References</a>
<ul class=toc>
<li class=no-num><a href="#normative-references">Normative
references</a>
<li class=no-num><a href="#other-references">Other references</a>
</ul>
<li class=no-num><a href="#index">Index</a>
<li class=no-num><a href="#property-index">Property index</a>
</ul>
<!--end-toc-->
<h2 id=introduction><span class=secno>1. </span>Introduction</h2>
<p><em>This section is non-normative.</em>
<p>Capturing the complex layouts of a typical magazine, newspaper, or
textbook requires capabilities beyond those available in existing CSS
modules. This is the purpose of the CSS regions module.
<p>The CSS regions module can be seen as an extension of the concept of
multi-column elements. With CSS Multi-column layout <a href="#CSS3COL"
rel=biblioentry>[CSS3COL]<!--{{CSS3COL}}--></a>, columns share the same
dimensions and define column boxes organized in rows. Content flows from
one column to the next.
<p>The multi-column model is an example of flowing content from one area to
another, where the areas are the multi-column element's column boxes and
the flow is made of the multi-column element's children.
<p>However, for more complex layouts, content needs to flow from one area
of the page to the next without limitation of the areas' sizes and
positions. These arbitrary areas are the target of specific content flows.
In this document these areas are called regions, and the content flows are
called named flows. Regions are based on the rectangular geometry of the
CSS box model. Elements in a named flow are taken out of the normal visual
formatting and rendered in a chain of regions.
<h3 id=named-flows-and-regions><span class=secno>1.1. </span>Named flows
and regions</h3>
<p>Consider the layout illustrated in figure 1.
<div class=figure> <img
alt="multiple chained regions which should receive content from a flow"
src="images/regions-intro.svg" width=400>
<p class=caption>Layout requiring sophisticated content flow</p>
</div>
<p>The designer's intent is to position an image in region &lsquo;<code
class=property>A</code>&rsquo; and to flow an article's text from region
&lsquo;<code class=css>1</code>&rsquo;, to region &lsquo;<code
class=css>2</code>&rsquo;, &lsquo;<code class=css>3</code>&rsquo; and
&lsquo;<code class=css>4</code>&rsquo;.
<p>The following code snippet shows the content to flow between the regions
1, 2, 3 and 4.
<pre>
&lt;div <em>id="article"</em>&gt;
&lt;h1&gt;Introduction&lt;/h1&gt;
&lt;p&gt;This is an example ...&lt;/p&gt;
&lt;h1&gt;More Details&lt;/h1&gt;
&lt;p&gt;This illustrates ...&lt;/p&gt;
&lt;p&gt;Then, the example ...&lt;/p&gt;
&lt;p&gt;Finally, this ...&lt;/p&gt;
&lt;/div&gt;
</pre>
<p>And the following snippet shows an example of elements that will be used
as regions.
<pre>
&lt;div id="region1"&gt;&lt;/div&gt;
&lt;div id="region2"&gt;&lt;/div&gt;
&lt;div id="region3"&gt;&lt;/div&gt;
&lt;div id="region4"&gt;&lt;/div&gt;
</pre>
<p>CSS layout facilities can position and size regions as needed. However,
there is no existing mechanism to associate the content with the regions
so that content flows as intended. Figure 2 shows an example of the
intended visual rendering of the content.
<div class=figure> <img
alt="Sample rendering showing a single thread of text flowing through a chain of regions"
src="images/regions-intro-rendering.png" width=450>
<p class=caption>Sample rendering for desired layout</p>
</div>
<p>The CSS regions module is independent of the layout of regions and the
mechanism used to create them. However, for simplicity, our example uses
elements as regions as shown in the previous code snippet.
<p>The following code example illustrates how the content of the
<code>article</code> element becomes a flow and how the areas &lsquo;<code
class=css>region1</code>&rsquo;, &lsquo;<code
class=css>region2</code>&rsquo;, &lsquo;<code
class=css>region3</code>&rsquo; and &lsquo;<code
class=css>region4</code>&rsquo; become regions that consume the
&lsquo;<code class=css>article_flow</code>&rsquo; content.
<div class=example>
<pre>
&lt;style&gt;
#article {
<strong>flow-into: article_flow;</strong>
}
#region1, #region2, #region3, #region4 {
<strong>flow-from: article_flow;</strong>
}
&lt;/style&gt;
</pre>
</div>
<p>The &lsquo;<code class=css>article_flow</code>&rsquo; value on the
&lsquo;<a href="#flow-into"><code
class=property>flow-into</code></a>&rsquo; property directs the
&lsquo;<code class=css>#article</code>&rsquo; element to the &lsquo;<code
class=css>article_flow</code>&rsquo; named flow. Setting the elements'
&lsquo;<a href="#flow-from"><code
class=property>flow-from</code></a>&rsquo; property to &lsquo;<code
class=css>article_flow</code>&rsquo; on elements makes them regions and
associates these regions with the named flow: the flow is &lsquo;<code
class=css>poured</code>&rsquo; into the desired regions.
<h3 id=region-styling><span class=secno>1.2. </span>Regions styling</h3>
<p>Region styling allows content to be styled depending on the region it
flows into. It is a form of context-based styling, similar to Media
Queries <a href="#MEDIAQ" rel=biblioentry>[MEDIAQ]<!--{{MEDIAQ}}--></a>
which enable or disable selectors depending on the rendering context. With
region styling, additional selectors may apply depending on the region
into which content flows.
<p>In our example, the designer wants to make text flowing into region 1
larger, bold and dark blue. In addition, <code
class=html>&lt;h1&gt;</code> headers should be crimson.
<p>This design can be expressed with region styling as shown below.
<div class=example>
<pre>
&lt;style&gt;
/*
* Default article styling.
*/
#article {
color:#777;
text-align: justify;
}
#article h1 {
border-left: 1px solid #777;
padding-left: 2ex;
display: run-in;
}
/*
* Additional styling to apply to content when it falls into
* region1
*/
<strong>@region #region1 {</strong>
#article {
font-weight: bold;
color: #0C3D5F;
font-size: larger;
}
#article h1 {
color: crimson;
border: none;
padding: 0px;
}
<strong>}</strong>
&lt;/style&gt;
</pre>
</div>
<p>The &lsquo;<code class=css>@region</code>&rsquo; rule for region 1
limits its selectors to content flowing into region 1. The following
figure shows how the rendering changes if we do not increase the font size
nor make it bold for content flowing into region 1. As more content can be
fitted, more content is subject to the contextual selectors, resulting in
more dark blue text into region 1.
<div class=figure> <img
alt="Illustrate how changing region styling affects the flow of content."
src="images/region-styling.png" width=450>
<p class=caption>Different rendering with a different region styling</p>
</div>
<h2 id=css-regions-concepts><span class=secno>2. </span>CSS regions
concepts</h2>
<p><em>This section is non-normative.</em>
<h3 id=regions><span class=secno>2.1. </span>Regions</h3>
<p class=index id=region title=region>A region is an element that generates
a <a href="http://www.w3.org/TR/CSS21/visuren.html#block-boxes">block
container box</a> and has an associated <a href="#named-flow0"><em>named
flow</em></a> (see the &lsquo;<a href="#flow-from"><code
class=property>flow-from</code></a>&rsquo; property).
<div class="issue moved">
<p>See <a
href="http://wiki.csswg.org/spec/css3-regions#issue-2-auto-sizing-of-regions"></a></p>
.
<p>There was a recent discussion on intrinsic sizing of regions which <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jun/0629.html">has
not been resolved</a></p>
.</div>
<h3 id=named-flow><span class=secno>2.2. </span>Named flow</h3>
<p>A <dfn id=named-flow0>named flow</dfn> is the ordered sequence of
elements associated with a flow with a given identifier. Elements in a
named flow are ordered according to the document order.
<p>Elements are placed into a named flow with the &lsquo;<a
href="#flow-into"><code class=property>flow-into</code></a>&rsquo;
property. The elements in a named flow are laid out in the chain of
regions that are associated with this named flow. <span
title=region>Regions</span> are organized in to a <span
title=region-chain>region chain</span> according to the document order.
<p>Content from a named flow is broken up between regions according to the
regions flow breaking rules.
<h3 id=regions-flow-breaking-rules><span class=secno>2.3. </span>Regions
flow breaking rules</h3>
<p>Breaking a named flow across multiple regions is similar to breaking a
document's content across multiple pages (see <a href="#CSS3PAGE"
rel=biblioentry>[CSS3PAGE]<!--{{CSS3PAGE}}--></a>) or a multi-column
element's content across column boxes (see <a href="#CSS3COL"
rel=biblioentry>[CSS3COL]<!--{{CSS3COL}}--></a>). One difference is that
page boxes are generated based on the available content whereas regions
are a predefined set of recipient boxes for the named flow content.
