path: root/src/imports/location/qdeclarativepositionsource.cpp

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#include <QtDeclarative/qdeclarativeinfo.h>
#include "qdeclarativepositionsource_p.h"
#include "qdeclarativeposition_p.h"
#include "qdeclarative.h"
#include <qnmeapositioninfosource.h>
#include <QFile>
#include <QTimer>

QT_BEGIN_NAMESPACE

/*!
    \qmlclass PositionSource QDeclarativePositionSource
    \inqmlmodule QtLocation 5
    \ingroup qml-QtLocation5-positioning
    \since QtLocation 5.0

    \brief The PositionSource element allows you to get information about your
    current position.

    The PositionSource element allows you to get information about your current position.
    You can receive information about things such as latitude, longitude, altitude, and
    speed.

    Support for location sources are platform dependant. When declaring a PositionSource element, a
    default PositionSource source shall be created. Supported positioning methods are held in
    \l positioningMethod. As a development convenience, one may also set data file as a source (NMEA format).
    Location updates are not necessarily started automatically upon element declaration, see \l start \l stop \l active
    and \l update.

    Here is very simple example QML to illustrate the usage:

    \snippet doc/src/snippets/declarative/declarative-location.qml 0

    \sa {QGeoPositionInfoSource}, {QGeoPositionInfo}, {QNmeaPositionInfoSource}, {QGeoCoordinate}

*/

QDeclarativePositionSource::QDeclarativePositionSource()
    : m_positionSource(0), m_positioningMethod(QDeclarativePositionSource::NoPositioningMethod),
      m_nmeaFile(0), m_active(false), m_singleUpdate(false), m_updateInterval(0)
{
    m_positionSource = QGeoPositionInfoSource::createDefaultSource(this);
    if (m_positionSource) {
        connect(m_positionSource, SIGNAL(positionUpdated(QGeoPositionInfo)),
                this, SLOT(positionUpdateReceived(QGeoPositionInfo)));
        m_positioningMethod = positioningMethod();
    }
#ifdef QDECLARATIVE_POSITION_DEBUG
    if (m_positionSource)
        qDebug("QDeclarativePositionSource QGeoPositionInfoSource::createDefaultSource SUCCESS");
    else
        qDebug("QDeclarativePositionSource QGeoPositionInfoSource::createDefaultSource FAILURE");
#endif
}

QDeclarativePositionSource::~QDeclarativePositionSource()
{
    delete m_nmeaFile;
    delete m_positionSource;
}

void QDeclarativePositionSource::setNmeaSource(const QUrl& nmeaSource)
{
    // Strip the filename. This is clumsy but the file may be prefixed in several
    // ways: "file:///", "qrc:///", "/", "" in platform dependant manner.
    QString localFileName = nmeaSource.toString();
    if (!QFile::exists(localFileName)) {
        if (localFileName.startsWith("qrc:///")) {
            localFileName.remove(0, 7);
        } else if (localFileName.startsWith("file:///")) {
            localFileName.remove(0, 7);
        }
        if (!QFile::exists(localFileName) && localFileName.startsWith("/")) {
            localFileName.remove(0,1);
        }
    }
    if (m_nmeaFileName == localFileName)
        return;
    m_nmeaFileName = localFileName;
    m_nmeaSource = nmeaSource;
    // The current position source needs to be deleted
    // because QNmeaPositionInfoSource can be bound only to a one file.
    if (m_positionSource) {
        delete m_positionSource;
        m_positionSource = 0;
    }
    // Create the NMEA source based on the given data. QML has automatically set QUrl
    // type to point to correct path. If the file is not found, check if the file actually
    // was an embedded resource file.
    delete m_nmeaFile;
    m_nmeaFile = new QFile(localFileName);
    if (!m_nmeaFile->exists()) {
        localFileName.prepend(":");
        m_nmeaFile->setFileName(localFileName);
    }
    if (m_nmeaFile->exists()) {
#ifdef QDECLARATIVE_POSITION_DEBUG
        qDebug() << "QDeclarativePositionSource NMEA File was found: " << localFileName;
#endif
        m_positionSource = new QNmeaPositionInfoSource(QNmeaPositionInfoSource::SimulationMode);
        (qobject_cast<QNmeaPositionInfoSource*>(m_positionSource))->setDevice(m_nmeaFile);
        connect(m_positionSource, SIGNAL(positionUpdated(QGeoPositionInfo)),
                this, SLOT(positionUpdateReceived(QGeoPositionInfo)));
        if (m_active && !m_singleUpdate) {
            // Keep on updating even though source changed
            QTimer::singleShot(0, this, SLOT(start()));
        }
    } else {
        qmlInfo(this) << tr("Nmea file not found.") << localFileName;
#ifdef QDECLARATIVE_POSITION_DEBUG
        qDebug() << "QDeclarativePositionSource NMEA File was not found: " << localFileName;
#endif
        if (m_active) {
            m_active = false;
            m_singleUpdate = false;
            emit activeChanged();
        }
    }
    if (m_positioningMethod != positioningMethod()) {
        m_positioningMethod = positioningMethod();
        emit positioningMethodChanged();
    }
    emit this->nmeaSourceChanged();
}

