logfilepositionsource.cpp Example File

logfilepositionsource/logfilepositionsource.cpp
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#include <QtCore> #include "logfilepositionsource.h" LogFilePositionSource::LogFilePositionSource(QObject *parent) : QGeoPositionInfoSource(parent), logFile(new QFile(this)), timer(new QTimer(this)) { connect(timer, SIGNAL(timeout()), this, SLOT(readNextPosition())); logFile->setFileName(":/simplelog.txt"); if (!logFile->open(QIODevice::ReadOnly)) qWarning() << "Error: cannot open source file" << logFile->fileName(); } QGeoPositionInfo LogFilePositionSource::lastKnownPosition(bool /*fromSatellitePositioningMethodsOnly*/) const { return lastPosition; } LogFilePositionSource::PositioningMethods LogFilePositionSource::supportedPositioningMethods() const { return AllPositioningMethods; } int LogFilePositionSource::minimumUpdateInterval() const { return 500; } void LogFilePositionSource::startUpdates() { int interval = updateInterval(); if (interval < minimumUpdateInterval()) interval = minimumUpdateInterval(); timer->start(interval); } void LogFilePositionSource::stopUpdates() { timer->stop(); } void LogFilePositionSource::requestUpdate(int /*timeout*/) { // For simplicity, ignore timeout - assume that if data is not available // now, no data will be added to the file later if (logFile->canReadLine()) readNextPosition(); else emit updateTimeout(); } void LogFilePositionSource::readNextPosition() { QByteArray line = logFile->readLine().trimmed(); if (!line.isEmpty()) { QList<QByteArray> data = line.split(' '); double latitude; double longitude; bool hasLatitude = false; bool hasLongitude = false; QDateTime timestamp = QDateTime::fromString(QString(data.value(0)), Qt::ISODate); latitude = data.value(1).toDouble(&hasLatitude); longitude = data.value(2).toDouble(&hasLongitude); if (hasLatitude && hasLongitude && timestamp.isValid()) { QGeoCoordinate coordinate(latitude, longitude); QGeoPositionInfo info(coordinate, timestamp); if (info.isValid()) { lastPosition = info; emit positionUpdated(info); } } } } QGeoPositionInfoSource::Error LogFilePositionSource::error() const { return QGeoPositionInfoSource::NoError; }