chrome/browser/extensions/api/settings_private/settings_private_event_router.h

   1 // Copyright 2015 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_EXTENSIONS_API_SETTINGS_PRIVATE_SETTINGS_PRIVATE_EVENT_ROUTER_H_
   6 #define CHROME_BROWSER_EXTENSIONS_API_SETTINGS_PRIVATE_SETTINGS_PRIVATE_EVENT_ROUTER_H_
   7
   8 #include "base/prefs/pref_change_registrar.h"
   9 #include "chrome/browser/chromeos/settings/cros_settings.h"
  10 #include "chrome/browser/extensions/api/settings_private/prefs_util.h"
  11 #include "components/keyed_service/core/keyed_service.h"
  12 #include "extensions/browser/event_router.h"
  13
  14 namespace content {
  15 class BrowserContext;
  16 }
  17
  18 namespace extensions {
  19
  20 class SettingsPrivateDelegate;
  21
  22 // This is an event router that will observe listeners to pref changes on the
  23 // appropriate pref service(s) and notify listeners on the JavaScript
  24 // settingsPrivate API.
  25 class SettingsPrivateEventRouter : public KeyedService,
  26                                    public EventRouter::Observer {
  27  public:
  28   static SettingsPrivateEventRouter* Create(
  29       content::BrowserContext* browser_context);
  30   ~SettingsPrivateEventRouter() override;
  31
  32  protected:
  33   explicit SettingsPrivateEventRouter(content::BrowserContext* context);
  34
  35   // KeyedService overrides:
  36   void Shutdown() override;
  37
  38   // EventRouter::Observer overrides:
  39   void OnListenerAdded(const EventListenerInfo& details) override;
  40   void OnListenerRemoved(const EventListenerInfo& details) override;
  41
  42   // This registrar monitors for user prefs changes.
  43   PrefChangeRegistrar user_prefs_registrar_;
  44
  45   // This registrar monitors for local state changes.
  46   PrefChangeRegistrar local_state_registrar_;
  47
  48  private:
  49   // Decide if we should listen for pref changes or not. If there are any
  50   // JavaScript listeners registered for the onPrefsChanged event, then we
  51   // want to register for change notification from the PrefChangeRegistrar.
  52   // Otherwise, we want to unregister and not be listening for pref changes.
  53   void StartOrStopListeningForPrefsChanges();
  54
  55   void OnPreferenceChanged(const std::string& pref_name);
  56
  57   PrefChangeRegistrar* FindRegistrarForPref(const std::string& pref_name);
  58
  59   typedef std::map<std::string,
  60                    linked_ptr<chromeos::CrosSettings::ObserverSubscription>>
  61       SubscriptionMap;
  62   SubscriptionMap cros_settings_subscription_map_;
  63
  64   content::BrowserContext* context_;
  65   bool listening_;
  66
  67   scoped_ptr<PrefsUtil> prefs_util_;
  68
  69   DISALLOW_COPY_AND_ASSIGN(SettingsPrivateEventRouter);
  70 };
  71
  72 }  // namespace extensions
  73
  74 #endif  // CHROME_BROWSER_EXTENSIONS_API_SETTINGS_PRIVATE_SETTINGS_PRIVATE_EVENT_ROUTER_H_