void QDeclarativePositionSource::setUpdateInterval(int updateInterval)
{
    if (m_updateInterval == updateInterval)
        return;

    m_updateInterval = updateInterval;
    if (m_positionSource) {
        m_positionSource->setUpdateInterval(updateInterval);
    }
    emit updateIntervalChanged();
}

/*!
    \qmlproperty url PositionSource::nmeaSource

    This property holds the source for NMEA data (file). One purpose of this
    property is to be of development convenience.

    Setting this property will override any other position source. Currently only
    files local to the .qml -file are supported. Nmea source is created in simulation mode,
    meaning that 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.

    If nmeaSource has been set for a PositionSource element, there is no way to revert
    back to non-file sources.
*/

QUrl QDeclarativePositionSource::nmeaSource() const
{
    return m_nmeaSource;
}

/*!
    \qmlproperty bool PositionSource::updateInterval

    This property holds the desired interval between updates (milliseconds).

    \sa {QGeoPositionInfoSource::updateInterval()}

*/

int QDeclarativePositionSource::updateInterval() const
{
    return m_updateInterval;
}

/*!
    \qmlproperty enumeration PositionSource::positioningMethod

    This property holds the supported positioning methods of the
    current source.

    \list
    \o NoPositioningMethod - No positioning methods supported (no source).
    \o SatellitePositioningMethod - Satellite-based positioning methods such as GPS is supported.
    \o NonSatellitePositioningMethod - Non satellite methods are supported.
    \o AllPositioningMethods - Combination of methods are supported.
    \endlist

*/

QDeclarativePositionSource::PositioningMethod QDeclarativePositionSource::positioningMethod() const
{
    if (m_positionSource) {
        QGeoPositionInfoSource::PositioningMethods methods = m_positionSource->supportedPositioningMethods();
        if (methods & QGeoPositionInfoSource::SatellitePositioningMethods) {
            //qDebug() << "Returning satellite: " << QDeclarativePositionSource::SatellitePositioningMethod;
            return QDeclarativePositionSource::SatellitePositioningMethod;
        } else if (methods & QGeoPositionInfoSource::NonSatellitePositioningMethods) {
            //qDebug() << "Returning non-satellite: " << QDeclarativePositionSource::NonSatellitePositioningMethod;
            return QDeclarativePositionSource::NonSatellitePositioningMethod;
        } else if (methods & QGeoPositionInfoSource::AllPositioningMethods) {
            //qDebug() << "Returning all: " << QDeclarativePositionSource::AllPositioningMethods;
            return QDeclarativePositionSource::AllPositioningMethods;
        }
    }
    //qDebug() << "Returning no-positioning: " << QDeclarativePositionSource::NoPositioningMethod;
    return QDeclarativePositionSource::NoPositioningMethod;
}

/*!
    \qmlmethod PositionSource::start()

    Requests updates from the location source.
    Uses \l updateInterval if set, default interval otherwise.
    If there is no source available, this method has no effect.

