Implement mediaGalleriesPrivate api to notify extensions about gallery changed events.

chrome/browser/extensions/api/media_galleries_private/media_galleries_private_api.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/extensions/api/media_galleries_private/media_galleries_private_api.h"
 
-#include "chrome/browser/extensions/api/media_galleries_private/media_galleries_private_api_factory.h"
+#include "base/bind.h"
+#include "base/file_path.h"
+#include "base/location.h"
+#include "base/string_number_conversions.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/extensions/api/media_galleries_private/gallery_watch_manager.h"
 #include "chrome/browser/extensions/api/media_galleries_private/media_galleries_private_event_router.h"
+#include "chrome/browser/extensions/api/media_galleries_private/media_gallery_extension_notification_observer.h"
 #include "chrome/browser/extensions/event_names.h"
 #include "chrome/browser/extensions/event_router.h"
 #include "chrome/browser/extensions/extension_system.h"
+#include "chrome/browser/media_gallery/media_file_system_registry.h"
+#include "chrome/browser/media_gallery/media_galleries_preferences.h"
+#include "chrome/browser/system_monitor/media_storage_util.h"
+#include "chrome/common/extensions/api/media_galleries_private.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_view_host.h"
 
 namespace extensions {
 
+namespace {
+
+// Returns the absolute file path of the gallery specified by the |gallery_id|.
+// Returns an empty file path if the |gallery_id| is invalid.
+FilePath GetGalleryAbsolutePath(chrome::MediaGalleryPrefId gallery_id,
+                                const Profile* profile,
+                                const Extension* extension) {
+  DCHECK(profile);
+  DCHECK(extension);
+  chrome::MediaFileSystemRegistry* registry =
+      g_browser_process->media_file_system_registry();
+  DCHECK(registry);
+  chrome::MediaGalleriesPreferences* preferences =
+      registry->GetPreferences(const_cast<Profile*>(profile));

[Lei Zhang, 2012/12/18 00:47:01]

Why do you take a Profile*, pass it in as a const Profile*, and then cast away
the const?

[kmadhusu, 2012/12/18 21:32:39]

Fixed. Passing Profile* as param.

+  if (!preferences)
+    return FilePath();
+
+  const chrome::MediaGalleryPrefIdSet permitted_galleries =
+      preferences->GalleriesForExtension(*extension);
+  if (permitted_galleries.empty() ||
+      permitted_galleries.find(gallery_id) == permitted_galleries.end())
+    return FilePath();
+
+  const chrome::MediaGalleriesPrefInfoMap& galleries_info =
+      preferences->known_galleries();
+  return chrome::MediaStorageUtil::FindDevicePathById(
+      galleries_info.find(gallery_id)->second.device_id);
+}
+
+// Returns GalleryWatchManager associated with the specified |profile|. Set
+// |create| to true, to create a GalleryWatchManager if it does not exists.
+GalleryWatchManager* GetGalleryWatchManagerOnFileThread(const Profile* profile,

[Lei Zhang, 2012/12/18 00:47:01]

Is this really needed?

Add can just do:
GalleryWatchManager* manager = GalleryWatchManager::GetForProfile(profile);

and Remove can just do:
if (GalleryWatchManager::HasForProfile(profile)))
  GalleryWatchManager::GetForProfile(profile)->StopGalleryWatch(...)

[kmadhusu, 2012/12/18 21:32:39]

Removed.
Done.

+                                                        bool create) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
+  if (!create && !GalleryWatchManager::HasForProfile(profile))
+    return NULL;
+  return GalleryWatchManager::GetForProfile(profile);
+}
+
+// Handles the profile shutdown event on the file thread to clean up
+// GalleryWatchManager.
+void HandleProfileShutdownOnFileThread(const Profile* profile) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
+  GalleryWatchManager::OnProfileShutdown(profile);
+}
+
+// Sets up a gallery watch on the file thread for the extension specified by the
+// |extension_id|.
+// |profile| specifies the extension profile.
+// |gallery_id| specifies the gallery identifier.
+// |gallery_file_path| specifies the absolute gallery path.
+// Returns true, if the watch setup operation was successful.
+bool SetupGalleryWatchOnFileThread(const Profile* profile,
+                                   const std::string& gallery_id,
+                                   const FilePath& gallery_file_path,
+                                   const std::string& extension_id) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
+  GalleryWatchManager* manager = GetGalleryWatchManagerOnFileThread(profile,
+                                                                    true);
+  DCHECK(manager);
+  return manager->StartGalleryWatch(gallery_id, gallery_file_path,
+                                    extension_id);
+}
+
+// Cancels the gallery watch for the extension specified by the |extension_id|
+// on the file thread.
+void RemoveGalleryWatchOnFileThread(const Profile* profile,
+                                    const FilePath& gallery_file_path,
+                                    const std::string& extension_id) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
+  GalleryWatchManager* manager = GetGalleryWatchManagerOnFileThread(profile,
+                                                                    false);
+  if (!manager)
+    return;
+  manager->StopGalleryWatch(gallery_file_path, extension_id);
+}
+
+}  // namespace
+
+
+///////////////////////////////////////////////////////////////////////////////
+//                      MediaGalleriesPrivateAPI                             //
+///////////////////////////////////////////////////////////////////////////////
+
 MediaGalleriesPrivateAPI::MediaGalleriesPrivateAPI(Profile* profile)
     : profile_(profile) {
+  DCHECK(profile_);
+  extension_notification_observer_.reset(
+      new MediaGalleryExtensionNotificationObserver(profile_));
   ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
       this, event_names::kOnAttachEventName);
-   ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
+  ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
       this, event_names::kOnDetachEventName);
-
+  ExtensionSystem::Get(profile_)->event_router()->RegisterObserver(
+      this, event_names::kOnGalleryChangedEventName);
 }
 
