kdelibs/kparts/factory.h

/* This file is part of the KDE project
   Copyright (C) 1999 Simon Hausmann <hausmann@kde.org>
             (C) 1999 David Faure <faure@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 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 __kparts_factory_h__
#define __kparts_factory_h__

#include <kpluginfactory.h>
#include <kparts/kparts_export.h>

#include <QWidget>

namespace KParts
{

class Part;

/**
 * A generic factory object to create a Part.
 *
 * Factory is an abstract class. Reimplement the
 * createPartObject() method to give it functionality.
 *
 * @see KPluginFactory.
 */
class KPARTS_EXPORT Factory : public KPluginFactory
{
    Q_OBJECT
public:
    Factory(QObject *parent = nullptr);
    virtual ~Factory();

    /**
     * Creates a part.
     *
     * The QStringList can be used to pass additional arguments to the part.
     * If the part needs additional arguments, it should take them as
     * name="value" pairs. This is the way additional arguments will get passed
     * to the part from eg. khtml. You can for example emebed the part into HTML
     * by using the following code:
     * \code
     *    <object type="my_mimetype" data="url_to_my_data">
     *        <param name="name1" value="value1">
     *        <param name="name2" value="value2">
     *    </object>
     * \endcode
     * This could result in a call to
     * \code
     *     createPart( parentWidget, parentObject, "KParts::Part",
     *                 QStringList("name1="value1"", "name2="value2") );
     * \endcode
     *
     * @returns the newly created part.
     *
     * createPart() automatically emits a signal KPluginFactory::objectCreated to tell
     * the library about its newly created object.  This is very
     * important for reference counting, and allows unloading the
     * library automatically once all its objects have been destroyed.
     */
    Part* createPart(QWidget *parentWidget = nullptr, QObject *parent = nullptr,
                     const char *classname = "KParts::Part", const QStringList &args = QStringList());

     /**
      * If you have a part contained in a shared library you might want to query
      * for meta-information like the about-data, or the KComponentData in general.
      * If the part is exported using KParts::GenericFactory then this method will
      * return the instance that belongs to the part without the need to instantiate
      * the part component.
      */
     virtual KComponentData partComponentData();

     /**
      * A convenience method for partComponentData that takes care of retrieving
      * the factory for a given library name and calling partComponentData on it.
      *
      * @param libraryName name of the library to query the instance from
      */
     static KComponentData partComponentDataFromLibrary(const QString &libraryName);

protected:
    /**
     * Reimplement this method in your implementation to create the Part.
     *
     * The QStringList can be used to pass additional arguments to the part.
     * If the part needs additional arguments, it should take them as
     * name="value" pairs. This is the way additional arguments will get passed
     * to the part from eg. khtml. You can for example emebed the part into HTML
     * by using the following code:
     * \code
     *    <object type="my_mimetype" data="url_to_my_data">
     *        <param name="name1" value="value1">
     *        <param name="name2" value="value2">
     *    </object>
     * \endcode
     * This could result in a call to
     * \code
     *     createPart( parentWidget, parentObject, "KParts::Part",
     *                 QStringList("name1="value1"", "name2="value2") );
     * \endcode
     *
     * @returns the newly created part.
     */
    virtual Part* createPartObject(QWidget *parentWidget = nullptr, QObject *parent = nullptr,
                                   const char *classname = "KParts::Part", const QStringList &args = QStringList()) = 0;

    /**
     * Reimplemented from KPluginFactory. Calls createPart()
     */
    virtual QObject* createObject(QObject *parent = nullptr,
                                  const char *classname = "QObject", const QStringList &args = QStringList());
};

}

#endif