<p><span title=region>Regions</span> are organized in to a <span
title=region-chain>region chain</span>.
<p>Each region in turn consumes content from its associated <a
href="#named-flow0">named flow</a>. The named flow content is positioned
in the <dfn id=current-region title=current-region>current region</dfn>
until a natural or forced region break occurs, at which point the <a
href="#current-region" title=current-region>current region</a> becomes the
next one in the <span title=region-chain>region chain</span>. If there are
no more <span>region</span>s in the region chain and there is still
content in the flow, the positioning of the remaining content is
controlled by the &lsquo;<a href="#region-overflow"><code
class=property>region-overflow</code></a>&rsquo; property on the last
<span>region</span> in the chain.
<h2 id=relation-to-document-events><span class=secno>3. </span>Relation to
document events</h2>
<p><em>This section is normative.</em>
<p>The CSS regions module does not alter the normal processing of events in
the document tree. In particular, if an event occurs on an element that is
part of a named flow, the <a
href="http://www.w3.org/TR/DOM-Level-3-Events/#dom-event-architecture">event's
bubble and capture phases</a> happen following the document tree order.
<h2 id=properties-and-rules><span class=secno>4. </span>Properties and
rules</h2>
<p><em>This section is normative.</em>
<h3 id=the-flow-into-property><span class=secno>4.1. </span>The &lsquo;<a
href="#flow-into"><code class=property>flow-into</code></a>&rsquo;
property</h3>
<p>The ‘flow-into’ property can place an element into a named flow.
Elements that belong to the same flow are laid out in the regions
associated with that flow.
<table class=propdef summary="flow property definition">
<tbody>
<tr>
<th>Name:
<td><dfn id=flow-into>flow-into</dfn>
<tr>
<th>Value:
<td>&lt;ident&gt; | none | inherit
<tr>
<th>Initial:
<td>none
<tr>
<th>Applies to:
<td>any element
<tr>
<th>Inherited:
<td>no
<tr>
<th>Percentages:
<td>N/A
<tr>
<th>Media:
<td>visual
<tr>
<th>Computed&nbsp;value:
<td>as specified
</table>
<dl>
<dt>none
<dd>The element is not moved to a named flow and normal CSS processing
takes place.
<dt><a
href="http://www.w3.org/TR/2011/REC-CSS2-20110607/syndata.html#value-def-identifier">&lt;ident&gt;</a>
<dd>The element is placed into the flow with the name &lsquo;<code
class=css>&lt;ident&gt;</code>&rsquo;. The element is said to have a <dfn
id=specified-flow>specified flow</dfn>. The values &lsquo;<code
class=property>none</code>&rsquo;, &lsquo;<code
class=property>inherit</code>&rsquo;, &lsquo;<code
class=property>default</code>&rsquo;, &lsquo;<code
class=property>auto</code>&rsquo; and &lsquo;<code
class=property>initial</code>&rsquo; are invalid flow names.
</dl>
<p>A named flow needs to be associated with one or more regions for its
elements to be visually formatted. If no region is associated with a given
named flow, the elements in the named flow are not rendered: they do not
generate boxes and are not displayed.
<p>The children of an element with a specified flow may themselves have a
specified flow.
<p>If an element has the same specified flow as one of its ancestors, it
becomes a sibling of it's ancestor for the purpose of layout in the
regions laying out content from that flow.
<p>The &lsquo;<a href="#flow-into"><code
class=property>flow-into</code></a>&rsquo; property does not affect the
CSS cascade and inheritance for the elements on which it is specified. The
&lsquo;<a href="#flow-into"><code
class=property>flow-into</code></a>&rsquo; property affects the visual
formatting of elements placed into a named flow and of regions laying out
content from a named flow.
<p>The edges of the first region in a region chain associated with a named
flow establish the rectangle that is the initial containing block of the
named flow.
<p>The first region defines the <a
href="http://www.w3.org/TR/css3-writing-modes/#writing-mode">writing
mode</a> for the entire flow. The writing mode on subsequent regions is
ignored.
<p>Elements in a named flow are sequenced in document order.
<div class=note>
<p><em>This note is informative.</em></p>
<p>The &lsquo;<a href="#flow-into"><code
class=property>flow-into</code></a>&rsquo; property moves an element into
the flow and the interplay with selectors should be considered carefully.</p>
<p>For example,</p>
<pre>table {flow-into: table-content}</pre>
<p>will move all tables in the &lsquo;<code
class=property>table-content</code>&rsquo; named flow. However, the</p>
<pre>table * {flow-into: table-content}</pre>
<p>selector will move all the descendants of table elements in the
&lsquo;<code class=property>table-content</code>&rsquo; named flow. This
will make all the descendants of table elements siblings in the named
flow. Having the descendants become siblings in the named flow results in
a different processing (see the <a
href="http://www.w3.org/TR/2011/REC-CSS2-20110607/tables.html#anonymous-boxes">CSS
2.1&lsquo;<code class=css>s anonymous table objects</code></a>). This
note illustrates how authors must exercise caution when choosing a
particular selector for setting the &rsquo;flow-into' property to avoid
unintended results.</p>
</div>
<p>The &lsquo;<a href="#flow-into"><code
class=property>flow-into</code></a>&rsquo; property does not apply to the
<code class=css>::first-line</code> and <code
class=css>::first-character</code>.
<p>The effect of &lsquo;<a href="#flow-into"><code
class=property>flow-into</code></a>&rsquo; on generated content such as
<code class=css>::marker</code>, <code class=css>::before</code> and <code
class=css>::after</code> is undefined. This may change depending on
implementation feedback.
<h3 id=the-flow-from-property><span class=secno>4.2. </span>The &lsquo;<a
href="#flow-from"><code class=property>flow-from</code></a>&rsquo;
property</h3>
<p>The &lsquo;<a href="#flow-from"><code
class=property>flow-from</code></a>&rsquo; property makes an element a
region and associates it with a named flow.
<div class=issue-marker><a
href="http://wiki.csswg.org/spec/css3-regions#issue-12should-we-allow-multi-column-elements-to-be-regions">Issue-12</a></div>
<table class=propdef summary="flow-from property definition">
<tbody>
<tr>
<th>Name:
<td><dfn id=flow-from>flow-from</dfn>
<tr>
<th>Value:
<td>&lt;ident&gt; | none | inherit
<tr>
<th>Initial:
<td>none
<tr>
<th>Applies to:
<td>Elements that generate a <a
href="http://www.w3.org/TR/CSS21/visuren.html#block-boxes">block
container box</a>. <br>
This might be expanded in future versions of the specification to allow
other types of containers to receive flow content.
<tr>
<th>Inherited:
<td>no
<tr>
<th>Percentages:
<td>N/A
<tr>
<th>Media:
<td>visual
<tr>
<th>Computed&nbsp;value:
<td>as specified
</table>
<dl>
<dt><strong>none</strong>
<dd>The element is not a <span title=region>region</span>.
<dt><strong>&lt;ident&gt;</strong>
<dd> If the &lsquo;<code class=property>content</code>&rsquo; property
computes to something else than &lsquo;<code
class=property>normal</code>&rsquo;, the element does not become a
region. If the &lsquo;<code class=property>content</code>&rsquo; property
computes to &lsquo;<code class=property>normal</code>&rsquo;, then the
element becomes a <span>region</span> and is ordered in a <span>region
chain</span> according to its document order. The content from the flow
with the <a
href="http://www.w3.org/TR/2011/REC-CSS2-20110607/syndata.html#value-def-identifier">&lt;ident&gt;</a>
name will be <a href="#region-flow-break">broken into segments</a> and
visually formatted in the <a
href="http://www.w3.org/TR/CSS21/visuren.html#principal-box">principal
boxes</a> of the regions in the region chain. If there is no flow with
name &lt;ident&gt;, then the element does not format any content
visually. <br>
Likewise, if the element is part of the flow with name &lt;ident&gt;,
then the element does not format any content visually.
</dl>
<p class=note>A region's document children are not visually formatted
unless they are directed to a named flow referenced by one or more
regions.
<div class=note>
<p>An element becomes a region when its &lsquo;<a href="#flow-from"><code
class=property>flow-from</code></a>&rsquo; property is set to a valid
&lt;ident&gt; value, even if there is no content contributing to the
referenced flow. For example:</p>
<pre>
&lt;style&gt;
.article{
flow-into: thread;
}
.region{
flow-from: thread;
}
&lt;/style&gt;
&lt;html&gt;
&lt;body&gt;
&lt;div class=region&gt;div content&lt;/div&gt;
&lt;/body&gt;
&lt;/html&gt;
</pre>
There is no element matching the <code>.article</code> selector and
therefore no content in the <code>thread</code> flow. However, the element
matching the <code>.region</code> selector is still associated with that
empty named flow and, consequently, its children are not formatted
visually.</div>
<div class=issue-marker><a
href="http://wiki.csswg.org/spec/css3-regions#issue-23should-regions-be-non-breakable">Issue-23</a></div>
<p><span title=region>Regions</span> create a new <a
href="http://www.w3.org/TR/CSS2/visuren.html#z-index">stacking
context</a>. <span title=region>Regions</span> establish a new <a
href="http://www.w3.org/TR/CSS2/visuren.html#block-formatting">block
formatting Context</a>.
