examples/Base/IPC/Async/RunComplete/RunComplete.cpp

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Description: 
Demonstrates asynchronous keyboard processing with messenger program.
Uses a single CMessageTimer active object which runs until completion. 
*/


#include "CommonFramework.h"

// panics
enum
        {
        EPanicAlreadyActive=1000,
        };


//
// -----> CTimedMessenger (definition)
//
class CTimedMessenger : public CTimer
        {
public:
          // Construction
        CTimedMessenger();
      // Destruction
        ~CTimedMessenger();

public:
          // Static construction
        static CTimedMessenger* NewLC(const TDesC& aGreeting,
                                          TInt aTicksRequested,
                                                                  TInt aTicksInterval
                                                                 );
        static CTimedMessenger* NewL(const TDesC& aGreeting,
                                         TInt aTicksRequested,
                                                                 TInt aTicksInterval
                                                                );

public:
          // Second phase construction
        void ConstructL(const TDesC& aGreeting,
                            TInt aTicksRequested,
                                        TInt aTicksInterval
                                   );

          // issue request
        void IssueRequest(); 

          // Cancel request
          // Defined as pure virtual by CActive;
          // implementation provided by this class.
        void DoCancel();

          // service completed request.
          // Defined as pure virtual by CActive;
          // implementation provided by this class.
        void RunL();

public:
          // data members defined by this class
        TBufC<20> iGreeting;   // Text of the greeting.
        TInt iTicksRequested;  // Total number of greetings CTimedMessenger
                               // will emit.
        TInt iTicksInterval;   // Number of seconds between each greeting.
        TInt iTicksDone;       // Number of greetings issued so far.
        };


//
// -----> CExampleScheduler (definition)
//
class CExampleScheduler : public CActiveScheduler
        {
public:
        void Error (TInt aError) const;
        };


//
// -----> CTimedMessenger (implementation)
//
CTimedMessenger::CTimedMessenger()
        : CTimer(CActive::EPriorityStandard)
          // Construct standard-priority active object
        {};

CTimedMessenger* CTimedMessenger::NewLC(const TDesC& aGreeting,
                                                                                TInt aTicksRequested,
                                                                                TInt aTicksInterval
                                                                           )
        {
        CTimedMessenger* self=new (ELeave) CTimedMessenger;
        CleanupStack::PushL(self);
        self->ConstructL(aGreeting,aTicksRequested,aTicksInterval);
        return self;
        }

CTimedMessenger* CTimedMessenger::NewL(const TDesC& aGreeting,
                                                                   TInt aTicksRequested,
                                                                           TInt aTicksInterval
                                                                          )
        {
        CTimedMessenger* self = NewLC(aGreeting,aTicksRequested,aTicksInterval);
        CleanupStack::Pop();
        return self;
        }

void CTimedMessenger::ConstructL(const TDesC& aGreeting,
                                                                 TInt aTicksRequested,
                                                                 TInt aTicksInterval
                                                                )
        {
          // Base class second-phase construction.
        CTimer::ConstructL();
          // Set members from arguments
        iGreeting       = aGreeting;       // Set greeting text.
        iTicksRequested = aTicksRequested; // Ticks requested
        iTicksInterval  = aTicksInterval;  // Interval between ticks
          // Add active object to active scheduler
        CActiveScheduler::Add(this); 
        }


CTimedMessenger::~CTimedMessenger()
        {
          // Make sure we're cancelled
        Cancel();
        }

void CTimedMessenger::DoCancel()
        {
          // Base class
        CTimer::DoCancel(); 
          // Reset this variable - needed if the object is re-activated later
        iTicksDone = 0;
          // Tell user
        _LIT(KMsgCancelled,"Outstanding Messenger request cancelled\n");
        console->Printf(KMsgCancelled); 
        }

void CTimedMessenger::IssueRequest()
        {
          // There should never be an outstanding request at this point.
        _LIT(KMsgAlreadyActive,"Is already Active");
        __ASSERT_ALWAYS(!IsActive(),User::Panic(KMsgAlreadyActive,EPanicAlreadyActive));
          // Request another wait
        CTimer::After( iTicksInterval*1000000);
        }

void CTimedMessenger::RunL()
        {
          // Handle request completion
          // One more tick done
        iTicksDone++;
          // Print greeting
        _LIT(KFormatString,"%S \n");
        console->Printf(KFormatString,&iGreeting);
          // Issue new request, or stop if we have reached the limit
        if (iTicksDone  < iTicksRequested)
                {
                IssueRequest();
                }
        else
                {
                _LIT(KMsgFinished,"Messenger finished \n");
                console->Printf(KMsgFinished);
                  // Reset this variable - needed if the object is re-activated later
                iTicksDone=0;
                  // Can now stop the active scheduler
                CActiveScheduler::Stop();
                }
        }


//
// -----> CExampleScheduler (implementation)
//
void CExampleScheduler::Error(TInt aError) const
        {
        _LIT(KMsgSchedErr,"CExampleScheduler-error");
        User::Panic(KMsgSchedErr,aError);
        }


//
// Do the example
//
LOCAL_C void doExampleL()
    {
          // Construct and install the active scheduler
        CExampleScheduler*  exampleScheduler = new (ELeave) CExampleScheduler;

          // Push onto the cleanup stack
        CleanupStack::PushL(exampleScheduler);

          // Install as the active scheduler
        CActiveScheduler::Install(exampleScheduler); 

      // Create a CTimedMessenger active object which will emit 3 messages
          // with an interval of 2 seconds between messages
        _LIT(KMsgExplanation,"A single CMessageTimer active object which runs until completion\n\n");
        console->Printf(KMsgExplanation);
        _LIT(KMsgGoodMorning,"Good Morning!");
        CTimedMessenger* myTimedMessage = CTimedMessenger::NewLC(KMsgGoodMorning,3,2);

          // Issue the first request
        myTimedMessage->IssueRequest();

      // Main part of program is a wait loop
          // This function completes when the scheduler stops
        CActiveScheduler::Start();

          // Remove from the cleanup stack and destroy:
          // 1. the CTimedMessenger active object
          // 2. exampleScheduler
        CleanupStack::PopAndDestroy(2); 
        }

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