sensoritem.cpp Example File

sensor_explorer/import/sensoritem.cpp
/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtSensors module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "sensoritem.h"
#include <QtCore/QDebug>
#include <QtSensors>

/*
    \class QSensorItem
    \brief The QSensorItem type provides information about the metadata from a sensors installed on the system.
*/

/*
    Construct a QSensorItem object with parent \a parent
*/
QSensorItem::QSensorItem(QObject* parent)
    : QObject(parent)
    , _qsensor(0)
{
}

/*
    Construct a QSensorItem object with QSensor \a sensor and parent \a parent
*/
QSensorItem::QSensorItem(QSensor* sensor, QObject* parent)
    : QObject(parent)
    , _qsensor(sensor)
{
}

/*
    Destructor of a QSensorItem
*/
QSensorItem::~QSensorItem()
{
}

/*
    \fn QSensorItem::startChanged()
    Notifies the client if the sensors has changed its start active status
*/

/*
    \property QSensorItem::start
    This property starts or stops the sensor
*/
bool QSensorItem::start()
{
    return (_qsensor ? _qsensor->isActive() : false);
}

void QSensorItem::setStart(bool run)
{
    if (_qsensor)
        _qsensor->setActive(run);
}

/*
    \property QSensorItem::id
    Returns the sensor id of the sensor item
*/
QString QSensorItem::id()
{
    return (_qsensor ? _qsensor->identifier() : "");
}

/*
    Set the new value \a val to the QPropertyInfo object \a property
*/
void QSensorItem::changePropertyValue(QPropertyInfo* property, const QString& val)
{
    if (_qsensor && _sensorProperties.contains(property)){
        if ( _qsensor->setProperty(property->name().toLatin1().constData(), QVariant(val)))
            updateSensorPropertyValues();
        else
            qWarning() << "new property value couldn't be set";
    }
}

/*
    Reading the metadata and activates the sensor.
*/
void QSensorItem::select()
{
    if (_sensorProperties.isEmpty()) {
        // Probe the reading using Qt's meta-object facilities
        //Read properties from reader
        QSensorReading *reading = _qsensor->reading();
        const QMetaObject *mo = reading->metaObject();
        int firstProperty = QSensorReading::staticMetaObject.propertyOffset();

        for (int i = firstProperty; i < mo->propertyCount(); ++i) {
            QString typeName = QLatin1String(mo->property(i).typeName());
            int crap = typeName.lastIndexOf("::");
            if (crap != -1)
                typeName = typeName.mid(crap + 2);

            QPropertyInfo* pi = new QPropertyInfo(mo->property(i).name()
                                                  , i
                                                  , isWriteable(mo->property(i).name())
                                                  , typeName
                                                  , "-"
                                                  , this);
            _readerProperties.append(pi);
        }

        //Read properties from sensor
        const QMetaObject *mo1 = _qsensor->metaObject();
        firstProperty = QSensorReading::staticMetaObject.propertyOffset();

        for (int i = firstProperty; i < mo1->propertyCount(); ++i) {
            QString propertyname = mo1->property(i).name();
            if (ignoreProperty(propertyname))
                continue;

            QString typeName = QLatin1String(mo1->property(i).typeName());
            int crap = typeName.lastIndexOf("::");
            if (crap != -1)
                typeName = typeName.mid(crap + 2);

            QPropertyInfo* pi = new QPropertyInfo(propertyname
                                                  , i
                                                  , isWriteable(propertyname)
                                                  , typeName
                                                  , "-"
                                                  , this);
            _sensorProperties.append(pi);
        }
        updateSensorPropertyValues();
        connect(_qsensor, SIGNAL(readingChanged()), this, SLOT(sensorReadingChanged()));
    }
    connect(_qsensor, SIGNAL(activeChanged()), SIGNAL(startChanged()));
}

/*
    Unselect the sensor by stopping the sensor.
*/
void QSensorItem::unSelect()
{
    _qsensor->stop();
    disconnect(_qsensor, SIGNAL(activeChanged()), this , SIGNAL(startChanged()));
}

