CBattery Non-MFC Class

Environment: Visual C++ 6 SP3

CBattery is a non-MFC class wrapper for the battery related Windows Power
Management API functions. It may be used by notebook/laptops system utilities
developed with Visual C++.

CBattery implements the following public methods:
 – BOOL SystemPowerStatusLoaded()
 – BOOL ReloadSystemPowerStatus()
 – SYSTEM_POWER_STATUS
SystemPowerStatus()
 – CBattery::AC_LINE_STATUS
ACLineStatus()
 – CBattery::BATTERY_FLAG
BatteryFlag()
 – CBattery::BOOL BatteryCharging()
 – BYTE BatteryLifePercent()
 – long BatteryFullTime()
 – long BatteryLifeTime()
 – BOOL BatteryIsUnknown()
 – BOOL BatteryIsCharging()
 – CBattery::DEVICE_POWER_STATE
GetDevicePowerState()
 – void SetDevice(HANDLE hDevice)
 – HANDLE GetDevice()

CBattery contains the following public constants:
 – Line status:
  
ACLS_OFFLINE
   ACLS_ONLINE
   ACLS_UNKNOWN

 – Battery status flags:
  
BF_HIGH
   BF_LOW
   BF_CRITICAL
   BF_CHARGING
   BF_NO_BATTERY
   BF_UNKNOWN
 
– Device power state:
  
DPS_OFF
   DPS_ON
   DPS_UNKNOWN

 – General constants:
  
UNKNOWN_BATTERY_LIFE_PERCENT
   UNKNOWN_BATTERY_FULL_TIME
   UNKNOWN_BATTERY_LIFE_TIME
   UNKNOWN_DEVICE_POWER_STATE

Notes:
 
– The system is only capable of estimating BatteryFullTime based on
calculations on BatteryLifeTime and BatteryLifePercent. Without
smart battery subsystems, this value may not be accurate enough to be useful.
 – The class does not use the
Sysinfo OCX control.
 – The system broadcasts the PBT_APMPOWERSTATUSCHANGE
event to all applications when the power status changes. When your application
receives this event, it should call the methods of the class again to
determine what changed.
 – Power management specifications
and white papers from the OnNow initiative home page are located at www.microsoft.com/hwdev/onnow.htm.
 – The PBT_* messages are
documented in the SDKs PBT.H.
 – An application can use CBattery::GetDevicePowerState
to determine whether a disk or other device is spun up. If the device is not
spun up, the application should defer accessing it.
 – For more details about APM, one
should check the Platform SDK: Hardware.
 – Unfortunately, power management
features dont work in Windows NT 4.0! However, if youre using a
specialized version of Windows NT, modified by your computer manufacturer, the
methods may work.
 – The demo included application
does not use all the all methods implemented in the CBattery class. Check the
Battery.cpp and Battery.h files for the class source code.

Downloads

Download source – 2 Kb
Download demo application – 40 Kb

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