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Modifiers.h

/*
 * Modifiers.h -- class interface for lists of modifiers
 * Copyright (C) 2002  Eric Lemings <elemings@users.sourceforge.net>
 *
 * This software is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this software; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA
 *
 * RCS: $Id: Modifiers.h,v 1.3 2003/04/13 05:25:51 elemings Exp $
 */

#ifdef __cplusplus

#  ifndef OGS_CORE_MODIFIERS_H
#    define OGS_CORE_MODIFIERS_H

#    include <cassert>
#    include <list>

#    include <ogs/Support.h>
#    include <ogs/core/Modifier.h>
#    include <ogs/core/Namespace.h>

OGS_BEGIN_CORE_NAMESPACE

class Modifiers: public std::list<Modifier*>,
                 public ogs::support::Object,
                 private ogs::support::Observer {
  public:
    class Event;

    Modifiers ();

    void addModifier (Modifier& modifier);
    void removeModifier (Modifier& modifier);

    Modifier::Value getValue () const;

  private:
    Modifier::Value _value;

    void handleEvent (ogs::support::Event& event);
};

inline
Modifiers::Modifiers ():
  _value (0) {
  // empty constructor body
}

inline Modifier::Value
Modifiers::getValue () const {
  return (this->_value);
}

class Modifiers::Event: public ogs::support::Event {
  public:
    enum Type {
      ADDED,
      REMOVED,
      CHANGED
    };

    Modifier::Value getPreviousValue () const;
    Type getType () const;
    Modifier& getModifier () const;

  protected:
    Event (Modifiers& modifiers, Type type, Modifier& modifier);

    friend void Modifiers::addModifier (Modifier& modifier);
    friend void Modifiers::removeModifier (Modifier& modifier);
    friend void Modifiers::handleEvent (ogs::support::Event& event);

  private:
    Modifier::Value _value;
    Type _type;
    Modifier* _modifier;
};

inline
Modifiers::Event::Event            (Modifiers& modifiers,
                                    Type type,
                                    Modifier& modifier):
  ogs::support::Event (modifiers),
  _value (modifiers.getValue ()),
  _type (type),
  _modifier (&modifier) {
  // empty constructor body
}

inline Modifier::Value
Modifiers::Event::getPreviousValue () const {
  return (this->_value);
}

inline Modifiers::Event::Type
Modifiers::Event::getType () const {
  return (this->_type);
}

inline Modifier&
Modifiers::Event::getModifier () const {
  assert (this->_modifier != NULL);
  return (*(this->_modifier));
}

OGS_END_CORE_NAMESPACE

#  endif /* !defined OGS_CORE_MODIFIERS_H */

#endif /* defined __cplusplus */

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