Reland: cros: Show notification when low-power charger connected

ash/system/chromeos/power/tray_power.h

 // Copyright (c) 2012 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_TRAY_POWER_H_
 #define ASH_SYSTEM_CHROMEOS_POWER_TRAY_POWER_H_
 
 #include "ash/system/tray/system_tray_item.h"
 #include "chromeos/power/power_manager_handler.h"
 
 class SkBitmap;
 
 namespace gfx {
+class Image;
 class ImageSkia;
 }
 
+namespace message_center {
+class MessageCenter;
+}
+
 namespace ash {
 namespace internal {
 
 namespace tray {
 class PowerNotificationView;
 class PowerTrayView;
 }
 
 enum IconSet {
   ICON_LIGHT,
   ICON_DARK
 };
 
-class TrayPower : public SystemTrayItem,
-                  public chromeos::PowerManagerHandler::Observer {
+class ASH_EXPORT TrayPower : public SystemTrayItem,
+                             public chromeos::PowerManagerHandler::Observer {
  public:
-  explicit TrayPower(SystemTray* system_tray);
+  // Visible for testing.
+  enum NotificationState {
+    NOTIFICATION_NONE,
+
+    // Low battery charge.
+    NOTIFICATION_LOW_POWER,
+
+    // Critically low battery charge.
+    NOTIFICATION_CRITICAL,
+  };
+
+  TrayPower(SystemTray* system_tray,
+            message_center::MessageCenter* message_center);
   virtual ~TrayPower();
 
   // Gets whether battery charging is unreliable for |supply_status|.
   // When a non-standard power supply is connected, the battery may
   // change from being charged to discharged frequently depending on the
   // charger power and power consumption, i.e usage. In this case we
   // do not want to show either a charging or discharging state.
   static bool IsBatteryChargingUnreliable(
       const chromeos::PowerSupplyStatus& supply_status);
 
   // Gets the icon index in the battery icon array image based on
   // |supply_status|.  If |supply_status| is uncertain about the power state,
   // returns -1.
   static int GetBatteryImageIndex(
       const chromeos::PowerSupplyStatus& supply_status);
 
   // Gets the horizontal offset in the battery icon array image based on
   // |supply_status|.
   static int GetBatteryImageOffset(
       const chromeos::PowerSupplyStatus& supply_status);
 
   // Looks up the actual icon in the icon array image for |image_index|.
   static gfx::ImageSkia GetBatteryImage(int image_index,
                                         int image_offset,
                                         bool charging_unreliable,
                                         IconSet icon_set);
 
+  // Returns an icon for the USB charger notification.
+  static gfx::Image GetUsbChargerNotificationImage();
+
   // Gets the battery accessible string for |supply_status|.
   static base::string16 GetAccessibleNameString(
       const chromeos::PowerSupplyStatus& supply_status);
 
   // Gets rounded battery percentage for |battery_percentage|.
   static int GetRoundedBatteryPercentage(double battery_percentage);
 
  private:
-  enum NotificationState {
-    NOTIFICATION_NONE,
-    NOTIFICATION_LOW_POWER,
-    NOTIFICATION_CRITICAL
-  };
+  friend class TrayPowerTest;
 
   // Overridden from SystemTrayItem.
   virtual views::View* CreateTrayView(user::LoginStatus status) OVERRIDE;
   virtual views::View* CreateDefaultView(user::LoginStatus status) OVERRIDE;
   virtual views::View* CreateNotificationView(
       user::LoginStatus status) OVERRIDE;
   virtual void DestroyTrayView() OVERRIDE;
   virtual void DestroyDefaultView() OVERRIDE;
   virtual void DestroyNotificationView() OVERRIDE;
   virtual void UpdateAfterLoginStatusChange(user::LoginStatus status) OVERRIDE;
   virtual void UpdateAfterShelfAlignmentChange(
       ShelfAlignment alignment) OVERRIDE;
 
   // Overridden from chromeos::PowerManagerHandler::Observer.
   virtual void OnPowerStatusChanged(
       const chromeos::PowerSupplyStatus& status) OVERRIDE;
 
   // Requests a power status update.
   void RequestStatusUpdate() const;
 
+  // Show a notification that a low-power USB charger has been connected.
+  // Returns true if a notification was shown or explicitly hidden.
+  bool MaybeShowUsbChargerNotification(
+      const chromeos::PowerSupplyStatus& old_status,
+      const chromeos::PowerSupplyStatus& new_status);
+
   // Sets |notification_state_|. Returns true if a notification should be shown.
   bool UpdateNotificationState(const chromeos::PowerSupplyStatus& status);
   bool UpdateNotificationStateForRemainingTime(int remaining_seconds);
   bool UpdateNotificationStateForRemainingPercentage(
       double remaining_percentage);
 
+  message_center::MessageCenter* message_center_;  // Not owned.
   tray::PowerTrayView* power_tray_;
   tray::PowerNotificationView* notification_view_;
   NotificationState notification_state_;
 
+  // Power supply status at the last update.
+  chromeos::PowerSupplyStatus last_power_supply_status_;
+
   DISALLOW_COPY_AND_ASSIGN(TrayPower);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_CHROMEOS_POWER_TRAY_POWER_H_