datasource.cpp Example File

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#include "datasource.h" #include <QtCharts/QXYSeries> #include <QtCharts/QAreaSeries> #include <QtQuick/QQuickView> #include <QtQuick/QQuickItem> #include <QtCore/QDebug> #include <QtCore/QRandomGenerator> #include <QtCore/QtMath> QT_CHARTS_USE_NAMESPACE Q_DECLARE_METATYPE(QAbstractSeries *) Q_DECLARE_METATYPE(QAbstractAxis *) DataSource::DataSource(QQuickView *appViewer, QObject *parent) : QObject(parent), m_appViewer(appViewer), m_index(-1) { qRegisterMetaType<QAbstractSeries*>(); qRegisterMetaType<QAbstractAxis*>(); generateData(0, 5, 1024); } void DataSource::update(QAbstractSeries *series) { if (series) { QXYSeries *xySeries = static_cast<QXYSeries *>(series); m_index++; if (m_index > m_data.count() - 1) m_index = 0; QVector<QPointF> points =; // Use replace instead of clear + append, it's optimized for performance xySeries->replace(points); } } void DataSource::generateData(int type, int rowCount, int colCount) { // Remove previous data m_data.clear(); // Append the new data depending on the type for (int i(0); i < rowCount; i++) { QVector<QPointF> points; points.reserve(colCount); for (int j(0); j < colCount; j++) { qreal x(0); qreal y(0); switch (type) { case 0: // data with sin + random component y = qSin(M_PI / 50 * j) + 0.5 + QRandomGenerator::global()->generateDouble(); x = j; break; case 1: // linear data x = j; y = (qreal) i / 10; break; default: // unknown, do nothing break; } points.append(QPointF(x, y)); } m_data.append(points); } }

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