- From: Elika Etemad via cvs-syncmail <cvsmail@w3.org>
- Date: Thu, 19 Jan 2012 02:52:04 +0000
- To: public-css-commits@w3.org
Update of /sources/public/csswg/css3-text
In directory hutz:/tmp/cvs-serv11085
Modified Files:
Overview.html Overview.src.html
Log Message:
Add Alan Stearns' text explaining why 'text-justify' leaves so much to the UA and how the restrictions in CSS3 Text can be applied to simple justification algorithms as well as to TeX
Index: Overview.html
===================================================================
RCS file: /sources/public/csswg/css3-text/Overview.html,v
retrieving revision 1.221
retrieving revision 1.222
diff -u -d -r1.221 -r1.222
--- Overview.html 18 Jan 2012 23:33:32 -0000 1.221
+++ Overview.html 19 Jan 2012 02:52:02 -0000 1.222
@@ -22,7 +22,7 @@
margin :auto;
}
</style>
- <link href="http://www.w3.org/StyleSheets/TR/W3C-WD.css" rel=stylesheet
+ <link href="http://www.w3.org/StyleSheets/TR/W3C-ED.css" rel=stylesheet
type="text/css">
<body>
@@ -32,17 +32,17 @@
<h1>CSS Text Level 3</h1>
- <h2 class="no-num no-toc" id=longstatus-date>W3C Working Draft 18 January
+ <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 19 January
2012</h2>
<dl>
- <dt>This version:</dt>
- <!--
- <dd><a href="http://dev.w3.org/csswg/css3-text/">$Date$ (CVS $Revision$)</a>
- -->
+ <dt>This version:
- <dd><a
- href="http://www.w3.org/TR/2012/WD-css3-text-20120118/">http://www.w3.org/TR/2012/WD-css3-text-20120118/</a>
+ <dd><a href="http://dev.w3.org/csswg/css3-text/">$Date: 2012/01/18
+ 23:33:32 $ (CVS $Revision$)</a> <!--
+ <dd><a href="http://www.w3.org/TR/2012/WD-css3-text-20120119/">http://www.w3.org/TR/2012/WD-css3-text-20120119/</a></dd>
+ -->
+
<dt>Latest version:
@@ -2275,6 +2275,31 @@
be followed when any justification method other than ‘<code
class=property>auto</code>’ is specified.
+ <div class=note>
+ <p>The guidelines in this level of CSS do not describe a complete
+ justification algorithm. They are merely a minimum set of requirements
+ that a complete algorithm should meet. Limiting the set of requirements
+ gives UAs some latitude in choosing a justification algorithm that meets
+ their needs.
+
+ <p>For instance, a basic but fast ‘<code
+ class=css>inter-word</code>’ justification algorithm might use a
+ simple greedy method for determining line breaks, then distribute space
+ using the <a href="#spacing">spacing limits provided</a>. This algorithm
+ could follow the guidelines by changing word spacing first, increasing
+ ‘<a href="#letter-spacing0"><code
+ class=property>letter-spacing</code></a>’ only if ‘<a
+ href="#word-spacing0"><code class=property>word-spacing</code></a>’
+ hit a limit.
+
+ <p>A more sophisticated but slower ‘<code
+ class=css>inter-word</code>’ justification algorithm might use a
+ Knuth/Plass method where spacing opportunities and spacing limits were
+ assigned weights and assessed with other line breaking considerations.
+ This algorithm could follow the guidelines by giving more weight to word
+ spacing than letter spacing.
+ </div>
+
<p id=expansion-opportunity>CSS defines <dfn
id=expansion-opportunities>expansion opportunities</dfn> as points where
the justification algorithm may alter spacing within the text. These
@@ -2501,9 +2526,6 @@
such as alternate glyphs or glyph compression to help justify the text
under any method. This behavior is not controlled by this level of CSS.
- <p class=issue>Add example of using ‘<a href="#text-justify0"><code
- class=property>text-justify</code></a>’ with the TeX algorithm.
