Spec the baseline of a flexbox.

Author: tabatkins

css3-flexbox/Overview.html

@@ -500,6 +500,28 @@ <h2 id=display-flexbox><span class=secno>3. </span> New values for
    Additionally, each of the <a href="#flexbox-item"><i>flexbox items</i></a>
    establishes a new formatting context for its contents.
 
+  <p> The baseline of a flexbox is:
+
+  <ul>
+   <li> If any of the <a href="#flexbox-item"><i>flexbox items</i></a> on the
+    flexbox's first line have a computed value of &lsquo;<a
+    href="#flex-align-baseline"><code class=css>baseline</code></a>&rsquo;
+    for &lsquo;<a href="#flex-item-align"><code
+    class=property>flex-item-align</code></a>&rsquo;, the flexbox's baseline
+    is the baseline of those <a href="#flexbox-item"><i>flexbox
+    items</i></a>.
+
+   <li> Otherwise, if the flexbox has at least one <a
+    href="#flexbox-item"><i>flexbox item</i></a>, and its first <a
+    href="#flexbox-item"><i>flexbox item</i></a>&lsquo;<code class=css>s
+    baseline is parallel to the flexbox</code>&rsquo;s <a
+    href="#main-axis"><i>main axis</i></a>, the flexbox's baseline is the
+    baseline of its first <a href="#flexbox-item"><i>flexbox item</i></a>.
+
+   <li> Otherwise, the flexbox's baseline is the "after" edge of its content
+    box.
+  </ul>
+
   <h2 id=flex-items><span class=secno>4. </span> Flexbox Items</h2>
 
   <p>The flexbox layout algorithm operates on boxes generated by <dfn

css3-flexbox/Overview.src.html

@@ -170,6 +170,24 @@ <h2 id='display-flexbox'>
 
 	<p>A flexbox establishes a new <dfn>flexbox formatting context</dfn> for its contents.  This is similar to a block formatting context root: floats do not intrude into the flexbox, and the flexbox's margins do not collapse with the margins of its contents.  Additionally, each of the <i>flexbox items</i> establishes a new formatting context for its contents.</p>
 
+	<p>
+		The baseline of a flexbox is:
+
+	<ul>
+		<li>
+			If any of the <i>flexbox items</i> on the flexbox's first line 
+			have a computed value of ''baseline'' for 'flex-item-align', 
+			the flexbox's baseline is the baseline of those <i>flexbox items</i>.
+
+		<li>
+			Otherwise, if the flexbox has at least one <i>flexbox item</i>,
+			and its first <i>flexbox item</i>'s baseline is parallel to the flexbox's <i>main axis</i>,
+			the flexbox's baseline is the baseline of its first <i>flexbox item</i>.
+
+		<li>
+			Otherwise, the flexbox's baseline is the "after" edge of its content box.
+	</ul>
+
 <h2 id='flex-items'>
 Flexbox Items</h2>