/*

* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

*

* This program is free software: you can redistribute it and/or modify

* it under the terms of the GNU Lesser General Public License as published by

* the Free Software Foundation, version 2.1 of the License.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

* GNU Lesser General Public License for more details.

*

* You should have received a copy of the GNU Lesser General Public License

* along with this program.  If not,

* see "http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html/".

*

* Description:

*

*/

#ifndef __KINETIC_HELPER_H__

#define __KINETIC_HELPER_H__

#include <QObject>

#include <QPoint>

#include <QTime>

class QTimer;

#define KINETIC_TIMEOUT  60

#define DECELERATION     100

class KineticScrollable

{

public:

    virtual void scrollTo(QPoint& pos) = 0;

    virtual QPoint getScrollPosition() = 0;

    virtual QPoint getInitialPosition() = 0;

    virtual QPointF getInitialSpeed() = 0;

};

class KineticHelper: public QObject

{

    Q_OBJECT

public:

    KineticHelper(KineticScrollable* scrollable, qreal decel = DECELERATION, int kineticTimeout = KINETIC_TIMEOUT);

    ~KineticHelper();

    void setDeceleration(qreal decel) { m_decel = decel; }

    void setKineticTimeout(int timeout) { m_kineticTimeout = timeout; }

    void stopScrolling();

    void startScrolling();

    bool isScrolling();

private slots:

    void kineticScroll();

private:

    KineticScrollable* m_scrollable;

    QPointF            m_initialSpeed;

    QPoint             m_initialPos;

    QTimer*            m_kineticTimer;

    int                m_kineticSteps;

    qreal              m_decel;

    int                m_kineticTimeout;

    QTime              m_actualTime;

    qreal              m_kineticScrollTime;

};

#endif //__KINETIC_HELPER_H__