1 /*

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

     3 * All rights reserved.

     4 *

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

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

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

     8 *

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

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

    11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    12 * GNU Lesser General Public License for more details.

    13 *

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

    15 * along with this program.  If not,

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

    17 *

    18 * Description:

    19 *

    20 */

    21 

    22 #ifndef KineticScroller_h

    23 #define KineticScroller_h

    24 

    25 #include "KineticScrollable.h"

    26 

    27 #include <QObject>

    28 

    29 namespace GVA {

    30 

    31 class KineticScroller : public QObject {

    32     Q_OBJECT

    33 

    34 public :

    35     enum OvershootPolicy {

    36         OvershootWhenScrollable,

    37         OvershootAlwaysOff,

    38         OvershootAlwaysOn,

    39     };

    40 

    41     enum Mode {

    42         AutoMode,

    43         PushMode

    44     };

    45 

    46     enum {

    47         MotionEventsPerSecond =  25

    48     };

    49 

    50     KineticScroller(KineticScrollable* scrollableView);

    51     ~KineticScroller();

    52 

    53     OvershootPolicy overshootPolicy() const;

    54     void setOvershootPolicy(OvershootPolicy policy);

    55 

    56     qreal decelerationFactor() const;

    57     void setDecelerationFactor(qreal f);

    58 

    59     int scrollsPerSecond() const;

    60     void setScrollsPerSecond(int sps);

    61 

    62     void reset();

    63     void doPan(QPoint delta);

    64     void doFlick(QPointF velocity);

    65     void stop();

    66 

    67 protected:

    68     void changeState(KineticScrollable::State newState);

    69     void setScrollPositionHelper(const QPoint& point);

    70 

    71     void handleScrollTimer();

    72     void handleIdleTimer();

    73     void timerEvent(QTimerEvent* ev);

    74 

    75 private:

    76     KineticScrollable* m_scrollableView;

    77 

    78     Mode m_mode;

    79     KineticScrollable::State m_state;

    80 

    81     QPoint m_motion;

    82     bool m_move;

    83 

    84     // overshoot

    85     OvershootPolicy m_overshootPolicy;

    86     int m_bounceSteps;

    87     QPoint m_maxOvershoot;

    88     int m_vmaxOvershoot;

    89     QPoint m_overshootDist;

    90     int m_overshooting; // the overshooting time in idleTimer steps

    91 

    92     // velocity

    93     QPointF m_velocity;

    94     qreal m_minVelocity;

    95     qreal m_maxVelocity;

    96     qreal m_deceleration;

    97     int m_scrollsPerSecond;

    98 

    99     // timer

   100     int m_idleTimerId;

   101     int m_scrollTimerId;

   102     int m_inactivityTimerId;

   103 };//KineticScroller

   104 

   105 }//namespace GVA

   106 

   107 #endif //KineticScroller_h