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50
51#ifndef FREQUENCYMONITOR_H
52#define FREQUENCYMONITOR_H
53
54#include <QObject>
55#include <QTimer>
56
57class FrequencyMonitorPrivate;
58
59/**
60 * Class for measuring frequency of events
61 *
62 * Occurrence of the event is notified by the client via the notify() slot.
63 * On a regular interval, both an instantaneous and a rolling average
64 * event frequency are calculated.
65 */
66class FrequencyMonitor : public QObject
67{
68 Q_OBJECT
69 Q_DECLARE_PRIVATE(FrequencyMonitor)
70 Q_PROPERTY(QString label READ label WRITE setLabel NOTIFY labelChanged)
71 Q_PROPERTY(bool active READ active WRITE setActive NOTIFY activeChanged)
72 Q_PROPERTY(int samplingInterval READ samplingInterval WRITE setSamplingInterval NOTIFY samplingIntervalChanged)
73 Q_PROPERTY(int traceInterval READ traceInterval WRITE setTraceInterval NOTIFY traceIntervalChanged)
74 Q_PROPERTY(qreal instantaneousFrequency READ instantaneousFrequency NOTIFY instantaneousFrequencyChanged)
75 Q_PROPERTY(qreal averageFrequency READ averageFrequency NOTIFY averageFrequencyChanged)
76
77public:
78 FrequencyMonitor(QObject *parent = 0);
79 ~FrequencyMonitor();
80
81 static void qmlRegisterType();
82
83 QString label() const;
84 bool active() const;
85 int samplingInterval() const;
86 int traceInterval() const;
87 qreal instantaneousFrequency() const;
88 qreal averageFrequency() const;
89
90signals:
91 void labelChanged(const QString &value);
92 void activeChanged(bool);
93 void samplingIntervalChanged(int value);
94 void traceIntervalChanged(int value);
95 void frequencyChanged();
96 void instantaneousFrequencyChanged(qreal value);
97 void averageFrequencyChanged(qreal value);
98
99public slots:
100 Q_INVOKABLE void notify();
101 Q_INVOKABLE void trace();
102 void setActive(bool value);
103 void setLabel(const QString &value);
104 void setSamplingInterval(int value);
105 void setTraceInterval(int value);
106
107private:
108 FrequencyMonitorPrivate *d_ptr;
109};
110
111#endif // FREQUENCYMONITOR_H
112

source code of qtmultimedia/examples/multimedia/video/snippets/frequencymonitor/frequencymonitor.h