xyseriesiodevice.cpp Example File

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  #include "xyseriesiodevice.h"
  #include <QtCharts/QXYSeries>

  XYSeriesIODevice::XYSeriesIODevice(QXYSeries * series, QObject *parent) :
      QIODevice(parent),
      m_series(series)
  {
  }

  qint64 XYSeriesIODevice::readData(char * data, qint64 maxSize)
  {
      Q_UNUSED(data)
      Q_UNUSED(maxSize)
      return -1;
  }

  qint64 XYSeriesIODevice::writeData(const char * data, qint64 maxSize)
  {
      qint64 range = 2000;
      QVector<QPointF> oldPoints = m_series->pointsVector();
      QVector<QPointF> points;
      int resolution = 4;

      if (oldPoints.count() < range) {
          points = m_series->pointsVector();
      } else {
          for (int i = maxSize/resolution; i < oldPoints.count(); i++)
              points.append(QPointF(i - maxSize/resolution, oldPoints.at(i).y()));
      }

      qint64 size = points.count();
      for (int k = 0; k < maxSize/resolution; k++)
          points.append(QPointF(k + size, ((quint8)data[resolution * k] - 128)/128.0));

      m_series->replace(points);
      return maxSize;
  }