001package org.cpsolver.ifs.model;
002
003import org.cpsolver.ifs.assignment.Assignment;
004
005/**
006 * IFS variable listener.
007 * 
008 * @see Variable
009 * 
010 * @author  Tomáš Müller
011 * @version IFS 1.3 (Iterative Forward Search)<br>
012 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
013 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
014 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
015 * <br>
016 *          This library is free software; you can redistribute it and/or modify
017 *          it under the terms of the GNU Lesser General Public License as
018 *          published by the Free Software Foundation; either version 3 of the
019 *          License, or (at your option) any later version. <br>
020 * <br>
021 *          This library is distributed in the hope that it will be useful, but
022 *          WITHOUT ANY WARRANTY; without even the implied warranty of
023 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
024 *          Lesser General Public License for more details. <br>
025 * <br>
026 *          You should have received a copy of the GNU Lesser General Public
027 *          License along with this library; if not see
028 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
029 * 
030 * @param <T> Value
031 */
032public interface VariableListener<T extends Value<?, T>> {
033    /**
034     * Called by the variable when a value is assigned to it
035     * 
036     * @param assignment current assignment
037     * @param iteration
038     *            current iteration
039     * @param value
040     *            assigned to the variable
041     */
042    public void variableAssigned(Assignment<?, T> assignment, long iteration, T value);
043
044    /**
045     * Called by the variable when a value is unassigned from it
046     * 
047     * @param assignment current assignment
048     * @param iteration
049     *            current iteration
050     * @param value
051     *            unassigned from the variable
052     */
053    public void variableUnassigned(Assignment<?, T> assignment, long iteration, T value);
054
055    /**
056     * Called by the variable when a value is permanently removed from its
057     * domain
058     * 
059     * @param iteration
060     *            current iteration
061     * @param value
062     *            removed from the variable's domain
063     */
064    public void valueRemoved(long iteration, T value);
065}