- From: Elika Etemad via cvs-syncmail <cvsmail@w3.org>
- Date: Tue, 30 Aug 2011 22:58:30 +0000
- To: public-css-commits@w3.org
Update of /sources/public/csswg/css3-values
In directory hutz:/tmp/cvs-serv29808
Modified Files:
Overview.html Overview.src.html
Log Message:
Sync value stages section against CSS2.1, make some editorial edits.
Index: Overview.html
===================================================================
RCS file: /sources/public/csswg/css3-values/Overview.html,v
retrieving revision 1.87
retrieving revision 1.88
diff -u -d -r1.87 -r1.88
--- Overview.html 16 Aug 2011 18:37:15 -0000 1.87
+++ Overview.html 30 Aug 2011 22:58:28 -0000 1.88
@@ -29,13 +29,13 @@
<h1 id=css3-template>CSS3 Values and Units</h1>
- <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 16 August 2011</h2>
+ <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 30 August 2011</h2>
<dl>
<dt>This version:
<dd><a
- href="http://www.w3.org/TR/2011/ED-css3-values-20110816/">http://www.w3.org/TR/2011/ED-css3-values-20110816/</a>
+ href="http://www.w3.org/TR/2011/ED-css3-values-20110830/">http://www.w3.org/TR/2011/ED-css3-values-20110830/</a>
<dt>Latest version:
@@ -284,20 +284,23 @@
‘<code class=css>attr()</code>’</a>
</ul>
- <li><a href="#specified-computed-used-and-actual-value"><span
- class=secno>10. </span>Specified, computed, used, and actual values</a>
+ <li><a href="#value-stages"><span class=secno>10. </span> Stages of Value
+ Computation</a>
<ul class=toc>
- <li><a href="#finding-the-specified-value"><span class=secno>10.1.
- </span>Finding the specified value</a>
+ <li><a href="#specified"><span class=secno>10.1. </span> Finding the
+ specified value</a>
- <li><a href="#finding-the-computed-value"><span class=secno>10.2.
- </span>Finding the computed value</a>
+ <li><a href="#computed"><span class=secno>10.2. </span> Finding the
+ computed value</a>
<li><a href="#finding-the-used-value"><span class=secno>10.3.
</span>Finding the used value</a>
- <li><a href="#finding-the-actual-value"><span class=secno>10.4.
- </span>Finding the actual value</a>
+ <li><a href="#actual"><span class=secno>10.4. </span> Finding the actual
+ value</a>
+
+ <li><a href="#stages-examples"><span class=secno>10.5. </span>
+ Examples</a>
</ul>
<li class=no-num><a href="#acknowledgments">Acknowledgments</a>
@@ -1732,85 +1735,123 @@
-->
- <h2 id=specified-computed-used-and-actual-value><span class=secno>10.
- </span>Specified, computed, used, and actual values</h2>
+ <h2 id=value-stages><span class=secno>10. </span> Stages of Value
+ Computation</h2>
+
+ <p class=issue>Shouldn't this section move to <a href="#CSS3CASCADE"
+ rel=biblioentry>[CSS3CASCADE]<!--{{CSS3CASCADE}}--></a>?
+
+ <p>Once a user agent has parsed a document and constructed a document tree,
+ it must assign, for every element in the tree, a value to every property
+ that applies to the target media type.
<p>The final value of a CSS3 property for a given element is the result of
- a four-step calculation. First, cascading and inheritance yields the <a
- href="#specified-value"><em>specified value</em></a> <a
- href="#CSS3CASCADE"
- rel=biblioentry>[CSS3CASCADE]<!--{{!CSS3CASCADE}}--></a>. Second, relative
- values are computed into absolute values as far as possible without
- formatting the document, thereby yielding the <a
- href="#computed-value"><em>computed value</em></a>. The computed value is
- transformed into the <a href="#used-value"><em>used value</em></a> in the
- formatting process. Finally, the computed value is transformed to the <a
- href="#actual-value"><em>actual value</em></a> based on constraints in the
- device and user agent.