<p>If the &lsquo;<code class=property>content</code>&rsquo; property is
defined on a region, it has no effect on the region's visual formatting.
<div class=note>
<p><em>This note is informative.</em></p>
<p>With regions, an element may be split across multiple regions and these
regions may overlap (for example if they are absolutely positioned). So
fragments of the same element can overlap each other. Since each element
has a single z-index, it would be required to find another mechanism to
decide in which order the  fragments are rendered. Since each region
creates a new stacking context, it is clear that each region is rendered
separately and their rendering order follows the regular CSS rendering
model.</p>
</div>
<p> Floats or other exclusions (see <a href="#CSS3-EXCLUSIONS"
rel=biblioentry>[CSS3-EXCLUSIONS]<!--{{CSS3-EXCLUSIONS}}--></a>)
potentially impact the content laid out in regions, just as for
non-regions.
<div class=example>
<p>In the following example, the inline content coming from the <code
class=html>body_text</code> <a href="#named-flow0">named flow</a> wraps
around the <code class=html>#float</code> box.</p>
<pre>
&lt;style&gt;
#float {
float: left;
width: 100px;
height: 300px;
}
#region1, #region2 {
width: 200px;
height: 200px;
flow-from: body_text;
}
#content {
flow-into: body_text;
}
&lt;/style&gt;
&lt;div id="float"&gt;&lt;/div&gt;
&lt;div id="region1"&gt;&lt;/div&gt;
&lt;div id="region2"&gt;&lt;/div&gt;
&lt;div id="content"&gt;&lt;/div&gt;
</pre>
</div>
<h4 id=auto-width-on-regions><span class=secno>4.2.1. </span>Auto width on
regions</h4>
<p>If a region's &lsquo;<code class=property>width</code>&rsquo; property
is computed to &lsquo;<code class=property>auto</code>&rsquo;, its
resolved value is computed based on the region's <em>::before</em> and
<em>::after</em> generated content only.
<h4 id=auto-height-on-regions><span class=secno>4.2.2. </span>Auto height
on regions</h4>
<p>If a region's &lsquo;<code class=property>height</code>&rsquo; property
is computed to &lsquo;<code class=property>auto</code>&rsquo;, its
resolved value is computed based on the region's <em>::before</em> and
<em>::after</em> generated content only.
<h3 id=region-flow-break><span class=secno>4.3. </span>Region flow break
properties: &lsquo;<a href="#break-before"><code
class=property>break-before</code></a>&rsquo;, &lsquo;<a
href="#break-after"><code class=property>break-after</code></a>&rsquo;,
&lsquo;<a href="#break-inside"><code
class=property>break-inside</code></a>&rsquo;</h3>
<p>User agents laying out content in multiple regions must determine where
content breaks occur. The problem of breaking content into segments
fitting in regions is similar to breaking content into pages or columns.
<p>Each break ends layout in the current region and causes remaining pieces
of content from the named flow to be visually formatted in the following
region in the region chain. Note that there is no region break in the last
region associated with a named flow.
<p>The following extends the &lsquo;<a href="#break-before"><code
class=property>break-before</code></a>&rsquo;, &lsquo;<a
href="#break-after"><code class=property>break-after</code></a>&rsquo; and
&lsquo;<a href="#break-inside"><code
class=property>break-inside</code></a>&rsquo; properties from the <a
href="#CSS3COL" rel=biblioentry>[CSS3COL]<!--{{!CSS3COL}}--></a>
specification to account for regions. The additional values are described
below.
<table class=propdef summary="break-before property definition">
<tbody>
<tr>
<td><em>Name:</em>
<td><dfn id=break-before>break-before</dfn>
<tr>
<td><em>Value:</em>
<td>auto | always | avoid | left | right | page | column | region |
avoid-page | avoid-column | avoid-region
<tr>
<td><em>Initial:</em>
<td>auto
<tr>
<td><em>Applies to:</em>
<td>block-level elements
<tr>
<td><em>Inherited:</em>
<td>no
<tr>
<td><em>Percentages:</em>
<td>N/A
<tr>
<td><em>Media:</em>
<td>paged
<tr>
<td><em>Computed&nbsp;value:</em>
<td>specified value
</table>
<table class=propdef summary="break-after property definition">
<tbody>
<tr>
<td><em>Name:</em>
<td><dfn id=break-after>break-after</dfn>
<tr>
<td><em>Value:</em>
<td>auto | always | avoid | left | right | page | column | region |
avoid-page | avoid-column | avoid-region
<tr>
<td><em>Initial:</em>
<td>auto
<tr>
<td><em>Applies to:</em>
<td>block-level elements
<tr>
<td><em>Inherited:</em>
<td>no
<tr>
<td><em>Percentages:</em>
<td>N/A
<tr>
<td><em>Media:</em>
<td>paged
<tr>
<td><em>Computed&nbsp;value:</em>
<td>specified value
</table>
<table class=propdef summary="break-inside property definition">
<tbody>
<tr>
<td><em>Name:</em>
<td><dfn id=break-inside>break-inside</dfn>
<tr>
<td><em>Value:</em>
<td>auto | avoid | avoid-page | avoid-column | avoid-region
<tr>
<td><em>Initial:</em>
<td>auto
<tr>
<td><em>Applies to:</em>
<td>block-level elements
<tr>
<td><em>Inherited:</em>
<td>no
<tr>
<td><em>Percentages:</em>
<td>N/A
<tr>
<td><em>Media:</em>
<td>paged
<tr>
<td><em>Computed&nbsp;value:</em>
<td>specified value
</table>
<p>These properties describe page, column and region break behavior
before/after/inside the generated box. These values are normatively
defined in <a href="#CSS3COL"
rel=biblioentry>[CSS3COL]<!--{{!CSS3COL}}--></a>:
<dl>
<dt>auto
<dd>Neither force nor forbid a page/column break before (after, inside)
the generated box.
<dt>always
<dd>Always force a page break before (after) the generated box.
<dt>avoid
<dd>Avoid a page/column break before (after, inside) the generated box.
<dt>left
<dd>Force one or two page breaks before (after) the generated box so that
the next page is formatted as a left page.
<dt>right
<dd>Force one or two page breaks before (after) the generated box so that
the next page is formatted as a right page.
<dt>page
<dd>Always force a page break before (after) the generated box.
<dt>column
<dd>Always force a column break before (after) the generated box.
<dt>avoid-page
<dd>Avoid a page break before (after, inside) the generated box.
<dt>avoid-column
<dd>Avoid a column break before (after, inside) the generated box.
</dl>
<p>This specification adds the following new values:
<dl>
<dt>region
<dd>Always force a region break before (after) the generated box.
<dt>avoid-region
<dd>Avoid a region break before (after, inside) the generated box.
</dl>
<p>When a break splits a box, the box's margins, borders, and padding have
no visual effect where the split occurs. However, the margin immediately
after a forced page/column/region break will be preserved. A forced
page/column/region break is a break that does not occur naturally.
<p><strong>Note:</strong> When the &lsquo;<code
class=property>avoid</code>&rsquo; value is used, regions may overflow. In
that case the &lsquo;<a href="#dom-namedflow-overflow"><code
class=property>overflow</code></a>&rsquo; property specified on the region
element should be used to determine how to render the overflow.
<h3 id=the-region-overflow-property><span class=secno>4.4. </span>The
region-overflow property</h3>
<table class=propdef summary="break-after property definition">
<tbody>
<tr>
<td><em>Name:</em>
<td><dfn id=region-overflow>region-overflow</dfn>
<tr>
<td><em>Value:</em>
<td>auto | break
<tr>
<td><em>Initial:</em>
<td>auto
<tr>
<td><em>Applies to:</em>
<td><em title="region element">region elements</em>
<tr>
<td><em>Inherited:</em>
<td>no
<tr>
<td><em>Percentages:</em>
<td>N/A
<tr>
<td><em>Media:</em>
<td>paged
<tr>
<td><em>Computed&nbsp;value:</em>
<td>specified value
</table>
<p>The &lsquo;<a href="#region-overflow"><code
class=property>region-overflow</code></a>&rsquo; property controls the
behavior of the <em id=last-region>last region</em> associated with a <a
href="#named-flow0">named flow</a>.
