/*

 * 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:  contentinfodb .

 *

 */

#ifndef CONTENTINFODB_H

#define CONTENTINFODB_H

#include <qobject.h>

#include <QSqlDatabase>

#include <qmutex.h>

#include "contentinfodbcommon.h"

CONTENTINFODB_CLASS(ContentinfodbTest)

class ContentInfoDb : public QObject

    {

Q_OBJECT

public:

    /**

     * Singleton construtor

     * @since S60 ?S60_version.

     */

    static ContentInfoDb* instance()

        {

        static QMutex mutex;

        if (!m_instance)

            {

            mutex.lock();

            m_instanceCounter++;

            if (!m_instance)

                {

                m_instance = new ContentInfoDb;

                }

            mutex.unlock();

            }

        return m_instance;

        }

    /**

     * Singleton destructor

     * @since S60 ?S60_version.

     */

    static void deleteinstance()

        {

        m_instanceCounter--;

        if ((m_instanceCounter <= 0) && (m_instance))

            {

            delete m_instance;

            m_instance = 0;

            }

        }

private:

    /**

     * Constructor.

     * @since S60 ?S60_version.

     */

    ContentInfoDb();

    /**

     * Destructor.

     * @since S60 ?S60_version.

     */

    ~ContentInfoDb();

public:

    /**

     * returns success/failure status.

     * @since S60 ?S60_version.

     * @param query

     */

    bool writeData(QString query);

    /**

     * returns success/failure status.

     * @since S60 ?S60_version.

     * @param query input

     */

    QStringList readData(QString query);

    /**

     * returns value at mentioned position

     * @param query input     

     */

    QString readStringData(QString query);

    /**

     * creates the table with the mentioned tablename.

     * @param tablename 

     * @param sql query

     */

    void createTable(QString tablename, QString query);

    /**

     * returns success/failure status.

     * @since S60 ?S60_version.

     */

    bool Open();

    /**     

     * close the database connection

     * @since S60 ?S60_version.     

     */

    void Close();

signals:

    /**     

     * signal to notify when updation happens in the contentinfodb

     */

    void dbUpdated();

private:

    /**

     * static instance to make single instance

     * Own.

     */

    static ContentInfoDb *m_instance;

    /**

     * counter for number for instance

     * Own.

     */

    static int m_instanceCounter;

    /**

     * database handle

     * Own.

     */

    QSqlDatabase m_db;

private:

    CONTENTINFODB_FRIEND_CLASS(ContentinfodbTest)

    };

#endif //CONTENTINFODB_H