Qt 5.7 | Qt Charts | Polar Chart Example | chartview.cpp Example File

Qt 5.7.1 Reference Documentation

# chartview.cpp Example File

polarchart/chartview.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
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      ** 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
          QList<QAbstractSeries *> seriesList = oldChart->series();
          QList<QAbstractAxis *> axisList = oldChart->axes();
          QList<QPair<qreal, qreal> > axisRanges;

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

          foreach (QAbstractSeries *series, seriesList)
              oldChart->removeSeries(series);

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

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

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

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