+ a four-step calculation:
- <h3 id=finding-the-specified-value><span class=secno>10.1. </span>Finding
- the <dfn id=specified-value>specified value</dfn></h3>
+ <ul>
+ <li>First, cascading and inheritance yields the <a
+ href="#specified-value0"><i>specified value</i></a>.
- <p>The <a href="#specified-value"><em>specified value</em></a> is the
- output of the <a href="http://www.w3.org/TR/CSS21/cascade.html">cascading
- and inheritance process</a>. <a href="#CSS21"
- rel=biblioentry>[CSS21]<!--{{!CSS21}}--></a>
+ <li>Second, relative values are computed into absolute values as far as
+ possible without formatting the document, thereby yielding the <a
+ href="#computed-value"><i>computed value</i></a>.
- <h3 id=finding-the-computed-value><span class=secno>10.2. </span>Finding
- the <dfn id=computed-value>computed value</dfn></h3>
+ <li>The computed value is transformed into the <a
+ href="#used-value0"><i>used value</i></a> in the formatting process.
- <p>Specified values may be absolute (i.e., they are not specified relative
- to another value, as in ‘<code class=property>red</code>’ or
- ‘<code class=css>2mm</code>’) or relative (i.e., they are
- specified relative to another value, as in ‘<code
- class=property>auto</code>’, ‘<code
- class=css>2em</code>’). For absolute values, no processing is needed
- to find the computed value.
+ <li>Finally, the computed value is transformed to the <a
+ href="#actual-value"><i>actual value</i></a> based on constraints of
+ local environment.
+ </ul>
- <p>For relative values, on the other hand, computation is necessary to find
- the computed values: percentages must be multiplied by a reference value
- (each property defines which value that is), values with relative units
- (em, ex, vh, vw) must be made absolute by multiplying with the appropriate
- reference size, certain keywords (e.g., ‘<code
+ <h3 id=specified><span class=secno>10.1. </span> Finding the <dfn
+ id=specified-value>specified value</dfn></h3>
+
+ <p>The <dfn id=specified-value0>specified value</dfn> is the output of the
+ <a href="http://www.w3.org/TR/CSS21/cascade.html">cascading and
+ inheritance process</a>. <a href="#CSS21"
+ rel=biblioentry>[CSS21]<!--{{!CSS21}}--></a> <a href="#CSS3CASCADE"
+ rel=biblioentry>[CSS3CASCADE]<!--{{CSS3CASCADE}}--></a>
+
+ <p class=note>If the output of the cascade is ‘<code
+ class=css>inherit</code>’ or ‘<code
+ class=css>initial</code>’, the specified value contains the
+ inherited or initial value, respectively. See examples (d) and (e) in the
+ <a href="#stages-examples">table below</a>.
+
+ <p>The cascading and inheritance process guarantees that a <a
+ href="#specified-value0"><i>specified value</i></a> exists for every
+ property on every element.
+
+ <h3 id=computed><span class=secno>10.2. </span> Finding the computed value</h3>
+
+ <p>A <a href="#specified-value0"><i>specified value</i></a> can be either
+ absolute (i.e., not relative to another value, as in ‘<code
+ class=property>red</code>’ or ‘<code
+ class=css>2mm</code>’) or relative (i.e., relative to another value,
+ as in ‘<code class=property>auto</code>’, ‘<code
+ class=css>2em</code>’).
+
+ <p>For absolute values, no extra processing is needed to find the computed
+ value. For relative values, on the other hand, computation is necessary to
+ find the computed value: percentages must be multiplied by a reference
+ value (each property defines which value that is), values with relative
+ units (em, ex, vh, vw) must be made absolute by multiplying with the
+ appropriate reference size, certain keywords (e.g., ‘<code
class=property>smaller</code>’, ‘<code
class=property>bolder</code>’) must be replaced according to their
- definitions. See example (f), (g) and (h) in the table below.
+ definitions, and valid relative URLs must be resolved to become absolute.
+ See examples (f), (g) and (h) in the <a href="#stages-examples">table
+ below</a>.
