1 /**************************************************************************** 2 ** 3 ** Copyright (C) 2017 The Qt Company Ltd. 4 ** Contact: http://www.qt.io/licensing/ 5 ** 6 ** This file is part of the Qt Quick Templates 2 module of the Qt Toolkit. 7 ** 8 ** $QT_BEGIN_LICENSE:LGPL3$ 9 ** Commercial License Usage 10 ** Licensees holding valid commercial Qt licenses may use this file in 11 ** accordance with the commercial license agreement provided with the 12 ** Software or, alternatively, in accordance with the terms contained in 13 ** a written agreement between you and The Qt Company. For licensing terms 14 ** and conditions see http://www.qt.io/terms-conditions. For further 15 ** information use the contact form at http://www.qt.io/contact-us. 16 ** 17 ** GNU Lesser General Public License Usage 18 ** Alternatively, this file may be used under the terms of the GNU Lesser 19 ** General Public License version 3 as published by the Free Software 20 ** Foundation and appearing in the file LICENSE.LGPLv3 included in the 21 ** packaging of this file. Please review the following information to 22 ** ensure the GNU Lesser General Public License version 3 requirements 23 ** will be met: https://www.gnu.org/licenses/lgpl.html. 24 ** 25 ** GNU General Public License Usage 26 ** Alternatively, this file may be used under the terms of the GNU 27 ** General Public License version 2.0 or later as published by the Free 28 ** Software Foundation and appearing in the file LICENSE.GPL included in 29 ** the packaging of this file. Please review the following information to 30 ** ensure the GNU General Public License version 2.0 requirements will be 31 ** met: http://www.gnu.org/licenses/gpl-2.0.html. 32 ** 33 ** $QT_END_LICENSE$ 34 ** 35 ****************************************************************************/ 36 37 #ifndef QQUICKVELOCITYCALCULATOR_P_P_H 38 #define QQUICKVELOCITYCALCULATOR_P_P_H 39 40 // 41 // W A R N I N G 42 // ------------- 43 // 44 // This file is not part of the Qt API. It exists purely as an 45 // implementation detail. This header file may change from version to 46 // version without notice, or even be removed. 47 // 48 // We mean it. 49 // 50 51 #include <QtCore/qpoint.h> 52 #include <QtCore/qelapsedtimer.h> 53 54 QT_BEGIN_NAMESPACE 55 56 class QQuickVelocityCalculator 57 { 58 public: 59 void startMeasuring(const QPointF &point1, qint64 timestamp = 0); 60 void stopMeasuring(const QPointF &m_point2, qint64 timestamp = 0); 61 void reset(); 62 QPointF velocity() const; 63 64 private: 65 QPointF m_point1; 66 QPointF m_point2; 67 qint64 m_point1Timestamp = 0; 68 qint64 m_point2Timestamp = 0; 69 // When a timestamp isn't available, we must use a timer. 70 // When stopMeasuring() has been called, we store the elapsed time in point2timestamp. 71 QElapsedTimer m_timer; 72 }; 73 74 QT_END_NAMESPACE 75 76 #endif // QQUICKVELOCITYCALCULATOR_P_P_H 77