Allow "auto" in the width="" and height="" attributes on <image>. (ACTION-3340)
authorCameron McCormack <cam@mcc.id.au>
Wed, 06 Feb 2013 12:27:34 +1100
changeset 433 da96436a276e
parent 432 0aaceac25225
child 434 ef2fa575d779
Allow "auto" in the width="" and height="" attributes on <image>. (ACTION-3340)
master/changes.html
master/struct.html
--- a/master/changes.html	Mon Jan 21 10:39:36 2013 +1100
+++ b/master/changes.html	Wed Feb 06 12:27:34 2013 +1100
@@ -74,6 +74,8 @@
   <li>Removed the <span class="attr-name">'externalResourcesRequired'</span> attribute.</li>
 
   <li>Added the <a>'discard'</a> element and the <span class="attr-name">'timelineBegin'</span> and <span class="attr-name">'playbackOrder'</span> attributes on the <a>'svg'</a> element, as defined in SVG Tiny 1.2.</li>
+
+  <li>Added the ability to use <span class="attr-value">'auto'</span> for the <a>'image/x'</a> and <a>'image/y'</a> attributes on <a>'image'</a>.</li>
 </ul>
 
 <h3 id="styling">Styling chapter</h3>
--- a/master/struct.html	Mon Jan 21 10:39:36 2013 +1100
+++ b/master/struct.html	Wed Feb 06 12:27:34 2013 +1100
@@ -1566,7 +1566,7 @@
       </tr>
       <tr>
         <td><dfn id="ImageElementWidthAttribute">width</dfn>, <dfn id="ImageElementHeightAttribute">height</dfn></td>
-        <td><a>&lt;length&gt;</a></td>
+        <td><a>&lt;length&gt;</a> | auto</td>
         <td>0</td>
         <td>yes</td>
       </tr>
@@ -1579,6 +1579,21 @@
     <p>A negative value for <a>'width'</a> or <a>'height'</a> is invalid
     (see <a href="implnote.html#ErrorProcessing">Error processing</a>).
     A value of zero for either attribute disables rendering of the element.</p>
+    <p class="ready-for-wg-review">The <span class="attr-value">'auto'</span> value for <a>'width'</a>
+    and <a>'height'</a> is used to size the <a>'image'</a> element automatically
+    based on the intrinsic size or aspect ratio of the referenced image.
+    If the intrinsic aspect ratio of the referenced image is unknown,
+    it is assumed to be 2:1.  If the intrinsic size of the referenced image
+    is unknown, it is assumed to be 300×150, just as is required for
+    CSS replaced elements.  If <span class="attr-value">'auto'</span> is
+    specified for just one of <a>'width'</a> or <a>'height'</a>, then
+    the other is determined based on the intrinsic aspect ratio.  The
+    automatically determined <a>'width'</a> and <a>'height'</a> values
+    are interpreted as user units, and are reflected in the
+    <a href="#__svg__SVGImageElement__x">x</a> and
+    <a href="#__svg__SVGImageElement__y">y</a> IDL attributes
+    as <a href="types.html#__svg__SVGLength__SVG_LENGTHTYPE_NUMBER">SVG_LENGTHTYPE_NUMBER</a>
+    values.</p>
   </dd>
   <dt>
     <table class="propdef attrdef">