sensoritem.cpp Example File

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  #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);
  }