FlightGearPositionProviderPlugin.cpp

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//
// This file is part of the Marble Virtual Globe.
//
// This program is free software licensed under the GNU LGPL. You can
// find a copy of this license in LICENSE.txt in the top directory of
// the source code.
//
// Copyright 2012 Ralf Habacker <ralf.habacker@freenet.de>
//

#include "FlightGearPositionProviderPlugin.h"

#include "MarbleDebug.h"
#include <math.h>

#include <QUdpSocket>

using namespace Marble;
/* TRANSLATOR Marble::FlightGearPositionProviderPlugin */

using namespace std;

FlightGearPositionProviderPlugin::FlightGearPositionProviderPlugin()
  : m_socket(0), m_speed( 0.0 ), m_track( 0.0 )
{
}

FlightGearPositionProviderPlugin::~FlightGearPositionProviderPlugin()
{
    delete m_socket;
}

QString FlightGearPositionProviderPlugin::name() const
{
    return tr( "FlightGear position provider Plugin" );
}

QString FlightGearPositionProviderPlugin::nameId() const
{
    return QString::fromLatin1( "flightgear" );
}

QString FlightGearPositionProviderPlugin::guiString() const
{
    return tr( "FlightGear" );
}

QString FlightGearPositionProviderPlugin::version() const
{
    return "1.0";
}

QString FlightGearPositionProviderPlugin::description() const
{
    return tr( "Reports the position of running flightgear application." );
}

QString FlightGearPositionProviderPlugin::copyrightYears() const
{
    return "2012";
}

QList<PluginAuthor> FlightGearPositionProviderPlugin::pluginAuthors() const
{
    return QList<PluginAuthor>()
            << PluginAuthor( QString::fromUtf8( "Ralf Habacker" ), "ralf.habacker@freenet.de" );

}

QIcon FlightGearPositionProviderPlugin::icon() const
{
    return QIcon();
}

void FlightGearPositionProviderPlugin::initialize()
{
    m_status = PositionProviderStatusAcquiring;
    emit statusChanged( m_status );

    m_socket = new QUdpSocket(this);
    m_socket->bind(QHostAddress::LocalHost, 5500);

    connect(m_socket, SIGNAL(readyRead()),
             this, SLOT(readPendingDatagrams()));
}

bool fixBadGPRMC(QByteArray &line)
{
    if (!line.startsWith("$GPRMC"))
        return false;

    QStringList parts = QString(line).split(',');
    if (parts[9].size() == 7) {
        parts[9].remove(4,1);
        line = parts.join(",").toLatin1();
        // update crc
        int crc = 0;
        for(int i=1; i < line.size()-3; i++) {
            crc ^= (int) line[i];
        }
        parts[11] = parts[11][0] + parts[11][1] +  QString::number(crc, 16).toUpper();

        line = parts.join(",").toLatin1();
        return true;
    }
    return false;
}

void FlightGearPositionProviderPlugin::readPendingDatagrams()
{
    while (m_socket->hasPendingDatagrams()) {
        QByteArray datagram;
        datagram.resize(m_socket->pendingDatagramSize());
        QHostAddress sender;
        quint16 senderPort;

        m_socket->readDatagram(datagram.data(), datagram.size(), &sender, &senderPort);
        foreach(QByteArray line, datagram.split('\n')) {
            fixBadGPRMC(line);
            //qDebug() << line;
            line.append( "\n" );
            parseNmeaSentence( line );
        }
    }
}

void FlightGearPositionProviderPlugin::parseNmeaSentence( const QString &sentence )
{
    PositionProviderStatus oldStatus = m_status;
    GeoDataCoordinates oldPosition = m_position;

    if ( sentence.startsWith( QLatin1String( "$GPRMC" ) ) ) {
        QStringList const values = sentence.split( ',' );
        if ( values.size() > 9 ) {
            if ( values[2] == "A" ) {
                m_speed = values[7].toDouble() * 0.514444; // knots => m/s
                m_track = values[8].toDouble();
                QString const date = values[9] + ' ' + values[1];
                m_timestamp = QDateTime::fromString( date, "ddMMyy HHmmss" );
                if (m_timestamp.date().year() <= 1930 && m_timestamp.date().year() >= 1900 ) {
                    m_timestamp = m_timestamp.addYears( 100 ); // Qt range is 1900-1999 for two-digits
                }
            }
            // Flightgear submits geoposition twice in one datagram, once
            // in GPRMC and once in GPGGA. Parsing one is sufficient
        }
    } else if ( sentence.startsWith( QLatin1String( "$GPGGA" ) ) ) {
        QStringList const values = sentence.split( ',' );
        if ( values.size() > 10 ) {
            if ( values[6] == 0 ) {
                m_status = PositionProviderStatusUnavailable; // no fix
            } else {
                double const lat = parsePosition( values[2], values[3] == "S" );
                double const lon = parsePosition( values[4], values[5] == "W" );
                double const unitFactor = values[10] == "F" ? FT2M : 1.0;
                double const alt = unitFactor * values[9].toDouble();
                m_position.set( lon, lat, alt, GeoDataCoordinates::Degree );
                m_accuracy.level = GeoDataAccuracy::Detailed;
                m_status = PositionProviderStatusAvailable;
            }
        }
    } else {
        return;
    }

    if ( m_status != oldStatus ) {
        emit statusChanged( m_status );
    }
    if ( m_position != oldPosition && m_status == PositionProviderStatusAvailable ) {
        emit positionChanged( m_position, m_accuracy );
    }
}

double FlightGearPositionProviderPlugin::parsePosition( const QString &value, bool isNegative ) const
{
    double pos = value.toDouble();
    pos = int( pos / 100.0 ) + ( pos - 100.0 * int( pos / 100.0 ) ) / 60.0;
    return isNegative ? -qAbs( pos ) : pos;
}

bool FlightGearPositionProviderPlugin::isInitialized() const
{
    return m_socket;
}

PositionProviderPlugin* FlightGearPositionProviderPlugin::newInstance() const
{
    return new FlightGearPositionProviderPlugin;
}

PositionProviderStatus FlightGearPositionProviderPlugin::status() const
{
    return m_status;
}

GeoDataCoordinates FlightGearPositionProviderPlugin::position() const
{
    return m_position;
}

GeoDataAccuracy FlightGearPositionProviderPlugin::accuracy() const
{
    return m_accuracy;
}

qreal FlightGearPositionProviderPlugin::speed() const
{
    return m_speed;
}

qreal FlightGearPositionProviderPlugin::direction() const
{
    return m_track;
}

QDateTime FlightGearPositionProviderPlugin::timestamp() const
{
    return m_timestamp;
}

QString FlightGearPositionProviderPlugin::error() const
{
    return QString();
}

Q_EXPORT_PLUGIN2( FlightGearPositionProviderPlugin, Marble::FlightGearPositionProviderPlugin )

#include "FlightGearPositionProviderPlugin.moc"