 MediaGalleriesPrivateAPI::~MediaGalleriesPrivateAPI() {
 }
 
 void MediaGalleriesPrivateAPI::Shutdown() {
   ExtensionSystem::Get(profile_)->event_router()->UnregisterObserver(this);
+  content::BrowserThread::PostTask(
+      content::BrowserThread::FILE, FROM_HERE,
+      base::Bind(&HandleProfileShutdownOnFileThread, profile_));
 }
 
 void MediaGalleriesPrivateAPI::OnListenerAdded(
-    const extensions::EventListenerInfo& details) {
+    const EventListenerInfo& details) {
   media_galleries_private_event_router_.reset(
       new MediaGalleriesPrivateEventRouter(profile_));
-  ExtensionSystem::Get(profile_)->event_router()->UnregisterObserver(this);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//              MediaGalleriesPrivateAddGalleryWatchFunction                 //
+///////////////////////////////////////////////////////////////////////////////
+
+bool MediaGalleriesPrivateAddGalleryWatchFunction::RunImpl() {
+  DCHECK(profile_);
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  if (!render_view_host() || !render_view_host()->GetProcess())
+    return false;
+
+  // First param is the gallery identifier to watch.
+  std::string gallery_id;
+  if (!args_->GetString(0, &gallery_id) || (gallery_id.empty()))
+    return false;
+
+  chrome::MediaGalleryPrefId gallery_pref_id = 0;
+  if (!base::StringToUint64(gallery_id, &gallery_pref_id)) {
+    HandleResponse(gallery_id, false);
+    return true;
+  }
+
+  FilePath gallery_file_path(
+      GetGalleryAbsolutePath(gallery_pref_id, profile_, GetExtension()));
+  if (gallery_file_path.empty()) {
+    HandleResponse(gallery_id, false);
+    return true;
+  }
+
+#if defined(OS_WIN)
+  content::BrowserThread::PostTaskAndReplyWithResult(
+      content::BrowserThread::FILE,
+      FROM_HERE,
+      base::Bind(&SetupGalleryWatchOnFileThread,
+                 profile_,
+                 gallery_id,
+                 gallery_file_path,
+                 extension_id()),
+      base::Bind(&MediaGalleriesPrivateAddGalleryWatchFunction::HandleResponse,
+                 this,
+                 gallery_id));
+#else
+  // Recursive gallery watch operation is not currently supported on
+  // non-windows platforms. Please refer to crbug.com/144491 for more details.
+  HandleResponse(gallery_id, false);
+#endif
+  return true;
+}
+
+void MediaGalleriesPrivateAddGalleryWatchFunction::HandleResponse(
+    const std::string& gallery_id,
+    bool success) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+  extensions::api::media_galleries_private::AddGalleryWatchResult result;
+  result.gallery_id = gallery_id;
+  result.success = success;
+  SetResult(result.ToValue().release());
+  SendResponse(true);
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+//              MediaGalleriesPrivateRemoveGalleryWatchFunction              //
+///////////////////////////////////////////////////////////////////////////////
+
+bool MediaGalleriesPrivateRemoveGalleryWatchFunction::RunImpl() {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+#if defined(OS_WIN)
+  // Remove gallery watch operation is currently supported on windows platforms.
+  // Please refer to crbug.com/144491 for more details.
+  if (!render_view_host() || !render_view_host()->GetProcess())
+    return false;
+
+  // First param is the gallery identifier.
+  std::string gallery_id;
+  if (!args_->GetString(0, &gallery_id) || (gallery_id.empty()))

[Lei Zhang, 2012/12/18 00:47:01]

Again, look in
out/Debug/gen/chrome/common/extensions/api/media_galleries_private.h for the
auto-generated class to use. This could should start out as:

scoped_ptr<Foo::Params> params(Foo::Params::Create(*args_));
EXTENSION_FUNCTION_VALIDATE(params.get());

Same with the add watcher case above.

[kmadhusu, 2012/12/18 21:32:39]

Done.

+    return false;
+
+  chrome::MediaGalleryPrefId gallery_pref_id = 0;
+  if (!base::StringToUint64(gallery_id, &gallery_pref_id))
+    return false;
+
+  FilePath gallery_file_path(
+      GetGalleryAbsolutePath(gallery_pref_id, profile_, GetExtension()));
+  if (gallery_file_path.empty())
+    return false;
+
+  content::BrowserThread::PostTask(
+      content::BrowserThread::FILE, FROM_HERE,
+      base::Bind(&RemoveGalleryWatchOnFileThread,
+                 profile_,
+                 gallery_file_path,
+                 extension_id()));
+#endif
+  return true;
 }
 
 }  // namespace extensions