001package net.sf.cpsolver.ifs.example.tt;
002
003import java.util.Set;
004
005import net.sf.cpsolver.ifs.model.BinaryConstraint;
006
007/**
008 * Binary dependence between two activities.
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 class Dependence extends BinaryConstraint<Activity, Location> {
030    public static final int TYPE_NO_DEPENDENCE = 0;
031    public static final int TYPE_BEFORE = 1;
032    public static final int TYPE_CLOSELY_BEFORE = 2;
033    public static final int TYPE_AFTER = 3;
034    public static final int TYPE_CLOSELY_AFTER = 4;
035    public static final int TYPE_CONCURRENCY = 5;
036    private int iType = TYPE_NO_DEPENDENCE;
037    private String iResourceId = null;
038
039    public Dependence(String id, int type) {
040        super();
041        iType = type;
042        iResourceId = id;
043    }
044
045    public int getType() {
046        return iType;
047    }
048
049    public String getResourceId() {
050        return iResourceId;
051    }
052
053    @Override
054    public void computeConflicts(Location location, Set<Location> conflicts) {
055        Activity activity = location.variable();
056        Activity another = another(activity);
057        Location anotherLocation = another.getAssignment();
058        if (anotherLocation == null)
059            return;
060        if (isFirst(activity)) {
061            if (!isConsistent(location.getSlot(), activity.getLength(), anotherLocation.getSlot(), another.getLength()))
062                conflicts.add(anotherLocation);
063        } else {
064            if (!isConsistent(anotherLocation.getSlot(), another.getLength(), location.getSlot(), activity.getLength()))
065                conflicts.add(anotherLocation);
066        }
067    }
068
069    public boolean isConsistent(int s1, int l1, int s2, int l2) {
070        switch (iType) {
071            case TYPE_BEFORE:
072                return s1 + l1 <= s2;
073            case TYPE_CLOSELY_BEFORE:
074                return s1 + l1 == s2;
075            case TYPE_AFTER:
076                return s2 + l2 <= s1;
077            case TYPE_CLOSELY_AFTER:
078                return s2 + l2 == s1;
079            case TYPE_CONCURRENCY:
080                return (s1 <= s2 && s2 + l2 <= s1 + l1) || (s2 <= s1 && s1 + l1 <= s2 + l2);
081            default:
082                return true;
083        }
084    }
085
086    @Override
087    public boolean inConflict(Location location) {
088        Activity activity = location.variable();
089        Activity another = another(activity);
090        Location anotherLocation = another.getAssignment();
091        if (anotherLocation == null)
092            return false;
093        if (isFirst(activity)) {
094            return !isConsistent(location.getSlot(), activity.getLength(), anotherLocation.getSlot(), another
095                    .getLength());
096        } else {
097            return !isConsistent(anotherLocation.getSlot(), another.getLength(), location.getSlot(), activity
098                    .getLength());
099        }
100    }
101
102    @Override
103    public boolean isConsistent(Location l1, Location l2) {
104        Activity a1 = l1.variable();
105        Activity a2 = l2.variable();
106        if (isFirst(a1)) {
107            return !isConsistent(l1.getSlot(), a1.getLength(), l2.getSlot(), a2.getLength());
108        } else {
109            return !isConsistent(l2.getSlot(), a2.getLength(), l1.getSlot(), a1.getLength());
110        }
111    }
112
113    @Override
114    public String getName() {
115        switch (iType) {
116            case TYPE_BEFORE:
117                return first().getName() + "<" + second().getName();
118            case TYPE_CLOSELY_BEFORE:
119                return first().getName() + "<|" + second().getName();
120            case TYPE_AFTER:
121                return first().getName() + ">" + second().getName();
122            case TYPE_CLOSELY_AFTER:
123                return first().getName() + "|>" + second().getName();
124            case TYPE_CONCURRENCY:
125                return first().getName() + "||" + second().getName();
126            default:
127                return first().getName() + "?" + second().getName();
128        }
129    }
130
131}