/*

* 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 "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:  Scans metadata for new files, updated files

*

*/

#ifndef CMPXMETADATASCANNER_H

#define CMPXMETADATASCANNER_H

#include <e32base.h>

class CMPXMedia;

class CMPXMediaArray;

class CMPXCollectionType;

class CMPXMetadataExtractor;

class MMPXMetadataScanObserver;

class MMPXFileScanStateObserver;

enum TExtractType

    {

    ENewFiles = 0,

    EModFiles = 1,

    EMaxFile  = 2

    };   

/**

 *  CMPXMetadataScanner

 *

 *  Extracts metadata from a list of files

 *

 *  @lib mpxfilehandler.lib

 *  @since S60 3.0

 */

NONSHARABLE_CLASS( CMPXMetadataScanner ): public CActive

    {

public:

    /**

    * Two phased constructor

    * @param aFs file server session

    * @param aAppArc apparc session

    * @param aTypesAry supported file types array

    * @param aObs metadata scanning observer

    * @param aStateObs scanning state observer

    * @return new instance of CMPXMetadataScanner

    */

    static CMPXMetadataScanner* NewL( RFs& aFs, 

                                      RApaLsSession& aAppArc,

                                      RPointerArray<CMPXCollectionType>& aTypesAry,

                                      MMPXMetadataScanObserver& aObs,

                                      MMPXFileScanStateObserver& aStateObs );

    /**

    * Two phased constructor

    * @param aFs file server session

    * @param aAppArc apparc session

    * @param aTypesAry supported file types array

    * @param aObs metadata scanning observer

    * @param aStateObs scanning state observer

    * @return new instance of CMPXMetadataScanner

    */

    static CMPXMetadataScanner* NewLC( RFs& aFs,

                                       RApaLsSession& aAppArc, 

                                       RPointerArray<CMPXCollectionType>& aTypesAry,

                                       MMPXMetadataScanObserver& aObs,

                                       MMPXFileScanStateObserver& aStateObs );

    /**

    * Virtual destructor

    */

    virtual ~CMPXMetadataScanner();

public: // New Functions 

    /**

    * Frees all memory allocated

    */

    void Reset();

    /**

    * Extracts metadata for the files in the file list

    */

    void Start();

    /**

    * Stops extraction of metadata for the files in the file list

    */

    void Stop();

    /**

    * Adds a new file to the scanning list

    * @param aFile file path to add to scan

    */

    void AddNewFileToScanL( const TDesC& aFile );

    /**

    * Adds a modified file to the scanning list

    * @param aFile file path to add to scan

    */

    void AddModifiedFileToScanL( const TDesC& aFile );

    /**

    * Extract the Media properties for a file

    * @param aFile file path to extract metadata

    * @return CMPXMedia* media for the file, ownership transferred

    */

    CMPXMedia* ExtractFileL( const TDesC& aFile );

protected: // From base class

    /**

    * From CActive

    */

    void DoCancel();

    /**

    * From CActive

    */

    void RunL();

private: // New Functions

    /**

    * Extract metadata from a few files

    * @return ETrue if there are no more files to extract

    *         EFalse otherwise

    */

    TBool DoExtractL(); 

private:

    /**

    * Private Constructor

    * @param aObs metadata scanning observer

    * @param aStateObs scanning state observer

    */

    CMPXMetadataScanner( MMPXMetadataScanObserver& aObs,

                         MMPXFileScanStateObserver& aStateObs );

    /**

    * 2nd phase constructor

    * @param aAppArc apparc session

    * @param aTypesAry supported file types array

    */

    void ConstructL( RFs& aFs, RApaLsSession& aAppArc,

                     RPointerArray<CMPXCollectionType>& aTypesAry );

private: // data

    RPointerArray<HBufC>  iNewFiles;

    RPointerArray<HBufC>  iModifiedFiles;

    CMPXMediaArray* iNewFileProps;

    CMPXMediaArray* iModifiedFileProps;

    TBool iExtracting;          // Are we extracting

    TInt  iExtractType; // What are we extracting

    TInt  iAryPos;              // Current array position

    CMPXMetadataExtractor* iExtractor;  // Metadata Utilities wrapper

    MMPXMetadataScanObserver& iObserver;

    MMPXFileScanStateObserver& iStateObserver;   

    };

#endif // CMPXMETADATASCANNER_H