Bug 1201146 - Introduce "Section" traversal rule. r=yzen

accessible/jsat/Traversal.jsm

@@ -224,6 +224,28 @@ this.TraversalRules = { // jshint ignore:line
         Filters.IGNORE;
     }, null, true),
 
+  /* A rule for Android's section navigation, lands on landmarks, regions, and
+     on headings to aid navigation of traditionally structured documents */
+  Section: new BaseTraversalRule(
+    [],
+    function Section_match(aAccessible) {
+      if (aAccessible.role === Roles.HEADING) {
+        return Filters.MATCH;
+      }
+
+      let matchedRole = Utils.matchRoles(aAccessible, [
+        'banner',
+        'complementary',
+        'contentinfo',
+        'main',
+        'navigation',
+        'search',
+        'region'
+        ]);
+
+      return matchedRole ? Filters.MATCH : Filters.IGNORE;
+    }, null, true),
+
   Entry: new BaseTraversalRule(
     [Roles.ENTRY,
      Roles.PASSWORD_TEXT]),

accessible/tests/mochitest/jsat/doc_traversal.html

@@ -82,16 +82,20 @@
     </li>
     <li id="listitem-2-3">JavaScript</li>
   </ul>
+  <section>
     <h6 id="heading-5">The last (visible) one!</h6>
     <img id="image-1" src="http://example.com" alt="">
     <img id="image-2" src="../moz.png" alt="stuff">
     <div id="image-3" tabindex="0" role="img">Not actually an image</div>
+  </section>
+  <section>
     <h4 id="heading-6" aria-hidden="true">Hidden header</h4>
     <a id="link-1" href="http://www.mozilla.org">Link</a>
     <a id="anchor-1">Words</a>
     <a id="link-2" href="http://www.mozilla.org">Link the second</a>
     <a id="anchor-2">Sentences</a>
     <a id="link-3" href="http://www.example.com">Link the third</a>
+  </section>
   <hr id="separator-1">
   <h6 id="heading-6"></h6>
   <table id="table-1">

accessible/tests/mochitest/jsat/test_traversal_helper.html

@@ -83,7 +83,9 @@
       testTraversalHelper('List',
         ['Programming Language', 'listitem-2-1', 'listitem-3-1']);
 
-      vc.position = null;
+      testTraversalHelper('Section',
+        ['heading-1', 'heading-2', 'heading-3',
+         'heading-5', 'link-1', 'statusbar-1']);
 
       SimpleTest.finish();
     }