[cros] Update wallpaper when displaying Gaia frame.

chrome/browser/resources/chromeos/login/user_pod_row.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 User pod row implementation.
  */
 
 cr.define('login', function() {
   /**
@@ skipping 408 matching lines @@
     // True if user pod has been activated with keyboard.
     // In case of activation with keyboard we delay wallpaper change.
     keyboardActivated_: false,
 
     // Focused pod.
     focusedPod_: undefined,
 
     // Activated pod, i.e. the pod of current login attempt.
     activatedPod_: undefined,
 
+    // Pod that was most recently focused, if any.
+    lastFocusedPod_: undefined,

[Nikita (slow), 2012/10/17 14:51:03]

You should probably clear that if user is deleted?

[Ivan Korotkov, 2012/10/17 15:34:10]

Done.

+
     // When moving through users quickly at login screen, set a timeout to
     // prevent loading intermediate wallpapers.
     loadWallpaperTimeout_: null,
 
     // Pods whose initial images haven't been loaded yet.
     podsWithPendingImages_: [],
 
     /** @inheritDoc */
     decorate: function() {
       this.style.left = 0;
@@ skipping 221 matching lines @@
         if (hadFocus && this.keyboardActivated_) {
           // Delay wallpaper loading to let user tab through pods without lag.
           this.loadWallpaperTimeout_ = window.setTimeout(
               this.loadWallpaper_.bind(this), WALLPAPER_LOAD_DELAY_MS);
         } else if (!this.firstShown_) {
           // Load wallpaper immediately if there no pod was focused
           // previously, and it is not a boot into user pod list case.
           this.loadWallpaper_();
         }
         this.firstShown_ = false;
-      } else {
-        chrome.send('userDeselected');
+        this.lastFocusedPod_ = podToFocus;
       }
       this.insideFocusPod_ = false;
       this.keyboardActivated_ = false;
     },
 
+    /**
+     * Loads wallpaper for the active user pod, if any.
+     */
     loadWallpaper_: function() {
       if (this.focusedPod_)
-        chrome.send('userSelectedDelayed', [this.focusedPod_.user.username]);
+        chrome.send('loadWallpaper', [this.focusedPod_.user.username]);
     },
 
     /**
+     * Resets wallpaper to the last active user's wallpaper, if any.
+     */
+    loadLastWallpaper_: function() {
+      if (this.lastFocusedPod_)
+        chrome.send('loadWallpaper', [this.lastFocusedPod_.user.username]);
+    },
+
+    /**
      * Returns the currently activated pod.
      * @type {UserPod}
      */
     get activatedPod() {
       return this.activatedPod_;
     },
     set activatedPod(pod) {
       if (pod && pod.activate())
         this.activatedPod_ = pod;
     },
@@ skipping 22 matching lines @@
     },
 
     /**
      * Resets input UI.
      * @param {boolean} takeFocus True to take focus.
      */
     reset: function(takeFocus) {
       this.disabled = false;
       if (this.activatedPod_)
         this.activatedPod_.reset(takeFocus);
+      this.loadLastWallpaper_();

[Nikita (slow), 2012/10/17 14:51:03]

I suspect that reset might be called multiple times for instance when you enter
password incorrectly.

I know that we would not load same wallpaper if it is already loaded (Biao?) but
we should not do this call here in the first place.

Should it be called when we cancel GAIA sign in?

[bshe, 2012/10/17 15:13:50]

We will not reload the same built in wallpaper. But for custom wallpaper or
online wallpaper, I believe we do.

On 2012/10/17 14:51:03, Nikita Kostylev wrote:

[Ivan Korotkov, 2012/10/17 15:34:10]

Fixed, now we only call loadLastWallpaper in response to "Cancel" click

     },
 
     /**
      * Shows signin UI.
      * @param {string} email Email for signin UI.
      */
     showSigninUI: function(email) {
       // Clear any error messages that might still be around.
       Oobe.clearErrors();
       this.disabled = true;
+      this.lastFocusedPod_ = this.getPodWithUsername_(email);
       Oobe.showSigninUI(email);
     },
 
     /**
      * Updates current image of a user.
      * @param {string} username User for which to update the image.
      */
     updateUserImage: function(username) {
       var pod = this.getPodWithUsername_(username);
       if (pod)
@@ skipping 165 matching lines @@
         this.classList.remove('images-loading');
         chrome.send('userImagesLoaded');
       }
     }
   };
 
   return {
     PodRow: PodRow
   };
 });