chromeos: Refactor system tray code into PowerStatus.

ash/system/chromeos/power/power_status.h

-// Copyright 2013 The Chromium Authors. All rights reserved.
+// 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 ASH_SYSTEM_CHROMEOS_POWER_POWER_STATUS_H_
 #define ASH_SYSTEM_CHROMEOS_POWER_POWER_STATUS_H_
 
 #include "ash/ash_export.h"
 #include "base/basictypes.h"
 #include "base/observer_list.h"
+#include "base/strings/string16.h"
+#include "base/time.h"
 #include "chromeos/dbus/power_manager_client.h"
 #include "chromeos/dbus/power_supply_status.h"
+#include "ui/gfx/image/image_skia.h"
 
 namespace ash {
 namespace internal {
 
+// PowerStatus is a singleton that receives updates about the system's
+// power status from chromeos::PowerManagerClient and makes the information
+// available to interested classes within Ash.
 class ASH_EXPORT PowerStatus : public chromeos::PowerManagerClient::Observer {
  public:
+  // Different styles of battery icons.
+  enum IconSet {
+    ICON_LIGHT,
+    ICON_DARK
+  };
+
+  // Interface for classes that wish to be notified when the power status
+  // has changed.
   class Observer {
    public:
     // Called when the power status changes.
-    virtual void OnPowerStatusChanged(
-        const chromeos::PowerSupplyStatus& power_status) = 0;
+    virtual void OnPowerStatusChanged() = 0;
 
    protected:
     virtual ~Observer() {}
   };
 
   virtual ~PowerStatus();
 
   // Sets the global instance. Must be called before any calls to Get().
   static void Initialize();
 
   // Destroys the global instance.
   static void Shutdown();
 
   // Returns true if the global instance is initialized.
   static bool IsInitialized();
 
   // Gets the global instance. Initialize must be called first.
   static PowerStatus* Get();
 
-  // Adds an observer.
+  void set_status_for_testing(const chromeos::PowerSupplyStatus& status) {
+    status_ = status;
+  }

[stevenjb, 2013/06/28 22:50:48]

nit: maybe put at the end of the public methods?

[Daniel Erat, 2013/06/28 23:22:42]

(leaving this here as discussed in person, since I've frequently seen inline
methods come after ctor/dtor/static, testing or not)

+
+  // Adds or removes an observer.

[stevenjb, 2013/06/28 22:50:48]

nit: '// chromeos::PowerManagerClient::Observer'

[Daniel Erat, 2013/06/28 23:22:42]

removed 'virtual' instead

   virtual void AddObserver(Observer* observer);
-
-  // Removes an observer.
   virtual void RemoveObserver(Observer* observer);
 
-  // Requests power status update.
+  // Requests updated status from the power manager.
   void RequestStatusUpdate();
 
-  // Gets the current power supply status.
-  chromeos::PowerSupplyStatus GetPowerSupplyStatus() const;
+  // Returns true if a battery is present.
+  bool IsBatteryPresent() const;
+
+  // Returns true if the battery is full.
+  bool IsBatteryFull() const;
+
+  // Returns the battery's remaining charge as a value in the range [0.0,
+  // 100.0].
+  double GetBatteryPercent() const;
+
+  // Returns the battery's remaining charge, rounded to an integer with a
+  // maximum value of 100.
+  int GetRoundedBatteryPercent() const;
+
+  // Returns true if the battery's time-to-full and time-to-empty estimates
+  // should not be displayed because the power manager is still calculating
+  // them.
+  bool IsBatteryTimeBeingCalculated() const;
+
+  // Returns the estimated time until the battery is empty (if line power
+  // is disconnected) or full (if line power is connected). These estimates
+  // should only be used if IsBatteryTimeBeingCalculated() returns false.
+  base::TimeDelta GetBatteryTimeToEmpty() const;
+  base::TimeDelta GetBatteryTimeToFull() const;
+
+  // Returns true if line power (including a charger of any type) is connected.
+  bool IsLinePowerConnected() const;
+
+  // Returns true if an official, non-USB charger is connected.
+  bool IsMainsChargerConnected() const;

[stevenjb, 2013/06/28 22:50:48]

s/Mains/Main ?

[Daniel Erat, 2013/06/28 23:22:42]

"Mains" matches the terminology in the kernel
(https://en.wikipedia.org/wiki/Mains_electricity). for what it's worth, i'll
probably get rid of this method later

+
+  // Returns true if a USB charger (which is likely to only support a low
+  // charging rate) is connected.
+  bool IsUsbChargerConnected() const;
+
+  // Returns the image that should be shown for the battery's current state.
+  gfx::ImageSkia GetBatteryImage(IconSet icon_set) const;
+
+  // Returns an string describing the current state for accessibility.
+  base::string16 GetAccessibleNameString() const;
 
  protected:
   PowerStatus();
 
  private:
   // Overriden from PowerManagerClient::Observer.
-  virtual void PowerChanged(
-      const chromeos::PowerSupplyStatus& power_status) OVERRIDE;
+  virtual void PowerChanged(const chromeos::PowerSupplyStatus& status) OVERRIDE;
 
   ObserverList<Observer> observers_;
 
-  // PowerSupplyStatus state.
-  chromeos::PowerSupplyStatus power_supply_status_;
+  // Current state.
+  chromeos::PowerSupplyStatus status_;
 
   DISALLOW_COPY_AND_ASSIGN(PowerStatus);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_POWER_POWER_STATUS_H_