/*

* 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:   Download operation interface definition

*

*/

#ifndef M_NCD_DOWNLOAD_OPERATION_H

#define M_NCD_DOWNLOAD_OPERATION_H

#include <e32cmn.h>

#include "ncdoperation.h"

#include "ncdinterfaceids.h"

#include "ncdoperationdatatypes.h"

class MNcdDownloadOperationObserver;

/**

 *  Download operation interface.

 *

 *  A download operation handles the downloading of one or more files.

 *

 *  The files are downloaded consecutively and in a predefined order.

 *  If parallel downloading is desired, multiple operations can be started.

 *

 *  Common uses for download operatios are downloading a downloadable node's 

 *  content and downloading graphics for nodes.

 *

 *  Download operations can be queried for the number of the download that is 

 *  currently being downloaded. The progress information is always relative

 *  to the current download.

 *  

 *  

 *  @see MNcdDownloadOperationObserver

 *  @see MNcdNodeDownload

 */

class MNcdDownloadOperation : public MNcdOperation

    {

public:

    /**

     * Unique identifier for the interface, required for all MCatalogsBase interfaces.

     *

     * 

     */

    enum { KInterfaceUid = ENcdDownloadOperationUid };    

    /**

     * Getter for file count. This is the total number of files this operation

     * is downloading.

     *

     * 

     * @return Total number of files to be downloaded.

     */

    virtual TInt FileCount() = 0;

    /**

     * Getter for current file number. This is the number of the

     * file that is currently being downloaded.

     *

     * 

     * @return Number of the file currently being downloaded.

     */

    virtual TInt CurrentFile() = 0;

    /**

     * Pause the download.

     *

     * @note Does nothing if the download was already paused, or if the

     *  operation is not yet started.

     *

     * 

     * @exception Leave System wide error code.

     */

    virtual void PauseL() = 0;

    /**

     * Resume a paused download.

     *

     * @note Does nothing if the download has not been paused, or if the

     *  operation is not yet started.

     *

     * 

     * @exception Leave System wide error code.

     */

    virtual void ResumeL() = 0;

    /**

     * Return the paused state of the download.

     *

     * 

     * @return ETrue, if the operation has been started and PauseL() has

     *  been called successfully, pausing the download. EFalse otherwise.

     */

    virtual TBool IsPaused() = 0;

    /**

     * Can download be paused

     *

     * @return ETrue if the operation can be paused, EFalse if pausing is not

     * allowed

     * @leave Symbian error code

     * @note Some DRM content is not pausable

     * @note Pausable state may change during the operation

     */

    virtual TBool IsPausableL() = 0;

    /**

     * Add a new observer for this download operation.

     *

     * If the observer has already been added, this function doesn't do anything.

     *

     * 

     * @exception Leave System wide error code.

     */

    virtual void AddObserverL( MNcdDownloadOperationObserver& aObserver ) = 0;

    /**

     * Remove an observer previously added with AddObserverL().

     *

     * @return ETrue if an observer was removed

     * 

     */

    virtual TBool RemoveObserver( MNcdDownloadOperationObserver& aObserver ) = 0;

    /**

     * Download data type getter

     *

     * @return Type of the data the operation is downloading

     * @see ncdoperationdatatypes.h

     */

    virtual TNcdDownloadDataType DownloadDataType() const = 0;

protected:

    /**

    * Destructor.

    *

    * @see MCatalogsBase::~MCatalogsBase

    */

    virtual ~MNcdDownloadOperation() {}

    };

#endif //  M_NCD_DOWNLOAD_OPERATION_H