device/battery/battery_status_service.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 DEVICE_BATTERY_BATTERY_STATUS_SERVICE_H_
   6 #define DEVICE_BATTERY_BATTERY_STATUS_SERVICE_H_
   7
   8 #include "base/callback_list.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/memory/singleton.h"
  11 #include "device/battery/battery_export.h"
  12 #include "device/battery/battery_status.mojom.h"
  13
  14 namespace base {
  15 class SingleThreadTaskRunner;
  16 }
  17
  18 namespace device {
  19 class BatteryStatusManager;
  20
  21 class DEVICE_BATTERY_EXPORT BatteryStatusService {
  22  public:
  23   typedef base::Callback<void(const BatteryStatus&)> BatteryUpdateCallback;
  24   typedef base::CallbackList<void(const BatteryStatus&)>
  25       BatteryUpdateCallbackList;
  26   typedef BatteryUpdateCallbackList::Subscription BatteryUpdateSubscription;
  27
  28   // Returns the BatteryStatusService singleton.
  29   static BatteryStatusService* GetInstance();
  30
  31   // Adds a callback to receive battery status updates.  Must be called on the
  32   // main thread. The callback itself will be called on the main thread as well.
  33   // NOTE: The callback may be run before AddCallback returns!
  34   scoped_ptr<BatteryUpdateSubscription> AddCallback(
  35       const BatteryUpdateCallback& callback);
  36
  37   // Gracefully clean-up.
  38   void Shutdown();
  39
  40   // Injects a custom battery status manager for testing purposes.
  41   void SetBatteryManagerForTesting(
  42       scoped_ptr<BatteryStatusManager> test_battery_manager);
  43
  44   // Returns callback to invoke when battery is changed. Used for testing.
  45   const BatteryUpdateCallback& GetUpdateCallbackForTesting() const;
  46
  47  private:
  48   friend struct DefaultSingletonTraits<BatteryStatusService>;
  49   friend class BatteryStatusServiceTest;
  50
  51   BatteryStatusService();
  52   virtual ~BatteryStatusService();
  53
  54   // Updates current battery status and sends new status to interested
  55   // render processes. Can be called on any thread via a callback.
  56   void NotifyConsumers(const BatteryStatus& status);
  57   void NotifyConsumersOnMainThread(const BatteryStatus& status);
  58   void ConsumersChanged();
  59
  60   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
  61   scoped_ptr<BatteryStatusManager> battery_fetcher_;
  62   BatteryUpdateCallbackList callback_list_;
  63   BatteryUpdateCallback update_callback_;
  64   BatteryStatus status_;
  65   bool status_updated_;
  66   bool is_shutdown_;
  67
  68   DISALLOW_COPY_AND_ASSIGN(BatteryStatusService);
  69 };
  70
  71 }  // namespace device
  72
  73 #endif  // DEVICE_BATTERY_BATTERY_STATUS_SERVICE_H_