<dl>
<dt>auto
<dd>Content flows as it would in a regular content element. If the content
exceeds the container box, it is subject to the <a
href="http://www.w3.org/TR/CSS21/visufx.html#propdef-overflow">overflow</a>
property's computed value on the region element. Region breaks must be
ignored on the last region.
<dt>break
<dd>
<p>If the content fits within the <em>region element</em>, then this
property has no effect. If the content does not fit within the
<em>region element</em>, the content breaks as if flow was going to
continue in a subsequent region. See the <a
href="#regions-flow-breaking-rules">breaking rules</a> section. A forced
region break takes precedence over a natural break point.</p>
<p>Flow content that follows the last break in the last region, if any is
not rendered.</p>
</dl>
<p>The &lsquo;<a href="#region-overflow"><code
class=property>region-overflow</code></a>&rsquo; property does not
influence the size of the region it applies to.
<p>The following code sample illustrates the usage of the &lsquo;<a
href="#region-overflow"><code
class=property>region-overflow</code></a>&rsquo; property.
<div class=example>
<pre>
&lt;style&gt;
#article {
flow-into: "article";
}
#region_1, #region_2 {
flow-from: article;
<strong>region-overflow: break;</strong> /* or none */
<strong>overflow: visible;</strong> /* or hidden */
}
&lt;/style&gt;
&lt;div id="article"&gt;...&lt;/div&gt;
&lt;div id="region_1"&gt;&lt;/div&gt;
&lt;div id="region_2"&gt;&lt;/div&gt;
</pre>
</div>
<div class=figure>
<table style="border: 1px solid gray;width: 100%;"
summary="Different values for the region-overflow property - Illustration.">
<tbody>
<tr>
<td>&lsquo;<code class=css>flow-into: "article"</code>&rsquo;
<td><code class=html>region_1</code> and <code
class=html>region_2</code>
<td>&lsquo;<code class=css>region-overflow: auto</code>&rsquo;<br>
&lsquo;<code class=css>overflow:visible</code>&rsquo;
<tr>
<td rowspan=3 style="vertical-align: top;"><img
alt="regions receiving the flow content"
src="images/region-overflow-flow.png">
<td><img alt="result if region-overflow is set to 'break'"
src="images/region-overflow-regions.png">
<td><img alt="regions receiving the flow content"
src="images/region-overflow-auto-overflow-visible.png">
<tr>
<td>&lsquo;<code class=css>region-overflow: break</code>&rsquo;
<td>&lsquo;<code class=css>region-overflow: auto</code>&rsquo;<br>
&lsquo;<code class=css>overflow:hidden</code>&rsquo;
<tr>
<td><img alt="result if region-overflow is set to 'break'"
src="images/region-overflow-break.png">
<td><img alt="regions receiving the flow content"
src="images/region-overflow-auto-overflow-hidden.png">
</table>
<p class=caption>Different values for the region-overflow property</p>
</div>
<div class=note>
<p>The &lsquo;<a href="#dom-namedflow-overflow"><code
class=property>overflow</code></a>&rsquo; property is honored on a
region: if region content overflows, such as the borders of elements on
the last line, the &lsquo;<a href="#dom-namedflow-overflow"><code
class=property>overflow</code></a>&rsquo; property controls the
visibility of the overflowing content. See the &lsquo;<a
href="#dom-namedflow-overflow"><code
class=property>overflow</code></a>&rsquo; property definition (<a
href="#CSS21" rel=biblioentry>[CSS21]<!--{{CSS21}}--></a>).</p>
</div>
<h3 id=the-at-region-style-rule><span class=secno>4.5. </span>The @region
rule</h3>
<p>An &lsquo;<code class=css>@region</code>&rsquo; rule contains style
declarations specific to particular regions.
<pre>
@region &lt;selector&gt; {
... CSS styling rules ...
}
</pre>
<p>The &lsquo;<code class=css>@region</code>&rsquo; rule consists of the
keyword &lsquo;<code class=css>@region</code>&rsquo; followed by a <a
href="http://www.w3.org/TR/css3-selectors/#selector-syntax">selector</a>
and a declarations block. The &lsquo;<code class=css>@region</code>&rsquo;
rule and the selector constitute the region's &lsquo;<code class=css>flow
segment</code>&rsquo; selector. The region's flow segment selector
specifies which range of elements in the flow are subject to the following
declaration blocks: it applies to the range (see <a
href="#DOM-LEVEL-2-TRAVERSAL-RANGE"
rel=biblioentry>[DOM-LEVEL-2-TRAVERSAL-RANGE]<!--{{DOM-LEVEL-2-TRAVERSAL-RANGE}}--></a>)
from the region's flow that flows in the selected region(s).
<p>Elements that are fully or partially in the &lsquo;<code class=css>flow
segment</code>&rsquo; may match any of the selectors found in the style
rule.
<p>Only a limited list of properties can be set in a region style rule:
<div class=issue-marker><a
href="http://wiki.csswg.org/spec/css3-regions#issue-20list-of-region-style-properties">Issue-20</a></div>
<ol>
<li><a href="http://www.w3.org/TR/CSS2/fonts.html">font properties</a>
<li><a href="http://www.w3.org/TR/CSS2/colors.html">color property</a>
<li><a href="http://www.w3.org/TR/css3-background/#backgrounds">background
property</a>
<li><a
href="http://www.w3.org/TR/CSS2/text.html#propdef-word-spacing">&lsquo;<code
class=property>word-spacing</code>&rsquo;</a>
<li><a
href="http://www.w3.org/TR/CSS2/text.html#propdef-letter-spacing">&lsquo;<code
class=property>letter-spacing</code>&rsquo;</a>
<li><a
href="http://www.w3.org/TR/CSS2/text.html#propdef-text-decoration">&lsquo;<code
class=property>text-decoration</code>&rsquo;</a>
<li><a
href="http://www.w3.org/TR/CSS2/text.html#propdef-text-transform">&lsquo;<code
class=property>text-transform</code>&rsquo;</a>
<li><a
href="http://www.w3.org/TR/CSS2/visudet.html#propdef-line-height">&lsquo;<code
class=property>line-height</code>&rsquo;</a>
<li><a href="http://www.w3.org/TR/css3-background/#borders">border
properties</a>
<li><a href="http://www.w3.org/TR/css3-background/#corners">rounded corner
properties</a>
<li><a href="http://www.w3.org/TR/css3-background/#border-images">border
images properties</a>
<li><a href="http://www.w3.org/TR/CSS2/box.html#margin-properties">margin
properties</a>
<li><a
href="http://www.w3.org/TR/CSS2/box.html#padding-properties">padding
properties</a>
<li><a href="http://www.w3.org/TR/css3-text/#text-shadow">&lsquo;<code
class=property>text-shadow</code>&rsquo; property</a>
<li><a
href="http://www.w3.org/TR/css3-background/#the-box-shadow">&lsquo;<code
class=property>box-shadow</code>&rsquo; property</a>
<li><a
href="http://www.w3.org/TR/css3-background/#the-box-decoration-break">&lsquo;<code
class=property>box-decoration-break</code>&rsquo; property</a>
<li><a
href="http://www.w3.org/TR/CSS2/visudet.html#the-width-property">&lsquo;<code
class=property>width</code>&rsquo; property</a>
</ol>
<div class=example id=region-style-example>
<p>In the following example, the named flow &lsquo;<code
class=css>article_flow</code>&rsquo; flows through &lsquo;<code
class=css>region_1</code>&rsquo; and &lsquo;<code
class=css>region_2</code>&rsquo;.</p>
<pre>
&lt;style&gt;
#div_1 {
<strong>flow-into: article_flow;</strong>
}
&lt;region1_sel&gt;, &lt;region2_sel&gt; {
<strong>flow-from: article_flow;</strong>
}
/* region style RSA */
<strong>@region &lt;region1_sel&gt;, &lt;region2_sel&gt;</strong> {
div {...}
p {...}
}
/* region style RSB */
<strong>@region &lt;region1_sel&gt;</strong> {
p {...}
}
&lt;/style&gt;
&lt;div id="div_1"&gt;
&lt;p id="p_1"&gt;...&lt;/p&gt;
&lt;p id="p_2"&gt;...&lt;/p&gt;
&lt;/div&gt;
</pre>
<div id="region_styling_illustration"> <img
alt="Illustration showing how a named flow content fits into regions to illustrate the @region styling."
