Class RatatoskDoubleValSubscriber

Inheritance Relationships

Base Type

  • public QObject

Class Documentation

class RatatoskDoubleValSubscriber : public QObject

Subscriber for DDS type Double as a QML element.

This class is a QML element and enables QML applications to gain access to a DDS signal type as a read-only QML property.

Public Functions

explicit RatatoskDoubleValSubscriber(QObject *parent = nullptr)


The initialization is deferred to an init() function.


parent[in] QObject pointer.

virtual ~RatatoskDoubleValSubscriber()


double val() const

Property accessor for double value in QML.


Real value as double.

QDateTime timestamp() const

Property accessor for timestamp in QML.


Timestamp as QML QDateTime.

void init(QtToDds *dds, const QString &topic, bool with_listener = true)

Initializes DDS reader and connects Qt signals and slots.

  • dds[in] Pointer to QtToDds instance.

  • topic[in] Name of DDS topic for which to subscribe.

  • with_listener[in] Use DdsReaderListener callback to trigger eventHeard() signal.

Public Slots

void updateValue()

Takes all new samples from the subscribed topic and uses the last sample.

This slot calls take() from the DDS reader and stores the last new sample as the current Double value. If there were a new sample it emits valChanged().


void valChanged(double val)

DDS value has changed.

This signal is connected to the QML RatatoskDoubleValSubscriber::val property.


val[out] New Real value.

void timestampChanged(QDateTime timestamp)

Timestamp of DDS value has changed.

This signal is connected to the QML RatatoskDoubleValSubscriber::timestamp property.


timestamp[out] New timestamp value.

void eventHeard()

DdsReaderListener calls this signal when there is data available on the subscribed topic.

If RatatoskDoubleValSubscriber is initialized with_listener=true, eventHeard() will be connected to the slot updateValue().


double val

DDS DoubleVal as double QML property.

QDateTime timestamp

Timestamp of sample.

Private Members

std::unique_ptr<sinspekto::Reader<ratatosk::types::DoubleVal>> m_reader

The DDS reader wrapper class.