kpluginfactory.h

/*  This file is part of the KDE project
    Copyright (C) 2007 Matthias Kretz <kretz@kde.org>
    Copyright (C) 2007 Bernhard Loos <nhuh.put@web.de>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.

*/

#ifndef KPLUGINFACTORY_H
#define KPLUGINFACTORY_H

#include "kcoreaddons_export.h"

#include <QObject>
#include <QVariant>
#include <QStringList>
#include <kexportplugin.h> // for source compat

class QWidget;

class KPluginFactoryPrivate;
namespace KParts
{
class Part;
}

#define KPluginFactory_iid "org.kde.KPluginFactory"

#define K_PLUGIN_FACTORY_DECLARATION_WITH_BASEFACTORY_SKEL(name, baseFactory, ...) \
    class name : public KPluginFactory \
    { \
        Q_OBJECT \
        Q_INTERFACES(KPluginFactory) \
        __VA_ARGS__ \
    public: \
        explicit name(); \
        ~name(); \
    };

#define K_PLUGIN_FACTORY_DECLARATION_WITH_BASEFACTORY_JSON(name, baseFactory, json) \
    K_PLUGIN_FACTORY_DECLARATION_WITH_BASEFACTORY_SKEL(name, baseFactory, Q_PLUGIN_METADATA(IID KPluginFactory_iid FILE json))

#define K_PLUGIN_FACTORY_DECLARATION_WITH_BASEFACTORY(name, baseFactory) \
    K_PLUGIN_FACTORY_DECLARATION_WITH_BASEFACTORY_SKEL(name, baseFactory, Q_PLUGIN_METADATA(IID KPluginFactory_iid))

#define K_PLUGIN_FACTORY_DEFINITION_WITH_BASEFACTORY(name, baseFactory, pluginRegistrations) \
    name::name() \
    { \
        pluginRegistrations \
    } \
    name::~name() {}

#define K_PLUGIN_FACTORY_WITH_BASEFACTORY(name, baseFactory, pluginRegistrations) \
    K_PLUGIN_FACTORY_DECLARATION_WITH_BASEFACTORY(name, baseFactory) \
    K_PLUGIN_FACTORY_DEFINITION_WITH_BASEFACTORY(name, baseFactory, pluginRegistrations)

#define K_PLUGIN_FACTORY_WITH_BASEFACTORY_JSON(name, baseFactory, jsonFile, pluginRegistrations) \
    K_PLUGIN_FACTORY_DECLARATION_WITH_BASEFACTORY_JSON(name, baseFactory, jsonFile) \
    K_PLUGIN_FACTORY_DEFINITION_WITH_BASEFACTORY(name, baseFactory, pluginRegistrations)

#define K_PLUGIN_FACTORY(name, pluginRegistrations) K_PLUGIN_FACTORY_WITH_BASEFACTORY(name, KPluginFactory, pluginRegistrations)

#define K_PLUGIN_FACTORY_WITH_JSON(name, jsonFile, pluginRegistrations)  K_PLUGIN_FACTORY_WITH_BASEFACTORY_JSON(name, KPluginFactory, jsonFile, pluginRegistrations)

#define K_PLUGIN_CLASS_WITH_JSON(classname, jsonFile) K_PLUGIN_FACTORY_WITH_JSON(classname ## Factory, jsonFile, registerPlugin<classname >();)

#define K_PLUGIN_FACTORY_DECLARATION(name) K_PLUGIN_FACTORY_DECLARATION_WITH_BASEFACTORY(name, KPluginFactory)

#define K_PLUGIN_FACTORY_DEFINITION(name, pluginRegistrations) K_PLUGIN_FACTORY_DEFINITION_WITH_BASEFACTORY(name, KPluginFactory, pluginRegistrations)

class KCOREADDONS_EXPORT KPluginFactory : public QObject
{
    Q_OBJECT
    Q_DECLARE_PRIVATE(KPluginFactory)
public:
    explicit KPluginFactory();

    ~KPluginFactory() override;

    template<typename T>
    T *create(QObject *parent = nullptr, const QVariantList &args = QVariantList());

    template<typename T>
    T *create(const QString &keyword, QObject *parent = nullptr, const QVariantList &args = QVariantList());

    template<typename T>
    T *create(QWidget *parentWidget, QObject *parent, const QString &keyword = QString(), const QVariantList &args = QVariantList());

