/*

* 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:    

*

*/

#ifndef HGSPRING_H

#define HGSPRING_H

#include <QPoint>

#include <QObject>

#include <QTime>

class QTimer;

/**

 * Spring physics class.

 */

class HgSpring : public QObject

{

    Q_OBJECT

    Q_PROPERTY(qreal mDamping READ damping WRITE setDamping)

    Q_PROPERTY(qreal mK READ k WRITE setK)

public:

    explicit HgSpring();    

    virtual ~HgSpring();

    qreal k() const;

    qreal damping() const;

    void setK(qreal K);

    void setDamping(qreal damping);

    void animateToPos(const QPointF& pos);

    void animateToPosAfterPanning(const QPointF& pos, qreal worldWidth);

    void gotoPos(const QPointF& pos);

    void cancel();

    bool isActive() const;

    void resetVelocity();

    const QPointF& startPos() const;

    const QPointF& pos() const;

    const QPointF& endPos() const;    

    const QPointF& velocity() const;

    bool updatePositionIfNeeded();

signals:

    void updated();

    void started();

    void ended();

private slots:

    void update();

private:

    Q_DISABLE_COPY(HgSpring)

    QPointF mStartPos;

    QPointF mPos;

    QPointF mEndPos;

    QPointF mEndPosOverListBoundary;

    QPointF mVelocity;

    qreal mK;

    qreal mDamping;

    int mAccumulator;

    QTimer* mTimer;

    QTime mPrevTime;

    bool mDoNotUpdate;

    bool mEndPosOverListEdge;

    qreal mWorldWidth;

};

#endif