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   scoped_ptr<BatteryUpdateSubscription> AddCallback(
  34       const BatteryUpdateCallback& callback);
  35
  36   // Gracefully clean-up.
  37   void Shutdown();
  38
  39   // Injects a custom battery status manager for testing purposes.
  40   void SetBatteryManagerForTesting(
  41       scoped_ptr<BatteryStatusManager> test_battery_manager);
  42
  43   // Returns callback to invoke when battery is changed. Used for testing.
  44   const BatteryUpdateCallback& GetUpdateCallbackForTesting() const;
  45
  46  private:
  47   friend struct DefaultSingletonTraits<BatteryStatusService>;
  48
  49   BatteryStatusService();
  50   virtual ~BatteryStatusService();
  51
  52   // Updates current battery status and sends new status to interested
  53   // render processes. Can be called on any thread via a callback.
  54   void NotifyConsumers(const BatteryStatus& status);
  55   void NotifyConsumersOnMainThread(const BatteryStatus& status);
  56   void ConsumersChanged();
  57
  58   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
  59   scoped_ptr<BatteryStatusManager> battery_fetcher_;
  60   BatteryUpdateCallbackList callback_list_;
  61   BatteryUpdateCallback update_callback_;
  62   BatteryStatus status_;
  63   bool status_updated_;
  64   bool is_shutdown_;
  65
  66   DISALLOW_COPY_AND_ASSIGN(BatteryStatusService);
  67 };
  68
  69 }  // namespace device
  70
  71 #endif  // DEVICE_BATTERY_BATTERY_STATUS_SERVICE_H_