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#include "qnmeapositioninfosource_p.h"

#include "qlocationutils_p.h"

#include <QIODevice>

#include <QBasicTimer>

#include <QTimerEvent>

#include <QTimer>

QTM_BEGIN_NAMESPACE

QNmeaRealTimeReader::QNmeaRealTimeReader(QNmeaPositionInfoSourcePrivate *sourcePrivate)

        : QNmeaReader(sourcePrivate)

{

}

void QNmeaRealTimeReader::readAvailableData()

{

    QGeoPositionInfo update;

    bool hasFix = false;

    char buf[1024];

    qint64 size = m_proxy->m_device->readLine(buf, sizeof(buf));

    while (size > 0) {

        if (m_proxy->parsePosInfoFromNmeaData(buf, size, &update, &hasFix))

            m_proxy->notifyNewUpdate(&update, hasFix);

        memset(buf, 0, size);

        size = m_proxy->m_device->readLine(buf, sizeof(buf));

    }

}

//============================================================

QNmeaSimulatedReader::QNmeaSimulatedReader(QNmeaPositionInfoSourcePrivate *sourcePrivate)

        : QNmeaReader(sourcePrivate),

        m_currTimerId(-1),

        m_hasValidDateTime(false)

{

}

QNmeaSimulatedReader::~QNmeaSimulatedReader()

{

    if (m_currTimerId > 0)

        killTimer(m_currTimerId);

}

void QNmeaSimulatedReader::readAvailableData()

{

    if (m_currTimerId > 0)     // we are already reading

        return;

    if (!m_hasValidDateTime) {      // first update

        Q_ASSERT(m_proxy->m_device && (m_proxy->m_device->openMode() & QIODevice::ReadOnly));

        if (!setFirstDateTime()) {

            //m_proxy->notifyReachedEndOfFile();

            qWarning("QNmeaPositionInfoSource: cannot find NMEA sentence with valid date & time");

            return;

        }

        m_hasValidDateTime = true;

        simulatePendingUpdate();

    } else {

        // previously read to EOF, but now new data has arrived

        processNextSentence();

    }

}

bool QNmeaSimulatedReader::setFirstDateTime()

{

    // find the first update with valid date and time

    QGeoPositionInfo update;

    bool hasFix = false;

    while (m_proxy->m_device->bytesAvailable() > 0) {

        char buf[1024];

        qint64 size = m_proxy->m_device->readLine(buf, sizeof(buf));

        if (size <= 0)

            continue;

        bool ok = m_proxy->parsePosInfoFromNmeaData(buf, size, &update, &hasFix);

        if (ok && update.timestamp().isValid()) {

            QPendingGeoPositionInfo pending;

            pending.info = update;

            pending.hasFix = hasFix;

            m_pendingUpdates.enqueue(pending);

            return true;

        }

    }

    return false;

}

void QNmeaSimulatedReader::simulatePendingUpdate()

{

    if (m_pendingUpdates.size() > 0) {

        // will be dequeued in processNextSentence()

        QPendingGeoPositionInfo &pending = m_pendingUpdates.head();

        if (pending.info.coordinate().type() != QGeoCoordinate::InvalidCoordinate)

            m_proxy->notifyNewUpdate(&pending.info, pending.hasFix);

    }

    processNextSentence();

}

void QNmeaSimulatedReader::timerEvent(QTimerEvent *event)

{

    killTimer(event->timerId());

    m_currTimerId = -1;

    simulatePendingUpdate();

}

void QNmeaSimulatedReader::processNextSentence()

{

    QGeoPositionInfo info;

    bool hasFix = false;

    int timeToNextUpdate = -1;

    QTime prevTime;

    if (m_pendingUpdates.size() > 0)

        prevTime = m_pendingUpdates.head().info.timestamp().time();

