Editor menubar example: Make Escape close submenu when focus in menub…

…ar (pull #723)

For issue #451:
* Adds ability to close open submenu  with Escape key when focus is in menubar.
* Add row to menubar keyboard table for Escape key.

examples/menubar/menubar-2/js/MenubarItemAction.js

@@ -126,6 +126,13 @@ MenubarItemAction.prototype.handleKeydown = function (event) {
       flag = true;
       break;
 
+    case this.keyCode.ESC:
+      if (this.popupMenu) {
+        this.popupMenu.close();
+      }
+      flag = true;
+      break;
+
     default:
       if (isPrintableCharacter(char)) {
         this.menubar.setFocusByFirstCharacter(this, char);

examples/menubar/menubar-2/menubar-2.html

@@ -159,6 +159,14 @@ <h3 id="kbd1_label">Menubar</h3>
           </th>
           <td>Opens submenu and moves focus to first item in the submenu.</td>
         </tr>
+        <tr>
+          <th>
+            <kbd>Escape</kbd>
+          </th>
+          <td>
+            If a submenu is open, closes it. Otherwise, does nothing.
+          </td>
+        </tr>
         <tr>
           <th>
             <kbd>Right Arrow</kbd>