Qt 5.9 | Qt Charts | Dynamic Spline Example | chart.cpp Example File

Qt 5.9.3 Reference Documentation

# chart.cpp Example File

dynamicspline/chart.cpp

      /****************************************************************************
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      ** 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.
      **
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      #include "chart.h"
      #include <QtCharts/QAbstractAxis>
      #include <QtCharts/QSplineSeries>
      #include <QtCharts/QValueAxis>
      #include <QtCore/QTime>
      #include <QtCore/QDebug>

      Chart::Chart(QGraphicsItem *parent, Qt::WindowFlags wFlags):
          QChart(QChart::ChartTypeCartesian, parent, wFlags),
          m_series(0),
          m_axis(new QValueAxis),
          m_step(0),
          m_x(5),
          m_y(1)
      {
          qsrand((uint) QTime::currentTime().msec());

          QObject::connect(&m_timer, &QTimer::timeout, this, &Chart::handleTimeout);
          m_timer.setInterval(1000);

          m_series = new QSplineSeries(this);
          QPen green(Qt::red);
          green.setWidth(3);
          m_series->setPen(green);
          m_series->append(m_x, m_y);

          addSeries(m_series);
          createDefaultAxes();
          setAxisX(m_axis, m_series);
          m_axis->setTickCount(5);
          axisX()->setRange(0, 10);
          axisY()->setRange(-5, 10);

          m_timer.start();
      }

      Chart::~Chart()
      {

      }

      void Chart::handleTimeout()
      {
          qreal x = plotArea().width() / m_axis->tickCount();
          qreal y = (m_axis->max() - m_axis->min()) / m_axis->tickCount();
          m_x += y;
          m_y = qrand() % 5 - 2.5;
          m_series->append(m_x, m_y);
          scroll(x, 0);
          if (m_x == 100)
              m_timer.stop();
      }