id="region_styling_img_2" name="region_styling_img_2"
src="images/region-styling-2.png">
<ul class=swatch-list>
<li><span class=swatch style="background:#1C75BC">&nbsp;</span>div div_1
<li><span class=swatch style="background:crimson">&nbsp;</span>paragraph
p_1
<li><span class=swatch style="background:white">&nbsp;</span>paragraph
p_2
<li><span class=swatch style="background:#E6E7E8">&nbsp;</span>range of
flow that fits into region_1
<li><span class=swatch style="background:#BCBEC0">&nbsp;</span>range of
flow that fits into region_2
</ul>
</div>
<p>The region style &lsquo;<code class=css>RSA</code>&rsquo; applies to
flow content that is laid out in either &lsquo;<code
class=css>region_1</code>&rsquo; or &lsquo;<code
class=css>region_2</code>&rsquo;.</p>
<p>The first rule set &lsquo;<code class=css>div {...}</code>&rsquo;
applies to all <code class=html>&lt;div&gt;</code> elements that fit
partially or fully into &lsquo;<code class=css>region_1</code>&rsquo; or
&lsquo;<code class=css>region_2</code>&rsquo;. <code
class=html>div_1</code> is split between &lsquo;<code
class=css>region_1</code>&rsquo; and &lsquo;<code
class=css>region_2</code>&rsquo; and gets the style from this style rule.</p>
<p>The second rule set &lsquo;<code class=css>p {...}</code>&rsquo;
applies to all <code class=html>&lt;p&gt;</code> elements that fit into
&lsquo;<code class=css>region_1</code>&rsquo; or &lsquo;<code
class=css>region_2</code>&rsquo;. In our example, both <code
class=html>p_1</code> and <code class=html>p_2</code> are selected.</p>
<p>The region style &lsquo;<code class=css>RSB</code>&rsquo; applies to
flow content that fits in &lsquo;<code class=css>region_1</code>&rsquo;.</p>
<p>The first rule set &lsquo;<code class=css>p {...}</code>&rsquo; matches
<code class=html>p_1</code> and <code class=html>p_2</code> because these
paragraphs flow into &lsquo;<code class=css>region_1</code>&rsquo;. Only
the segment of <code class=html>p_2</code> that flows into <code
class=html>region_1</code> is styled with this rule.</p>
</div>
<div class="issue stale">
<p>Making issue stale because this issue has not been raised on the
mailing list and we will wait for implementation feedback. Is the
proposed restriction that elements are only selected selector in a rule
set appearing in an @region rule sufficient?
</div>
<div class="issue moved"> <a
href="http://wiki.csswg.org/spec/css3-regions#issue-14region-lines-pseudo-selector">Moved
to specification Wiki</a>. There is <a
href="http://lists.w3.org/Archives/Public/www-style/2011May/0518.html">concern</a>
that the &lsquo;<code class=css>first-line</code>&rsquo; precedent is
underspecified and that more specification is needed in addition to
referencing the existing precedent.</div>
<p>The specificity of the selectors in a &lsquo;<code
class=css>@region</code>&rsquo; rule is calculated as <a
href="http://www.w3.org/TR/css3-selectors/#specificity">defined</a> in the
CSS Selectors module (see <a href="#SELECT"
rel=biblioentry>[SELECT]<!--{{SELECT}}--></a>). In other words, the
&lsquo;<code class=css>@region</code>&rsquo; rule adds an extra condition
to the selector's matching, but does not change the selector's
specificity. This is the same behavior as selectors appearing in
&lsquo;<code class=css>@media</code>&rsquo; rules declaration blocks (see
<a href="#MEDIAQ" rel=biblioentry>[MEDIAQ]<!--{{MEDIAQ}}--></a>), where
the rule does not influence the selectors' specificity.
<p>Consequently, selectors that match a given element (as describe above),
participate in the <a
href="http://www.w3.org/TR/2011/REC-CSS2-20110607/cascade.html#cascading-order">CSS
Cascading order</a> as defined in <a href="#CSS21"
rel=biblioentry>[CSS21]<!--{{!CSS21}}--></a>.
<div class=note> Region styling does not apply to nested regions. If a
region &lsquo;<code class=property>A</code>&rsquo; receives content from a
flow that contains region &lsquo;<code class=property>B</code>&rsquo;, the
content that flows into &lsquo;<code class=property>B</code>&rsquo; does
not receive the region styling specified for region &lsquo;<code
class=property>A</code>&rsquo;.</div>
<h2 id="pseudo_elements"><span class=secno>5. </span>Pseudo-elements</h2>
<p><em>This section is normative.</em>
<p>It can be useful to visually mark the content to highlight that a
content thread is flowing from region to region. For example, a marker
such as <em>&lsquo;<code class=css>continues on page 3</code>&rsquo;</em>
clearly indicates, at the end of a region, that there is more content in
the flow which can be found on &lsquo;<code class=css>page 3</code>&rsquo;
(in this example, the notion of page is application specific).
<p>The &lsquo;<code class=css>::before</code>&rsquo; and &lsquo;<code
class=css>::after</code>&rsquo; pseudo-elements (see <a href="#SELECT"
rel=biblioentry>[SELECT]<!--{{!SELECT}}--></a>) let content authors mark
the beginning and end of a region with such markers.
<h3 id=processing-model><span class=secno>5.1. </span>Processing model</h3>
<p>The &lsquo;<code class=css>::before</code>&rsquo; content is laid out in
the region prior to any other content coming from the flow. Note that it
is possible to set the &lsquo;<code class=css>::before</code>&rsquo;
pseudo-element's &lsquo;<code class=property>display</code>&rsquo;
property to &lsquo;<code class=property>run-in</code>&rsquo; to align it
with the content's inline boxes.
<p>The &lsquo;<code class=css>::after</code>&rsquo; content is laid out in
the region after laying out the flow content. Then, flow content is
removed from the region to accommodate for the &lsquo;<code
class=css>::after</code>&rsquo; content. Accommodating means that the
&lsquo;<code class=css>::after</code>&rsquo; content is laid out without
overflowing the region. If there is still not enough room to accommodate
for the &lsquo;<code class=css>::after</code>&rsquo; content after
removing all flow content, then the &lsquo;<code
class=css>::after</code>&rsquo; content overflows. The &lsquo;<code
class=property>display</code>&rsquo; property of the &lsquo;<code
class=css>::after</code>&rsquo; content should be set to &lsquo;<code
class=property>run-in</code>&rsquo; to align with the region's content's
inline boxes. In that case, the &lsquo;<code
class=css>::after</code>&rsquo; content becomes the last inline box of the
previous element in the flow that has some visual rendering in the region
and can accommodate for the &lsquo;<code class=css>::after</code>&rsquo;
box.
<h2 id="cssom_view_and_css_regions"><span class=secno>6. </span>CSSOM view
and CSS regions</h2>
<p><em>This section is normative.</em>
<p>Since content may flow into multiple regions, authors need a way to
determine if there are enough regions to flow all the content from a named
flow. This is especially important considering that the size of regions
may change depending on the display context. For example, flowing the same
content on a mobile phone with a small screen may require more regions
than on a large desktop display.
<p>Another example where creating more regions might be needed: if the user
may change the font size of text flowing through regions, new regions may
be needed to accommodate for the additional space required to fit the
larger text or some regions may need to be removed for smaller text.
<div class=note>
<p>Since an element may be split into multiple regions, invoking <code
class=idl><a
href="http://www.w3.org/TR/cssom-view/#dom-element-getclientrects">getClientRects</a></code>
on it must return the list of rectangles for the element in all the
regions it is part of.</p>
</div>
<h3 id=the-namedflow-interface><span class=secno>6.1. </span>The NamedFlow
interface</h3>
<p>The <code class=idl>getFlowByName</code> method on the <a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#i-Document"><code
class=idl>Document</code></a> interface provides access to the document's
<a href="#named-flow0">named flow</a> instances.
<pre class=idl>
[Supplemental] interface <a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#i-Document">Document</a> {
<a
href="#dom-namedflow">NamedFlow</a>
getFlowByName(<a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#DOMString">DOMString</a> name);
};
</pre>
<p>The <dfn id=dom-namedflow><code class=idl>NamedFlow</code></dfn>
interface offers a representation of the <a href="#named-flow0">named
flow</a>.
<pre class=idl>
interface <a href="#dom-namedflow">NamedFlow</a> {
readonly attribute boolean <a
href="#dom-namedflow-overflow">overflow</a>;
readonly attribute <a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#ID-536297177">NodeList</a> contentNodes;
<a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#ID-536297177">NodeList</a> getRegionsByContentNode(<a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#ID-1950641247">Node</a> node);
};
};</pre>
<p>The <dfn id=dom-namedflow-overflow><code class=idl>overflow</code></dfn>
property is true if the named flow does not fully fit in the associated
regions. Otherwise, it is false. A <a href="#dom-namedflow"><code
class=idl>NamedFlow</code></a> object is live.
<p>The <dfn id=dom-namedflow-contentnodes>contentNodes</dfn> property
returns an ordered collection of nodes that constitute the named flow.
Note that this collection is live: every time it is queried it must return
the same object, and the object is always up to date.
<p>The <dfn
id=dom-namedflow-getregionsbycontentnodes>getRegionsByContentNode()</dfn>
method gets a collection of regions that contain at least part of the
target content node. This can be used to navigate by bookmark in paginated
view: the method returns regions containing the bookmarked element, which
are then passed to pagination UI to show desired region or page.
