/*

* Copyright (c) 2008-2009 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:   Thumbnail creator: provides thumbnails and generates on background

*

*/

/**

 * @internal reviewed 30/07/2007 by Simon Brooks

 */

#ifndef C_GLXTNTHUMBNAILCREATOR_H

#define C_GLXTNTHUMBNAILCREATOR_H

#include "glxtnstd.h"

#include "glxtntask.h"

#include <glxmediaid.h>

#include <glxpanic.h>

#include <glxthumbnailinfo.h>

class CGlxtnFileUtility;

class CGlxSettingsModel;

class MGlxtnThumbnailCreatorClient;

class MGlxtnThumbnailStorage;

class TGlxThumbnailRequest;

/**

 *  CGlxtnThumbnailCreator

 *

 *  Thumbnail creator is the thumbnail engine, and it loads and generates 

 *  thumbnails on the foreground and generates non-created thumbnails on

 *  the background

 *

 * @ingroup glx_thumbnail_creator

 */

class CGlxtnThumbnailCreator : public CBase

    {

public:

    /**

    * Starts the provisioning of a thumbnail.  This will result in a callback

    * to MGlxtnThumbnailCreatorClient::ThumbnailFetchComplete().

    */

    IMPORT_C static CGlxtnThumbnailCreator* InstanceL();

    /**

    * Decrement the reference count, and delete the instance if the count

    * becomes zero.  Ensures any tasks using the given storage are cancelled.

    * @param aStorage Pointer to storage used by client, or NULL.

    */

    IMPORT_C void Close(MGlxtnThumbnailStorage* aStorage);

    /**

    * Destructor.

    */

	~CGlxtnThumbnailCreator();

    /**

    * Starts the provisioning of a thumbnail.  This will result in a callback

    * to MGlxtnThumbnailCreatorClient::ThumbnailFetchComplete().

    * @param aRequestInfo Parameters for required thumbnail.

    * @param aClient Client initiating the request.

    */

    IMPORT_C void FetchThumbnailL(const TGlxThumbnailRequest& aRequestInfo,

                                    MGlxtnThumbnailCreatorClient& aClient);

    /**

    * Starts deleting all stored thumbnails for a given item.  This will result

    * in a callback to MGlxtnThumbnailCreatorClient::ThumbnailDeletionComplete().

    * @param aItemId ID of the media item.

    * @param aClient Client initiating the request.

    */

    IMPORT_C void DeleteThumbnailsL(const TGlxMediaId& aItemId,

                                    MGlxtnThumbnailCreatorClient& aClient);

    /**

    * Starts the filtering of items for which a thumbnail is available from a

    * list of item IDs.  This will result in a callback to

    * MGlxtnThumbnailCreatorClient::FilterAvailableComplete().

    * @param aItemArray Array of item IDs, from which those with thumbnails

    *                   should be removed.

    * @param aSize Size of thumbnail required.

    * @param aClient Client initiating the request.

    */

    IMPORT_C void FilterAvailableThumbnailsL(

                    const TArray<TGlxMediaId>& aItemArray, const TSize& aSize,

                    MGlxtnThumbnailCreatorClient& aClient);

    /**

    * Starts the cleanup of obsolete thumbnails from storage.  There is no

    * callback indicating completion of the request.

    * @param aStorage Pointer to storage used by client.

    */

    IMPORT_C void CleanupThumbnailsL(MGlxtnThumbnailStorage* aStorage);

    /** 

    * Cancel any ongoing tasks for a given item.  This ensures the TNC is not

    * locking the media file.

    * @param aItemId ID of the media item.

    */

    IMPORT_C void CancelRequest(const TGlxMediaId& aItemId);

private:

	CGlxtnThumbnailCreator();

	void ConstructL();

private:

    /** Task manager */

    CGlxtnTaskManager* iTaskManager;

    /** File utility used by the tasks */

    CGlxtnFileUtility* iFileUtility;

    /** Reference count of the single instance */

    TInt iReferenceCount;

    /** Settings Model used by the background tasks */

    CGlxSettingsModel* iSettingsModel;

    };

#endif // C_GLXTNTHUMBNAILCREATOR_H