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  59   // available or be no longer valid.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  63   // to become available or no longer valid.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