    001package org.cpsolver.ifs.model;
    002
    003import java.util.Set;
    004
    005import org.cpsolver.ifs.assignment.Assignment;
    006
    007
    008/**
    009 * IFS constraint listener.
    010 *
    011 * @see Constraint
    012 *
    013 * @author  Tomáš Müller
    014 * @version IFS 1.3 (Iterative Forward Search)<br>
    015 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    016 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    017 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    018 * <br>
    019 *          This library is free software; you can redistribute it and/or modify
    020 *          it under the terms of the GNU Lesser General Public License as
    021 *          published by the Free Software Foundation; either version 3 of the
    022 *          License, or (at your option) any later version. <br>
    023 * <br>
    024 *          This library is distributed in the hope that it will be useful, but
    025 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    026 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    027 *          Lesser General Public License for more details. <br>
    028 * <br>
    029 *          You should have received a copy of the GNU Lesser General Public
    030 *          License along with this library; if not see
    031 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    032 * @param <V> Variable
    033 * @param <T> Value
    034 */
    035public interface ConstraintListener<V extends Variable<V, T>, T extends Value<V, T>> {
    036    /**
    037     * Called by the constraint, before a value is assigned to its variable.
    038     *
    039     * @param assignment current assignment
    040     * @param iteration
    041     *            current iteration
    042     * @param constraint
    043     *            source constraint
    044     * @param assigned
    045     *            value which will be assigned to its variable (
    046     *            {@link Value#variable()})
    047     * @param unassigned
    048     *            set of conflicting values which will be unassigned by the
    049     *            constraint before it assigns the given value
    050     */
    051    public void constraintBeforeAssigned(Assignment<V, T> assignment, long iteration, Constraint<V, T> constraint, T assigned, Set<T> unassigned);
    052
    053    /**
    054     * Called by the constraint, after a value is assigned to its variable.
    055     *
    056     * @param assignment current assignment
    057     * @param iteration
    058     *            current iteration
    059     * @param constraint
    060     *            source constraint
    061     * @param assigned
    062     *            value which was assigned to its variable (
    063     *            {@link Value#variable()})
    064     * @param unassigned
    065     *            set of conflicting values which were unassigned by the
    066     *            constraint before it assigned the given value
    067     */
    068    public void constraintAfterAssigned(Assignment<V, T> assignment, long iteration, Constraint<V, T> constraint, T assigned, Set<T> unassigned);
    069}