-
<div class=example>
<p>3.8 Line Adjustment in <a href="#JLREQ"
rel=biblioentry>[JLREQ]<!--{{JLREQ}}--></a> gives an example of a set of
@@ -2708,7 +2730,8 @@
<!-- -->:lang(en) { word-spacing: 100%; }</pre>
<p>The following example will <em>add</em> half the the width of the
- “0” glyph to word spacing character [[CSS3VALUES]]:
+ “0” glyph to word spacing character <a href="#CSS3VAL"
+ rel=biblioentry>[CSS3VAL]<!--{{CSS3VAL}}--></a>:
<pre>p { word-spacing: 0.5ch; }</pre>
</div>
@@ -4337,9 +4360,9 @@
<p>This property accepts a comma-separated list of shadow effects to be
applied to the text of the element. Values are interpreted as for <a
href="http://www.w3.org/TR/css3-background/#the-box-shadow">‘<code
- class=property>box-shadow</code>’</a>. [[!CSS3BACKGROUND]] The
- shadow is applied to all of the element's text as well as any text
- decorations it specifies.
+ class=property>box-shadow</code>’</a>. <a href="#CSS3BG"
+ rel=biblioentry>[CSS3BG]<!--{{!CSS3BG}}--></a> The shadow is applied to
+ all of the element's text as well as any text decorations it specifies.
<p>The shadow effects are applied front-to-back: the first shadow is on
top. The shadows may thus overlay each other, but they never overlay the
@@ -4685,6 +4708,16 @@
</dd>
<!---->
+ <dt id=CSS3VAL>[CSS3VAL]
+
+ <dd>Håkon Wium Lie; Tab Atkins; Elika J. Etemad. <a
+ href="http://www.w3.org/TR/2011/WD-css3-values-20110906/"><cite>CSS
+ Values and Units Module Level 3.</cite></a> 6 September 2011. W3C Working
+ Draft. (Work in progress.) URL: <a
+ href="http://www.w3.org/TR/2011/WD-css3-values-20110906/">http://www.w3.org/TR/2011/WD-css3-values-20110906/</a>
+ </dd>
+ <!---->
+
<dt id=JIS4051>[JIS4051]
<dd><cite>Formatting rules for Japanese documents
Index: Overview.src.html
===================================================================
RCS file: /sources/public/csswg/css3-text/Overview.src.html,v
retrieving revision 1.321
retrieving revision 1.322
diff -u -d -r1.321 -r1.322
--- Overview.src.html 19 Jan 2012 00:15:36 -0000 1.321
+++ Overview.src.html 19 Jan 2012 02:52:02 -0000 1.322
@@ -37,10 +37,10 @@
<dl>
<dt>This version:</dt>
- <!--
<dd><a href="http://dev.w3.org/csswg/css3-text/">$Date$ (CVS $Revision$)</a>
- -->
+ <!--
<dd><a href="http://www.w3.org/TR/[YEAR]/WD-css3-text-[CDATE]/">http://www.w3.org/TR/[YEAR]/WD-css3-text-[CDATE]/</a></dd>
+ -->
<dt>Latest version:</dt>
<dd><a href="http://www.w3.org/TR/css3-text/">http://www.w3.org/TR/css3-text/</a></dd>
<dt>Latest editor's draft:</dt>
@@ -1628,6 +1628,26 @@
be followed when any justification method other than 'auto' is
specified.</p>
+ <div class="note">
+ <p>The guidelines in this level of CSS do not describe a complete
+ justification algorithm. They are merely a minimum set of requirements
+ that a complete algorithm should meet. Limiting the set of requirements
+ gives UAs some latitude in choosing a justification algorithm that
+ meets their needs.
+
+ <p>For instance, a basic but fast ''inter-word'' justification algorithm
+ might use a simple greedy method for determining line breaks, then
+ distribute space using the <a href="#spacing">spacing limits provided</a>.
+ This algorithm could follow the guidelines by changing word spacing
+ first, increasing 'letter-spacing' only if 'word-spacing' hit a limit.
+
+ <p>A more sophisticated but slower ''inter-word'' justification algorithm
+ might use a Knuth/Plass method where spacing opportunities and spacing
+ limits were assigned weights and assessed with other line breaking
+ considerations. This algorithm could follow the guidelines by giving
+ more weight to word spacing than letter spacing.
+ </div>
+
<p id="expansion-opportunity">CSS defines <dfn>expansion opportunities</dfn>
as points where the justification algorithm may alter spacing within
the text. These expansion opportunities fall into priority
@@ -1803,9 +1823,6 @@
justify the text under any method. This behavior is not controlled by
this level of CSS.</p>
- <p class="issue">Add example of using 'text-justify' with the TeX
- algorithm.</p>
-
<div class="example">
<p>3.8 Line Adjustment in [[JLREQ]] gives an example of a set of rules for
how a text formatter can justify Japanese text.
Received on Thursday, 19 January 2012 02:52:11 UTC