/* *  This file is part of the KDE libraries *  Copyright (C) 2003 Apple Computer, Inc. * *  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., 59 Temple Place - Suite 330, *  Boston, MA 02111-1307, USA. * */#ifndef KJS_SCOPE_CHAIN_H#define KJS_SCOPE_CHAIN_Hnamespace KJS {    class ObjectImp;        class ScopeChainNode {    public:        ScopeChainNode(ScopeChainNode *n, ObjectImp *o)            : next(n), object(o), refCount(1) { }        ScopeChainNode *next;        ObjectImp *object;        int refCount;    };    class ScopeChain {    public:        ScopeChain() : _node(0) { }        ~ScopeChain() { deref(); }        ScopeChain(const ScopeChain &c) : _node(c._node)            { if (_node) ++_node->refCount; }        ScopeChain &operator=(const ScopeChain &);        bool isEmpty() const { return !_node; }        ObjectImp *top() const { return _node->object; }	ObjectImp *bottom() const;        void clear() { deref(); _node = 0; }        void push(ObjectImp *);        void pop();                void mark();            private:        ScopeChainNode *_node;                void deref() { if (_node && --_node->refCount == 0) release(); }        void ref() const;                void release();    };}; // namespace KJS#endif // KJS_SCOPE_CHAIN_H