[Media Galleries] Lazily initialize the storage monitor.

chrome/browser/ui/webui/options/media_galleries_handler.cc

 // 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.
 
 #include "chrome/browser/ui/webui/options/media_galleries_handler.h"
 
 #include "base/bind.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/media_galleries/media_file_system_registry.h"
 #include "chrome/browser/media_galleries/media_galleries_preferences.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/chrome_select_file_policy.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_view.h"
 #include "content/public/browser/web_ui.h"
 #include "grit/generated_resources.h"
 
 namespace options {
 
 using chrome::MediaGalleriesPreferences;
 using chrome::MediaGalleriesPrefInfoMap;
 using chrome::MediaGalleryPrefInfo;
 
-MediaGalleriesHandler::MediaGalleriesHandler() {
+MediaGalleriesHandler::MediaGalleriesHandler()
+    : weak_ptr_factory_(this) {
 }
 
 MediaGalleriesHandler::~MediaGalleriesHandler() {
   if (select_file_dialog_.get())
     select_file_dialog_->ListenerDestroyed();
 }
 
 void MediaGalleriesHandler::GetLocalizedValues(DictionaryValue* values) {
   DCHECK(values);
 
@@ skipping 14 matching lines @@
     return;
 
   if (pref_change_registrar_.IsEmpty()) {
     pref_change_registrar_.Init(profile->GetPrefs());
     pref_change_registrar_.Add(
         prefs::kMediaGalleriesRememberedGalleries,
         base::Bind(&MediaGalleriesHandler::OnGalleriesChanged,
                    base::Unretained(this)));
   }
 
+  // Note: this call will set up the StorageMonitor through a call to
+  // GetPreferencesAsync. That is needed not only to populate the
+  // initial page contents, but also to hook the preferences up to
+  // device notifications so the change listener receives events.
   OnGalleriesChanged();
 }
 
 void MediaGalleriesHandler::RegisterMessages() {
   web_ui()->RegisterMessageCallback(
       "addNewGallery",
       base::Bind(&MediaGalleriesHandler::HandleAddNewGallery,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
       "forgetGallery",
       base::Bind(&MediaGalleriesHandler::HandleForgetGallery,
                  base::Unretained(this)));
 }
 
 void MediaGalleriesHandler::OnGalleriesChanged() {
   Profile* profile = Profile::FromWebUI(web_ui());
-  chrome::MediaGalleriesPreferences* preferences =
-      g_browser_process->media_file_system_registry()->GetPreferences(profile);
+      g_browser_process->media_file_system_registry()->GetPreferencesAsync(
+          profile,
+          base::Bind(&MediaGalleriesHandler::OnGalleriesChangedWithPreferences,
+                     weak_ptr_factory_.GetWeakPtr()));
+}
 
+void MediaGalleriesHandler::OnGalleriesChangedWithPreferences(
+    chrome::MediaGalleriesPreferences* preferences) {
   ListValue list;
   const MediaGalleriesPrefInfoMap& galleries = preferences->known_galleries();
   for (MediaGalleriesPrefInfoMap::const_iterator iter = galleries.begin();
        iter != galleries.end(); ++iter) {
     const MediaGalleryPrefInfo& gallery = iter->second;
     if (gallery.type == MediaGalleryPrefInfo::kBlackListed)
       continue;
 
     DictionaryValue* dict = new DictionaryValue();
     dict->SetString("displayName", gallery.display_name);
@@ skipping 23 matching lines @@
 
 void MediaGalleriesHandler::HandleForgetGallery(const base::ListValue* args) {
   std::string string_id;
   uint64 id = 0;
   if (!args->GetString(0, &string_id) ||
       !base::StringToUint64(string_id, &id)) {
     NOTREACHED();
     return;
   }
 
-  chrome::MediaGalleriesPreferences* prefs =
-      g_browser_process->media_file_system_registry()->GetPreferences(
-          Profile::FromWebUI(web_ui()));
-  prefs->ForgetGalleryById(id);
+  g_browser_process->media_file_system_registry()->GetPreferencesAsync(
+      Profile::FromWebUI(web_ui()),
+      base::Bind(&MediaGalleriesHandler::HandleForgetGalleryWithPreferences,
+                 weak_ptr_factory_.GetWeakPtr(), id));
+}
+
+void MediaGalleriesHandler::HandleForgetGalleryWithPreferences(
+    uint64 id,
+    chrome::MediaGalleriesPreferences* preferences) {
+  preferences->ForgetGalleryById(id);
 }
 
 void MediaGalleriesHandler::FileSelected(const base::FilePath& path,
                                          int index,
                                          void* params) {
-  chrome::MediaGalleriesPreferences* prefs =
-      g_browser_process->media_file_system_registry()->GetPreferences(
-          Profile::FromWebUI(web_ui()));
-  prefs->AddGalleryByPath(path);
+  g_browser_process->media_file_system_registry()->GetPreferencesAsync(
+      Profile::FromWebUI(web_ui()),
+      base::Bind(&MediaGalleriesHandler::FileSelectedWithPreferences,
+                 weak_ptr_factory_.GetWeakPtr(), path));
+}
+
+void MediaGalleriesHandler::FileSelectedWithPreferences(
+    base::FilePath path,
+    chrome::MediaGalleriesPreferences* preferences) {
+  preferences->AddGalleryByPath(path);
 }
 
 }  // namespace options