Improve accessibility of user image selection screen.

chrome/browser/resources/shared/js/cr/ui/grid.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // require: list_selection_model.js
 // require: list_selection_controller.js
 // require: list.js
 
 /**
  * @fileoverview This implements a grid control. Grid contains a bunch of
@@ skipping 332 matching lines @@
    */
   function GridSelectionController(selectionModel, grid) {
     this.selectionModel_ = selectionModel;
     this.grid_ = grid;
   }
 
   GridSelectionController.prototype = {
     __proto__: ListSelectionController.prototype,
 
     /**
+     * Check if accessibility is enabled: if ChromeVox is running
+     * (which provides spoken feedback for accessibility), make up/down
+     * behave the same as left/right. That's because the 2-dimensional
+     * structure of the grid isn't exposed, so it makes more sense to a
+     * user who is relying on spoken feedback to flatten it.
+     * @return {boolean} True if accessibility is enabled.
+     */
+    isAccessibilityEnabled: function() {
+      return (window.cvox && cvox.Api && cvox.Api &&

[Evan Stade, 2012/05/07 20:58:02]

cvox.Api checked twice

+              cvox.Api.isChromeVoxActive && cvox.Api.isChromeVoxActive());
+    },
+
+    /**
      * Returns the index below (y axis) the given element.
      * @param {number} index The index to get the index below.
      * @return {number} The index below or -1 if not found.
      * @override
      */
     getIndexBelow: function(index) {
+      if (this.isAccessibilityEnabled())
+        return this.getIndexAfter(index);
       var last = this.getLastIndex();
       if (index == last) {

[Evan Stade, 2012/05/07 20:58:02]

no curlies

         return -1;
       }
       index += this.grid_.columns;
       return Math.min(index, last);
     },
 
     /**
      * Returns the index above (y axis) the given element.
      * @param {number} index The index to get the index above.
      * @return {number} The index below or -1 if not found.
      * @override
      */
     getIndexAbove: function(index) {
+      if (this.isAccessibilityEnabled())
+        return this.getIndexBefore(index);
       if (index == 0) {

[Evan Stade, 2012/05/07 20:58:02]

no curlies

         return -1;
       }
       index -= this.grid_.columns;
       return Math.max(index, 0);
     },
 
     /**
      * Returns the index before (x axis) the given element.
      * @param {number} index The index to get the index before.
      * @return {number} The index before or -1 if not found.
@@ skipping 16 matching lines @@
       return index + 1;
     }
   };
 
   return {
     Grid: Grid,
     GridItem: GridItem,
     GridSelectionController: GridSelectionController
   };
 });