- <p>Also, relative URIs are computed into absolute URIs at this stage. The
- computed value of invalid and absolute URIs is the same as the specified
- value.
+ <p>The <dfn id=computed-value>computed value</dfn> is the result of
+ resolving the <a href="#specified-value0"><i>specified value</i></a>
+ insofar as possible without formatting the document, as defined in the
+ "Computed value" line of the property definition tables.
+
+ <p class=note>The <a href="#computed-value"><i>computed value</i></a> is
+ the value that is transferred from parent to child during inheritance.
+
+ <p>The computed value exists even when the property does not apply (as
+ defined by the ‘<code class=css>Applies To</code>’ line).
+ However, some properties may define the computed value of a property for
+ an element to depend on whether the property applies to that element.
<h3 id=finding-the-used-value><span class=secno>10.3. </span>Finding the
<dfn id=used-value>used value</dfn></h3>
- <p>Computed values are processed as far as possible without formatting the
- document. Some values, however, can only be determined when the document
- is being laid out. For example, if the width of an element is set to be a
- certain percentage of its containing block, the width cannot be determined
- until the width of the containing block has been determined. The used
- value is the result of taking the computed value and resolving any
+ <p><i>Computed values</i> are processed as far as possible without
+ formatting the document. Some values, however, can only be determined when
+ the document is being laid out. For example, if the width of an element is
+ set to be a certain percentage of its containing block, the width cannot
+ be determined until the width of the containing block has been determined.
+ The <dfn id=used-value0>used value</dfn> is the result of taking the <a
+ href="#computed-value"><i>computed value</i></a> and resolving any
remaining dependencies into an absolute value.
- <h3 id=finding-the-actual-value><span class=secno>10.4. </span>Finding the
- <dfn id=actual-value>actual value</dfn></h3>
+ <h3 id=actual><span class=secno>10.4. </span> Finding the actual value</h3>
- <p>A used value is in principle ready to be used, but a user agent may not
- be able to make use of the value in a given environment. For example, a
- user agent may only be able to render borders with integer pixel widths
- and may therefore have to approximate the computed width. Also, the font
- size of an element may need adjustment based on the availability of fonts
- or the value of the ‘<code
- class=property>font-size-adjust</code>’ property. The actual value
- is the computed value after adjustments have been made.
+ <p>A <a href="#used-value0"><i>used value</i></a> is in principle ready to
+ be used, but a user agent may not be able to make use of the value in a
+ given environment. For example, a user agent may only be able to render
+ borders with integer pixel widths and may therefore have to approximate
+ the computed width. Also, the font size of an element may need adjustment
+ based on the availability of fonts or the value of the ‘<code
+ class=property>font-size-adjust</code>’ property. The <dfn
+ id=actual-value>actual value</dfn> is the used value after any such
+ approximations have been made.
- <p>By probing the actual values of elements, much can be learned about how
- the document is laid out. However, not all information is recorded in the
- actual values. For example, the actual value of the ‘<code
- class=property>page-break-after</code>’ property does not reflect
- whether there is a page break or not after the element. Similarly, the
- actual value of ‘<code class=property>orphans</code>’ does not
- reflect how many orphan lines there is in a certain element. See examples
- (j) and (k) in the table below.
+ <p class=note> By probing the actual values of elements, much can be
+ learned about how the document is laid out. However, not all information
+ is recorded in the actual values. For example, the actual value of the
+ ‘<code class=property>page-break-after</code>’ property does
+ not reflect whether there is a page break or not after the element.
+ Similarly, the actual value of ‘<code
+ class=property>orphans</code>’ does not reflect how many orphan
+ lines there is in a certain element. See examples (j) and (k) in the <a
+ href="#stages-examples">table below</a>.
