/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Designer of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL-EXCEPT$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef EXTENSION_H
#define EXTENSION_H

#include <QtCore/QString>
#include <QtCore/QObject>

QT_BEGIN_NAMESPACE

#define Q_TYPEID(IFace) QLatin1String(IFace##_iid)

class QAbstractExtensionFactory
{
public:
    virtual ~QAbstractExtensionFactory() {}

    virtual QObject *extension(QObject *object, const QString &iid) const = 0;
};
Q_DECLARE_INTERFACE(QAbstractExtensionFactory, "org.qt-project.Qt.QAbstractExtensionFactory")

class QAbstractExtensionManager
{
public:
    virtual ~QAbstractExtensionManager() {}

    virtual void registerExtensions(QAbstractExtensionFactory *factory, const QString &iid) = 0;
    virtual void unregisterExtensions(QAbstractExtensionFactory *factory, const QString &iid) = 0;

    virtual QObject *extension(QObject *object, const QString &iid) const = 0;
};
Q_DECLARE_INTERFACE(QAbstractExtensionManager, "org.qt-project.Qt.QAbstractExtensionManager")

#if defined(Q_CC_MSVC) && (_MSC_VER < 1300)

template <class T>
inline T qt_extension_helper(QAbstractExtensionManager *, QObject *, T)
{ return 0; }

template <class T>
inline T qt_extension(QAbstractExtensionManager* manager, QObject *object)
{ return qt_extension_helper(manager, object, T(0)); }

#define Q_DECLARE_EXTENSION_INTERFACE(IFace, IId) \
const char * const IFace##_iid = IId; \
Q_DECLARE_INTERFACE(IFace, IId) \
template <> inline IFace *qt_extension_helper<IFace *>(QAbstractExtensionManager *manager, QObject *object, IFace *) \
{ QObject *extension = manager->extension(object, Q_TYPEID(IFace)); return (IFace *)(extension ? extension->qt_metacast(IFace##_iid) : 0); }

#else

template <class T>
inline T qt_extension(QAbstractExtensionManager *, QObject *)
{ return Q_NULLPTR; }

#define Q_DECLARE_EXTENSION_INTERFACE(IFace, IId) \
const char * const IFace##_iid = IId; \
Q_DECLARE_INTERFACE(IFace, IId) \
template <> inline IFace *qt_extension<IFace *>(QAbstractExtensionManager *manager, QObject *object) \
{ QObject *extension = manager->extension(object, Q_TYPEID(IFace)); return extension ? static_cast<IFace *>(extension->qt_metacast(IFace##_iid)) : static_cast<IFace *>(Q_NULLPTR); }

#endif

QT_END_NAMESPACE

#endif // EXTENSION_H