Fix custom wallpaper going back from wallpaper 2 to wallpaper 1

chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_manager.js

 // Copyright (c) 2013 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.
 
 /**
  * WallpaperManager constructor.
  *
  * WallpaperManager objects encapsulate the functionality of the wallpaper
  * manager extension.
  *
  * @constructor
  * @param {HTMLElement} dialogDom The DOM node containing the prototypical
  *     extension UI.
  */
 
 function WallpaperManager(dialogDom) {
   this.dialogDom_ = dialogDom;
   this.storage_ = chrome.storage.local;
   this.document_ = dialogDom.ownerDocument;
   this.enableOnlineWallpaper_ = loadTimeData.valueExists('manifestBaseURL');
   this.selectedCategory = null;
+  this.selectedItem_ = null;
   this.progressManager_ = new ProgressManager();
   this.customWallpaperData_ = null;
   this.currentWallpaper_ = null;
   this.wallpaperRequest_ = null;
   this.backgroundPage_ = null;
   this.wallpaperDirs_ = WallpaperDirectories.getInstance();
   this.fetchBackgroundPage_();
   this.fetchManifest_();
 }
 
@@ skipping 421 matching lines @@
     }
   };
 
   /**
    * Constructs the thumbnails grid.
    */
   WallpaperManager.prototype.initThumbnailsGrid_ = function() {
     this.wallpaperGrid_ = $('wallpaper-grid');
     wallpapers.WallpaperThumbnailsGrid.decorate(this.wallpaperGrid_);
 
-    this.wallpaperGrid_.addEventListener('change',
-        this.onThumbnailSelectionChanged_.bind(this));
+    this.wallpaperGrid_.addEventListener('change', this.onChange_.bind(this));
     this.wallpaperGrid_.addEventListener('dblclick', this.onClose_.bind(this));
   };
 
   /**
+   * Handles change event dispatched by wallpaper grid.
+   */
+  WallpaperManager.prototype.onChange_ = function() {
+    // splice may dispatch a change event because the position of selected
+    // element changing. But the actual selected element may not change after
+    // splice. Check if the new selected element equals to the previous selected
+    // element before continuing. Otherwise, wallpaper may reset to previous one
+    // as described in http://crbug.com/229036.
+    if (this.selectedItem_ == this.wallpaperGrid_.selectedItem)
+      return;
+    this.selectedItem_ = this.wallpaperGrid_.selectedItem;
+    this.onSelectedItemChanged_();
+  };
+
+  /**
    * Closes window if no pending wallpaper request.
    */
   WallpaperManager.prototype.onClose_ = function() {
     if (this.wallpaperRequest_) {
       this.wallpaperRequest_.addEventListener('loadend', function() {
         // Close window on wallpaper loading finished.
         window.close();
       });
     } else {
       window.close();
@@ skipping 131 matching lines @@
         break;
       default:
         msg = 'Unknown Error';
         break;
     }
     console.error('Error: ' + msg);
     this.showError_(str('accessFileFailure'));
   };
 
   /**
-   * Handles click on a different thumbnail in wallpaper grid.
+   * Handles changing of selectedItem in wallpaper manager.
    */
-  WallpaperManager.prototype.onThumbnailSelectionChanged_ = function() {
-    var selectedItem = this.wallpaperGrid_.selectedItem;
-    if (selectedItem && selectedItem.source == 'ADDNEW')
+  WallpaperManager.prototype.onSelectedItemChanged_ = function() {
+    this.setWallpaperAttribution_(this.selectedItem_);
+
+    if (!this.selectedItem_ || this.selectedItem_.source == 'ADDNEW')
       return;
 
-    if (selectedItem && selectedItem.baseURL &&
-        !this.wallpaperGrid_.inProgramSelection) {
-      if (selectedItem.source == wallpapers.WallpaperSourceEnum.Custom) {
+    if (this.selectedItem_.baseURL && !this.wallpaperGrid_.inProgramSelection) {
+      if (this.selectedItem_.source == wallpapers.WallpaperSourceEnum.Custom) {
         var items = {};
-        var key = selectedItem.baseURL;
+        var key = this.selectedItem_.baseURL;
         var self = this;
         this.storage_.get(key, function(items) {
-          selectedItem.layout = items[key] ? items[key] : 'CENTER_CROPPED';
-          self.setSelectedWallpaper_(selectedItem);
+          self.selectedItem_.layout =
+              items[key] ? items[key] : 'CENTER_CROPPED';
+          self.setSelectedWallpaper_(self.selectedItem_);
         });
       } else {
-        this.setSelectedWallpaper_(selectedItem);
+        this.setSelectedWallpaper_(this.selectedItem_);
       }
     }
-    this.setWallpaperAttribution_(selectedItem);
   };
 
   /**
    * Set attributions of wallpaper with given URL. If URL is not valid, clear
    * the attributions.
    * @param {{baseURL: string, dynamicURL: string, layout: string,
    *          author: string, authorWebsite: string, availableOffline: boolean}}
    *     selectedItem selected wallpaper item in grid.
    * @private
    */
@@ skipping 107 matching lines @@
           dirEntry.getFile(fileName, {create: true}, function(fileEntry) {
             fileEntry.createWriter(function(fileWriter) {
               fileWriter.onwriteend = function(e) {
                 $('set-wallpaper-layout').disabled = false;
                 var wallpaperInfo = {
                   baseURL: fileName,
                   layout: layout,
                   source: wallpapers.WallpaperSourceEnum.Custom,
                   availableOffline: true
                 };
+                self.wallpaperGrid_.dataModel.splice(0, 0, wallpaperInfo);
+                self.wallpaperGrid_.selectedItem = wallpaperInfo;
+                self.wallpaperGrid_.activeItem = wallpaperInfo;
                 self.currentWallpaper_ = fileName;
                 var items = {};
                 items[self.currentWallpaper_] = layout;
                 self.storage_.set(items, function() {});
-                self.wallpaperGrid_.dataModel.splice(0, 0, wallpaperInfo);
-                self.wallpaperGrid_.selectedItem = wallpaperInfo;
-                self.wallpaperGrid_.activeItem = wallpaperInfo;
               };
 
               fileWriter.onerror = errorHandler;
 
               var blob = new Blob([new Int8Array(thumbnail)],
                                   {'type' : 'image\/jpeg'});
               fileWriter.write(blob);
             }, errorHandler);
           }, errorHandler);
         };
@@ skipping 231 matching lines @@
           }
         }
       }
       this.wallpaperGrid_.dataModel = wallpapersDataModel;
       this.wallpaperGrid_.selectedItem = selectedItem;
       this.wallpaperGrid_.activeItem = selectedItem;
     }
   };
 
 })();