[css2] Processed StevenP's comments.

bert-github · bert-github · commit f0094597808d · 1998-03-15T22:44:21.000Z
Removed some redundancy. Moved @import from media.src to here. --HG-- extra : convert_revision : svn%3A73dc7c4b-06e6-40f3-b4f7-9ed1dbc14bfc/trunk%401189
diff --git a/css2/cascade.src b/css2/cascade.src
@@ -1,6 +1,6 @@
 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
 <html lang="en">
-<!-- $Id: cascade.src,v 2.12 1998-03-14 23:30:05 ijacobs Exp $ -->
+<!-- $Id: cascade.src,v 2.13 1998-03-15 22:44:21 bbos Exp $ -->
 <HEAD>
 <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
 <TITLE>Assigning property values, Cascading, and Inheritance</TITLE>
@@ -29,22 +29,24 @@ on the following mechanisms (in order of precedence):</p>
 
 <ol>
 <li>If the <a href="#cascade">cascade</a> results in a value,
-use it. If the value is 'inherit', use the value of the parent
-element.
+use it. <!-- If the value is 'inherit', use the value of the parent
+element. -->
 
-<li>Otherwise, if the value is <a href="#inheritance">inherited</a>,
-use it.
+<li>Otherwise, if the property is <a
+href="#inheritance">inherited</a>, use the value of the parent
+element, usually the actual value.
 
 <li>Otherwise use the property's <span class="index-def"
 title="initial value">initial value</span>. The <a
 name="initial-value">initial value</a> of each property is indicated
 in the property's definition.
 </ol>
 
-<P>The root of the <a href="conform.html#doctree">document tree</a>
-cannot use values from the parent element since it has no parent. As a
-substitute, the initial value should be used whenever the root element
-needs a value from a parent element.
+<P>Since it has no parent, the root of the <a
+href="conform.html#doctree">document tree</a> cannot use values from
+the parent element; in this case, the initial value is used if
+necessary.
+
 
 <h3><span class="index-def" title="computed value">
 <a name="computed-value">Computed values</a>
@@ -55,11 +57,16 @@ needs a value from a parent element.
 relative to another value, as in 'red' or '2mm') or relative (i.e.,
 they are specified relative to another value, as in 'auto', '2em', and
 '12%'). For absolute values, no computation is needed to find the
-computed value.  Relative values, on the other hand, must be
-transformed into computed <a href="syndata.html#values">values</a>
-as described in the chapter on <a href="syndata.html">syntax</a>.
-Each property defines the meaning of that property's percentage
-values.
+computed value.
+
+<p>Relative values, on the other hand, must be transformed into
+computed values: percentages must be multiplied by the referenced
+actual value (each property defines which value that is), values with
+relative units (em, ex, px) must be made absolute by multiplying with
+the appropriate font or pixel size, 'auto' values must be computed by
+the formulas given with each property, certain keywords ('smaller',
+'bolder', 'inherit') must be replaced according to their definitions.
+
 
 <h3><span class="index-def" title="actual value">
 <a name="actual-value">Actual values</a></span></h3>
@@ -73,8 +80,8 @@ applied.
 
 
 <P>In most cases, elements inherit actual values. However, there are
-some properties whose specified or calculated values may be inherited
-(e.g., a number value for the <span
+some properties whose specified or computed values may be inherited
+(e.g., the number value for the <span
 class="propinst-line-height">'line-height'</span> property). The
 definition of a property whose actual value is not what other elements
 inherit will clearly say so.
@@ -108,20 +115,23 @@ class="propinst-vertical-align">'vertical-align'</span>.
 
 <H2><a name="inheritance">Inheritance</a></h2>
 
-<P>Some actual values are inherited by the children of an element in
-the <a href="conform.html#doctree">document tree</a>.
+<P>Some values are inherited by the children of an element in
+the <a href="conform.html#doctree">document tree</a>. Each property <a
+href="about.html#property-defs">defines</a> whether it is inherited or
+not.
 
