1 

     2 #ifndef SCROLLHELPER_H_

     3 #define SCROLLHELPER_H_

     4 

     5 #include <QPropertyAnimation>

     6 #include <QRectF>

     7 #include <QPoint>

     8 #include <QTime>

     9 #include <QTimer>

    10 #include "uitimer.h"

    11 

    12 namespace GVA {

    13 class ScrollHelper: public QObject

    14 {

    15     Q_OBJECT

    16     

    17 public:

    18     enum ScrollMode {

    19         ReadyMode = 0,

    20         PanScrollMode,

    21         KineticScrollMode

    22     };

    23     

    24     enum ScrollState {

    25         IdleState = 0,   // no scrolling

    26         ActiveState, // scroll poins added

    27         WaitState    // no new scroll points

    28     };

    29     

    30     enum ScrollProperty {

    31         Geometry,

    32         Position,

    33         Velocity

    34     };

    35     

    36     ScrollHelper(QObject* scrolledWidget);

    37     ~ScrollHelper();

    38     void scroll(QPointF& delta);

    39     

    40     bool isScrolling();

    41     void panFromOvershoot();

    42     void setFlickDurationLimits(int minDuration, int midDuration, int maxDuration);

    43     void setFlickSpeedLimits(qreal minSpeed, qreal midSpeed, qreal maxSpeed);

    44     void setDeceleration(qreal decel);

    45     qreal getDeceleration();

    46     void kineticScroll(QPointF& speed);

    47     QSizeF viewportSize();

    48     void setViewportSize(const QSizeF& size);

    49     void setFlickLimits(qreal minFlick, qreal midFlick, qreal maxFlick);

    50     void stopScrollNoSignal();

    51 

    52 public slots:

    53     void stopScroll();    

    54     void scrollTimerCallback();

    55     void scrollAnimationStateChanged(QAbstractAnimation::State newState,

    56                                      QAbstractAnimation::State);

    57 signals:

    58     void scrollFinished();

    59 

    60 private:

    61     void reset();

    62     void doScroll(QPointF& delta);

    63     QPointF getScrollPos();

    64     QPointF getMaxScrollPos();

    65     void setScrollPos(QPointF& pos);

    66     bool clampScrollPosition(QPointF& scrollPos);

    67     void startScrollAnimation(QPointF& scrollPos, QPointF& targetPos,

    68                               int duration, QEasingCurve::Type& easingCurveType);

    69     int calcScrollDuration(const QPointF& speed, const QPointF& delta);

    70     int calcScrollDuration(qreal motionFactor);

    71     QPointF calcTargetScrollPosAndDuration(const QPointF& speed,

    72                                            const QPointF& scrollPos, int& duration);

    73     qreal calcMotionFactor(const qreal speed);

    74     QPointF calcDeceleration(const QPointF& initSpeed, const QPointF& distance, long time);

    75     QPointF speedForNextInterval(const QPointF& initSpeed, long timeInterval, const QPointF& decel);

    76 private:

    77     ScrollMode          m_scrollMode;

    78     ScrollState         m_scrollState;

    79     QPointF             m_scrollDelta;

    80     QPointF             m_curScrollPos;

    81     QPropertyAnimation* m_scrollAnimation;

    82     UiTimer*            m_scrollTimer;

    83     QObject*            m_scrolledWidget;

    84     int                 m_minFlickDuration;

    85     int                 m_maxFlickDuration;

    86     int                 m_midFlickDuration;

    87     qreal               m_minFlickSpeed;

    88     qreal               m_maxFlickSpeed;

    89     qreal               m_midFlickSpeed;

    90     qreal               m_decel;

    91     QPointF             m_decelVec;

    92     QSizeF              m_viewportSize;

    93     qreal               m_maxFlickInViewportUnits;

    94     qreal               m_minFlickInViewportUnits;

    95     qreal               m_midFlickInViewportUnits;

    96     bool                m_lockToY;

    97     bool                m_lockToX;

    98     QPointF             m_targetScrollPos;

    99     QPointF             m_startScrollPos;

   100     QPointF             m_kineticSpeed;

   101     long                m_scrollTotalDuration;

   102     long                m_scrollDuration;

   103     QEasingCurve::Type  m_easingCurveType;

   104     QEasingCurve*       m_easingCurve;

   105     QEasingCurve*       m_easingCurveOvershoot;

   106     QEasingCurve*       m_curEasingCurve;

   107 };

   108 }

   109 #endif /* SCROLLHELPER_H_ */