/**************************************************************************
/* This class implements a round-robin array
/*
/* Copyright (c) 2006 by Bernhard Bablok (mail@bablokb.de)
/*
/* 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; see the file COPYING.  If not, write to
/* the Free Software Foundation Inc., 59 Temple Place - Suite 330,
/* Boston, MA  02111-1307 USA
/**************************************************************************/


/**
   This class implements a round-robin array.

   @version $Revision: 1.1 $
   @author  $Author: bablokb $
*/

public class RRArray {

  //////////////////////////////////////////////////////////////////////////////

  /**
     Current index.
  */

  private int iCurrentIndex;

  /**
     Array of Objects.
  */

  private Object[] iArray;

  //////////////////////////////////////////////////////////////////////////////

  /**
     Constructor.
  */

  public RRArray(Object[] array) {
    iArray = array;
  }

  //////////////////////////////////////////////////////////////////////////////

  /**
     Return current object.
  */

  public synchronized Object getCurrent() {
    if (iArray != null) {
      return iArray[iCurrentIndex];
    } else {
      throw new IllegalStateException();
    }
  }

  //////////////////////////////////////////////////////////////////////////////

  /**
     Return next object.
  */

  public synchronized Object getNext() {
    if (iArray != null) {
      if (iCurrentIndex < iArray.length-1) {
	iCurrentIndex++;
      } else {
	iCurrentIndex=0;
      }
      return iArray[iCurrentIndex];
    } else {
      throw new IllegalStateException();
    }
  }

  //////////////////////////////////////////////////////////////////////////////

  /**
     Return previous object.
  */

  public synchronized Object getPrev() {
    if (iArray != null) {
      if (iCurrentIndex > 0) {
	iCurrentIndex--;
      } else {
	iCurrentIndex=iArray.length-1;
      }
      return iArray[iCurrentIndex];
    } else {
      throw new IllegalStateException();
    }
  }
}