<p>With the <a href="#dom-namedflow"><code class=idl>NamedFlow</code></a>
interface, authors can easily check if all content has been fitted into
existing regions. If it has, the overflow property would be false.
<h3 id=extension-to-the-element-interface><span class=secno>6.2.
</span>Extension to the Element interface</h3>
<p>When an region is an actual <a
href="http://www.w3.org/TR/DOM-Level-3-Core/glossary.html#dt-element">element</a>,
it is convenient to easily find out if content fully fits into the
<span>region</span> or not. The supplemental interface on <a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#ID-745549614"><code
class=idl>Element</code></a> provides that functionality.
<pre class=idl>
[Supplemental] interface <a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#ID-745549614">Element</a> {
readonly attribute <a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#DOMString">DOMString</a> <a
href="#dom-element-regionoverflow">regionOverflow</a>;
getter <a
href="#">Range</a>[] <a
href="#dom-element-getregionflowranges">getRegionFlowRanges()</a>;
};
</pre>
<p>The <dfn id=dom-element-regionoverflow><code
class=idl>regionOverflow</code></dfn> attribute can take one of the
following values:
<dl>
<dt>&lsquo;<a href="#dom-namedflow-overflow"><code
class=property>overflow</code></a>&rsquo;
<dd>the region element's content overflows the region's <a
href="http://www.w3.org/TR/CSS21/box.html#box-dimensions">content
box</a>. Note that the region's <a
href="http://www.w3.org/TR/CSS21/visufx.html#overflow"><code
class=idl>overflow</code></a> property value can be used to control the
visibility of the overflowing content. This means that the region is the
last one in the <span title=region-chain>region chain</span> and not able
to fit the remaining content from the <a href="#named-flow0">named
flow</a>.
<dt>&lsquo;<code class=property>fit</code>&rsquo;
<dd>the region element's content fits into the region's <a
href="http://www.w3.org/TR/CSS21/box.html#box-dimensions">content
box</a>. It does not overflow. If the region is the last one in the <span
title=region-chain>region chain</span>, it means that the content fits
without overflowing. If the region is not the last one in the region
chain, that means the <a href="#named-flow0">named flow</a> content is
further fitted in subsequent regions. In particular, in this last case,
that means the region may have received no content from the <a
href="#named-flow0">named flow</a> (for example if the region is too
small to accommodate any content).
<dt>&lsquo;<code class=property>empty</code>&rsquo;
<dd>the region element has no content and is empty. All content from the
<a href="#named-flow0">named flow</a> was fitted in regions with a lower
document order.
<dt>&lsquo;<code class=property>undefined</code>&rsquo;
<dd>The element is not a <span>region</span>.
</dl>
<p>The <dfn id=dom-element-getregionflowranges>getRegionFlowRanges</dfn>
method returns an array of <a
href="http://www.w3.org/TR/DOM-Level-2-Traversal-Range/ranges.html#Level-2-Range-idl">
Range</a> instances corresponding to the content from the region flow that
is positioned in the region.
<p>If an element is not a <span>region</span>, the <a
href="#dom-element-getregionflowranges"><code class=idl><span
title="#document-element-getregionflowranges">getRegionFlowRanges</span></code></a>
method throws a <a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#ID-17189187"><code
class=idl>DOMException</code></a> with the <a
href="http://www.w3.org/TR/DOM-Level-3-Core/core.html#DOMException-INVALID_ACCESS_ERR"><code
class=idl>INVALID_ACCESS_ERR</code></a> error code.
<div class=note> The Element interface extension is only available to
regions that are document elements and not to regions that are
pseudo-elements.</div>
<div class="issue resolved">
<p><a
href="http://www.w3.org/Style/CSS/Tracker/actions/350">ACTION-350</a> was
created to add the API to the specification draft.</p>
<p>It has been <a
href="http://lists.w3.org/Archives/Public/www-style/2011May/0379.html">suggested</a>
to add an API to find which region displays an element in a named flow.
Should we add such an API? How would it work in a &lsquo;<code
class=property>multi-view</code>&rsquo; context as suggested by Alex.</p>
</div>
<h3 id=region-flow-layout-events><span class=secno>6.3. </span>Region flow
layout events</h3>
<p>Region <a
href="http://www.w3.org/TR/DOM-Level-3-Events/#glossary-event">Event
Targets</a> dispatch <code class=idl>regionLayoutUpdate</code> events when
there is a possible layout change of their named flow segment.
<table border=0 cellpadding=2 cellspacing=0 class=event-desc
summary="This table contains information about the semantics of the given event type">
<tbody>
<tr class="assert must">
<th>Type
<td class=eventname><strong><code>regionLayoutUpdate</code></strong>
<tr class="assert must">
<th>Interface
<td><code>UIEvent</code>
<tr class="assert must">
<th>Sync / Async
<td>Async
<tr class="assert must">
<th>Bubbles
<td>Yes
<tr class="assert must">
<th>Target
<td><code>Element</code>
<tr class="assert must">
<th>Cancelable
<td>Yes
<tr class="assert must">
<th>Default action
<td>none
<tr class="assert must">
<th>Context info
<td>
<ul>
<li><code class=attribute-name>Event.target</code>: region whose
layout may have changed
</ul>
</table>
<h2 id=relation-to-other-specifications><span class=secno>7.
</span>Relation to other specifications</h2>
<p>This specification is related to other specifications as described in
the <a href="#references">references</a> section. In addition, it is
related to the following specifications:
<ol>
<li>CSS Exclusions Module <a href="#CSS3-EXCLUSIONS"
rel=biblioentry>[CSS3-EXCLUSIONS]<!--{{CSS3-EXCLUSIONS}}--></a>. This
module defines a generic way to define arbitrarily shaped exclusions into
which content can flow or around which content can flow. This can be seen
as an extension to the way CSS floats provide rectangular areas into
which content flows and around which content flows. In advanced layout
designs, it is expected that the CSS Exclusions module will be commonly
combined with the CSS regions module.
<li>CSS Line Grid Module <a href="#CSS3-LINE-GRID"
rel=biblioentry>[CSS3-LINE-GRID]<!--{{CSS3-LINE-GRID}}--></a>. This
module defines a concept of line grid to align the position of lines in
different elements. The line grid functionality is related and needed for
aligning content flowing in separate regions.
</ol>
<h2 id=usecases><span class=secno>8. </span>Use Cases</h2>
<p>Use cases are described on <a
href="http://wiki.csswg.org/spec/css3-regions/regions-use-cases">this
page</a>.
<h2 id=conformance><span class=secno>9. </span>Conformance</h2>
<h2 id=changes><span class=secno>10. </span>Changes</h2>
<h3 id="changes_from_June_09_2011"><span class=secno>10.1. </span>Changes
from <a href="http://www.w3.org/TR/2011/WD-css3-regions-20110609/">June
09<sup>th</sup> 2011</a> version</h3>
<ul>
<li>Editorial changes (typos, rephrasings).
<li>Made &lsquo;<code class=property>content-order</code>&rsquo; a
&lt;integer&gt; and not a &lt;float&gt; following a working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jun/0329.html">resolution</a>
<li>Added Alex Mogilevsky as an editor
<li>Flow names became &lt;ident&gt; instead of &lt;string&gt; following a
working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jun/0413.html">resolution</a>
<li>Removed issue about possibly altering the DOM Events model for region
events following a working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jun/0413.html">resolution</a>
<li>Made the "relation to document events" section informative following a
working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jun/0413.html">resolution</a>
<li>Removed issue in section "The NamedFlow interface" following the
working group's <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jun/0413.html">resolution</a>
to have both NamedFlow and the Element interface extension
<li>Following a working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jun/0413.html">resolution</a>:
<ul>
<li>Turned the first issue in the "Extensions to the Element interface"
into a note explaining that the NamedFlow interface can be used when
regions are pseudo-elements.
<li>Added NamedFlowUpdate
</ul>
<li>Excluded &lsquo;<code class=property>none</code>&rsquo;, &lsquo;<code
class=property>inherit</code>&rsquo; and &lsquo;<code
class=property>initial</code>&rsquo; from the possible identifier names
on the flow property following <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jun/0583.html">discussion</a>
on the mailing list.
<li>Simplified integration discussion on multi-column layout and just
state that since column boxes are not addressable by selectors, they
cannot be regions.
<li>Added specification of how the &lsquo;<a href="#flow-into"><code
class=property>flow-into</code></a>&rsquo; property interacts with
object, embed and iframe elements.
<li>Excluded &lsquo;<code class=property>default</code>&rsquo; from the
possible identifier names on the flow property because it <a
href="http://www.w3.org/TR/2006/WD-css3-values-20060919/#keywords">may
get reserved</a>.
