MDL-63628 accessibility: Trigger file links with keyboard

mod/folder/module.js

@@ -25,7 +25,7 @@
 M.mod_folder = {};
 
 M.mod_folder.init_tree = function(Y, id, expand_all) {
-    Y.use('yui2-treeview', function(Y) {
+    Y.use('yui2-treeview', 'node-event-simulate', function(Y) {
         var tree = new Y.YUI2.widget.TreeView(id);
 
         tree.subscribe("clickEvent", function(node, event) {
@@ -33,6 +33,12 @@ M.mod_folder.init_tree = function(Y, id, expand_all) {
             return false;
         });
 
+        tree.subscribe("enterKeyPressed", function(node) {
+            // We want keyboard activation to trigger a click on the first link.
+            Y.one(node.getContentEl()).one('a').simulate('click');
+            return false;
+        });
+
         if (expand_all) {
             tree.expandAll();
         } else {