Ring.java

/*                        FileMenuActionListener.java

  Copyright 2003, Bil Lewis

  This program 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 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 General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA   
*/

package com.lambda.Debugger;


import java.util.*;

class Ring extends ArrayList {
    private int index = 0;

    public Object cycle() {
	index--;
	if (index < 0) index = size()-1;
	if (size() == 0) throw new DebuggerException("Can't cycle empty ring.");
	return get(index);
    }

    public boolean add(Object o) {
	super.add(o);
	index++;
	return true;
    }

    public void clear(Object o) {
	super.clear();
	index=0;
    }
}