Qt 5.8 | Qt Charts | Dynamic Spline Example | chart.cpp Example File

Qt 5.8.0 Reference Documentation

# chart.cpp Example File

dynamicspline/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
      ** 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 https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** GNU General Public License Usage
      ** 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
      ** included in the packaging of this file. Please review the following
      ** information to ensure the GNU General Public License requirements will
      ** be met: https://www.gnu.org/licenses/gpl-3.0.html.
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #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, SIGNAL(timeout()), this, SLOT(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();
      }