    // find the next update with a valid time (as long as the time is valid,

    // we can calculate when the update should be emitted)

    while (m_proxy->m_device && m_proxy->m_device->bytesAvailable() > 0) {

        char buf[1024];

        qint64 size = m_proxy->m_device->readLine(buf, sizeof(buf));

        if (size <= 0)

            continue;

        if (m_proxy->parsePosInfoFromNmeaData(buf, size, &info, &hasFix)) {

            QTime time = info.timestamp().time();

            if (time.isValid()) {

                if (!prevTime.isValid()) {

                    timeToNextUpdate = 0;

                    break;

                }

                timeToNextUpdate = prevTime.msecsTo(time);

                if (timeToNextUpdate >= 0)

                    break;

            }

        }

    }

    if (timeToNextUpdate < 0)

        return;

    m_pendingUpdates.dequeue();

    QPendingGeoPositionInfo pending;

    pending.info = info;

    pending.hasFix = hasFix;

    m_pendingUpdates.enqueue(pending);

    m_currTimerId = startTimer(timeToNextUpdate);

}

//============================================================

QNmeaPositionInfoSourcePrivate::QNmeaPositionInfoSourcePrivate(QNmeaPositionInfoSource *parent)

        : QObject(parent),

        m_invokedStart(false),

        m_source(parent),

        m_nmeaReader(0),

        m_updateTimer(0),

        m_requestTimer(0),

        m_noUpdateLastInterval(false),

        m_updateTimeoutSent(false),

        m_connectedReadyRead(false)

{

}

QNmeaPositionInfoSourcePrivate::~QNmeaPositionInfoSourcePrivate()

{

    delete m_nmeaReader;

    delete m_updateTimer;

}

bool QNmeaPositionInfoSourcePrivate::openSourceDevice()

{

    if (!m_device) {

        qWarning("QNmeaPositionInfoSource: no QIODevice data source, call setDevice() first");

        return false;

    }

    if (!m_device->isOpen() && !m_device->open(QIODevice::ReadOnly)) {

        qWarning("QNmeaPositionInfoSource: cannot open QIODevice data source");

        return false;

    }

    connect(m_device, SIGNAL(aboutToClose()), SLOT(sourceDataClosed()));

    connect(m_device, SIGNAL(readChannelFinished()), SLOT(sourceDataClosed()));

    connect(m_device, SIGNAL(destroyed()), SLOT(sourceDataClosed()));

    return true;

}

void QNmeaPositionInfoSourcePrivate::sourceDataClosed()

{

    if (m_nmeaReader && m_device && m_device->bytesAvailable())

        m_nmeaReader->readAvailableData();

}

void QNmeaPositionInfoSourcePrivate::readyRead()

{

    if (m_nmeaReader)

        m_nmeaReader->readAvailableData();

}

bool QNmeaPositionInfoSourcePrivate::initialize()

{

    if (m_nmeaReader)

        return true;

    if (!openSourceDevice())

        return false;

    if (m_updateMode == QNmeaPositionInfoSource::RealTimeMode)

        m_nmeaReader = new QNmeaRealTimeReader(this);

    else

        m_nmeaReader = new QNmeaSimulatedReader(this);

    return true;

}

void QNmeaPositionInfoSourcePrivate::prepareSourceDevice()

{

    // some data may already be available

    if (m_updateMode == QNmeaPositionInfoSource::SimulationMode) {

        if (m_nmeaReader && m_device->bytesAvailable())

            m_nmeaReader->readAvailableData();

    }

    if (!m_connectedReadyRead) {

        connect(m_device, SIGNAL(readyRead()), SLOT(readyRead()));

        m_connectedReadyRead = true;

    }

}

bool QNmeaPositionInfoSourcePrivate::parsePosInfoFromNmeaData(const char *data, int size,

        QGeoPositionInfo *posInfo, bool *hasFix)

{

    return m_source->parsePosInfoFromNmeaData(data, size, posInfo, hasFix);

}

void QNmeaPositionInfoSourcePrivate::startUpdates()

