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