Fix custom wallpaper going back from wallpaper 2 to wallpaper 1

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

Index: chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_manager.js
diff --git a/chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_manager.js b/chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_manager.js
index 22ef6cf57eef24ae5f76e37cd0d7a736552f0510..274fc76588e0d0ef1f7f8288a9fd6c9748e52ec1 100644
--- a/chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_manager.js
+++ b/chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_manager.js
@@ -621,11 +621,20 @@ function WallpaperManager(dialogDom) {
    */
   WallpaperManager.prototype.onThumbnailSelectionChanged_ = function() {

[flackr, 2013/04/16 01:28:41]

This method and description seem to be inaccurately described. This is handling
a change of the wallpaper model which may have changed the selected thumbnail.

[bshe, 2013/04/16 16:19:26]

Done.

     var selectedItem = this.wallpaperGrid_.selectedItem;
-    if (selectedItem && selectedItem.source == 'ADDNEW')
+    this.setWallpaperAttribution_(selectedItem);
+
+    // splice may dispatch a change event because the position of selected
+    // element changing. But the actual selected element didn't 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 (!selectedItem || selectedItem.source == 'ADDNEW' ||
+        selectedItem == this.wallpaperGrid_.previousSelectedItem) {
       return;
+    }
 
-    if (selectedItem && selectedItem.baseURL &&
-        !this.wallpaperGrid_.inProgramSelection) {
+    this.wallpaperGrid_.previousSelectedItem = selectedItem;

[flackr, 2013/04/16 01:28:41]

previousSelectedItem doesn't belong in wallpaperGrid since wallpaperGrid doesn't
care whether the selectedItem actually change. You could store the
active/selected/displayed (whichever you think is the best name) item as a
member of this class and only act if it changes. Could this not be checked
against this.currentWallpaper or this.wallpaperGrid_.activeItem or would that
not be correct?

[bshe, 2013/04/16 16:19:26]

I can't use currentWallpaper or activeItem to replace previousSelectedItem. They
are not always the same. For example, if we select a thumbnail and failed to set
the corresponding wallpaper, activeItem and currentWallpaper wont change but the
selectedItem changed. Then we select another item, the previousSelectedItem !=
currentWallpaper or activeItem in that case.

You mean just move previousSelectedItem to this class, right? I have created a
new onChange_ function to call this function only when selectedItem changes.

On 2013/04/16 01:28:41, flackr wrote:

+    if (selectedItem.baseURL && !this.wallpaperGrid_.inProgramSelection) {
       if (selectedItem.source == wallpapers.WallpaperSourceEnum.Custom) {
         var items = {};
         var key = selectedItem.baseURL;
@@ -638,7 +647,6 @@ function WallpaperManager(dialogDom) {
         this.setSelectedWallpaper_(selectedItem);
       }
     }
-    this.setWallpaperAttribution_(selectedItem);
   };
 
   /**
@@ -769,7 +777,6 @@ function WallpaperManager(dialogDom) {
                 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;