{

    if (m_invokedStart)

        return;

    m_invokedStart = true;

    m_pendingUpdate = QGeoPositionInfo();

    m_noUpdateLastInterval = false;

    bool initialized = initialize();

    if (!initialized)

        return;

    if (m_updateMode == QNmeaPositionInfoSource::RealTimeMode) {

        // skip over any buffered data - we only want the newest data

        if (m_device->bytesAvailable()) {

            if (m_device->isSequential())

                m_device->readAll();

            else

                m_device->seek(m_device->bytesAvailable());

        }

    }

    if (m_updateTimer)

        m_updateTimer->stop();

    if (m_source->updateInterval() > 0) {

        if (!m_updateTimer)

            m_updateTimer = new QBasicTimer;

        m_updateTimer->start(m_source->updateInterval(), this);

    }

    if (initialized)

        prepareSourceDevice();

}

void QNmeaPositionInfoSourcePrivate::stopUpdates()

{

    m_invokedStart = false;

    if (m_updateTimer)

        m_updateTimer->stop();

    m_pendingUpdate = QGeoPositionInfo();

    m_noUpdateLastInterval = false;

}

void QNmeaPositionInfoSourcePrivate::requestUpdate(int msec)

{

    if (m_requestTimer && m_requestTimer->isActive())

        return;

    if (msec <= 0 || msec < m_source->minimumUpdateInterval()) {

        emit m_source->updateTimeout();

        return;

    }

    if (!m_requestTimer) {

        m_requestTimer = new QTimer(this);

        connect(m_requestTimer, SIGNAL(timeout()), SLOT(updateRequestTimeout()));

    }

    bool initialized = initialize();

    if (!initialized) {

        emit m_source->updateTimeout();

        return;

    }

    m_requestTimer->start(msec);

    if (initialized)

        prepareSourceDevice();

}

void QNmeaPositionInfoSourcePrivate::updateRequestTimeout()

{

    m_requestTimer->stop();

    emit m_source->updateTimeout();

}

void QNmeaPositionInfoSourcePrivate::notifyNewUpdate(QGeoPositionInfo *update, bool hasFix)

{

    // include <QDebug> before uncommenting

    //qDebug() << "QNmeaPositionInfoSourcePrivate::notifyNewUpdate()" << update->timestamp() << hasFix << m_invokedStart << (m_requestTimer && m_requestTimer->isActive());

    QDate date = update->timestamp().date();

    if (date.isValid()) {

        m_currentDate = date;

    } else {

        // some sentence have time but no date

        QTime time = update->timestamp().time();

        if (time.isValid() && m_currentDate.isValid())

            update->setTimestamp(QDateTime(m_currentDate, time, Qt::UTC));

    }

    if (hasFix && update->isValid()) {

        if (m_requestTimer && m_requestTimer->isActive()) {

            m_requestTimer->stop();

            emitUpdated(*update);

        } else if (m_invokedStart) {

            if (m_updateTimer && m_updateTimer->isActive()) {

                // for periodic updates, only want the most recent update

                m_pendingUpdate = *update;

                if (m_noUpdateLastInterval) {

                    emitPendingUpdate();

                    m_noUpdateLastInterval = false;

                }

            } else {

                emitUpdated(*update);

            }

        }

        m_lastUpdate = *update;

    }

}

void QNmeaPositionInfoSourcePrivate::timerEvent(QTimerEvent *)

{

    emitPendingUpdate();

}

void QNmeaPositionInfoSourcePrivate::emitPendingUpdate()

{

    if (m_pendingUpdate.isValid()) {

        m_updateTimeoutSent = false;

        m_noUpdateLastInterval = false;

        emitUpdated(m_pendingUpdate);

        m_pendingUpdate = QGeoPositionInfo();

    } else {

        if (m_noUpdateLastInterval && !m_updateTimeoutSent) {

            m_updateTimeoutSent = true;

            m_pendingUpdate = QGeoPositionInfo();

            emit m_source->updateTimeout();

        }

        m_noUpdateLastInterval = true;

    }

}

void QNmeaPositionInfoSourcePrivate::emitUpdated(const QGeoPositionInfo &update)

{

    m_lastUpdate = update;

    emit m_source->positionUpdated(update);

}

//=========================================================

/*!

