chrome/browser/speech/extension_api/tts_engine_extension_observer.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_SPEECH_EXTENSION_API_TTS_ENGINE_EXTENSION_OBSERVER_H_
   6 #define CHROME_BROWSER_SPEECH_EXTENSION_API_TTS_ENGINE_EXTENSION_OBSERVER_H_
   7
   8 #include "base/scoped_observer.h"
   9 #include "components/keyed_service/core/keyed_service.h"
  10 #include "extensions/browser/event_router.h"
  11 #include "extensions/browser/extension_registry.h"
  12 #include "extensions/browser/extension_registry_observer.h"
  13
  14 class Profile;
  15
  16 // Profile-keyed class that observes the extension registry to determine load of
  17 // extension-based tts engines.
  18 class TtsEngineExtensionObserver
  19     : public KeyedService,
  20       public extensions::EventRouter::Observer,
  21       public extensions::ExtensionRegistryObserver {
  22  public:
  23   static TtsEngineExtensionObserver* GetInstance(Profile* profile);
  24
  25   // Returns if this observer saw the given extension load. Adds |extension_id|
  26   // as loaded immediately if |update| is set to true.
  27   bool SawExtensionLoad(const std::string& extension_id, bool update);
  28
  29   // Implementation of KeyedService.
  30   void Shutdown() override;
  31
  32   // Implementation of extensions::EventRouter::Observer.
  33   void OnListenerAdded(const extensions::EventListenerInfo& details) override;
  34
  35   // extensions::ExtensionRegistryObserver overrides.
  36   void OnExtensionUnloaded(
  37       content::BrowserContext* browser_context,
  38       const extensions::Extension* extension,
  39       extensions::UnloadedExtensionInfo::Reason reason) override;
  40
  41  private:
  42   explicit TtsEngineExtensionObserver(Profile* profile);
  43   ~TtsEngineExtensionObserver() override;
  44
  45   bool IsLoadedTtsEngine(const std::string& extension_id);
  46
  47   ScopedObserver<extensions::ExtensionRegistry,
  48                  extensions::ExtensionRegistryObserver>
  49       extension_registry_observer_;
  50
  51   Profile* profile_;
  52
  53   std::set<std::string> engine_extension_ids_;
  54
  55   friend class TtsEngineExtensionObserverFactory;
  56
  57   DISALLOW_COPY_AND_ASSIGN(TtsEngineExtensionObserver);
  58 };
  59
  60 #endif  // CHROME_BROWSER_SPEECH_EXTENSION_API_TTS_ENGINE_EXTENSION_OBSERVER_H_