chart.cpp Example File | Qt Charts 5.12.12

- Qt 5.12
- Qt Charts
- Zoom Line Example
- chart.cpp Example File
- Qt Charts | Commercial or GPLv3

# chart.cpp Example File

zoomlinechart/chart.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2016 The Qt Company Ltd.
     ** Contact: https://www.qt.io/licensing/
     **
     ** This file is part of the Qt Charts module of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:GPL$
     ** Commercial License Usage
     ** Licensees holding valid commercial Qt licenses may use this file in
     ** accordance with the commercial license agreement provided with the
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     ** Alternatively, this file may be used under the terms of the GNU
     ** General Public License version 3 or (at your option) any later version
     ** approved by the KDE Free Qt Foundation. The licenses are as published by
     ** the Free Software Foundation and appearing in the file LICENSE.GPL3
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     #include "chart.h"
     #include <QtWidgets/QGesture>
     #include <QtWidgets/QGraphicsScene>
     #include <QtWidgets/QGraphicsView>

     Chart::Chart(QGraphicsItem *parent, Qt::WindowFlags wFlags)
         : QChart(QChart::ChartTypeCartesian, parent, wFlags)
     {
         // Seems that QGraphicsView (QChartView) does not grab gestures.
         // They can only be grabbed here in the QGraphicsWidget (QChart).
         grabGesture(Qt::PanGesture);
         grabGesture(Qt::PinchGesture);
     }

     Chart::~Chart()
     {

     }

     bool Chart::sceneEvent(QEvent *event)
     {
         if (event->type() == QEvent::Gesture)
             return gestureEvent(static_cast<QGestureEvent *>(event));
         return QChart::event(event);
     }

     bool Chart::gestureEvent(QGestureEvent *event)
     {
         if (QGesture *gesture = event->gesture(Qt::PanGesture)) {
             QPanGesture *pan = static_cast<QPanGesture *>(gesture);
             QChart::scroll(-(pan->delta().x()), pan->delta().y());
         }

         if (QGesture *gesture = event->gesture(Qt::PinchGesture)) {
             QPinchGesture *pinch = static_cast<QPinchGesture *>(gesture);
             if (pinch->changeFlags() & QPinchGesture::ScaleFactorChanged)
                 QChart::zoom(pinch->scaleFactor());
         }

         return true;
     }