chartview.cpp Example File

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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 "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;
  }