how to pass qobject as argument from signal to slot in qt connect

Question

My original code passed a QStringList from the signal to the slot and then returned a QList. Everything worked fine but I needed to change both the QStringList and QList in

Answer 1

Usually QObject is passed by pointer, not by reference (note that QObject cannot be copied and cannot be passed by value). QObject* is registered as a meta type by default. So creating a signal and a slot with QObject* argument is enough to get them work:

private slots:
  void test_slot(QObject* object);

signals:
  void test_signal(QObject* object);

Initialization:

connect(this, SIGNAL(test_signal(QObject*)), this, SLOT(test_slot(QObject*)));

Emitting:

QObject* object = new QObject();
emit test_signal(object);

Of course the signal and the slot could be in different classes.