/*

  * $Source$

  * $Revision$

  *

  * Copyright (C) 2000 William Chesters

  *

  * Part of Melati (http://melati.org), a framework for the rapid

  * development of clean, maintainable web applications.

  *

  * Melati is free software; Permission is granted to copy, distribute

  * and/or modify this software under the terms either:

  *

  * a) 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,

  *

  *    or

  *

  * b) any version of the Melati Software License, as published

  *    at http://melati.org

  *

  * You should have received a copy of the GNU General Public License and

  * the Melati Software License along with this program;

  * if not, write to the Free Software Foundation, Inc.,

  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the

  * GNU General Public License and visit http://melati.org to obtain the

  * Melati Software License.

  *

  * Feel free to contact the Developers of Melati (http://melati.org),

  * if you would like to work out a different arrangement than the options

  * outlined here.  It is our intention to allow Melati to be used by as

  * wide an audience as possible.

  *

  * 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.

  *

  * Contact details for copyright holder:

  *

  *     William Chesters <williamc At paneris.org>

  *     http://paneris.org/~williamc

  *     Obrechtstraat 114, 2517VX Den Haag, The Netherlands

  */

 package org.melati.poem;

 import java.util.Enumeration;

 /**

  * A pointer to a subset of a {@link Table}.

  *

  * Note this doesn't do quite what you'd expect, and can't unless it parses

  * the selection's <code>whereClause</code> in order to determine what a 

  * valid value is, so use a simple where clause.

  */

 public class RestrictedReferencePoemType<P extends Persistent> extends ReferencePoemType {

   private final CachedSelection<P> selection;

   /**

    * Constructor.

    * @param selection a CachedSelection of that is the sub-set

    * @param nullable whether instance may be null

    */

   public RestrictedReferencePoemType(CachedSelection<P> selection,

                                      boolean nullable) {

     super(selection.getTable(), nullable);

     this.selection = selection;

   }

   protected Enumeration<Integer> _possibleRaws() {

     return selection.troids();

   }

 }