Disable wallpaper button in Guest mode settings

ui/webui/resources/js/chromeos/ui_account_tweaks.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.
 
 /**
  * @fileoverview This file contains methods that allow to tweak
  * internal page UI based on the status of current user (owner/user/guest).
  * It is assumed that required data is passed via i18n strings
  * (using loadTimeData dictionary) that are filled with call to
  * AddAccountUITweaksLocalizedValues in ui_account_tweaks.cc.
@@ skipping 39 matching lines @@
   };
 
   /**
    * @return {boolean} Whether we're currently in supervised user mode.
    */
   UIAccountTweaks.loggedInAsSupervisedUser = function() {
     return loadTimeData.getBoolean('loggedInAsSupervisedUser');
   };
 
   /**
+   * Enables an element unless it should be disabled for the session type.
+   *
+   * @param {!Element} element Element that should be enabled.
+   */
+  UIAccountTweaks.enableElementIfPossible = function(element) {

[stevenjb, 2014/09/25 15:45:33]

Again, this function name seems too generic for the logic.

[michaelpg, 2014/09/29 18:50:56]

enableElementIfAllowed? enableElementIfEditable? tryToEnableElement?

enableElementForSessionType?

+    if (cr.isChromeOS) {

[stevenjb, 2014/09/25 15:45:33]

Shouldn't this always be true since this is in js/chromeos?

[michaelpg, 2014/09/29 18:50:56]

Yes. I've done a sanity check anyway, and nothing is calling this function
outside of chrome OS.

+      var sessionType;
+      if (UIAccountTweaks.loggedInAsGuest())
+        sessionType = SESSION_TYPE_GUEST;
+      else if (UIAccountTweaks.loggedInAsPublicAccount())
+        sessionType = SESSION_TYPE_PUBLIC;
+
+      if (sessionType &&
+          element.getAttribute(sessionType +'-visibility') == 'disabled') {
+        return;
+      }
+    }
+
+    element.disabled = false;
+  }
+
+  /**
    * Disables or hides some elements in specified type of session in ChromeOS.
    * All elements within given document with *sessionType*-visibility
    * attribute are either hidden (for *sessionType*-visibility="hidden")
    * or disabled (for *sessionType*-visibility="disabled").
    *
    * @param {Document} document Document that should processed.
    * @param {string} sessionType name of the session type processed.
    * @private
    */
   UIAccountTweaks.applySessionTypeVisibility_ = function(document,
@@ skipping 84 matching lines @@
       };
     }
   };
 
   // Export
   return {
     UIAccountTweaks: UIAccountTweaks
   };
 
 });