/*
    Updates the property values from QSensor
*/
void QSensorItem::updateSensorPropertyValues()
{
    if (_qsensor){
        const QMetaObject *mo = _qsensor->metaObject();
        for (int i = 0; i < _sensorProperties.count(); i++){
            QVariant val = mo->property(_sensorProperties[i]->index()).read(_qsensor);
            _sensorProperties[i]->setValue(convertValue(_sensorProperties[i]->typeName(), val));
        }
    }
}

/*
    \fn QSensorItem::propertiesChanged()
    Notifies the client if the list of the properties was changed
*/

/*
    Updates the property values from the QSensorReader
*/
void QSensorItem::sensorReadingChanged()
{
    QSensorReading *reading = _qsensor->reading();
    const QMetaObject *mo = reading->metaObject();
    for (int i = 0; i < _readerProperties.count(); i++){
        QVariant val = mo->property(_readerProperties[i]->index()).read(reading);
        _readerProperties[i]->setValue(convertValue(_readerProperties[i]->typeName(), val));
    }
}

/*
    Returns true if the property with the name \a propertyname should be ignored
*/
bool QSensorItem::ignoreProperty(const QString& propertyname)
{
    if (propertyname == "reading" ||
        propertyname == "active" ||
        propertyname == "identifier" ||
        propertyname == "connectedToBackend" ||
        propertyname == "busy")
        return true;

    return false;
}

/*
    Returns true if the property with the name \a propertyname is writeable
*/
bool QSensorItem::isWriteable(const QString& propertyname)
{
    if (_qsensor){
        const QMetaObject *mo = _qsensor->metaObject();
        int propertyindex = mo->indexOfProperty(propertyname.toLocal8Bit().constData());
        if (propertyindex >= 0){
            QMetaProperty prop = mo->property(propertyindex);
            return prop.isWritable();
        }
        else {
            QSensorReading *reading = _qsensor->reading();
            const QMetaObject *moreader = reading->metaObject();
            propertyindex = moreader->indexOfProperty(propertyname.toLocal8Bit().constData());
            if (propertyindex >= 0){
                QMetaProperty prop = mo->property(propertyindex);
                return prop.isWritable();
            }
        }
    }

    return false;
}

/*
    Convert the variant \a val dependent on the type \a type and returns the converted value as a QString
*/
QString QSensorItem::convertValue(const QString& type, const QVariant& val)
{
    if (type == "LightLevel"){
        switch (val.toInt()) {
            case 1: return "Dark";
            case 2: return "Twilight";
            case 3: return "Light";
            case 4: return "Bright";
            case 5: return "Sunny";
            default: return "Undefined";
        }
    }
    else if (type == "Orientation"){
        switch (val.toInt()) {
            case 1: return "TopUp";
            case 2: return "TopDown";
            case 3: return "LeftUp";
            case 4: return "RightUp";
            case 5: return "FaceUp";
            case 6: return "FaceDown";
            default: return "Undefined";
        }
    }
    else if (type == "qrangelist"){
        qrangelist rangelist = val.value<qrangelist>();
        QStringList ranges;
        foreach (const qrange &r, rangelist) {
            if (r.first == r.second)
                ranges << QString("%1 Hz").arg(r.first);
            else
                ranges << QString("%1-%2 Hz").arg(r.first).arg(r.second);
        }
        if (ranges.count() > 0)
            return ranges.join(", ");
        return "-";
    }
    else if (type == "qoutputrangelist") {
        qoutputrangelist rangelist = val.value<qoutputrangelist>();
        QStringList ranges;
        foreach (const qoutputrange &r, rangelist) {
            ranges << QString("(%1, %2) += %3").arg(r.minimum).arg(r.maximum).arg(r.accuracy);
        }
        if (ranges.count() > 0)
            return ranges.join(", ");
        return "-";
    }

    return val.toString();
}

/*
    \property QSensorItem::properties
    Returns a list of all properties from the sensor
*/
QQmlListProperty<QPropertyInfo> QSensorItem::properties()
{
    _properties.clear();
    _properties.append(_sensorProperties);
    _properties.append(_readerProperties);
    return QQmlListProperty<QPropertyInfo> (this, _properties);
}

© 2015 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.