    \class QNmeaPositionInfoSource

    \brief The QNmeaPositionInfoSource class provides positional information using a NMEA data source.

    \ingroup location

    NMEA is a commonly used protocol for the specification of one's global

    position at a certain point in time. The QNmeaPositionInfoSource class reads NMEA

    data and uses it to provide positional data in the form of

    QGeoPositionInfo objects.

    A QNmeaPositionInfoSource instance operates in either \l {RealTimeMode} or

    \l {SimulationMode}. These modes allow NMEA data to be read from either a

    live source of positional data, or replayed for simulation purposes from

    previously recorded NMEA data.

    The source of NMEA data is set with setDevice().

    Use startUpdates() to start receiving regular position updates and stopUpdates() to stop these

    updates.  If you only require updates occasionally, you can call requestUpdate() to request a

    single update.

    In both cases the position information is received via the positionUpdated() signal and the

    last known position can be accessed with lastKnownPosition().

*/

/*!

    \enum QNmeaPositionInfoSource::UpdateMode

    Defines the available update modes.

    \value RealTimeMode Positional data is read and distributed from the data source as it becomes available. Use this mode if you are using a live source of positional data (for example, a GPS hardware device).

    \value SimulationMode The data and time information in the NMEA source data is used to provide positional updates at the rate at which the data was originally recorded. Use this mode if the data source contains previously recorded NMEA data and you want to replay the data for simulation purposes.

*/

/*!

    Constructs a QNmeaPositionInfoSource instance with the given \a parent

    and \a updateMode.

*/

QNmeaPositionInfoSource::QNmeaPositionInfoSource(UpdateMode updateMode, QObject *parent)

        : QGeoPositionInfoSource(parent),

        d(new QNmeaPositionInfoSourcePrivate(this))

{

    d->m_updateMode = updateMode;

    d->m_device = 0;

}

/*!

    Destroys the position source.

*/

QNmeaPositionInfoSource::~QNmeaPositionInfoSource()

{

    delete d;

}

/*!

    Parses an NMEA sentence string into a QGeoPositionInfo.

    The default implementation will parse standard NMEA sentences.

    This method should be reimplemented in a subclass whenever the need to deal with non-standard

    NMEA sentences arises.

    The parser reads \a size bytes from \a data and uses that information to setup \a posInfo and

    \a hasFix.  If \a hasFix is set to false then \a posInfo may contain only the time or the date

    and the time.

    Returns true if the sentence was succsesfully parsed, otherwise returns false and should not

    modifiy \a posInfo or \a hasFix.

*/

bool QNmeaPositionInfoSource::parsePosInfoFromNmeaData(const char *data, int size,

        QGeoPositionInfo *posInfo, bool *hasFix)

{

    return QLocationUtils::getPosInfoFromNmea(data, size, posInfo, hasFix);

}

/*!

    Returns the update mode.

*/

QNmeaPositionInfoSource::UpdateMode QNmeaPositionInfoSource::updateMode() const

{

    return d->m_updateMode;

}

/*!

    Sets the NMEA data source to \a device. If the device is not open, it

    will be opened in QIODevice::ReadOnly mode.

    The source device can only be set once and must be set before calling

    startUpdates() or requestUpdate().

    \bold {Note:} The \a device must emit QIODevice::readyRead() for the

    source to be notified when data is available for reading.

*/

void QNmeaPositionInfoSource::setDevice(QIODevice *device)

{

    if (device != d->m_device) {

        if (!d->m_device)

            d->m_device = device;

        else

            qWarning("QNmeaPositionInfoSource: source device has already been set");

    }

}