#ifndef KCOREADDONS_NO_DEPRECATED
    template<typename T>
    KCOREADDONS_DEPRECATED
    T *create(QObject *parent, const QStringList &args)
    {
        return create<T>(parent, stringListToVariantList(args));
    }
#endif

#ifndef KCOREADDONS_NO_DEPRECATED
    KCOREADDONS_DEPRECATED QObject *create(QObject *parent = nullptr, const char *classname = "QObject", const QStringList &args = QStringList())
    {
        return create(classname, nullptr, parent, stringListToVariantList(args), QString());
    }
#endif

    static QVariantList stringListToVariantList(const QStringList &list);

    static QStringList variantListToStringList(const QVariantList &list);

Q_SIGNALS:
    void objectCreated(QObject *object);

protected:
    typedef QObject *(*CreateInstanceFunction)(QWidget *, QObject *, const QVariantList &);

    template<class impl>
    struct InheritanceChecker {
        CreateInstanceFunction createInstanceFunction(KParts::Part *)
        {
            return &createPartInstance<impl>;
        }
        CreateInstanceFunction createInstanceFunction(QWidget *)
        {
            return &createInstance<impl, QWidget>;
        }
        CreateInstanceFunction createInstanceFunction(...)
        {
            return &createInstance<impl, QObject>;
        }
    };

    explicit KPluginFactory(KPluginFactoryPrivate &dd);

    template<class T>
    void registerPlugin(const QString &keyword = QString(), CreateInstanceFunction instanceFunction
                        = InheritanceChecker<T>().createInstanceFunction(reinterpret_cast<T *>(0)))
    {
        registerPlugin(keyword, &T::staticMetaObject, instanceFunction);
    }

    KPluginFactoryPrivate *const d_ptr;

#ifndef KCOREADDONS_NO_DEPRECATED
    virtual KCOREADDONS_DEPRECATED QObject *createObject(QObject *parent, const char *className, const QStringList &args);
#endif

#ifndef KCOREADDONS_NO_DEPRECATED
    virtual KCOREADDONS_DEPRECATED KParts::Part *createPartObject(QWidget *parentWidget, QObject *parent, const char *classname, const QStringList &args);
#endif

    virtual QObject *create(const char *iface, QWidget *parentWidget, QObject *parent, const QVariantList &args, const QString &keyword);

    template<class impl, class ParentType>
    static QObject *createInstance(QWidget *parentWidget, QObject *parent, const QVariantList &args)
    {
        Q_UNUSED(parentWidget);
        ParentType *p = nullptr;
        if (parent) {
            p = qobject_cast<ParentType *>(parent);
            Q_ASSERT(p);
        }
        return new impl(p, args);
    }

    template<class impl>
    static QObject *createPartInstance(QWidget *parentWidget, QObject *parent, const QVariantList &args)
    {
        return new impl(parentWidget, parent, args);
    }

private:
    void registerPlugin(const QString &keyword, const QMetaObject *metaObject, CreateInstanceFunction instanceFunction);
};

typedef KPluginFactory KLibFactory;

template<typename T>
inline T *KPluginFactory::create(QObject *parent, const QVariantList &args)
{
    QObject *o = create(T::staticMetaObject.className(), parent && parent->isWidgetType() ? reinterpret_cast<QWidget *>(parent) : nullptr, parent, args, QString());

    T *t = qobject_cast<T *>(o);
    if (!t) {
        delete o;
    }
    return t;
}

template<typename T>
inline T *KPluginFactory::create(const QString &keyword, QObject *parent, const QVariantList &args)
{
    QObject *o = create(T::staticMetaObject.className(), parent && parent->isWidgetType() ? reinterpret_cast<QWidget *>(parent) : nullptr, parent, args, keyword);

    T *t = qobject_cast<T *>(o);
    if (!t) {
        delete o;
    }
    return t;
}

template<typename T>
inline T *KPluginFactory::create(QWidget *parentWidget, QObject *parent, const QString &keyword, const QVariantList &args)
{
    QObject *o = create(T::staticMetaObject.className(), parentWidget, parent, args, keyword);

    T *t = qobject_cast<T *>(o);
    if (!t) {
        delete o;
    }
    return t;
}

Q_DECLARE_INTERFACE(KPluginFactory, KPluginFactory_iid)

#endif // KPLUGINFACTORY_H