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examples/SysLibs/Streaming/CompoundClass/CompoundClass.cpp

// Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies).
// All rights reserved.
// This component and the accompanying materials are made available
// under the terms of "Eclipse Public License v1.0"
// which accompanies this distribution, and is available
// at the URL "http://www.eclipse.org/legal/epl-v10.html".
//
// Initial Contributors:
// Nokia Corporation - initial contribution.
//
// Contributors:
//
// Description:
// Example to demonstrate the streaming of a compound object to
// a single stream.
//


#include "CommonStreamStore.h"
#include <s32file.h>

                                // Constructs a CCompound object and externalizes
                                // it to a single stream.
LOCAL_C void doMakeAndExternalizeL(const TDesC& aName);

                                // Internalizes a CCompound object from
                                // the stream
LOCAL_C void doInternalizeL(const TDesC& aName);

                                // Displays content of a CCompound object
class CCompound;
LOCAL_C void doShow(const TDesC& aHeading,const CCompound& theSimple);

                                // Defintion of classes used by the example
class CClassA
        {
public :
        void ExternalizeL(RWriteStream& aStream) const;
        void InternalizeL(RReadStream& aStream);
public :
        TBuf<32> iBufferA;
        TInt     iXA;
        TUint    iYA;
        };


class CClassB
        {
public :
        void ExternalizeL(RWriteStream& aStream) const;
        void InternalizeL(RReadStream& aStream);
public :
        TBuf<32> iBufferB;
        };


class TClassC
        {
public :
        void ExternalizeL(RWriteStream& aStream) const;
        void InternalizeL(RReadStream& aStream);
public :
        TReal iZC;
        };

        
class CCompound : public CBase
        {
public :
        ~CCompound();
        static          CCompound* NewLC();
        static          CCompound* NewLC(CStreamStore& aStore,TStreamId anId);
        static          CCompound* NewL(CStreamStore& aStore,TStreamId anId);
        TStreamId       StoreL(CStreamStore& store);
        void            RestoreL(CStreamStore& aStore,TStreamId anId);
        void            InternalizeL(RReadStream& aStream);
        void            ExternalizeL(RWriteStream& aStream) const;
private:
    void                ConstructL();
        void            ConstructL(CStreamStore& aStore,TStreamId anId);
public :
        CClassA* iCa;
        CClassB* iCb;
        TClassC  iTc;
        };
         
// The file name, extension and path for the file store
        _LIT(KFullNameOfFileStore,"\\epoc32ex\\data\\stcompnd.dat");


// Do the example
LOCAL_C void doExampleL()
    {
                                            // make sure directory exists
        fsSession.MkDirAll(KFullNameOfFileStore);
        doMakeAndExternalizeL(KFullNameOfFileStore);
        doInternalizeL(KFullNameOfFileStore);
        }

LOCAL_C void doMakeAndExternalizeL(const TDesC& aName)
        {
        TParse  filestorename;

        fsSession.Parse(aName,filestorename);
                                // construct file store object - the file to contain the
                                // the store replaces any existing file of the same name.
        CFileStore* store = CDirectFileStore::ReplaceLC(fsSession,filestorename.FullName(),EFileWrite);

                                // Must say what kind of file store
    store->SetTypeL(KDirectFileStoreLayoutUid);

                                // Construct an object of type CCompound 
                                // and put some data into it.
        CCompound* thecompound = CCompound::NewLC();

        _LIT(KTxtClassAText,"CClassA text");
        _LIT(KTxtClassBText,"CClassB text");

        thecompound->iCa->iBufferA = KTxtClassAText;
        thecompound->iCa->iXA      = -1;
        thecompound->iCa->iYA      = 2;
        thecompound->iCb->iBufferB = KTxtClassBText;
        thecompound->iTc.iZC       = 3.456;

                                // Show contents of the CCompound object (and its
                                // components)
        _LIT(KTxtInitialContent,"... Initial content of CCompound");
        doShow(KTxtInitialContent,*thecompound);
                                        
                                // Store the compound object to a single stream
                                // and save the stream id as the root id. 
        TStreamId  id = thecompound->StoreL(*store);

                                // Set the stream id as the root
        store->SetRootL(id);

                                // Commit changes to the store
        store->CommitL();

                                // Destroy:
                                // 1. the CCompound object
                                // 2. the store object (this also closes 
                                //    the file containing the store)
                                // Remove both from the cleanup stack
        CleanupStack::PopAndDestroy(2);
        }

LOCAL_C void doInternalizeL(const TDesC& aName)
        {
        TParse  filestorename;
        
        fsSession.Parse(aName,filestorename);
                                // construct file store object - specifying the file
                                // containing the store.
        CFileStore* store = CDirectFileStore::OpenLC(fsSession,filestorename.FullName(),EFileRead);
        
                                // Construct a CCompound object  
                                // from the root stream created earlier.
        CCompound* thecompound = CCompound::NewL(*store,store->Root());

                                // Show contents of the CCompound object (and its
                                // components)
        _LIT(KTxtRestoredContent,"... Restored CCompound content.");
        doShow(KTxtRestoredContent,*thecompound);
                                
                                // destroy the store object (this also closes the file
                                // containing the store) 
        CleanupStack::PopAndDestroy();

