    001package org.cpsolver.coursett.preference;
    002
    003import org.cpsolver.coursett.Constants;
    004
    005/**
    006 * Preference combination. <br>
    007 * <br>
    008 * A preference can be:
    009 * <ul>
    010 * <li>R .. required
    011 * <li>P .. prohibited
    012 * <li>number .. soft preference (smaller value is better)
    013 * </ul>
    014 *
    015 * @author  Tomáš Müller
    016 * @version CourseTT 1.3 (University Course Timetabling)<br>
    017 *          Copyright (C) 2006 - 2014 Tomáš Müller<br>
    018 *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
    019 *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
    020 * <br>
    021 *          This library is free software; you can redistribute it and/or modify
    022 *          it under the terms of the GNU Lesser General Public License as
    023 *          published by the Free Software Foundation; either version 3 of the
    024 *          License, or (at your option) any later version. <br>
    025 * <br>
    026 *          This library is distributed in the hope that it will be useful, but
    027 *          WITHOUT ANY WARRANTY; without even the implied warranty of
    028 *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    029 *          Lesser General Public License for more details. <br>
    030 * <br>
    031 *          You should have received a copy of the GNU Lesser General Public
    032 *          License along with this library; if not see
    033 *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
    034 */
    035public abstract class PreferenceCombination {
    036    boolean iIsRequired = false;
    037    boolean iIsProhibited = false;
    038
    039    public PreferenceCombination() {}
    040
    041    public PreferenceCombination(PreferenceCombination c) {
    042        iIsProhibited = c.iIsProhibited;
    043        iIsRequired = c.iIsRequired;
    044    }
    045
    046    /** Add preference a preference
    047     * @param prologPref prolog preference (R for required, P for prohibited, -2 strongly preferred, ... 2 strongly discouraged)
    048     **/
    049    public void addPreferenceProlog(String prologPref) {
    050        addPreferenceInt(Constants.preference2preferenceLevel(prologPref));
    051    }
    052
    053    /** Returns combined preference from the given preferences
    054     * @param intPref preference
    055     **/
    056    public void addPreferenceInt(int intPref) {
    057        String prologPref = Constants.preferenceLevel2preference(intPref);
    058        if (Constants.sPreferenceRequired.equals(prologPref))
    059            iIsRequired = true;
    060        if (Constants.sPreferenceProhibited.equals(prologPref))
    061            iIsProhibited = true;
    062    }
    063
    064    public boolean isRequired() {
    065        return iIsRequired && !iIsProhibited;
    066    }
    067
    068    public boolean isProhibited() {
    069        return iIsProhibited;
    070    }
    071
    072    public abstract PreferenceCombination clonePreferenceCombination();
    073
    074    public abstract int getPreferenceInt();
    075
    076    public String getPreferenceProlog() {
    077        if (iIsProhibited)
    078            return Constants.sPreferenceProhibited;
    079        if (iIsRequired)
    080            return Constants.sPreferenceRequired;
    081        return Constants.preferenceLevel2preference(getPreferenceInt());
    082    }
    083
    084    public static PreferenceCombination getDefault() {
    085        return new SumPreferenceCombination();
    086    }
    087}