Categories: Symbian C++ | Code Examples | Telephony | Power Management

This page was last modified 20:16, 15 December 2007.

From Forum Nokia Wiki

CBatteryCheck implementation illustrates how to check and monitor the battery status of S60 3rd Edition devices with CTelephony API.

The implementation is pretty simple, and when using this one only thing to do in calling class is to implement the callback interface and then to construct an instance of the CBatteryCheck.

When constructing CBatteryCheck, the initial battery level is checked with GetBatteryInfo()-function and after this function returns and calls back the RunL, all changes in battery status are monitored by calling NotifyChange for the battery status.

In the callback the aChangeStatus variable has the value of the current percentage of the battery power left, and the aStatus indicates the battery status:

- CTelephony::EPoweredByBattery: Normal battery operation

- CTelephony::EBatteryConnectedButExternallyPowered: Battery charger connected

- CTelephony::ENoBatteryConnected: No battery (powered by charger)

- CTelephony::EPowerStatusUnknown: Unknown battery status.

BatteryLevel.cpp

CBatteryCheck::~CBatteryCheck()
{
	Cancel();
	delete iTelephony;
}
 
void CBatteryCheck::ConstructL(void)
{
    iTelephony = CTelephony::NewL();
    GetBatteryInfo();
}
 
CBatteryCheck::CBatteryCheck(MBatteryObserver& aObserver)
: CActive(EPriorityStandard),iObserver(aObserver),iBatteryInfoV1Pckg(iBatteryInfoV1)
{
	CActiveScheduler::Add(this);
}
 
void CBatteryCheck::GetBatteryInfo()
{
    if(iTelephony && !IsActive())
    {
    	iGettingBattery = ETrue;
   	 	iTelephony->GetBatteryInfo(iStatus, iBatteryInfoV1Pckg);
    	SetActive();
    }
}
 
void CBatteryCheck::RunL()
{
    iObserver.BatteryLevelL(iBatteryInfoV1.iChargeLevel,iBatteryInfoV1.iStatus);
	
	if(iStatus != KErrCancel)
	{
		iTelephony->NotifyChange(iStatus,CTelephony::EBatteryInfoChange,
                                         iBatteryInfoV1Pckg);	
		SetActive();
	}
 
	iGettingBattery = EFalse;
}
 
void CBatteryCheck::DoCancel()
{
	if(iGettingBattery)
    	        iTelephony->CancelAsync(CTelephony::EGetBatteryInfoCancel);
	else
		iTelephony->CancelAsync(CTelephony::EBatteryInfoChangeCancel);
}

BatteryLevel.h

#include <Etel3rdParty.h>
 
 
class MBatteryObserver
	{
	public:
	     virtual void BatteryLevelL(TUint aChargeStatus,
                                        CTelephony::TBatteryStatus aStatus) = 0;
	};
	
class CBatteryCheck : public CActive
  { 
public:
    CBatteryCheck(MBatteryObserver& aObserver);
    void ConstructL(void);
    ~CBatteryCheck();
private:	
    void GetBatteryInfo();
    void RunL();
    void DoCancel();
private:
    MBatteryObserver& 			iObserver;
    CTelephony* 			iTelephony;
    CTelephony::TBatteryInfoV1 		iBatteryInfoV1;
    CTelephony::TBatteryInfoV1Pckg 	iBatteryInfoV1Pckg;
    TBool				iGettingBattery;
   };