qquickvelocitycalculator_p_p.h

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// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#ifndef QQUICKVELOCITYCALCULATOR_P_P_H
#define QQUICKVELOCITYCALCULATOR_P_P_H
 
//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
 
#include <QtCore/qpoint.h>
#include <QtCore/qelapsedtimer.h>
#include <QtCore/private/qglobal_p.h>
 
QT_BEGIN_NAMESPACE
 
class QQuickVelocityCalculator
{
public:
    void startMeasuring(const QPointF &point1, qint64 timestamp = 0);
    void stopMeasuring(const QPointF &m_point2, qint64 timestamp = 0);
    void reset();
    QPointF velocity() const;
 
private:
    QPointF m_point1;
    QPointF m_point2;
    qint64 m_point1Timestamp = 0;
    qint64 m_point2Timestamp = 0;
    // When a timestamp isn't available, we must use a timer.
    // When stopMeasuring() has been called, we store the elapsed time in point2timestamp.
    QElapsedTimer m_timer;
};
 
QT_END_NAMESPACE
 
#endif // QQUICKVELOCITYCALCULATOR_P_P_H