Add PeripheralBatteryObserver

chrome/browser/chromeos/power/peripheral_battery_observer.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_CHROMEOS_POWER_PERIPHERAL_BATTERY_OBSERVER_H_
+#define CHROME_BROWSER_CHROMEOS_POWER_PERIPHERAL_BATTERY_OBSERVER_H_
+
+#include <map>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/weak_ptr.h"
+#include "chromeos/dbus/power_manager_client.h"
+#include "device/bluetooth/bluetooth_adapter.h"
+
+namespace chromeos {
+
+class BluetoothDevice;
+
+// This observer listens for peripheral device battery status and shows
+// notifications for low battery conditions.
+class PeripheralBatteryObserver : public PowerManagerClient::Observer,
+                                  public device::BluetoothAdapter::Observer {
+ public:
+  // This class registers/unregisters itself as an observer in ctor/dtor.
+  PeripheralBatteryObserver();
+  virtual ~PeripheralBatteryObserver();
+
+  void InitializeOnBluetoothReady(

[Daniel Erat, 2013/04/09 02:06:18]

can this be private instead of public?

[Yufeng Shen (Slow to review), 2013/04/10 05:54:08]

Done.

+      scoped_refptr<device::BluetoothAdapter> adapter);
+
+  // PowerManagerClient::Observer implementation.
+  virtual void PeripheralBatteryStatusReceived(const std::string& path,
+                                               const std::string& name,
+                                               int level) OVERRIDE;
+
+  // device::BluetoothAdapter::Observer implementation.
+  virtual void DeviceChanged(device::BluetoothAdapter* adapter,
+                             device::BluetoothDevice* device) OVERRIDE;
+  virtual void DeviceRemoved(device::BluetoothAdapter* adapter,
+                             device::BluetoothDevice* device) OVERRIDE;
+ private:
+  struct BatteryInfo {
+   public:
+    BatteryInfo() : level_(-1) {}
+    BatteryInfo(const std::string& name,
+                int level,
+                base::TimeTicks notification_timestamp,
+                base::TimeTicks update_timestamp)
+        : name_(name),
+          level_(level),
+          last_notification_timestamp_(notification_timestamp),
+          last_update_timestamp_(update_timestamp) {
+    }
+
+    const std::string& name() const { return name_; }

[Daniel Erat, 2013/04/09 02:06:18]

you don't need getters and setters now that this is a struct

[Yufeng Shen (Slow to review), 2013/04/10 05:54:08]

Done.

+    void set_name(const std::string& name) { name_ = name; }
+
+    int level() const { return level_; }
+    void set_level(int level) { level_ = level; }
+
+    const base::TimeTicks& last_notification_timestamp() const {
+      return last_notification_timestamp_;
+    }
+    void set_notification_timestamp(const base::TimeTicks& timestamp) {
+      last_notification_timestamp_ = timestamp;
+    }
+
+    const base::TimeTicks& last_update_timestamp() const {
+      return last_update_timestamp_;
+    }
+    void set_update_timestamp(const base::TimeTicks& timestamp) {
+      last_update_timestamp_ = timestamp;
+    }
+
+   private:
+    // Human readable name for the device. It is changeable.
+    std::string name_;

[Daniel Erat, 2013/04/09 02:06:18]

make these public and remove the trailing underscores

http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Structs_vs._Cl...

http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Variable_Names

[Yufeng Shen (Slow to review), 2013/04/10 05:54:08]

Done.

+    // Battery leve within range [0, 100], and -1 for unknown level.
+    int level_;
+    base::TimeTicks last_notification_timestamp_;
+    base::TimeTicks last_update_timestamp_;
+  };
+
+  bool IsBluetoothHIDBattery(const std::string& path);
+  std::string ExtractBluetoothAddress(const std::string& path);

[Daniel Erat, 2013/04/09 02:06:18]

these methods don't look like they need to be class members.  if that's correct,
just make them be functions in the anonymous namespace in the .cc file

[Yufeng Shen (Slow to review), 2013/04/10 05:54:08]

Done.

+
+  void RemoveBattery(const std::string& key);
+
+  // Post a low battery notification with unique id |id|, Return true if the

[Daniel Erat, 2013/04/09 02:06:18]

nit: s/Post/Posts/, s/,/./, s/Return/Returns/

[Yufeng Shen (Slow to review), 2013/04/10 05:54:08]

Done.

+  // noitification is posted, false if not.

[Daniel Erat, 2013/04/09 02:06:18]

sp: notification

[Yufeng Shen (Slow to review), 2013/04/10 05:54:08]

Done.

+  bool PostNotification(const std::string& id, const BatteryInfo& battery);
+
+  void CancelNotification(const std::string& id);

[Daniel Erat, 2013/04/09 02:06:18]

please use consistent parameter names instead of 'id', 'key', etc., assuming
that these are all the same thing.  i'd recommend 'address', since that seems to
be what it actually is

[Yufeng Shen (Slow to review), 2013/04/10 05:54:08]

Done.

+
+  // Record of existing battery infomation. For bluetooh HID device, the key
+  // is the address of the bluetooth device.
+  std::map<std::string, BatteryInfo> batteries_;

[Daniel Erat, 2013/04/09 02:06:18]

nit: add a blank line after this one to set it apart from the following members
and make it more clear that its comment doesn't refer to them

[Yufeng Shen (Slow to review), 2013/04/10 05:54:08]

Done.

+  scoped_refptr<device::BluetoothAdapter> bluetooth_adapter_;
+  scoped_ptr<base::WeakPtrFactory<PeripheralBatteryObserver> > weakptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(PeripheralBatteryObserver);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_POWER_PERIPHERAL_BATTERY_OBSERVER_H_