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 "base/values.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/gallery_watch_manager_factory.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 "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_view_host.h"
 
 namespace extensions {
 
+namespace {
+
+typedef base::Callback<void(bool success)> AddGalleryCallback;
+
+// 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));
+  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);
+}
+
+// Handles the profile shutdown event on the file thread to clean up
+// GalleryWatchManagerFactory.
+void HandleProfileShutdownOnFileThread(const Profile* profile) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
+  GalleryWatchManagerFactory::GetInstance()->OnProfileShutdown(profile);
+}
+
+// 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,
+                                                        bool create) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  if (!create &&
+      !GalleryWatchManagerFactory::GetInstance()->HasForProfile(profile))
+    return NULL;
+  return GalleryWatchManagerFactory::GetInstance()->GetForProfile(profile);
+}
+
+// Set up 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.
+// |add_gallery_callback| specifies the callback that is called when the setup
+// operation is complete. It notifies the extension about the watch request
+// result.
+void SetupGalleryWatchOnFileThread(
+    const Profile* profile,
+    const std::string& gallery_id,
+    const FilePath& gallery_file_path,
+    const std::string& extension_id,
+    const AddGalleryCallback& add_gallery_callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  bool success = false;
+  GalleryWatchManager* manager = GetGalleryWatchManagerOnFileThread(profile,
+                                                                    true);
+  if (manager) {
+    success = manager->StartGalleryWatch(gallery_id, gallery_file_path,
+                                         extension_id);
+  }
+  content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
+                                   base::Bind(add_gallery_callback, success));
+}
+
+// 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(BrowserThread::CurrentlyOn(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);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//                      MediaGalleryWatchFunctionBase                        //
+///////////////////////////////////////////////////////////////////////////////
+
+MediaGalleryWatchFunctionBase::MediaGalleryWatchFunctionBase() {
+}
+
+#if defined (OS_WIN)
+bool MediaGalleryWatchFunctionBase::RunImpl() {
+  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;
+  }
+
+  PerformGalleryWatchOperation(gallery_id, gallery_file_path);
+  return true;
+}
+#else
+bool MediaGalleryWatchFunctionBase::RunImpl() {

[Lei Zhang, 2012/12/15 02:00:29]

You shouldn't have to write this function twice.

[kmadhusu, 2012/12/17 23:58:05]

Done.

+  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;
+
+  // Gallery watch operations are not currently supported on non-windows
+  // platforms. Please refer to crbug.com/144491 for more details.
+  HandleResponse(gallery_id, false);
+  return true;
+}
+#endif
+
+
+///////////////////////////////////////////////////////////////////////////////
+//              MediaGalleriesPrivateAddGalleryWatchFunction                 //
+///////////////////////////////////////////////////////////////////////////////
+
+void MediaGalleriesPrivateAddGalleryWatchFunction::PerformGalleryWatchOperation(
+    const std::string& gallery_id,
+    const FilePath& gallery_watch_path) {
+  DCHECK(profile_);
+  content::BrowserThread::PostTask(

[Lei Zhang, 2012/12/15 02:00:29]

Can you PostTaskAndReplyWithResult() instead?

[kmadhusu, 2012/12/17 23:58:05]

Done.

+      content::BrowserThread::FILE, FROM_HERE,
+      base::Bind(
+          &SetupGalleryWatchOnFileThread,
+          profile_,
+          gallery_id,
+          gallery_watch_path,
+          extension_id(),
+          base::Bind(
+              &MediaGalleriesPrivateAddGalleryWatchFunction::HandleResponse,
+              this,
+              gallery_id)));
+}
+
+void MediaGalleriesPrivateAddGalleryWatchFunction::HandleResponse(
+    const std::string& gallery_id,
+    bool success) {
+  scoped_ptr<base::DictionaryValue> result(new base::DictionaryValue());

[Lei Zhang, 2012/12/15 02:00:29]

Look for an AddGalleryWatchResult class in
out/Debug/gen/chrome/common/extensions/api/media_galleries_private.h

You should fill in the class members and call fooResult.ToValue().release();

[kmadhusu, 2012/12/17 23:58:05]

Done.

+  result->SetString("galleryId", gallery_id);
+  result->SetBoolean("success", success);
+  SetResult(result.release());
+  SendResponse(true);
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+//              MediaGalleriesPrivateRemoveGalleryWatchFunction              //
+///////////////////////////////////////////////////////////////////////////////
+
+void MediaGalleriesPrivateRemoveGalleryWatchFunction::
+PerformGalleryWatchOperation(const std::string& gallery_id,
+                             const FilePath& gallery_watch_path) {
+  content::BrowserThread::PostTask(
+      content::BrowserThread::FILE, FROM_HERE,
+      base::Bind(&RemoveGalleryWatchOnFileThread, profile_,
+                 gallery_watch_path, extension_id()));
+  HandleResponse(gallery_id, true);
+}
+
+void MediaGalleriesPrivateRemoveGalleryWatchFunction::HandleResponse(
+    const std::string& gallery_id,
+    bool success) {
+  SendResponse(true);
 }
 
 }  // namespace extensions