chart.cpp Example File

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  #include "chart.h"
  #include <QtWidgets/QGesture>
  #include <QtWidgets/QGraphicsScene>
  #include <QtWidgets/QGraphicsView>

  Chart::Chart(QGraphicsItem *parent, Qt::WindowFlags wFlags)
      : QChart(QChart::ChartTypeCartesian, parent, wFlags)
  {
      // Seems that QGraphicsView (QChartView) does not grab gestures.
      // They can only be grabbed here in the QGraphicsWidget (QChart).
      grabGesture(Qt::PanGesture);
      grabGesture(Qt::PinchGesture);
  }

  Chart::~Chart()
  {

  }

  bool Chart::sceneEvent(QEvent *event)
  {
      if (event->type() == QEvent::Gesture)
          return gestureEvent(static_cast<QGestureEvent *>(event));
      return QChart::event(event);
  }

  bool Chart::gestureEvent(QGestureEvent *event)
  {
      if (QGesture *gesture = event->gesture(Qt::PanGesture)) {
          QPanGesture *pan = static_cast<QPanGesture *>(gesture);
          QChart::scroll(-(pan->delta().x()), pan->delta().y());
      }

      if (QGesture *gesture = event->gesture(Qt::PinchGesture)) {
          QPinchGesture *pinch = static_cast<QPinchGesture *>(gesture);
          if (pinch->changeFlags() & QPinchGesture::ScaleFactorChanged)
              QChart::zoom(pinch->scaleFactor());
      }

      return true;
  }