How to use CPeriodic for a steady stream of ticks

http://wiki.forum.nokia.com/index.php/How_to_use_CPeriodic_for_a_steady_stream_of_ticks

In the header file

// IMPLEMENTATION SPECIFIC CONSTANTS
const TInt KPeriodicTimerInterval5Sec(5000000);
 
class CMyClass : public CBase
    {
 
    // ...
 
    private: // New functions
 
        /**
         * The call back function.
         * /param aAny A pointer to this class.
         */
        static TInt PeriodicTimerCallBack(TAny* aAny);
 
        /**
         * Notice that this is a sample fuction.
         *
         */
        void SomeFunction();
 
    private:    // Member data
 
        /**
         * The periodic timer.
         * Owned by CMyClass
         */
        CPeriodic* iPeriodicTimer;
    };

 

In the cpp file

// ----------------------------------------------------------------------------
// CMyClass::~CMyClass()
// Destructor.
// ----------------------------------------------------------------------------
//
CMyClass::~CMyClass()
    {
    // ...
 
    if(iPeriodicTimer)
        {
        // Calling Cancel without checking if the timer is active is safe
        iPeriodicTimer->Cancel();
        }
    delete iPeriodicTimer;
 
    // ...
    }
 
// ----------------------------------------------------------------------------
// CMyClass::ConstructL()
// Perform second phase construction of this object.
// ----------------------------------------------------------------------------
//
void CMyClass::ConstructL()
    {
    // ...
 
    // Initialize the periodic timer.
    iPeriodicTimer = CPeriodic::NewL(CActive::EPriorityIdle);
    // Start the periodic timer, when ever the time elapsed
    // the PeriodicTimerCallBack() will get called.
    // Notice: The timer will periodically hit the PeriodicTimerCallBack
    // until you cancel the timer by calling iPeriodicTimer->Cancel().
    iPeriodicTimer->Start(
        KPeriodicTimerInterval5Sec, KPeriodicTimerInterval5Sec, 
        TCallBack(PeriodicTimerCallBack, this));
 
    // ...
    }
 
// ----------------------------------------------------------------------------
// CMyClass::PeriodicTimerCallBack(TAny* aAny)
// The call back function.
// ----------------------------------------------------------------------------
//
TInt CMyClass::PeriodicTimerCallBack(TAny* aAny)
	{
	CMyClass* self = static_cast<CMyClass*>( aAny );
 
        // TODO: The below call is a sample function,
        // you may change it to your requirement.
	self->SomeFunction();
 
        // Cancel the timer when the callback should not be called again.
        // Call: self->iPeriodicTimer->Cancel();
 
	return KErrNone; // Return value ignored by CPeriodic
	}
 
// ----------------------------------------------------------------------------
// CMyClass::SomeFunction(TAny* aAny)
// Notice that this is a sample fuction.
// ----------------------------------------------------------------------------
//
void CMyClass::SomeFunction()
    {
    // TODO: Your code!
    }