components/web_resource/promo_resource_service.h

   1 // Copyright 2012 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 COMPONENTS_WEB_RESOURCE_PROMO_RESOURCE_SERVICE_H_
   6 #define COMPONENTS_WEB_RESOURCE_PROMO_RESOURCE_SERVICE_H_
   7
   8 #include <string>
   9
  10 #include "base/callback_forward.h"
  11 #include "base/callback_list.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "components/web_resource/web_resource_service.h"
  14
  15 class PrefRegistrySimple;
  16 class PrefService;
  17
  18 namespace base {
  19 class DictionaryValue;
  20 }
  21
  22 namespace user_prefs {
  23 class PrefRegistrySyncable;
  24 }
  25
  26 namespace version_info {
  27 enum class Channel;
  28 }
  29
  30 namespace web_resource {
  31
  32 class NotificationPromo;
  33
  34 // A PromoResourceService fetches data from a web resource server to be used to
  35 // dynamically change the appearance of the New Tab Page. For example, it has
  36 // been used to fetch "tips" to be displayed on the NTP, or to display
  37 // promotional messages to certain groups of Chrome users.
  38 class PromoResourceService : public WebResourceService {
  39  public:
  40   using StateChangedCallbackList = base::CallbackList<void()>;
  41   using StateChangedSubscription = StateChangedCallbackList::Subscription;
  42
  43   static void RegisterPrefs(PrefRegistrySimple* registry);
  44   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
  45   static void MigrateUserPrefs(PrefService* user_prefs);
  46
  47   PromoResourceService(PrefService* local_state,
  48                        version_info::Channel channel,
  49                        const std::string& application_locale,
  50                        net::URLRequestContextGetter* request_context,
  51                        const char* disable_network_switch,
  52                        const ParseJSONCallback& parse_json_callback);
  53   ~PromoResourceService() override;
  54
  55   // Registers a callback called when the state of a web resource has been
  56   // changed. A resource may have been added, removed, or altered.
  57   scoped_ptr<StateChangedSubscription> RegisterStateChangedCallback(
  58       const base::Closure& closure);
  59
  60  private:
  61   // Schedule a notification that a web resource is either going to become
  62   // available or be no longer valid.
  63   void ScheduleNotification(const NotificationPromo& notification_promo);
  64
  65   // Schedules the initial notification for when the web resource is going
  66   // to become available or no longer valid. This performs a few additional
  67   // checks than ScheduleNotification, namely it schedules updates immediately
  68   // if the promo service or Chrome locale has changed.
  69   void ScheduleNotificationOnInit();
  70
  71   // If delay_ms is positive, schedule notification with the delay.
  72   // If delay_ms is 0, notify immediately by calling WebResourceStateChange().
  73   // If delay_ms is negative, do nothing.
  74   void PostNotification(int64 delay_ms);
  75
  76   // Notify listeners that the state of a web resource has changed.
  77   void PromoResourceStateChange();
  78
  79   // WebResourceService override to process the parsed information.
  80   void Unpack(const base::DictionaryValue& parsed_json) override;
  81
  82   // List of callbacks called when the state of a web resource has changed.
  83   StateChangedCallbackList callback_list_;
  84
  85   // Allows the creation of tasks to send a notification.
  86   // This allows the PromoResourceService to notify the New Tab Page immediately
  87   // when a new web resource should be shown or removed.
  88   base::WeakPtrFactory<PromoResourceService> weak_ptr_factory_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(PromoResourceService);
  91 };
  92
  93 }  // namespace web_resource
  94
  95 #endif  // COMPONENTS_WEB_RESOURCE_PROMO_RESOURCE_SERVICE_H_