klibloader.h

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/* This file is part of the KDE libraries
   Copyright (C) 1999 Torben Weis <weis@kde.org>

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License version 2 as published by the Free Software Foundation.

   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 KLIBLOADER_H
#define KLIBLOADER_H

#include <kglobal.h>

#include <QtCore/QObject>
#include <QtCore/QStringList>
#include <QtCore/QHash>
#include <QtCore/QLibrary>
#include <QtCore/QtPlugin>

#include "kpluginfactory.h"
#include "kpluginloader.h"
#include "klibrary.h"

#ifndef KDE_NO_DEPRECATED

# define K_EXPORT_COMPONENT_FACTORY( libname, factory ) \
    extern "C" { KDE_EXPORT KPluginFactory *init_##libname() { return new factory; } }

class KDECORE_EXPORT KLibLoader : public QObject //krazy:exclude=dpointer (private class is kept as a global static)
{
    friend class KLibrary;
    friend class KLibraryPrivate;
    friend class KLibLoaderPrivate;

    Q_OBJECT
public:
    KPluginFactory* factory( const QString &libname, QLibrary::LoadHints loadHint = 0);

    KLibrary* library( const QString &libname, QLibrary::LoadHints loadHint = 0 );

    QString lastErrorMessage() const;

    void unloadLibrary( const QString &libname );

    static KDE_DEPRECATED KLibLoader* self();

    static QString findLibrary(const QString &libname, const KComponentData &cData = KGlobal::mainComponent());

    enum ComponentLoadingError {
        ErrNoLibrary = 1, /*< the specified library could not be loaded. Use KLibLoader::lastErrorMessage for details*/
        ErrNoFactory, /*< the library does not export a factory */
        ErrNoComponent, /*< the factory does not support creating components of the specified type */
        ErrServiceProvidesNoLibrary, /*< the specified service provides no shared library (when using KService) */
        ErrNoServiceFound /*< no service implementing the given servicetype and fullfilling the given constraint expression can be found (when using KServiceTypeTrader) */
    };

    static QString errorString( int componentLoadingError );


    template <typename T>
    static KDE_DEPRECATED T *createInstance(const QString &keyword, const QString &libname, QObject *parent = 0,
                              const QVariantList &args = QVariantList(),
                              int *error = 0 )
    {
        KLibrary *library = KLibLoader::self()->library( libname );
        if ( !library )
        {
            if ( error )
                *error = ErrNoLibrary;
            return 0;
        }
        KPluginFactory *factory = library->factory();
        if ( !factory )
        {
            library->unload();
            if ( error )
                *error = ErrNoFactory;
            return 0;
        }
        QObject *object = factory->template create<T>(keyword, parent, args);
        T *res = qobject_cast<T *>( object );
        if ( !res )
        {
            delete object;
            library->unload();
            if ( error )
                *error = ErrNoComponent;
        }
        return res;
    }

    template <typename T>
    static KDE_DEPRECATED T *createInstance( const QString &libname, QObject *parent = 0,
                              const QVariantList &args = QVariantList(),
                              int *error = 0 )
    {
        return createInstance<T>(QString(), libname, parent, args, error);
    }

    template <typename T>
    static KDE_DEPRECATED T *createInstance( const QString &libname, QObject *parent,
                              const QStringList &args,
                              int *error = 0 )
    {
        KLibrary *library = KLibLoader::self()->library( libname );
        if ( !library )
        {
            if ( error )
                *error = ErrNoLibrary;
            return 0;
        }
        KPluginFactory *factory = library->factory();
        if ( !factory )
        {
            library->unload();
            if ( error )
                *error = ErrNoFactory;
            return 0;
        }
        QObject *object = factory->template create<T>(parent, args);
        T *res = qobject_cast<T *>( object );
        if ( !res )
        {
            delete object;
            library->unload();
            if ( error )
                *error = ErrNoComponent;
        }
        return res;
    }

private:
    ~KLibLoader();

    KLibLoader();
};

#endif
#endif