-<P>All properties accept the 'inherit' keyword. For an inherited
+<!--<P>All properties accept the 'inherit' keyword. For an inherited
 property, this value is merely an explicit statement of the
 inheritance. For a property that is not inherited according to its
 definition, this value forces inheritance.
+[Already in next section. BB] -->
 
 <div class="html-example"><P>
 Suppose there is an H1 element with an emphasizing element (EM)
 inside:</p>
 
 <PRE>
-  &lt;H1&gt;The headline &lt;EM&gt;is&lt;/EM&gt; important!&lt;/H1&gt;
+&lt;H1&gt;The headline &lt;EM&gt;is&lt;/EM&gt; important!&lt;/H1&gt;
 </PRE>
 
 <P>If no color has been assigned to the EM element, the emphasized
@@ -135,7 +145,8 @@ class="propinst-font-family">'font-family'</span> and <span
 class="propinst-font-size">'font-size'</span>.
 -->
 
-<P>The root of the document tree cannot inherit values.
+<!-- <P>The root of the document tree cannot inherit values.
+[Already stated under "specified values". BB]-->
 
 <P> To set a "default" style property for a document, authors may set
 the property on the root of the document tree. In HTML, for example,
@@ -149,22 +160,25 @@ property is inherited, all descendants of the BODY element will
 inherit the color 'black':
 
 <PRE>
-    BODY { color: black; }
+BODY { color: black; }
 </PRE>
 
+<!--
 <P>Not all style properties are inherited, for example <span
 class="propinst-background">'background'</span>. But in the case of
 <span class="propinst-background">'background'</span>, the <em>visual
 effect</em> may be propagated to descendants. A
 background specified for the root element, as in:</p>
 
 <PRE>
-    BODY { background: url(texture.gif) white; }
+BODY { background: url(texture.gif) white; }
 </PRE>
 
 <P>will shine through any descendants unless they specify a value for
 <span class="propinst-background-color">'background-color'</span>
 other than 'transparent' (the initial value).
+
+[Why explain that here? BB]-->
 </div>
 
 <div class="example"><P> 
@@ -174,16 +188,16 @@ specified</a> percentage values are not inherited; only
 the style sheet:
 
 <pre>
-  BODY { font-size: 10pt }
-  H1 { font-size: 120% }
+BODY { font-size: 10pt }
+H1 { font-size: 120% }
 </pre>
 
 <p>and the document fragment:
 
 <pre class="html-example">
-  &lt;BODY&gt;
-    &lt;H1&gt;A &lt;EM&gt;large&lt;/EM&gt; heading&lt;/H1&gt;
-  &lt;/BODY&gt;
+&lt;BODY&gt;
+  &lt;H1&gt;A &lt;EM&gt;large&lt;/EM&gt; heading&lt;/H1&gt;
+&lt;/BODY&gt;
 </pre>
 
 <p>The <a href="#computed-value">computed value</a> of the <span
@@ -212,6 +226,47 @@ element's parent.
 http://lists.w3.org/Archives/Member/w3c-css-wg/1998JanMar/0054.html
 -IJ -->
 
+<H2><a name="at-import">The @import rule</a></h2>
+
+<P>The <span class="index-def"
+title="@import"><dfn>'@import'</dfn></span> rule allows users to import
+style rules in other style sheets. The '@import' keyword must be
+followed by the URI of the style sheet to include. Any @import rules
+must precede all rule sets in a style sheet.
+
+<div class="example"><P> 
+Both of these import rules are valid; the
+first one illustrates that the "url()" syntax may be replaced by a
+string in the
+@import rule:</p>
+
+<PRE>
+@import "mystyle.css";
+@import url(herstyle.css);
+</PRE>
+</div>
+
+<p>So that user agents can avoid retrieving resources for unsupported
+<a href="media.html">media types</a>, authors may specify
+media-dependent <span class="index-inst"
+title="@import">@import</span> rules.  These <span class="index-def"
+title="conditional import|media-dependent import">conditional
+imports</span> specify comma-separated media types after the URI.
+
+<div class="example">
+<p>The following rules have the same effect as if the imported style
+sheet were wrapped in an @media rule for the same media, but it may
+save the UA a fruitless download.
+
+<pre>
+@import url(fineprint.css) print;
+@import url(bluish.css) projection, tv;
+</pre>
+</div>
+
+<p>In the absence of any media types, the import is
+unconditional. Specifying 'all' for the medium has the same effect.
+
 <H2><a name="cascade">The cascade</a></h2>
 
 <P>Style sheets may have three different origins: author, user, and
