1 files changed, 108 insertions, 0 deletions
diff --git a/src/quicktemplates2/qquickvelocitycalculator.cpp b/src/quicktemplates2/qquickvelocitycalculator.cpp
new file mode 100644
index 00000000..be3b2fef
--- /dev/null
+++ b/src/quicktemplates2/qquickvelocitycalculator.cpp
@@ -0,0 +1,108 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Templates 2 module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qquickvelocitycalculator_p_p.h"
+
+#include <QtCore/qdebug.h>
+
+QT_BEGIN_NAMESPACE
+
+/*
+    Usage:
+
+    QQuickVelocityCalculator velocityCalculator;
+
+    // ...
+
+    velocityCalcular.startMeasuring(event->pos(), event->timestamp());
+    velocityCalcular.stopMeasuring(event->pos(), event->timestamp());
+
+    // ...
+
+    if (velocityCalculator.velocity().x() > someAmount)
+        doSomething();
+    else if (velocityCalculator.velocity().x() < -someAmount)
+        doSomethingElse();
+*/
+
+QQuickVelocityCalculator::QQuickVelocityCalculator() :
+    m_point1Timestamp(0),
+    m_point2Timestamp(0)
+{
+}
+
+void QQuickVelocityCalculator::startMeasuring(const QPointF &point1, qint64 timestamp)
+{
+    m_point1 = point1;
+
+    if (timestamp != 0)
+        m_point1Timestamp = timestamp;
+    else
+        m_timer.start();
+}
+
+void QQuickVelocityCalculator::stopMeasuring(const QPointF &point2, qint64 timestamp)
+{
+    if (timestamp == 0 && !m_timer.isValid()) {
+        qWarning() << "QQuickVelocityCalculator: a call to stopMeasuring() must be preceded by a call to startMeasuring()";
+        return;
+    }
+
+    m_point2 = point2;
+    m_point2Timestamp = timestamp != 0 ? timestamp : m_timer.elapsed();
+    m_timer.invalidate();
+}
+
+void QQuickVelocityCalculator::reset()
+{
+    m_point1 = QPointF();
+    m_point2 = QPointF();
+    m_point1Timestamp = 0;
+    m_point2Timestamp = 0;
+    m_timer.invalidate();
+}
+
+QPointF QQuickVelocityCalculator::velocity() const
+{
+    if ((m_point2Timestamp == 0 || m_point1Timestamp == m_point2Timestamp) && !m_timer.isValid())
+        return QPointF();
+
+    const qreal secondsElapsed = (m_point2Timestamp != 0 ? m_point2Timestamp - m_point1Timestamp : m_timer.elapsed()) / 1000.0;
+    const QPointF distance = m_point2 - m_point1;
+    return distance / secondsElapsed;
+}
+
+QT_END_NAMESPACE