chartview.cpp Example File

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  ** Contact: https://www.qt.io/licensing/
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  ** This file is part of the Qt Charts module of the Qt Toolkit.
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  #include "chartview.h"
  #include <QtGui/QMouseEvent>

  ChartView::ChartView(QChart *chart, QWidget *parent) :
      QChartView(chart, parent),
      m_isTouching(false)
  {
      setRubberBand(QChartView::RectangleRubberBand);
  }

  bool ChartView::viewportEvent(QEvent *event)
  {
      if (event->type() == QEvent::TouchBegin) {
          // By default touch events are converted to mouse events. So
          // after this event we will get a mouse event also but we want
          // to handle touch events as gestures only. So we need this safeguard
          // to block mouse events that are actually generated from touch.
          m_isTouching = true;

          // Turn off animations when handling gestures they
          // will only slow us down.
          chart()->setAnimationOptions(QChart::NoAnimation);
      }
      return QChartView::viewportEvent(event);
  }

  void ChartView::mousePressEvent(QMouseEvent *event)
  {
      if (m_isTouching)
          return;
      QChartView::mousePressEvent(event);
  }

  void ChartView::mouseMoveEvent(QMouseEvent *event)
  {
      if (m_isTouching)
          return;
      QChartView::mouseMoveEvent(event);
  }

  void ChartView::mouseReleaseEvent(QMouseEvent *event)
  {
      if (m_isTouching)
          m_isTouching = false;

      // Because we disabled animations when touch event was detected
      // we must put them back on.
      chart()->setAnimationOptions(QChart::SeriesAnimations);

      QChartView::mouseReleaseEvent(event);
  }

  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(-10, 0);
          break;
      case Qt::Key_Right:
          chart()->scroll(10, 0);
          break;
      case Qt::Key_Up:
          chart()->scroll(0, 10);
          break;
      case Qt::Key_Down:
          chart()->scroll(0, -10);
          break;
      default:
          QGraphicsView::keyPressEvent(event);
          break;
      }
  }