/*
 *  $Source: /cvsroot2/open/projects/WebARTS/ca/bc/webarts/widgets/ClassConstants.java,v $
 *  $Name:  $
 *  Current File Status:   $Revision: 567 $
 *  $Date: 2012-11-03 20:36:02 -0700 (Sat, 03 Nov 2012) $
 *  $Locker:  $
 *  Copyright (C) 2001-2004 WebARTS Design, North Vancouver Canada
 */
/*
 *  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; version 2 of the License.
 *
 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package ca.bc.webarts.widgets;

import java.util.Collection;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.NoSuchElementException;

/**
 *  A class to automate the assignment and usage of enumerated Class Constants.
 *
 *  <P>It is a combination Enumeration and Hashtable.
 *
 * <P>It takes a list of constant names (Strings) and Hashes a unique int with them.
 *  This allows the user to access the Constants via an Enum mechanism or a Hash
 *  mechanism.
 *
 * @author     tom gutwin
 * @created    June 9, 2001
 */
public class ClassConstants extends Hashtable
     implements Enumeration
{
  /**
   *  The current index into the Enumeration of Constants.
   *
   * @since
   */
  private int            currentIndex_ = 0;


  /**
   * The number of Constants defined/assigned.
   *
   * @since
   */
  private int            numConstants_ = 0;

  /**
   *  The enumeration of constant names.
   *
   * @since
   */
  private Enumeration    enum_ = null;


  /**
   *  The collection of int valkues assigned to the instantiated class
   * constants.
   *
   * @since
   */
  private Collection     values_ = null;


  /**
   *  Default constructor that takes a list of names and assigns constant numbers
   *  starting from 0 and incrementing by 1.
   *
   * @param  constantNames  the list of names to give the constants
   * @since
   */
  public ClassConstants(String[] constantNames)
  {
    this(0, 1, constantNames);
  }


  /**
   *  Constructor that takes a list of names and assigns constant numbers starting
   *  from the passed in 'startVal' and incrementing by 1.
   *
   * @param  startVal       the int to start the enumeration at
   * @param  constantNames  the list of names to give the constants
   * @since
   */
  public ClassConstants(int startVal, String[] constantNames)
  {
    this(startVal, 1, constantNames);
  }


  /**
   *  Constructor that takes a list of names and assigns constant numbers starting
   *  from the passed in 'startVal' and incrementing by the passed in stepVal.
   *
   * @param  startVal       the int to start the enumeration at
   * @param  stepVal        the int to step the enumeration by
   * @param  constantNames  the list of names to give the constants
   * @since
   */
  public ClassConstants(int startVal,
                        int stepVal,
                        String[] constantNames)
  {
    for (int i = startVal; i < constantNames.length * stepVal; i += stepVal)
    {
      put(constantNames, new Integer(i));
    }
    values_ = values();
    enum_ = keys();
  }


  /**
   *  Gets the Constant valueof the ClassConstants object
   *
   * @param  constName  the constant to get
   * @return            The Value Of the Constant
   * @since
   */
  public int getValueOf(String constName)
  {
    return ((Integer)(this.get(constName))).intValue() ;
  }


  /**
   *  Does this classes enumeration of constants have any more elements.
   *
   * @return    true if the enum has mor elements, false if done
   * @since
   */
  public boolean hasMoreElements()
  {
    boolean retVal = false;
    if (enum_ != null)
    {
      retVal = enum_.hasMoreElements();
    }
    return retVal;
  }


  /**
   *  Returns the next enumerated Constant as an Object.
   *
   * @return                             Description of the Returned Value
   * @exception  NoSuchElementException  Description of Exception
   * @since
   */
  public Object nextElement() throws java.util.NoSuchElementException
  {
    Object retVal = null;
    if (enum_ != null && hasMoreElements())
    {
      retVal = enum_.nextElement();
    }
    if (retVal == null)
    {
      throw new java.util.NoSuchElementException();
    }
    return retVal;
  }


  /**
   *  Gets the next Enumerated Clas Constant Name.
   *
   * @return  the next Enumerated Clas Constant Name.
   * @since
   * @throws  NoSuchElementException
   */
  public String nextConstantName() throws java.util.NoSuchElementException
  {
    String retVal = null;
    if (enum_ != null && hasMoreElements())
    {
      retVal = (String)enum_.nextElement();
    }
    if (retVal == null)
    {
      throw new java.util.NoSuchElementException();
    }
    return retVal;
  }


  /**
   *  Compares the passed in Constant name with
   *
   * @param  constName  Constant name to compare
   * @param  val        the int value to compare to the passed in Constant.
   * @return            true if the same false if not.
   * @since
   */
  public boolean equals(String constName, int val)
  {
    return (getValueOf(constName) == val);
  }


  /**
   *  Description of the Method
   *
   * @param  constName  Description of Parameter
   * @return            Description of the Returned Value
   * @since
   */
  public boolean contains(String constName)
  {
    return this.containsKey(constName);
  }
}