/*

* Copyright (c) 2010 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:  Home screen active callback in HsBackupRestoreObserver.

*

*/

#ifndef HSBACKUPRESTOREACTIVECALLBACK_H

#define HSBACKUPRESTOREACTIVECALLBACK_H

#include <e32base.h>    // CBase

#include <connect/abclient.h>

class HsBackupRestoreObserver;

/**

 *  Home screen active callback in backup/restore.

 *

 *  @lib hsdomainmodel

 *  @since S60 ^4

 */

NONSHARABLE_CLASS(CHsBURActiveCallback) : public CBase, 

	                                     public conn::MActiveBackupDataClient

    {

public:

    IMPORT_C static CHsBURActiveCallback* NewL(HsBackupRestoreObserver* observer);

    virtual ~CHsBURActiveCallback();    

// new functions

// from base class MActiveBackupDataClient

    /**

     * This method informs the active backup data client that all 

     * snapshots have been supplied. If the client has not

     * received a snapshot then it should perform a base backup

     */

    virtual void AllSnapshotsSuppliedL();

    /**

     * This method receives all or part of a snapshot of data to allow 

     * calculation of an incremental backup.  The snapshot is one that

     * was previously supplied by the data owner.  The snapshot data 

     * should be read from the location supplied. The snapshot data may

     * be larger than the location supplied in which case the routine 

     * will be called repeatedly until all data has been supplied.

     *

     * Snapshot data will also be supplied as part of a restore operation

     *        

     * @param aDrive the drive being backed up

     * @param aBuffer a pointer to the base of the location from whence 

     *        data can be copied.

     * @param aLastSection ETrue if this is the last section of snapshot 

     *        data, else EFalse.

     */

    virtual void ReceiveSnapshotDataL(

        TDriveNumber aDrive, TDesC8& aBuffer, TBool aLastSection);

    /**

     * This method returns the expected size of backup data that will be

     * supplied. If an incremental backup is underway then this method

     * then this method will not be called until after 

     * ReceiveSnapshotDataL(). The size data will be used for the purpose

     * of tracking progess during a backup. If it is inaccurate then the

     * user may see irregular progress but the actual backup data will 

     * not be affected so it is acceptable to return an estimated value.

     *

     * @param aDrive the drive being backed up.

     * @return the size of the data that will be returned

     */

    virtual TUint GetExpectedDataSize(TDriveNumber aDrive);

    /**

     * This method returns a snapshot of data to accompany a backup. The 

     * snapshot is expected to contain details on files / data being 

     * backed up. The format of the snapshot is only meaningful to the

     * data owner. The snapshot will be supplied if the data owner is 

     * asked for an incremental backup and for a restore operation. The 

     * snapshot data should be copied to the location supplied.

     *

     * The snapshot data may be larger than the location supplied in 

     * which case the routine will be called repeatedly until all data

     * has been retrieved.

     *

     * @param aDrive the drive being backed up

     * @param aBuffer a pointer to the base of the location where data 

     *        can be copied.

     * @param aFinished on return ETrue if all data has been returned 

     *        for this drive, else EFalse.

     */

    virtual void GetSnapshotDataL( 

        TDriveNumber aDrive, TPtr8& aBuffer, TBool& aFinished);

    /**

     * This method prepares the implementor to return backup data. It 

     * will be followed by a sequence of calls to request the actual 

     * data.

     *        

     * @param aDrive the drive being backed up.

     */

    virtual void InitialiseGetBackupDataL(TDriveNumber aDrive);

    /**

     * This method requests a section of backup data.  

     * InitialiseGetBackupDataL() will have been called previously to

     * specify the drive concerned.  The data returned may be base or

     * incremental depending on the type of backup and the capability of

     * the data owner.

     *

     * @param aBuffer a pointer to the base of the location where data 

     *        can be copied.

     * @param aFinished on return ETrue if all data has been returned 

     *        for this drive, else EFalse.

     */

    virtual void GetBackupDataSectionL(TPtr8& aBuffer, TBool& aFinished);

    /**

     * This method prepares the implementor to receive base restore data

     * for a drive. It will be followed by a sequence of calls to supply

     * the actual data.

     *

     * @param aDrive the drive being restored.

     */

    virtual void InitialiseRestoreBaseDataL(TDriveNumber aDrive);

    /**

     * This method receives a section of base restore data.

     * InitialiseRestoreBaseDataL() will have been called previously to 

     * specify the drive concerned.

     *

     * @param aBuffer a pointer to the base of the location whence data

     *        can be read.

     * @param aFinished ETrue if all data has been returned for this 

     *        drive, else EFalse.

     */

    virtual void RestoreBaseDataSectionL(TDesC8& aBuffer, TBool aFinished);

    /**

     * This method prepares the implementor to receive incremental 

     * restore data for a drive. It will be followed by a sequence 

     * of calls to supply the actual data.  If multiple increments

     * are supplied then this methid will be called before each increment

     *

     * @param aDrive the drive being restored.

     */

    virtual void InitialiseRestoreIncrementDataL(TDriveNumber aDrive);

    /**

     * This method receives a section of increment restore data.

     * InitialiseRestoreIncrementDataL() will have been called 

     * previously to specify the drive concerned.

     *

     * @param aBuffer a pointer to the base of the location whence data 

     *        can be read.

     * @param aFinished ETrue if all data has been returned for this 

     *        increment, else EFalse.

     */

    virtual void RestoreIncrementDataSectionL(TDesC8& aBuffer, TBool aFinished);

    /**

     * This method is called when all data to be restored has been 

     * supplied.

     *

     * @param aDrive the drive being restored.

     */

    virtual void RestoreComplete(TDriveNumber aDrive);   

    /**

     * This method is called if copying of data is terminated prematurely 

     * to allow the implementor to tidy up.  The same method applies to 

     * all types of data and to backup and restore.

     */

    virtual void TerminateMultiStageOperation();

    /**

     * Gets a 32-bit checksum for its private data.

     * This routine is for test purposes.  It must be implemented but an

     * invariant checksum value can be provided.  Some tests may cause 

     * checksum values to be compared.

     *

     * @param aDrive the drive containing data being checksummed

     * @return the 32-bit checksum

     */

    virtual TUint GetDataChecksum(TDriveNumber aDrive);

private:

    CHsBURActiveCallback(HsBackupRestoreObserver* observer);

    void ConstructL();

private: // data

	// Bacup/Restore observer. Not own.

    HsBackupRestoreObserver *iObserver;

    };

#endif // HSBACKUPRESTOREACTIVECALLBACK_H