    001package net.sf.cpsolver.ifs.model;
    002
    003import java.util.Set;
    004
    005/**
    006 * IFS constraint listener.
    007 *
    008 * @see Constraint
    009 *
    010 * @version IFS 1.2 (Iterative Forward Search)<br>
    011 *          Copyright (C) 2006 - 2010 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 */
    029public interface ConstraintListener<T extends Value<?, T>> {
    030    /**
    031     * Called by the constraint, before a value is assigned to its variable.
    032     *
    033     * @param iteration
    034     *            current iteration
    035     * @param constraint
    036     *            source constraint
    037     * @param assigned
    038     *            value which will be assigned to its variable (
    039     *            {@link Value#variable()})
    040     * @param unassigned
    041     *            set of conflicting values which will be unassigned by the
    042     *            constraint before it assigns the given value
    043     */
    044    public void constraintBeforeAssigned(long iteration, Constraint<?, T> constraint, T assigned, Set<T> unassigned);
    045
    046    /**
    047     * Called by the constraint, after a value is assigned to its variable.
    048     *
    049     * @param iteration
    050     *            current iteration
    051     * @param constraint
    052     *            source constraint
    053     * @param assigned
    054     *            value which was assigned to its variable (
    055     *            {@link Value#variable()})
    056     * @param unassigned
    057     *            set of conflicting values which were unassigned by the
    058     *            constraint before it assigned the given value
    059     */
    060    public void constraintAfterAssigned(long iteration, Constraint<?, T> constraint, T assigned, Set<T> unassigned);
    061}