/**
* Copyright (c) 1999-2014, Ecole des Mines de Nantes
* All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the Ecole des Mines de Nantes nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* Created by IntelliJ IDEA.
* User: Jean-Guillaume Fages
* Date: 04/02/13
* Time: 15:48
*/
package solver.variables;
import solver.exception.ContradictionException;
import solver.exception.SolverException;
import solver.explanations.Deduction;
import solver.explanations.Explanation;
import solver.variables.events.IEventType;
import solver.variables.events.IntEventType;
/**
* Container representing a task:
* It ensures that: start + duration = end
*
* @author Jean-Guillaume Fages
* @since 04/02/2013
*/
public class Task {
//***********************************************************************************
// VARIABLES
//***********************************************************************************
private IntVar start, duration, end;
private IVariableMonitor update;
//***********************************************************************************
// CONSTRUCTORS
//***********************************************************************************
/**
* Container representing a task:
* It ensures that: start + duration = end
*
* @param s start variable
* @param d duration variable
* @param e end variable
*/
public Task(IntVar s, IntVar d, IntVar e) {
start = s;
duration = d;
end = e;
if (s.hasEnumeratedDomain() || d.hasEnumeratedDomain() || e.hasEnumeratedDomain()) {
update = new IVariableMonitor() {
@Override
public void onUpdate(Variable var, IEventType evt) throws ContradictionException {
boolean fixpoint = true;
while (fixpoint) {
// start
fixpoint = start.updateLowerBound(end.getLB() - duration.getUB(), this);
fixpoint |= start.updateUpperBound(end.getUB() - duration.getLB(), this);
// end
fixpoint |= end.updateLowerBound(start.getLB() + duration.getLB(), this);
fixpoint |= end.updateUpperBound(start.getUB() + duration.getUB(), this);
// duration
fixpoint |= duration.updateLowerBound(end.getLB() - start.getUB(), this);
fixpoint |= duration.updateUpperBound(end.getUB() - start.getLB(), this);
}
}
@Override
public void explain(Deduction d, Explanation e) {
throw new SolverException("A task cannot explain itself yet.");
}
};
} else {
update = new IVariableMonitor() {
@Override
public void onUpdate(Variable var, IEventType evt) throws ContradictionException {
// start
start.updateLowerBound(end.getLB() - duration.getUB(), this);
start.updateUpperBound(end.getUB() - duration.getLB(), this);
// end
end.updateLowerBound(start.getLB() + duration.getLB(), this);
end.updateUpperBound(start.getUB() + duration.getUB(), this);
// duration
duration.updateLowerBound(end.getLB() - start.getUB(), this);
duration.updateUpperBound(end.getUB() - start.getLB(), this);
}
@Override
public void explain(Deduction d, Explanation e) {
throw new SolverException("A task cannot explain itself yet.");
}
};
}
start.addMonitor(update);
duration.addMonitor(update);
end.addMonitor(update);
}
//***********************************************************************************
// METHODS
//***********************************************************************************
/**
* Applies BC-filtering so that start + duration = end
*
* @throws ContradictionException
*/
public void ensureBoundConsistency() throws ContradictionException {
update.onUpdate(start, IntEventType.REMOVE);
}
//***********************************************************************************
// ACCESSORS
//***********************************************************************************
public IntVar getStart() {
return start;
}
public void setStart(IntVar start) {
this.start = start;
}
public IntVar getDuration() {
return duration;
}
public void setDuration(IntVar duration) {
this.duration = duration;
}
public IntVar getEnd() {
return end;
}
public void setEnd(IntVar end) {
this.end = end;
}
}