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2**
3** Copyright (C) 2016 The Qt Company Ltd.
4** Contact: https://www.qt.io/licensing/
5**
6** This file is part of the Qt Charts module of the Qt Toolkit.
7**
8** $QT_BEGIN_LICENSE:GPL$
9** Commercial License Usage
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21** the Free Software Foundation and appearing in the file LICENSE.GPL3
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28****************************************************************************/
29
30// W A R N I N G
31// -------------
32//
33// This file is not part of the Qt Chart API. It exists purely as an
34// implementation detail. This header file may change from version to
35// version without notice, or even be removed.
36//
37// We mean it.
38
39#ifndef SCROLLER_P_H
40#define SCROLLER_P_H
41
42#include <QtCharts/QChartGlobal>
43#include <QtCore/QObject>
44#include <QtCore/QBasicTimer>
45#include <QtCore/QElapsedTimer>
46#include <QtCore/QPointF>
47#include <QtCharts/private/qchartglobal_p.h>
48
49QT_BEGIN_NAMESPACE
50class QGraphicsSceneMouseEvent;
51QT_END_NAMESPACE
52
53QT_CHARTS_BEGIN_NAMESPACE
54
55class Scroller;
56class QLegend;
57
58class Q_CHARTS_PRIVATE_EXPORT ScrollTicker : public QObject
59{
60 Q_OBJECT
61public:
62 explicit ScrollTicker(Scroller *scroller, QObject *parent = 0);
63 void start(int interval);
64 void stop();
65protected:
66 void timerEvent(QTimerEvent *event);
67
68private:
69 QBasicTimer m_timer;
70 Scroller *m_scroller;
71};
72
73class Q_CHARTS_PRIVATE_EXPORT Scroller
74{
75public:
76 enum State {
77 Idle,
78 Pressed,
79 Move,
80 Scroll
81 };
82
83 Scroller();
84 virtual ~Scroller();
85
86 virtual void setOffset(const QPointF &point) = 0;
87 virtual QPointF offset() const = 0;
88
89 void move(const QPointF &delta);
90 void scrollTo(const QPointF &delta);
91
92 void handleMousePressEvent(QGraphicsSceneMouseEvent *event);
93 void handleMouseMoveEvent(QGraphicsSceneMouseEvent *event);
94 void handleMouseReleaseEvent(QGraphicsSceneMouseEvent *event);
95
96 void scrollTick();
97
98private:
99 void startTicker(int interval);
100 void stopTicker();
101
102private:
103 void calculateSpeed(const QPointF &position);
104 void lowerSpeed(QPointF &speed, qreal maxSpeed = 100);
105
106private:
107 ScrollTicker m_ticker;
108 QElapsedTimer m_timeStamp;
109 QPointF m_speed;
110 QPointF m_fraction;
111 int m_timeTresholdMin;
112 int m_timeTresholdMax;
113
114 State m_state;
115 QPointF m_pressPos;
116 QPointF m_lastPos;
117 qreal m_treshold;
118};
119
120QT_CHARTS_END_NAMESPACE
121
122#endif /* SCROLLER_P_H */
123

source code of qtcharts/src/charts/scroller_p.h