/*

* 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 KineticScroller_h

#define KineticScroller_h

#include "KineticScrollable.h"

#include <QObject>

namespace GVA {

class KineticScroller : public QObject {

    Q_OBJECT

public :

    enum OvershootPolicy {

        OvershootWhenScrollable,

        OvershootAlwaysOff,

        OvershootAlwaysOn,

    };

    enum Mode {

        AutoMode,

        PushMode

    };

    enum {

        MotionEventsPerSecond =  25

    };

    KineticScroller(KineticScrollable* scrollableView);

    ~KineticScroller();

    OvershootPolicy overshootPolicy() const;

    void setOvershootPolicy(OvershootPolicy policy);

    qreal decelerationFactor() const;

    void setDecelerationFactor(qreal f);

    int scrollsPerSecond() const;

    void setScrollsPerSecond(int sps);

    void reset();

    void doPan(QPoint delta);

    void doFlick(QPointF velocity);

    void stop();

protected:

    void changeState(KineticScrollable::State newState);

    void setScrollPositionHelper(const QPoint& point);

    void handleScrollTimer();

    void handleIdleTimer();

    void timerEvent(QTimerEvent* ev);

private:

    KineticScrollable* m_scrollableView;

    Mode m_mode;

    KineticScrollable::State m_state;

    QPoint m_motion;

    bool m_move;

    // overshoot

    OvershootPolicy m_overshootPolicy;

    int m_bounceSteps;

    QPoint m_maxOvershoot;

    int m_vmaxOvershoot;

    QPoint m_overshootDist;

    int m_overshooting; // the overshooting time in idleTimer steps

    // velocity

    QPointF m_velocity;

    qreal m_minVelocity;

    qreal m_maxVelocity;

    qreal m_deceleration;

    int m_scrollsPerSecond;

    // timer

    int m_idleTimerId;

    int m_scrollTimerId;

    int m_inactivityTimerId;

};//KineticScroller

}//namespace GVA

#endif //KineticScroller_h