List of available signals at runtime

Question

I need to get list of available signals from particular QWidget at runtime.

For example, the QWidget is QPushButton and I'd like to get this list:

"clicked()"
"pressed()"
"released()"
"toggled()"
"destroyed()"
...

Can you give me a hint how to do that? Thank you

Answer 1

This is the code to get all the signals in the inheritance tree. It would be easy to adjust to your needs should you not need all of them:

main.cpp

#include <QStringList>
#include <QApplication>
#include <QPushButton>
#include <QMetaObject>
#include <QMetaMethod>
#include <QDebug>

int main(int argc, char **argv)
{
    QApplication application(argc, argv);
    QPushButton pushButton;
    const QMetaObject* metaObject = pushButton.metaObject();
    do {
        for (int i = metaObject->methodOffset(); i < metaObject->methodCount(); ++i) {
            QMetaMethod metaMethod = metaObject->method(i);
            if (metaMethod.methodType() == QMetaMethod::Signal)
                qDebug() << metaMethod.methodSignature();
        }
    } while ((metaObject = metaObject->superClass()));
    return application.exec();
}

main.pro

TEMPLATE = app
TARGET = main
QT += widgets
SOURCES += main.cpp

Build and Run

qmake && make && ./main

Output

"pressed()"
"released()"
"clicked(bool)"
"clicked()"
"toggled(bool)"
"windowTitleChanged(QString)"
"windowIconChanged(QIcon)"
"windowIconTextChanged(QString)"
"customContextMenuRequested(QPoint)"
"destroyed(QObject*)"
"destroyed()"
"objectNameChanged(QString)"