001    package net.sf.cpsolver.ifs.model;
002    
003    /**
004     * IFS variable listener.
005     * 
006     * @see Variable
007     * 
008     * @version IFS 1.2 (Iterative Forward Search)<br>
009     *          Copyright (C) 2006 - 2010 Tomas Muller<br>
010     *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
011     *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
012     * <br>
013     *          This library is free software; you can redistribute it and/or modify
014     *          it under the terms of the GNU Lesser General Public License as
015     *          published by the Free Software Foundation; either version 3 of the
016     *          License, or (at your option) any later version. <br>
017     * <br>
018     *          This library is distributed in the hope that it will be useful, but
019     *          WITHOUT ANY WARRANTY; without even the implied warranty of
020     *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
021     *          Lesser General Public License for more details. <br>
022     * <br>
023     *          You should have received a copy of the GNU Lesser General Public
024     *          License along with this library; if not see
025     *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
026     */
027    public interface VariableListener<T extends Value<?, T>> {
028        /**
029         * Called by the variable when a value is assigned to it
030         * 
031         * @param iteration
032         *            current iteration
033         * @param value
034         *            assigned to the variable
035         */
036        public void variableAssigned(long iteration, T value);
037    
038        /**
039         * Called by the variable when a value is unassigned from it
040         * 
041         * @param iteration
042         *            current iteration
043         * @param value
044         *            unassigned from the variable
045         */
046        public void variableUnassigned(long iteration, T value);
047    
048        /**
049         * Called by the variable when a value is permanently removed from its
050         * domain
051         * 
052         * @param iteration
053         *            current iteration
054         * @param value
055         *            removed from the variable's domain
056         */
057        public void valueRemoved(long iteration, T value);
058    }