koffice/lib/kross/api/object.h

/***************************************************************************
 * object.h
 * This file is part of the KDE project
 * copyright (C)2004-2006 by Sebastian Sauer (mail@dipe.org)
 *
 * This program 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 program 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 program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 ***************************************************************************/

#ifndef KROSS_API_OBJECT_H
#define KROSS_API_OBJECT_H

#include <tqstring.h>
#include <tqvaluelist.h>
#include <tqmap.h>
#include <tqvariant.h>
//#include <tqobject.h>
#include <ksharedptr.h>

#include "../main/krossconfig.h"

namespace Kross { namespace Api {

    // Forward declaration.
    class List;

    /**
     * The common Object class all other object-classes are
     * inheritated from.
     *
     * The Object class is used as base class to provide
     * common functionality. It's similar to what we know 
     * in Python as PyObject or in TQt as TQObject.
     *
     * Inherited from e.g. \a Value, \a Module and \a Class .
     *
     * This class implementates reference counting for shared
     * objects. So, no need to take care of freeing objects.
     */
    class Object : public KShared
    {
        public:

            /**
             * Shared pointer to implement reference-counting.
             */
            typedef KSharedPtr<Object> Ptr;

            /**
             * Constructor.
             */
            explicit Object();

            /**
             * Destructor.
             */
            virtual ~Object();

            /**
             * Return the class name. This could be something
             * like "Kross::Api::Object" for this object. The
             * value is mainly used for display purposes.
             *
             * \return The name of this class.
             */
            virtual const TQString getClassName() const = 0;

            /**
             * \return a string representation of the object or
             * it's content. This method is mainly used for
             * debugging and testing purposes.
             */
            virtual const TQString toString();

            /**
             * Pass a call to the object and evaluated it recursive
             * down the object-hierachy. Objects like \a Class are able
             * to handle call's by just implementing this function.
             * If the call is done the \a called() method will be
             * executed recursive from bottom up the call hierachy.
             *
             * \throws TypeException if the object or the name
             *         is not callable.
             * \param name Each call has a name that says what
             *        should be called. In the case of a \a Class
             *        the name is the functionname.
             * \param arguments The list of arguments passed to
             *        the call.
             * \return The call-result as \a Object::Ptr instance or
             *         NULL if the call has no result.
             */
            virtual Object::Ptr call(const TQString& name, KSharedPtr<List> arguments);

            /**
             * Return a list of supported callable objects.
             *
             * \return List of supported calls.
             */
            virtual TQStringList getCalls() { return TQStringList(); }
            //FIXME replace function with getChildren() functionality ?

            /**
             * Try to convert the \a Object instance to the
             * template class T.
             *
             * \throw TypeException if the cast failed.
             * \param object The Object to cast.
             * \return The to a instance from template type T
             *         casted Object.
             */
            template<class T> static T* fromObject(Object::Ptr object);

            /**
             * This method got used by the \a ProxyFunction classes
             * to translate an unknown \p TYPE to a \a Object instance.
             * Classes like \a Value or \a ListT or \a Class are
             * overwriting this method to transparently translate these
             * passed type while this method just assumes that the
             * type is already a \a Object instance.
             */
            template<typename TYPE>
            static Object::Ptr toObject(TYPE t) { return t; }
    };

}}

#include "exception.h"

namespace Kross { namespace Api {

template<class T> inline T* Object::fromObject(Object::Ptr object)
{
    T* t = (T*) object.data();
    if(! t)
        throw KSharedPtr<Exception>( new Exception(TQString("Object \"%1\" invalid.").arg(object ? object->getClassName() : "")) );
    return t;
}

}} 

#endif