src_corelib_kernel_qmetaobject.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
#include <QMetaObject>
#include <QMetaMethod>
#include <QByteArray>
#include <QStringView>
 
//! [0]
class MyClass : public QObject
{
    Q_OBJECT
    Q_CLASSINFO("author", "Sabrina Schweinsteiger")
    Q_CLASSINFO("url", "http://doc.moosesoft.co.uk/1.0/")
 
public:
    //...
};
//! [0]
 
 
void wrapInFunction(QObject *obj, QObject *thread)
{
    {
        //! [1]
        QByteArray normType = QMetaObject::normalizedType(" int    const  *");
        // normType is now "const int*"
        //! [1]
    }
 
    {
        //! [2]
        QMetaObject::invokeMethod(thread, "quit", Qt::QueuedConnection);
        //! [2]
    }
 
#if 0
    //! [3]
    QMetaObject::invokeMethod: Unable to handle unregistered datatype 'MyType'
    //! [3]
#endif
 
    {
        //! [invokemethod-no-macro]
        QString retVal;
        QMetaObject::invokeMethod(obj, "compute", Qt::DirectConnection,
                                  qReturnArg(retVal),
                                  QString("sqrt"), 42, 9.7);
        //! [invokemethod-no-macro]
    }
 
    {
        //! [invokemethod-no-macro-other-types]
        QString retVal;
        QMetaObject::invokeMethod(obj, "compute", Qt::DirectConnection,
                                  qReturnArg(retVal),
                                  QStringView(u"sqrt"), qsizetype(42), 9.7f);
        //! [invokemethod-no-macro-other-types]
    }
 
    {
    //! [4]
        QString retVal;
        QMetaObject::invokeMethod(obj, "compute", Qt::DirectConnection,
                                  Q_RETURN_ARG(QString, retVal),
                                  Q_ARG(QString, "sqrt"),
                                  Q_ARG(int, 42),
                                  Q_ARG(double, 9.7));
    //! [4]
    }
}
 
class MainWindow : public QObject
{
    Q_OBJECT
    public:
        void show() {}
 
    //! [10]
        // In the class MainWindow declaration
        #ifndef Q_MOC_RUN
        // define the tag text as empty, so the compiler doesn't see it
        #  define MY_CUSTOM_TAG
        #endif
        //...
        private slots:
            MY_CUSTOM_TAG void testFunc();
    //! [10]
};
 
void examples(QObject *obj, QObject *pushButton)
{
    {
        //! [propertyCount]
        const QMetaObject* metaObject = obj->metaObject();
        QStringList properties;
        for (int i = metaObject->propertyOffset(); i < metaObject->propertyCount(); ++i)
            properties << QString::fromLatin1(metaObject->property(i).name());
        //! [propertyCount]
    }
 
    {
        //! [methodCount]
        const QMetaObject* metaObject = obj->metaObject();
        QStringList methods;
        for (int i = metaObject->methodOffset(); i < metaObject->methodCount(); ++i)
            methods << QString::fromLatin1(metaObject->method(i).methodSignature());
        //! [methodCount]
 
        //! [6]
        int methodIndex = pushButton->metaObject()->indexOfMethod("animateClick()");
        QMetaMethod method = metaObject->method(methodIndex);
        method.invoke(pushButton, Qt::QueuedConnection);
        //! [6]
    }
 
#if 0
    //! [7]
    QMetaMethod::invoke: Unable to handle unregistered datatype 'MyType'
    //! [7]
#endif
 
    {
        //! [invoke-no-macro]
        QString retVal;
        QByteArray normalizedSignature = QMetaObject::normalizedSignature("compute(QString, int, double)");
        int methodIndex = obj->metaObject()->indexOfMethod(normalizedSignature);
        QMetaMethod method = obj->metaObject()->method(methodIndex);
        method.invoke(obj, Qt::DirectConnection, qReturnArg(retVal),
                      QString("sqrt"), 42, 9.7);
        //! [invoke-no-macro]
    }
 
    {
        //! [invoke-no-macro-other-types]
        QString retVal;
        QByteArray normalizedSignature = QMetaObject::normalizedSignature("compute(QByteArray, qint64, long double)");
        int methodIndex = obj->metaObject()->indexOfMethod(normalizedSignature);
        QMetaMethod method = obj->metaObject()->method(methodIndex);
        method.invoke(obj, Qt::DirectConnection, qReturnArg(retVal),
                      QByteArray("sqrt"), qint64(42), 9.7L);
        //! [invoke-no-macro-other-types]
    }
 
    {
        //! [8]
        QString retVal;
        QByteArray normalizedSignature = QMetaObject::normalizedSignature("compute(QString, int, double)");
        int methodIndex = obj->metaObject()->indexOfMethod(normalizedSignature);
        QMetaMethod method = obj->metaObject()->method(methodIndex);
        method.invoke(obj,
                      Qt::DirectConnection,
                      Q_RETURN_ARG(QString, retVal),
                      Q_ARG(QString, "sqrt"),
                      Q_ARG(int, 42),
                      Q_ARG(double, 9.7));
        //! [8]
    }
 
    {
        //! [9]
        QMetaMethod destroyedSignal = QMetaMethod::fromSignal(&QObject::destroyed);
        //! [9]
    }
 
    {
        //! [11]
            MainWindow win;
            win.show();
 
            int functionIndex = win.metaObject()->indexOfSlot("testFunc()");
            QMetaMethod mm = win.metaObject()->method(functionIndex);
            qDebug() << mm.tag(); // prints MY_CUSTOM_TAG
        //! [11]
    }
}