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// Copyright (C) 2017 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Milian Wolff <milian.wolff@kdab.com>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
#ifndef SIGNALHANDLER_H
#define SIGNALHANDLER_H
//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists for the convenience
// of other Qt classes. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//
#include <Qt3DCore/qt3dcore_global.h>
#include <QtCore/QDebug>
#include <QtCore/QHash>
#include <QtCore/QMetaMethod>
#include <QtCore/QObject>
#include <private/qglobal_p.h>
QT_BEGIN_NAMESPACE
namespace Qt3DCore {
class Q_3DCORESHARED_EXPORT PropertyChangeHandlerBase : public QObject
{
Q_OBJECT
public:
PropertyChangeHandlerBase(QObject *parent = nullptr);
/**
* Connect to the change signal of @p property in @p object.
*/
void connectToPropertyChange(const QObject *object, int propertyIndex);
/**
* Disconnect from the change signal of @p property in @p object.
*/
void disconnectFromPropertyChange(const QObject *object, int propertyIndex);
};
/**
* The property change handler is similar to QSignalSpy, but geared towards the usecase of Qt3D.
*
* It allows connecting to any number of property change signals of the receiver object and forwards
* the signal invocations to the Receiver by calling its propertyChanged function.
*/
template<class Receiver>
class PropertyChangeHandler : public PropertyChangeHandlerBase
{
public:
PropertyChangeHandler(Receiver *receiver, QObject *parent = nullptr);
/**
* @internal
*
* Custom implementation of qt_metacall which calls propertyChanged() on the receiver for
* connected signals.
*/
int qt_metacall(QMetaObject::Call call, int methodId, void **args) override;
private:
Receiver *m_receiver;
};
template<class Receiver>
PropertyChangeHandler<Receiver>::PropertyChangeHandler(Receiver *receiver, QObject *parent)
: PropertyChangeHandlerBase(parent)
, m_receiver(receiver)
{
}
template<class Receiver>
int PropertyChangeHandler<Receiver>::qt_metacall(QMetaObject::Call call, int methodId, void **args)
{
methodId = QObject::qt_metacall(call, methodId, args);
if (methodId < 0)
return methodId;
if (call == QMetaObject::InvokeMetaMethod) {
m_receiver->propertyChanged(methodId);
return -1;
}
return methodId;
}
}
QT_END_NAMESPACE
#endif // SIGNALHANDLER_H