    \sa stop, update, active
*/

void QDeclarativePositionSource::start()
{
    if (m_positionSource) {
        // Safe to set, setting zero means using default value
        m_positionSource->setUpdateInterval(m_updateInterval);
        m_positionSource->startUpdates();
        if (!m_active) {
            m_active = true;
            emit activeChanged();
        }
    }
}

/*!
    \qmlmethod PositionSource::update()

    A convenience method to request single update from the location source.
    If there is no source available, this method has no effect.

    \sa start, stop, active
*/

void QDeclarativePositionSource::update()
{
    if (m_positionSource) {
        if (!m_active) {
            m_active = true;
            m_singleUpdate = true;
            emit activeChanged();
        }
        // Use default timeout value. Set active before calling the
        // update request because on some platforms there may
        // be results immediately.
        m_positionSource->requestUpdate();
    }
}

/*!
    \qmlmethod PositionSource::stop()

    Stops updates from the location source.
    If there is no source available or it is not active,
    this method has no effect.

    \sa start, update, active
*/

void QDeclarativePositionSource::stop()
{
    if (m_positionSource) {
        m_positionSource->stopUpdates();
        if (m_active) {
            m_active = false;
            emit activeChanged();
        }
    }
}

/*!
    \qmlsignal PositionSource::positionChanged()

    This signal is sent when a position update has been received
    from the location source. Upon receiving this signal, at least
    position::latitude, position::longitude, and position::timestamp
    members of the \l position have been updated.

    \sa updateInterval

*/

/*!
    \qmlproperty bool PositionSource::active

    This property indicates whether the position source is (/should be)
    active. Setting this property to false equals calling \l stop, and
    setting this property true equals calling \l start.

    \sa start, stop, update

*/

void QDeclarativePositionSource::setActive(bool active)
{
    if (active == m_active)
        return;

    if (active)
        QTimer::singleShot(0, this, SLOT(start())); // delay ensures all properties have been set
    else
        stop();
}

bool QDeclarativePositionSource::isActive() const
{
    return m_active;
}

/*!
    \qmlproperty Position PositionSource::position

    This property holds the last known positional data.

    The Position element has different positional member variables,
    whose validity can be checked with appropriate validity functions
    (e.g. sometimes an update does not have speed or altitude data).

    However, whenever a \l positionChanged signal has been received, at least
    position::coordinate::latitude, position::coordinate::longitude, and position::timestamp can
    be assumed to be valid.

    \sa start, stop, update

*/

QDeclarativePosition* QDeclarativePositionSource::position()
{
    return &m_position;
}

void QDeclarativePositionSource::positionUpdateReceived(const QGeoPositionInfo& update)
{
    if (update.isValid()) {
        m_position.setTimestamp(update.timestamp());
        m_position.setCoordinate(update.coordinate());
        if (update.hasAttribute(QGeoPositionInfo::GroundSpeed)) {
            m_position.setSpeed(update.attribute(QGeoPositionInfo::GroundSpeed));
        }
        if (update.hasAttribute(QGeoPositionInfo::HorizontalAccuracy)) {
            m_position.setHorizontalAccuracy(update.attribute(QGeoPositionInfo::HorizontalAccuracy));
        }
        if (update.hasAttribute(QGeoPositionInfo::VerticalAccuracy)) {
            m_position.setVerticalAccuracy(update.attribute(QGeoPositionInfo::VerticalAccuracy));
        }
        emit positionChanged();
    } else {
        m_position.invalidate();
    }
    if (m_singleUpdate && m_active) {
        m_active = false;
        m_singleUpdate = false;
        emit activeChanged();
    }
}

#include "moc_qdeclarativepositionsource_p.cpp"

QT_END_NAMESPACE