<li>Added to the definition of &lsquo;<code
class=property>auto</code>&rsquo; on &lsquo;<a
href="#region-overflow"><code
class=property>region-overflow</code></a>&rsquo; specifying that region
breaks must be ignored.
<li>Renamed &lsquo;<code class=css>Document.flowWithName</code>&rsquo; to
&lsquo;<code class=css>Document.getFlowByName</code>&rsquo; since it is
not a property.
<li>Added a note that a &lsquo;<a href="#dom-namedflow"><code
class=property>NamedFlow</code></a>&rsquo; instance is live.
<li>Added an &lsquo;<code class=property>undefined</code>&rsquo; string
value to the regionOverflow property on the Element interface extension.
<li>Renamed NamedFlowEvent to regionLayoutUpdate to avoid having
&lsquo;<code class=property>Event</code>&rsquo; in the event name.
<li>Added description for special behavior of iframe/object/embed as flow
source
<li>Removed issue on copying content to a named flow instead of moving
elements to named flow following working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Aug/0069.html">resolution</a>.
<li>Removed issue on content:flow-from v.s., flow-from property following
working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Aug/0069.html">resolution</a>.
<li>Renamed &lsquo;<code class=property>flow</code>&rsquo; to &lsquo;<a
href="#flow-into"><code class=property>flow-into</code></a>&rsquo;
following working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Aug/0069.html">resolution</a>.
<li>Updated the css3-grid-align example following working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Aug/0069.html">resolution</a>
that it should use &lt;div&gt; instead of grid-cell pseudo elements that
were removed from the CSS Grid Layout specification.
<li>Renamed &lsquo;<code class=property>from-flow</code>&rsquo; to
&lsquo;<a href="#flow-from"><code
class=property>flow-from</code></a>&rsquo; following a working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Aug/0069.html">resolution</a>.
<li>Limited the applicability of &lsquo;<code class=css>content:
flow-from()</code>&rsquo; to block container box and added a note that
this might be expanded in the future, following a working group <a
href="http://lists.w3.org/Archives/Public/www-style/2011Aug/0069.html">resolution</a>.
<li>Removed issue about API to find which region displays an element in a
named flow since <a
href="http://www.w3.org/Style/CSS/Tracker/actions/350">ACTION-350</a> was
created to add this API.
<li>In the &lsquo;<code class=property>flow</code>&rsquo; property
description, removed the required wrapper anonymous block as agreed on <a
href="http://lists.w3.org/Archives/Public/www-style/2011Aug/0161.html">mailing
list discussion</a>.
<li>Reworded the paragraph on how regions create a new stacking context,
as per the <a
href="http://lists.w3.org/Archives/Public/www-style/2011Aug/0025.html">mailing
list discussion</a>.
<li>Reworked the "CSS regions Model" section to now be "CSS regions
Layout". Moved the definition of a region as the first sub-section.
<li>Removed the "Visual Formatting Model and Flows" section to match the
new Regions Model (now CSS regions Layout) section.
<li>Moved the sections on allowed region breaks, forced region breaks and
"best" regions breaks to follow the property definitions to follow the
formatting of the paged media section in CSS 2.1.
<li>Added note about why regions create a new stacking context following
the discussion on the <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jul/0158.html">mailing
list</a>.
<li>Removed sentence about content:none making elements disconnected
following the discussion on the <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jul/0158.html">mailing
list</a>.
<li>Removed sentence about content:none making elements disconnected
following the discussion on the <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jul/0158.html">mailing
list</a>.
<li>Added the ::region-before and a ::region-after pseudo-elements.
<li>Added note of caution when using selectors and the &lsquo;<a
href="#flow-into"><code class=property>flow-into</code></a>&rsquo;
property following a <a
href="http://lists.w3.org/Archives/Public/www-style/2011Jul/0191.html">mailing
list discussion</a>.
<li>Removed sections about allowed, forced and best region breaks to align
with the multi-column specification approach and until the group agrees
on where and how the general issue of breaks (regions/pages/columns)
should be addressed.
<li>Removed the section on Integration with other specifications since
specifications that was superfluous especially since there is no specific
integration with multi column, grid or template layout.
<li>Added a note that regions establish a new block formatting context.
<li>Renamed content-order to region-order.
<li>Added a note about overflowing content in regions (e.g., for content
with borders).
<li>Added a note that a region cannot layout content it is part of (to
avoid creating a circular dependency) in the flow-from description,
specifying that if flow-from references the flow an element is part of,
then the element does not format anything visually.
<li>Replaced &lsquo;<code
class=css>content:flow-from(&lt;ident&gt;)</code>&rsquo; with
&lsquo;<code class=css>flow-from: &lt;ident&gt;</code>&rsquo; following a
<a href="http://krijnhoetmer.nl/irc-logs/css/20110824">working group
resolution</a>.
<li>Added more specific wording about auto width and auto height,
following <a
href="http://www.w3.org/Style/CSS/Tracker/actions/351">ACTION 351</a>.
<li>Reworked section on region markers to now use &lsquo;<code
class=css>::before</code>&rsquo; and &lsquo;<code
class=css>::after</code>&rsquo; and explain how &lsquo;<code
class=css>display:run-in</code>&rsquo; works with regions.
<li>Modified the @region style rule to remove the ::region-lines
pseudo-selector.
<li>Removed the &lsquo;<code class=property>region-order</code>&rsquo;
property following implementation feedback.
<li>Specified that region-overflow does not influence a region's size.
<li>Specified that the flow's writing mode is defined by the first
region's writing mode following <a
href="http://lists.w3.org/Archives/Public/www-style/2011Aug/0306.html">mailing
list discussion</a>.
<li>Made iframe, object and embed support of flow-into optional following
<a
href="http://lists.w3.org/Archives/Public/www-style/2011Sep/0073.html">mailing
list discussion</a>.
<li>Clarified that flow content following the last break in the last
region is not rendered, following <a
href="http://lists.w3.org/Archives/Public/www-style/2011Oct/0167.html">mailing
list discussions.</a>
<li>Modified the rule for computing the width and height of a region when
they are set to auto, following <a
href="http://lists.w3.org/Archives/Public/www-style/2011Oct/0216.html">a
mailing list discussion.</a>
<li>Added &lsquo;<code class=property>auto</code>&rsquo; to the list of
invalid flow identifiers.
<li>Made &lsquo;<code class=property>none</code>&rsquo; the initial value
for &lsquo;<a href="#flow-into"><code
class=property>flow-into</code></a>&rsquo; and aligned with &lsquo;<a
href="#flow-from"><code class=property>flow-from</code></a>&rsquo;, as
explained in this <a
href="http://lists.w3.org/Archives/Public/www-style/2011Oct/0576.html">email</a>.
Also allowed the &lsquo;<code class=property>inherit</code>&rsquo; value
on &lsquo;<a href="#flow-from"><code
class=property>flow-from</code></a>&rsquo; and &lsquo;<a
href="#flow-into"><code class=property>flow-into</code></a>&rsquo; (same
email).
<li>Added note about nested region styling following <a
href="http://lists.w3.org/Archives/Public/www-style/2011Oct/0650.html">a
mailing list discussion</a>.
<li>Added additional DOM interface following <a
href="http://www.w3.org/Style/CSS/Tracker/actions/350">Action 350</a>.
<li>Clarified that a region becomes a region only if its &lsquo;<code
class=property>content</code>&rsquo; property computes to normal,
following the resolution of <a
href="http://wiki.csswg.org/spec/css3-regions#issue-22content-vs-flow-from-precedence">Issue
22</a>.
<li>Removed text about special iframe behavior as a result of <a
href="http://www.w3.org/Style/CSS/Tracker/actions/376">ACTION 376</a>.
<li>Made the selectors explicit in the initial section code examples,
following discussion in <a
href="http://krijnhoetmer.nl/irc-logs/css/20111030">San Jose, October
2011</a> face to face meeting.
<li>Added section on use cases following <a
href="http://www.w3.org/Style/CSS/Tracker/actions/377">ACTION-377</a>.
</ul>
<h2 class=no-num id=acknowledgments>Acknowledgments</h2>
<p>The editors are grateful to the CSS working group for their feedback and
help with the genesis of this specification.
<p>In addition, the editors would like to thank the following individuals
for their contributions, either during the conception of CSS regions or
during its development and specification review process:
<ul>
<li>Rossen Atanassov, Microsoft Corporation.
<li>Andrei Bucur, Adobe Systems, Inc.
<li>Alexandru Chiculita, Adobe Systems, Inc.
<li>Arno Gourdol, Adobe Systems, Inc.
<li>Mihnea Ovidenie, Adobe Systems, Inc.
<li>Virgil Palanciuc, Adobe Systems, Inc.