+
+ <h3 id=stages-examples><span class=secno>10.5. </span> Examples</h3>
<table>
<tbody>
@@ -2043,16 +2084,6 @@
</dd>
<!---->
- <dt id=CSS3CASCADE>[CSS3CASCADE]
-
- <dd>Håkon Wium Lie. <a
- href="http://www.w3.org/TR/2005/WD-css3-cascade-20051215"><cite>CSS3
- module: Cascading and inheritance.</cite></a> 15 December 2005. W3C
- Working Draft. (Work in progress.) URL: <a
- href="http://www.w3.org/TR/2005/WD-css3-cascade-20051215">http://www.w3.org/TR/2005/WD-css3-cascade-20051215</a>
- </dd>
- <!---->
-
<dt id=CSS3COLOR>[CSS3COLOR]
<dd>Tantek Çelik; Chris Lilley; L. David Baron. <a
@@ -2227,7 +2258,8 @@
<li>s, <a href="#s" title=s><strong>6.2.</strong></a>
<li>specified value, <a href="#specified-value" title="specified
- value"><strong>10.1.</strong></a>
+ value"><strong>10.1.</strong></a>, <a href="#specified-value0"
+ title="specified value"><strong>10.1.</strong></a>
<li><a href="#string-value"><code><string></code></a>, <a
href="#string-value" title="<string>"><strong>3.3.</strong></a>
@@ -2243,6 +2275,7 @@
href="#url-value" title="<url>"><strong>3.4.</strong></a>
<li>used value, <a href="#used-value" title="used
+ value"><strong>10.3.</strong></a>, <a href="#used-value0" title="used
value"><strong>10.3.</strong></a>
<li>vh, <a href="#vh-unit" title=vh><strong>5.1.2.</strong></a>
Index: Overview.src.html
===================================================================
RCS file: /sources/public/csswg/css3-values/Overview.src.html,v
retrieving revision 1.90
retrieving revision 1.91
diff -u -d -r1.90 -r1.91
--- Overview.src.html 16 Aug 2011 18:37:15 -0000 1.90
+++ Overview.src.html 30 Aug 2011 22:58:28 -0000 1.91
@@ -1298,74 +1298,107 @@
-->
-<h2>Specified, computed, used, and actual values</h2>
+<h2 id="value-stages">
+Stages of Value Computation</h2>
-<p>The final value of a CSS3 property for a given element is the
-result of a four-step calculation. First, cascading and inheritance
-yields the <em>specified value</em> [[!CSS3CASCADE]]. Second, relative
-values are computed into absolute values as far as possible without
-formatting the document, thereby yielding the <em>computed value</em>.
-The computed value is transformed into the <em>used value</em> in the
-formatting process. Finally, the computed value is transformed to
-the <em>actual value</em> based on constraints in the device and user agent.</p>
+ <p class="issue">Shouldn't this section move to [[CSS3CASCADE]]?</p>
-<h3>Finding the <dfn>specified value</dfn></h3>
+ <p>Once a user agent has parsed a document and constructed a document tree,
+ it must assign, for every element in the tree, a value to every property
+ that applies to the target media type.
-<p>The <em>specified value</em> is the output of the
-<a href="http://www.w3.org/TR/CSS21/cascade.html">cascading and inheritance
-process</a>. [[!CSS21]]
+ <p>The final value of a CSS3 property for a given element is the
+ result of a four-step calculation:
+ <ul>
+ <li>First, cascading and inheritance yields the <i>specified value</i>.
+ <li>Second, relative values are computed into absolute values as far
+ as possible without formatting the document, thereby yielding the
+ <i>computed value</i>.
+ <li>The computed value is transformed into the <i>used value</i> in the
+ formatting process.
+ <li>Finally, the computed value is transformed to the <i>actual value</i>
+ based on constraints of local environment.
+ </ul>
-<h3>Finding the <dfn>computed value</dfn></h3>
+<h3 id="specified">
+Finding the <dfn>specified value</dfn></h3>
-<p>Specified values may be absolute (i.e., they are not specified
-relative to another value, as in 'red' or '2mm') or relative (i.e.,
-they are specified relative to another value, as in 'auto', '2em').
