/*

* Copyright (c) 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:   VideoCollectionWrapper class definition

* 

*/

#ifndef __VIDEOCOLLECTIONWRAPPER_H__

#define __VIDEOCOLLECTIONWRAPPER_H__

// INCLUDES

#include <QObject>

#include <qabstractitemmodel.h>

#include "videocollectionexport.h"

// FORWARD DECLARATIONS

class VideoCollectionWrapperPrivate;

class VideoSortFilterProxyModel;

/**

 * Class is used as an interface of the video collection QT wrapper.

 * 

 * Singleton instance is deleted when it's not used anymore by clients. At instantion time  

 * reference count is incremented. Client must call decreaseReferenceCount when it doesn't 

 * need the instance anymore. When reference count is 0 the instance is destroyed.

 * 

 * * Usage:

 *  @code

 *  #include "videocollectionwrapper.h"

 *  #include "videosortfilterproxymodel.h"

 *  

 *  ...

 *  ////

 *  // Getting the instances

 *  ////

 *  VideoCollectionWrapper *wrapper = VideoCollectionWrapper::instance();

 * 

 *  VideoSortFilterProxyModel *model = wrapper->getModel();

 *  ...

 *  ////

 *  // Opening collection and start fetching video item data

 *  ////

 *  if(model)

 *  {

 *      mModel->open(VideoListWidget::ELevelVideos);

 *  }

 *  // see model documentation for the open funtionality

 *

 *  /////

 *  // Instance is not used anymore. 

 *  // Wrapper owns the model, so client should not deallocate it

 *  /////

 *  wrapper->decreaseReferenceCount();

 *  wrapper = 0; // Don't use before new instantion.

 * 

 *  @endcode

 * 

 */

class VIDEOCOLLECTION_DLL_EXPORT VideoCollectionWrapper : public QObject         

{    

    /**

     * define to be able to use signals and slots

     */

    Q_OBJECT

public: // Constructor

    /**

     * Returns singleton instance for this class.

     * 

     * WARNING! Not safe to call this from destructor of another function scope static object!

     * 

     * @return The singleton instance.

     */

    static VideoCollectionWrapper *instance();

    /**

     * Decreases the reference count, when count reaches zero cleanup is done.

     * 

     */

    void decreaseReferenceCount();    

	/**

     * Returns pointer to model

     * 

     * @return address to model or NULL if fails.

     */    

    VideoSortFilterProxyModel* getModel();

    /**

     * Method can be used by client to emit status signal

     * containing status code from particular async status.

     * 

     * @param statusCode code of status

     * 

     * @param additional additional information for the code

     */

    void sendAsyncStatus(int statusCode, QVariant &additional);

signals:     

    /**

     * Signal that can be emitted by the wrapper to indicate status

     * of some async operation.

     * 

     * See videocollectioncommon.h for codes

     * 

     * @param status code of status

     * 

     * @param additional additional information for the code

     */

    void asyncStatus(int statusCode, QVariant &additional);

private:

    /**

     * Private contructor.

     */    

    VideoCollectionWrapper(); 

    /**

     * Private destructor.

     *

     */

    virtual ~VideoCollectionWrapper();    

    /**

     * disables copy-constructor and assingment operator

     */

    Q_DISABLE_COPY(VideoCollectionWrapper)    

private:

	/**

     * d -pointer for actual implementation

     */ 

    VideoCollectionWrapperPrivate *d;

    /**

     * Reference count.

     */

    int mReferenceCount;

    /**

     * Singleton instance.

     */

    static VideoCollectionWrapper* mInstance;

};

#endif  // __VIDEOCOLLECTIONWRAPPER_H__

// End of file