chartview.cpp Example File

polarchart/chartview.cpp
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 ** Contact: https://www.qt.io/licensing/
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 ** This file is part of the Qt Charts module of the Qt Toolkit.
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 ** $QT_BEGIN_LICENSE:GPL$
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 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
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 ** the Free Software Foundation and appearing in the file LICENSE.GPL3
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 #include "chartview.h"
 #include <QtGui/QMouseEvent>
 #include <QtCore/QDebug>
 #include <QtCharts/QAbstractAxis>
 #include <QtCharts/QValueAxis>

 QT_CHARTS_USE_NAMESPACE

 ChartView::ChartView(QWidget *parent)
     : QChartView(parent)
 {
 }

 void ChartView::keyPressEvent(QKeyEvent *event)
 {
     switch (event->key()) {
     case Qt::Key_Plus:
         chart()->zoomIn();
         break;
     case Qt::Key_Minus:
         chart()->zoomOut();
         break;
     case Qt::Key_Left:
         chart()->scroll(-1.0, 0);
         break;
     case Qt::Key_Right:
         chart()->scroll(1.0, 0);
         break;
     case Qt::Key_Up:
         chart()->scroll(0, 1.0);
         break;
     case Qt::Key_Down:
         chart()->scroll(0, -1.0);
         break;
     case Qt::Key_Space:
         switchChartType();
         break;
     default:
         QGraphicsView::keyPressEvent(event);
         break;
     }
 }

 void ChartView::switchChartType()
 {
     QChart *newChart;
     QChart *oldChart = chart();

     if (oldChart->chartType() == QChart::ChartTypeCartesian)
         newChart = new QPolarChart();
     else
         newChart = new QChart();

     // Move series and axes from old chart to new one
     const QList<QAbstractSeries *> seriesList = oldChart->series();
     const QList<QAbstractAxis *> axisList = oldChart->axes();
     QList<QPair<qreal, qreal> > axisRanges;

     for (QAbstractAxis *axis : axisList) {
         QValueAxis *valueAxis = static_cast<QValueAxis *>(axis);
         axisRanges.append(QPair<qreal, qreal>(valueAxis->min(), valueAxis->max()));
     }

     for (QAbstractSeries *series : seriesList)
         oldChart->removeSeries(series);

     for (QAbstractAxis *axis : axisList) {
         oldChart->removeAxis(axis);
         newChart->addAxis(axis, axis->alignment());
     }

     for (QAbstractSeries *series : seriesList) {
         newChart->addSeries(series);
         for (QAbstractAxis *axis : axisList)
             series->attachAxis(axis);
     }

     int count = 0;
     for (QAbstractAxis *axis : axisList) {
         axis->setRange(axisRanges[count].first, axisRanges[count].second);
         count++;
     }

     newChart->setTitle(oldChart->title());
     setChart(newChart);
     delete oldChart;
 }