Passing Q_GADGET as signal parameter from C ++ to QML

Cannot get property of C ++ object inside QML code. The object is passed as a parameter to the signal.

It is expected that in QML it is possible to highlight an text

object property Record

. And the value should be abc

. QML sees an object as QVariant(Record)

, and its property text

as undefined

.

Record

is a value type of type QPoint

, so it uses a declaration Q_GADGET

.

HPP:

#ifndef LISTENP_HPP_
#define LISTENP_HPP_

#include <QObject>

#include "Record.hpp"

class ListenP: public QObject
{
Q_OBJECT

public:
    ListenP();
    virtual ~ListenP();

    void emitGotRecord();

signals:
    void gotRecord(Record r);
};

#endif /* LISTENP_HPP_ */

      

        
        
        
      

    

caste:

#include "ListenP.hpp"

ListenP::ListenP() :
        QObject()
{
}

ListenP::~ListenP()
{
}

void ListenP::emitGotRecord()
{
    emit gotRecord(Record("abc"));
}

      

        
        
        
      

    

hpp to write:

#ifndef RECORD_HPP_
#define RECORD_HPP_

#include <QObject>
#include <QMetaType>

class Record
{
Q_GADGET

Q_PROPERTY(QString text READ text WRITE setText)

public:
    Record(const QString& text = "");
    ~Record();

    QString text() const
    {
        return m_text;
    }

    void setText(const QString& text)
    {
        m_text = text;
    }

private:
    QString m_text;
};

Q_DECLARE_METATYPE(Record)

#endif /* RECORD_HPP_ */

      

        
        
        
      

    

cpp to write:

#include "Record.hpp"

Record::Record(const QString& text) :
        m_text(text)
{
}

Record::~Record()
{
}

namespace
{
const int RecordMetaTypeId = qMetaTypeId<Record>();
}

      

        
        
        
      

    

The QML part:

Connections {
    target: listenPModel
    onGotRecord: {
        console.log(r)
        console.log(r.text)
    }
}

      

        
        
        
      

    

main part:

QGuiApplication app(argc, argv);

auto listenP = std::make_shared<ListenP>();
QQuickView view;
view.rootContext()->setContextProperty("listenPModel", &*listenP);
view.setSource(QStringLiteral("src/qml/main.qml"));
view.show();

QtConcurrent::run([=]
{
    QThread::sleep(3);
    listenP->emitGotRecord();
});

return app.exec();

      

        
        
        
      

    

The log shows:

qml: QVariant(Record)
qml: undefined