main.cpp Example File | Qt Charts 5.12.9

- Qt 5.12
- Qt Charts
- DateTimeAxis Example
- main.cpp Example File
- Qt Charts | Commercial or GPLv3

# main.cpp Example File

datetimeaxis/main.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
     ** Software or, alternatively, in accordance with the terms contained in
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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
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     ** the Free Software Foundation and appearing in the file LICENSE.GPL3
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     #include <QtWidgets/QApplication>
     #include <QtWidgets/QMainWindow>
     #include <QtCharts/QChartView>
     #include <QtCharts/QLineSeries>
     #include <QtCore/QDateTime>
     #include <QtCharts/QDateTimeAxis>
     #include <QtCore/QFile>
     #include <QtCore/QTextStream>
     #include <QtCore/QDebug>
     #include <QtCharts/QValueAxis>

     QT_CHARTS_USE_NAMESPACE

     int main(int argc, char *argv[])
     {
         QApplication a(argc, argv);

         QLineSeries *series = new QLineSeries();

         // data from http://www.swpc.noaa.gov/ftpdir/weekly/RecentIndices.txt
         // http://www.swpc.noaa.gov/ftpdir/weekly/README
         // http://www.weather.gov/disclaimer
         QFile sunSpots(":sun");
         if (!sunSpots.open(QIODevice::ReadOnly | QIODevice::Text)) {
             return 1;
         }

         QTextStream stream(&sunSpots);
         while (!stream.atEnd()) {
             QString line = stream.readLine();
             if (line.startsWith("#") || line.startsWith(":"))
                 continue;
             QStringList values = line.split(" ", QString::SkipEmptyParts);
             QDateTime momentInTime;
             momentInTime.setDate(QDate(values[0].toInt(), values[1].toInt() , 15));
             series->append(momentInTime.toMSecsSinceEpoch(), values[2].toDouble());
         }
         sunSpots.close();

         QChart *chart = new QChart();
         chart->addSeries(series);
         chart->legend()->hide();
         chart->setTitle("Sunspots count (by Space Weather Prediction Center)");

         QDateTimeAxis *axisX = new QDateTimeAxis;
         axisX->setTickCount(10);
         axisX->setFormat("MMM yyyy");
         axisX->setTitleText("Date");
         chart->addAxis(axisX, Qt::AlignBottom);
         series->attachAxis(axisX);

         QValueAxis *axisY = new QValueAxis;
         axisY->setLabelFormat("%i");
         axisY->setTitleText("Sunspots count");
         chart->addAxis(axisY, Qt::AlignLeft);
         series->attachAxis(axisY);

         QChartView *chartView = new QChartView(chart);
         chartView->setRenderHint(QPainter::Antialiasing);

         QMainWindow window;
         window.setCentralWidget(chartView);
         window.resize(820, 600);
         window.show();

         return a.exec();
     }