<li>Christoph Päper
<li>Anton Prowse, Invited Expert.
<li>Peter Sorotokin, Adobe Systems, Inc.
<li>Alan Stearns, Adobe Systems, Inc.
<li>Stephen Zilles, Adobe Systems, Inc.
<li>David Hyatt, Apple Inc.
</ul>
<h2 class=no-num id=references>References</h2>
<h3 class=no-num id=normative-references>Normative references</h3>
<!--begin-normative-->
<!-- Sorted by label -->
<dl class=bibliography>
<dt 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
Sheets Level 2 Revision 1 (CSS&#160;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>
</dd>
<!---->
<dt id=CSS3COL>[CSS3COL]
<dd>H&#229;kon Wium Lie. <a
href="http://www.w3.org/TR/2011/CR-css3-multicol-20110412"><cite>CSS
Multi-column Layout Module.</cite></a> 12 April 2011. W3C Candidate
Recommendation. (Work in progress.) URL: <a
href="http://www.w3.org/TR/2011/CR-css3-multicol-20110412">http://www.w3.org/TR/2011/CR-css3-multicol-20110412</a>
</dd>
<!---->
<dt id=SELECT>[SELECT]
<dd>Tantek &#199;elik; et al. <a
href="http://www.w3.org/TR/2011/REC-css3-selectors-20110929/"><cite>Selectors
Level 3.</cite></a> 29 September 2011. W3C Recommendation. URL: <a
href="http://www.w3.org/TR/2011/REC-css3-selectors-20110929/">http://www.w3.org/TR/2011/REC-css3-selectors-20110929/</a>
</dd>
<!---->
</dl>
<!--end-normative-->
<h3 class=no-num id=other-references>Other references</h3>
<!--begin-informative-->
<!-- Sorted by label -->
<dl class=bibliography>
<dt style="display: none"><!-- keeps the doc valid if the DL is empty -->
<!---->
<dt id=CSS3-EXCLUSIONS>[CSS3-EXCLUSIONS]
<dd>Vincent Hardy. <a
href="http://dev.w3.org/csswg/css3-exclusions/"><cite>CSS Exclusions
Module.</cite></a> Proposal for a CSS module. (Retrieved 15 November
2011) URL: <a
href="http://dev.w3.org/csswg/css3-exclusions/">http://dev.w3.org/csswg/css3-exclusions/</a>
</dd>
<!---->
<dt id=CSS3-FLEXBOX>[CSS3-FLEXBOX]
<dd>Tab Atkins Jr.; Alex Mogilevsky; L. David Baron. <a
href="http://www.w3.org/TR/2011/WD-css3-flexbox-20110322/"><cite>Flexible
Box Layout Module.</cite></a> 22 March 2011. W3C Working Draft. (Work in
progress.) URL: <a
href="http://www.w3.org/TR/2011/WD-css3-flexbox-20110322/">http://www.w3.org/TR/2011/WD-css3-flexbox-20110322/</a>
</dd>
<!---->
<dt id=CSS3-GRID-LAYOUT>[CSS3-GRID-LAYOUT]
<dd>Alex Mogilevsky; et al. <a
href="http://www.w3.org/TR/2011/WD-css3-grid-layout-20110407"><cite>Grid
Layout.</cite></a> 7 April 2011. W3C Working Draft. (Work in progress.)
URL: <a
href="http://www.w3.org/TR/2011/WD-css3-grid-layout-20110407">http://www.w3.org/TR/2011/WD-css3-grid-layout-20110407</a>
</dd>
<!---->
<dt id=CSS3-LINE-GRID>[CSS3-LINE-GRID]
<dd>Koji Ishii. <a href="http://dev.w3.org/csswg/css-line-grid/"><cite>CSS
Line Grid Module.</cite></a> Proposal for a CSS module. (Retrieved 26
October 2011) URL: <a
href="http://dev.w3.org/csswg/css-line-grid/">http://dev.w3.org/csswg/css-line-grid/</a>
</dd>
<!---->
<dt id=CSS3GRID>[CSS3GRID]
<dd>Alex Mogilevsky; Markus Mielke. <a
href="http://www.w3.org/TR/2007/WD-css3-grid-20070905"><cite>CSS Grid
Positioning Module Level&#160;3.</cite></a> 5 September 2007. W3C Working
Draft. (Work in progress.) URL: <a
href="http://www.w3.org/TR/2007/WD-css3-grid-20070905">http://www.w3.org/TR/2007/WD-css3-grid-20070905</a>
</dd>
<!---->
<dt id=CSS3LAYOUT>[CSS3LAYOUT]
<dd>Bert Bos; C&#233;sar Acebal. <a
href="http://www.w3.org/TR/2010/WD-css3-layout-20100429"><cite>CSS
Template Layout Module.</cite></a> 29 April 2010. W3C Working Draft.
(Work in progress.) URL: <a
href="http://www.w3.org/TR/2010/WD-css3-layout-20100429">http://www.w3.org/TR/2010/WD-css3-layout-20100429</a>
</dd>
<!---->
<dt id=CSS3PAGE>[CSS3PAGE]
<dd>H&#229;kon Wium Lie; Melinda Grant. <a
href="http://www.w3.org/TR/2006/WD-css3-page-20061010"><cite>CSS3 Module:
Paged Media.</cite></a> 10 October 2006. W3C Working Draft. (Work in
progress.) URL: <a
href="http://www.w3.org/TR/2006/WD-css3-page-20061010">http://www.w3.org/TR/2006/WD-css3-page-20061010</a>
</dd>
<!---->
<dt id=DOM-LEVEL-2-TRAVERSAL-RANGE>[DOM-LEVEL-2-TRAVERSAL-RANGE]
<dd>Joe Kesselman; et al. <a
href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Traversal-Range-20001113"><cite>Document
Object Model (DOM) Level 2 Traversal and Range Specification.</cite></a>
13 November 2000. W3C Recommendation. URL: <a
href="http://www.w3.org/TR/2000/REC-DOM-Level-2-Traversal-Range-20001113">http://www.w3.org/TR/2000/REC-DOM-Level-2-Traversal-Range-20001113</a>
</dd>
<!---->
<dt id=MEDIAQ>[MEDIAQ]
<dd>H&#229;kon Wium Lie; et al. <a
href="http://www.w3.org/TR/2010/CR-css3-mediaqueries-20100727/"><cite>Media
Queries.</cite></a> 27 July 2010. W3C Candidate Recommendation. (Work in
progress.) URL: <a
href="http://www.w3.org/TR/2010/CR-css3-mediaqueries-20100727/">http://www.w3.org/TR/2010/CR-css3-mediaqueries-20100727/</a>
</dd>
<!---->
</dl>
<!--end-informative-->
<h2 class=no-num id=index>Index</h2>
<!--begin-index-->
<ul class=indexlist>
<li>break-after, <a href="#break-after"
title=break-after><strong>4.3.</strong></a>
<li>break-before, <a href="#break-before"
title=break-before><strong>4.3.</strong></a>
<li>break-inside, <a href="#break-inside"
title=break-inside><strong>4.3.</strong></a>
<li>contentNodes, <a href="#dom-namedflow-contentnodes"
title=contentNodes><strong>6.1.</strong></a>
<li>current-region, <a href="#current-region"
title=current-region><strong>2.3.</strong></a>
<li>flow-from, <a href="#flow-from"
title=flow-from><strong>4.2.</strong></a>
<li>flow-into, <a href="#flow-into"
title=flow-into><strong>4.1.</strong></a>
<li>getRegionFlowRanges, <a href="#dom-element-getregionflowranges"
title=getRegionFlowRanges><strong>6.2.</strong></a>
<li>getRegionsByContentNode(), <a
href="#dom-namedflow-getregionsbycontentnodes"
title="getRegionsByContentNode()"><strong>6.1.</strong></a>
<li><a href="#dom-namedflow"><code class=idl>NamedFlow</code></a>, <a
href="#dom-namedflow" title=NamedFlow><strong>6.1.</strong></a>
<li>named flow, <a href="#named-flow0"
title="named flow"><strong>2.2.</strong></a>
<li><a href="#dom-namedflow-overflow"><code class=idl>overflow</code></a>,
<a href="#dom-namedflow-overflow"
title=overflow><strong>6.1.</strong></a>
<li>region, <a href="#region" title=region>2.1.</a>
<li><a href="#dom-element-regionoverflow"><code
class=idl>regionOverflow</code></a>, <a
href="#dom-element-regionoverflow"
title=regionOverflow><strong>6.2.</strong></a>
<li>region-overflow, <a href="#region-overflow"
title=region-overflow><strong>4.4.</strong></a>
<li>specified flow, <a href="#specified-flow"
title="specified flow"><strong>4.1.</strong></a>
</ul>
<!--end-index-->
<h2 class=no-num id=property-index>Property index</h2>
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