/*

* 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 folders for media files

*

*/

#ifndef CMPXFOLDERSCANNER_H

#define CMPXFOLDERSCANNER_H

#include <e32base.h>

#include <f32file.h>

#include <badesca.h>

// FORWARD DECLARATIONS

class MMPXFileAdditionObserver;

class MMPXFileScanStateObserver;

/**

 *  CMPXFolderScanner

 *

 *  Scans a particular drive for files

 *

 *  @lib mpxfilehandler

 *  @since S60 3.0

 */

NONSHARABLE_CLASS( CMPXFolderScanner ) : public CActive

    {

public:

    /**

    * Two-phased constructor

    * @param aObserver file addition observer

    * @param aStateObserver scanning state observer

    * @param aFs file session

    */

    static CMPXFolderScanner* NewL( MMPXFileAdditionObserver& aObserver,

                                    MMPXFileScanStateObserver& aStateObs,

                                    RFs& aFs );

    /**

    * Virtual destructor

    */

    virtual ~CMPXFolderScanner();

    /**

    * Scan a particular drive for files

    * @param aDrive the drive to scan

    */

    void ScanL( RArray<TPath>& aDrive );

protected: // From Base Class

    /**

    * From CActive

    */

    void RunL();

    /**

    * From CActive

    */

    void DoCancel();

    /**

    *  From CActive

    */

    TInt RunError(TInt aError);    

private: // New Functions

    /**

    * Continues the scanning procedure

    * @return ETrue if it is done, EFalse if there is more work to do

    */

    TBool DoScanL();    

    /**

    * Setup the object to scan the next drive

    * @return ETrue if there are more folders to scan

    *         EFalse if the scanning process is complete

    */

    TBool SetupNextDriveToScanL();

    /**

    * Handles what to do when scanning is done

    * @param aErr error to return to the client

    */

    void DoScanCompleteL( TInt aErr );

    /**

    * Execute asynchronous reading RDir

    */

    void ReadDirEntry();

private:

    /**

    * Private constructor

    * @param aObserver file addition observer

    * @param aStateObserver scanning state observer

    * @param aFs file session

    */

    CMPXFolderScanner( MMPXFileAdditionObserver& aObserver,

                       MMPXFileScanStateObserver& aStateObs,

                       RFs& aFs );

    /**

    * 2nd Phase constructor

    */

    void ConstructL();

private: // data

    /**

     * An entry delegates a scanning folder

     */

    class CDirQueueEntry : public CBase

        {

        public:

            /**

             * Push a scanning folder into a directory queue

             * @param aDirQueue directory queue

             * @param aDirEntry entry delegates a scanning folder

             */

            static void PushL( RPointerArray< CDirQueueEntry >& aDirQueue,

                               CDirQueueEntry* aDirEntry );

            /**

             * Pop and destroy a scanning folder from a directory queue

             * @param aDirQueue directory queue

             */

            static void PopAndDestroy( RPointerArray< CDirQueueEntry >& aDirQueue );

            /**

             * Two-phased constructor

             * @param aFullPath full path of this folder

             */

            static CDirQueueEntry* NewL( const TDesC& aFullPath );

            /**

             * Virtual destructor

             */

            virtual ~CDirQueueEntry();

            /**

             * Get next entry of this folder

             * @return next entry of this folder,

             *         NULL if no next entry

             */

            const TEntry* NextEntry();

            /**

             * Reset the position of the EntryArray

             */

            void ResetPosition();

        private:

            /**

             * Private constructor

             */

            CDirQueueEntry();

            /**

             * 2nd phase constructor

             * @param full path of this folder

             */

            void ConstructL( const TDesC& aFullPath );

        public: //data

            /**

             * Full path of this folder

             * Owned

             */

            HBufC* iFullPath;

            /**

             * Current position of EntryArray

             */

            TInt iPos;

            /**

             * RDir object of this folder

             * Owned

             */

            RDir iDir;

            /**

             * EntryArray of this folder

             */

            TEntryArray iEntryArray;

        };

    MMPXFileAdditionObserver&     iObserver; 

    MMPXFileScanStateObserver&    iStateObserver; 

    RFs&  iFs; // Not owned

    // Droves or folders that we want to scan

    RArray<TPath>                 iDrivesToScan;

    // Flag to indicate if we are scanning or not

    TBool                         iScanning;

    // Scanner objects

    RPointerArray< CDirQueueEntry > iDirQueue; // Owned

    CDirQueueEntry*                 iCurDirQueueEntry; // Not Owned

    HBufC*                          iCurFullPath; // Not Owned

    };

#endif // CMPXFOLDERSCANNER_H