/*

* Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "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:  Definition of CFileReader

*

*/

#ifndef CFILEREADER_H

#define CFILEREADER_H

//  INCLUDES

#include <e32base.h>

#include <f32file.h>

// CONSTANTS

// MACROS

// DATA TYPES

enum TFileEvent

    {

    EGotResponseBodyData,

    ESucceeded,

    EFailed

    };

// FUNCTION PROTOTYPES

// FORWARD DECLARATIONS

class FileConnection;

// CLASS DECLARATION

/**

*  This is a simple incremental file reader.

*  @lib resLoader.lib

*  @since 3.1

*/

class CFileReader : public CActive

    {

    public:  // Constructors and destructor        

        /**

        * Two-phased constructor.

        * @since 3.1

        * @param aFile File to read.

        * @param aChunkSize Chunk size to be read in one turn.

        * @param aFileReaderCallback Observer object-file transaction.

        * @return File reader object

        */

        static CFileReader* NewL( RFile& aFile, TInt aChunkSize, FileConnection* aFileConnection );

        /**

        * Destructor.

        */

        virtual ~CFileReader();

    public: // New functions

        /**

        * Start reading the file from the beginning.

        * @since 3.1

        * @param 

        * @return void

        */

        void StartReading();

        /**

        * Stop reading 

        * @since 3.1

        * @param 

        * @return void

        */

        void StopReading();

        /**

        * Get partial body buffer.

        * @since 3.1

        * @param aChunkBuffer Pointer to the partial body buffer

        * @return void

        */

        void GetChunkBuffer( TPtrC8& aChunkBuffer );

        /**

        * Purge the chunk buffer.

        * @since 3.1

        * @param 

        * @return void

        */

        void ReleaseChunkBuffer();

    public: // from CActive

        /**

        * Cancel active object

        * @since 3.1

        * @param

        * @return void

        */

        void DoCancel();

        /**

        * Asynchronous handling of transaction events.

        * @since 3.1

        * @param 

        * @return void

        */

        void RunL();

    private:

        /**

        * Construct.

        * @since 3.1

        * @param aFile File to read.

        * @param aChunkSize Chunk size to be read in one turn.

        * @param aFileReaderCallback Observer object-file transaction.

        * @return void

        */

        CFileReader( RFile& aFile, TInt aChunkSize, FileConnection* aFileConnection );

        /**

        * By default Symbian 2nd phase constructor is private.

        */

        void ConstructL();

        /**

        * Read from the file from the current position.

        * @since 3.1

        * @param 

        * @return void

        */

        void ReadFile();

    private:    // Data

        // file to read

        RFile         m_file;

        // actual file position 

        TInt          m_filePos;

        // chunk size to read in one turn

        TInt          m_chunkSize;

        // chunk buffer

        HBufC8*       m_chunkBuffer;

        // observer object

        FileConnection* m_fileConnection;

        // pointer to the chunk buffer

        TPtr8         m_chunkBufPtr;

        // ETrue if the file transaction is cancelled

        TBool         m_stopReading;

  };

#endif      // CFILEREADER_H

// End of File