-For absolute values, no processing is needed to find the computed
-value.</p>
+ <p>The <dfn>specified value</dfn> is the output of the
+ <a href="http://www.w3.org/TR/CSS21/cascade.html">cascading and inheritance
+ process</a>. [[!CSS21]] [[CSS3CASCADE]]
-<p>For relative values, on the other hand, computation is necessary to
-find the computed values: percentages must be multiplied by a
+ <p class="note">If the output of the cascade is ''inherit'' or ''initial'',
+ the specified value contains the inherited or initial value, respectively.
+ See examples (d) and (e) in the <a href="#stages-examples">table below</a>.
+
+ <p>The cascading and inheritance process guarantees that a <i>specified value</i>
+ exists for every property on every element.
+
+<h3 id="computed">
+Finding the computed value</h3>
+
+ <p>A <i>specified value</i> can be either absolute
+ (i.e., not relative to another value, as in 'red' or '2mm')
+ or relative (i.e., relative to another value, as in 'auto', '2em').
+
+ <p>For absolute values, no extra processing is needed to find the computed
+ value. For relative values, on the other hand, computation is necessary to
+ find the computed value: percentages must be multiplied by a
reference value (each property defines which value that is), values
with relative units (em, ex, vh, vw) must be made absolute by multiplying
with the appropriate reference size, certain keywords
(e.g., 'smaller', 'bolder') must be replaced according to their
-definitions. See example (f), (g) and (h) in the table below.</p>
+ definitions, and valid relative URLs must be resolved to become absolute.
+ See examples (f), (g) and (h) in the <a href="#stages-examples">table below</a>.
-<p>Also, relative URIs are computed into absolute URIs at this stage.
-The computed value of invalid and absolute URIs is the same as the
-specified value.
+ <p>The <dfn>computed value</dfn> is the result of resolving the
+ <i>specified value</i> insofar as possible without formatting the
+ document, as defined in the "Computed value" line of the property
+ definition tables.
+ <p class="note">The <i>computed value</i> is the value that is
+ transferred from parent to child during inheritance.
+
+ <p>The computed value exists even when the property does not apply
+ (as defined by the 'Applies To' line). However, some properties may
+ define the computed value of a property for an element to depend on
+ whether the property applies to that element.
<h3>Finding the <dfn>used value</dfn></h3>
-<p>Computed values are processed as far as possible without formatting
+ <p><i>Computed values</i> are processed as far as possible without formatting
the document. Some values, however, can only be determined when the
document is being laid out. For example, if the width of an element is
set to be a certain percentage of its containing block, the width
cannot be determined until the width of the containing block has been
-determined. The used value is the result of taking the computed value
-and resolving any remaining dependencies into an absolute value.
-
+ determined. The <dfn>used value</dfn> is the result of taking the
+ <i>computed value</i> and resolving any remaining dependencies into an
+ absolute value.
-<h3>Finding the <dfn>actual value</dfn></h3>
+<h3 id="actual">
+Finding the actual value</h3>
-<p>A used value is in principle ready to be used, but a user agent may
+<p>A <i>used value</i> is in principle ready to be used, but a user agent may
not be able to make use of the value in a given environment. For
example, a user agent may only be able to render borders with integer
pixel widths and may therefore have to approximate the computed width.
Also, the font size of an element may need adjustment based on the
availability of fonts or the value of the 'font-size-adjust' property.
-The actual value is the computed value after adjustments have been
-made.
+ The <dfn>actual value</dfn> is the used value after any such approximations
+ have been made.
-<p>By probing the actual values of elements, much can be learned about
+ <p class="note">
+By probing the actual values of elements, much can be learned about
how the document is laid out. However, not all information is recorded
in the actual values. For example, the actual value of the
'page-break-after' property does not reflect whether there is a page
break or not after the element. Similarly, the actual value of
'orphans' does not reflect how many orphan lines there is in a certain
-element. See examples (j) and (k) in the table below.
+element.
+ See examples (j) and (k) in the <a href="#stages-examples">table below</a>.
+<h3 id="stages-examples">
+Examples</h3>
<table>
<tbody>
Received on Tuesday, 30 August 2011 22:58:32 UTC