examples/Base/IPC/Async/AcceptPrintInput/AcceptPrintInput.cpp

/*
Copyright (c) 2000-2010 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

* Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.
* Neither the name of Nokia Corporation nor the names of its contributors
  may be used to endorse or promote products derived from this software
  without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Description: 
Asynchronous keyboard processing with messenger program.
A single CWriteKeyProcessor active object (derived from 
class CActiveConsole) which accepts and prints keyboard
input to a console.
*/


#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;
        };


//
// -----> CActiveConsole (definition)
//
// An abstract class which provides the facility to issue key requests. 
//
class CActiveConsole : public CActive
        {
public:
          // Construction
        CActiveConsole(CConsoleBase* aConsole);
        void ConstructL();

          // Destruction
        ~CActiveConsole();

          // Issue request
        void RequestCharacter();
        
          // 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();

          // Called from RunL() - an implementation must be provided
          // by derived classes to handle the completed request
        virtual void ProcessKeyPress(TChar aChar) = 0; 
          
protected:
          // Data members defined by this class
        CConsoleBase* iConsole; // A console for reading from
        };


//
// -----> CWriteKeyProcessor (definition)
//
// This class is derived from CActiveConsole. 
// Request handling: accepts input from the keyboard and outputs it 
// to the console.
//
class CWriteKeyProcessor : public CActiveConsole
        {
public:
          // Construction
        CWriteKeyProcessor(CConsoleBase* aConsole);

public:
          // Static constuction
        static CWriteKeyProcessor *NewLC (CConsoleBase* aConsole);
        static CWriteKeyProcessor *NewL(CConsoleBase* aConsole);

public:
          // Service request
        void ProcessKeyPress(TChar aChar);
        };


//
// -----> 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(KFormatString1,"%S \n");
        console->Printf(KFormatString1,&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);
        }


//
// -----> CActiveConsole (implementation)
//
CActiveConsole::CActiveConsole( CConsoleBase* aConsole) 
        : CActive(CActive::EPriorityUserInput)
          // Construct high-priority active object
        {
        iConsole = aConsole;
        }

void CActiveConsole::ConstructL()
        {
          // Add to active scheduler
        CActiveScheduler::Add(this);
        }

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

void  CActiveConsole::DoCancel()
        {
        iConsole->ReadCancel();
        }

void  CActiveConsole::RunL()
        {
          // Handle completed request
        ProcessKeyPress(TChar(iConsole->KeyCode()));
        }

void CActiveConsole::RequestCharacter()
        {
          // A request is issued to the CConsoleBase to accept a
          // character from the keyboard.
        iConsole->Read(iStatus); 
        SetActive();
        }


//
// -----> CWriteKeyProcessor (implementation)
//
CWriteKeyProcessor::CWriteKeyProcessor(CConsoleBase* aConsole)
        : CActiveConsole(aConsole)
          
        {};

CWriteKeyProcessor* CWriteKeyProcessor::NewLC(CConsoleBase* aConsole)
        {
        CWriteKeyProcessor* self=new (ELeave) CWriteKeyProcessor(aConsole);
        CleanupStack::PushL(self);
        self->ConstructL();
        return self;
        }

CWriteKeyProcessor* CWriteKeyProcessor::NewL(CConsoleBase* aConsole)
        {
        CWriteKeyProcessor* self=NewLC(aConsole);
        CleanupStack::Pop();
        return self;
        }

void CWriteKeyProcessor::ProcessKeyPress(TChar aChar)
        {
          // "Esc" character prints a new line and stops the scheduler
        _LIT(KTextEsc,"\n");
        if (aChar == EKeyEscape)
                {
                iConsole->Printf(KTextEsc);
                CActiveScheduler::Stop();
                return;
                }

          // "Enter" prints a new line character
          // An alphabetic or space is printed as a character;
          // anything else is printed as an integer.
        if (aChar == EKeyEnter)
                iConsole->Printf(KTextEsc);
        else
                {
                _LIT(KFormatString2,"%c");
                _LIT(KFormatString3,"%d");
                if (aChar.IsAlphaDigit()|| aChar.IsSpace())
                        iConsole->Printf(KFormatString2,TUint(aChar));
                else
                        iConsole->Printf(KFormatString3,TUint(aChar));
                }

          // Issue another request 
        RequestCharacter();
        }


//
// 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 CWriteKeyProcessor active object
        _LIT(KTitleMsg,"A single CWriteKeyProcessor active object.\nIt accepts and prints keyboard input to the console.\nPress ESC to end.\n\n");
        console->Printf(KTitleMsg);
        CWriteKeyProcessor* keyProcesser = CWriteKeyProcessor::NewLC(console);

          // Issue the first request
        keyProcesser->RequestCharacter();

          // 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 CWriteKeyProcessor active object
          // 2. exampleScheduler
        CleanupStack::PopAndDestroy(2); 
        }

---