Qt Mobility Reference Documentation

QSensorReading Class Reference

The QSensorReading class holds the readings from the sensor. More...

 #include <QSensorReading>

Inherited by QAccelerometerReading, QAmbientLightReading, QCompassReading, QMagnetometerReading, QOrientationReading, QProximityReading, QRotationReading, and QTapReading.


Properties


Public Functions

void setTimestamp ( qtimestamp timestamp )
qtimestamp timestamp () const
QVariant value ( int index ) const
int valueCount () const

Macros

DECLARE_READING ( classname )
IMPLEMENT_READING ( classname )

Detailed Description

The QSensorReading class holds the readings from the sensor.

Note that QSensorReading is not particularly useful by itself. The interesting data for each sensor is defined in a sub-class of QSensorReading.


Property Documentation

timestamp : const QtMobility::qtimestamp

This property holds the timestamp of the reading.

Access functions:

qtimestamp timestamp () const

See also qtimestamp.


Member Function Documentation

void QSensorReading::setTimestamp ( qtimestamp timestamp )

Sets the timestamp of the reading.

See also timestamp().

QVariant QSensorReading::value ( int index ) const

Returns the value of the property at index.

Note that this function is slower than calling the data function directly.

Here is an example of getting a property via the different mechanisms available.

Accessing directly provides the best performance but requires compile-time knowledge of the data you are accessing.

 QAccelerometerReading *reading = ...;
 qreal x = reading->x();

You can also access a property by name. To do this you must call QObject::property().

 qreal x = reading->property("x").value<qreal>();

Finally, you can access values via numeric index.

 qreal x = reading->value(0).value<qreal>();

Note that value() can only access properties declared with Q_PROPERTY() in sub-classes of QSensorReading.

See also valueCount() and QObject::property().

int QSensorReading::valueCount () const

Returns the number of extra properties that the reading has.

Note that this does not count properties declared in QSensorReading.

As an example, this returns 3 for QAccelerometerReading because there are 3 properties defined in that class.


Macro Documentation

DECLARE_READING ( classname )

The DECLARE_READING macro adds some required methods to a reading class.

This macro should be used for all reading classes. Pass the classname of your reading class.

 class MyReading : public QSensorReading
 {
     Q_OBJECT
     Q_PROPERTY(qreal myprop READ myprop)
     DECLARE_READING(MyReading)
 public:
     qreal myprop() const;
     vod setMyprop(qreal myprop);
 };

See also IMPLEMENT_READING().

IMPLEMENT_READING ( classname )

The IMPLEMENT_READING macro implements the required methods for a reading class.

This macro should be used for all reading classes. It should be placed into a single compilation unit (source file), not into a header file. Pass the classname of your reading class.

 IMPLEMENT_READING(MyReading)

See also DECLARE_READING().


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Qt Mobility Project 1.1.0