                                // Now destroy the CCompound object
        delete thecompound;
        }

_LIT(KTxtNewLine,"\n");
_LIT(KFormatType1,"\n%d");
_LIT(KFormatType2,"\n%S");
_LIT(KFormatType3,"\n%u");
_LIT(KFormatType4,"\n%f");

LOCAL_C void doShow(const TDesC& aHeading,const CCompound& aCompound)
        {
        console->Printf(KTxtNewLine);
        console->Printf(aHeading);
        console->Printf(KFormatType2,&aCompound.iCa->iBufferA);
        console->Printf(KFormatType1,aCompound.iCa->iXA);
        console->Printf(KFormatType3,aCompound.iCa->iYA);
        console->Printf(KFormatType2,&aCompound.iCb->iBufferB);
        console->Printf(KFormatType4,aCompound.iTc.iZC);
        console->Printf(KTxtNewLine);
        }

//***************************************************************
//***************************************************************

                                // The CCompound destructor
CCompound::~CCompound()
        {
        delete iCa;
        delete iCb;
        }

                                // Construct a new plain CCompound object and
                                // place on the cleanup stack.
CCompound* CCompound::NewLC()
        {
        CCompound* self=new (ELeave) CCompound;
        CleanupStack::PushL(self);
        self->ConstructL();
        return self;
        }

                                // Complete the construction of the 
                                // plain CCompound object
void CCompound::ConstructL()
        {
        iCa = new (ELeave) CClassA;
        iCb = new (ELeave) CClassB;
        }

                                // Construct a new CCompound object from 
                                // the input stream.
CCompound* CCompound::NewL(CStreamStore& aStore,TStreamId anId)
        {
        CCompound* self=CCompound::NewLC(aStore,anId);
        CleanupStack::Pop();
        return self;
        }

                                // Construct a new CCompound object from 
                                // the root stream of the store and 
                                // place on the cleanup stack.
CCompound* CCompound::NewLC(CStreamStore& aStore,TStreamId anId)
        {
        CCompound* self=new (ELeave) CCompound;
        CleanupStack::PushL(self);
        self->ConstructL(aStore,anId);
        return self;
        }

                                // Complete the construction of the 
                                // CCompound object
void CCompound::ConstructL(CStreamStore& aStore,TStreamId anId)
        {
        iCa = new (ELeave) CClassA;
        iCb = new (ELeave) CClassB;
        RestoreL(aStore,anId);
        }

void CCompound::RestoreL(CStreamStore& aStore,TStreamId anId)
        {
        RStoreReadStream instream;
        instream.OpenLC(aStore,anId);
        InternalizeL(instream);
                                        // Cleanup the stream object.
        CleanupStack::PopAndDestroy();                  
        }

                                // Read the components and data members 
                                // of the CCompound object from the stream.
void CCompound::InternalizeL(RReadStream& aStream)
        {
        aStream >> *iCa;        
        aStream >> *iCb;
        aStream >> iTc;
        }

TStreamId CCompound::StoreL(CStreamStore& aStore)
        {
        RStoreWriteStream outstream;
        TStreamId id = outstream.CreateLC(aStore);
                                // Stream out this CCompound object
        ExternalizeL(outstream);
                                // Commit changes to the stream
        outstream.CommitL();
                                // Cleanup the stream object.
        CleanupStack::PopAndDestroy();
        return id;
        }
                                // Write the components and data members 
                                // of the CCompound object to the stream
void CCompound::ExternalizeL(RWriteStream& aStream) const
        {
        aStream << *iCa;
        aStream << *iCb;
        aStream << iTc;
        }

//***************************************************************
//***************************************************************

                                // Read the data members of the CClassA 
                                // object from the stream.
void CClassA::InternalizeL(RReadStream& aStream)
        {
        aStream >> iBufferA;
        iXA = aStream.ReadInt32L();
        iYA = aStream.ReadUint32L();
        }  
                                // Write the data members of the CClassA 
                                // object to the stream.
void CClassA::ExternalizeL(RWriteStream& aStream)const
        {
        aStream << iBufferA;
        aStream.WriteInt32L(iXA);
        aStream.WriteUint32L(iYA);
        }  

//***************************************************************
//***************************************************************

                                // Read the data member(s) of the CClassB 
                                // object from the stream.
void CClassB::InternalizeL(RReadStream& aStream)
        {
        aStream >> iBufferB;
        }
                                // Write the data member(s) of the CClassB 
                                // object to the stream.
void CClassB::ExternalizeL(RWriteStream& aStream) const
        {
        aStream << iBufferB;
        }  

//***************************************************************
//***************************************************************

                                // Write the data member(s) of the TClassC 
                                // object to the stream.
void TClassC::ExternalizeL(RWriteStream& aStream) const
        {
        aStream.WriteReal64L(iZC);
        }  
                                // Read the data member(s) of the TClassC 
                                // object from the stream.
void TClassC::InternalizeL(RReadStream& aStream)
        {
        iZC = aStream.ReadReal64L();
        }  
                



        
        

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Copyright ©2010 Nokia Corporation and/or its subsidiary(-ies).
All rights reserved. Unless otherwise stated, these materials are provided under the terms of the Eclipse Public License v1.0.