001/*
002 * Copyright (c) 2005-2010 The Regents of the University of California.
003 * All rights reserved.
004 *
005 * '$Author: welker $'
006 * '$Date: 2010-05-06 05:21:26 +0000 (Thu, 06 May 2010) $' 
007 * '$Revision: 24234 $'
008 * 
009 * Permission is hereby granted, without written agreement and without
010 * license or royalty fees, to use, copy, modify, and distribute this
011 * software and its documentation for any purpose, provided that the above
012 * copyright notice and the following two paragraphs appear in all copies
013 * of this software.
014 *
015 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
016 * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
017 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
018 * THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
019 * SUCH DAMAGE.
020 *
021 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
022 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
023 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
024 * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
025 * CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
026 * ENHANCEMENTS, OR MODIFICATIONS.
027 *
028 */
029
030package org.resurgence.actor;
031
032import ptolemy.actor.TypedAtomicActor;
033import ptolemy.actor.TypedIOPort;
034import ptolemy.actor.parameters.PortParameter;
035import ptolemy.data.BooleanToken;
036import ptolemy.data.IntToken;
037import ptolemy.data.Token;
038import ptolemy.data.expr.StringParameter;
039import ptolemy.data.type.BaseType;
040import ptolemy.kernel.CompositeEntity;
041import ptolemy.kernel.util.Attribute;
042import ptolemy.kernel.util.IllegalActionException;
043import ptolemy.kernel.util.NameDuplicationException;
044
045//////////////////////////////////////////////////////////////////////////
046//// BooleanAccumulator
047
048/**
049 * This actor reads a sequence of boolean values and writes one boolean value
050 * from their combination.
051 * 
052 * @author Wibke Sudholt, University and ETH Zurich, November 2004
053 * @version $Id: BooleanAccumulator.java 24234 2010-05-06 05:21:26Z welker $
054 */
055public class BooleanAccumulator extends TypedAtomicActor {
056
057        /**
058         * Construct a BooleanAccumulator with the given container and name.
059         * 
060         * @param container
061         *            The container.
062         * @param name
063         *            The name of this actor.
064         * @exception IllegalActionException
065         *                If the entity cannot be contained by the proposed
066         *                container.
067         * @exception NameDuplicationException
068         *                If the container already has an actor with this name.
069         */
070        public BooleanAccumulator(CompositeEntity container, String name)
071                        throws NameDuplicationException, IllegalActionException {
072                super(container, name);
073
074                booleans = new TypedIOPort(this, "booleans", true, false);
075                booleans.setTypeEquals(BaseType.BOOLEAN);
076
077                combination = new TypedIOPort(this, "combination", false, true);
078                combination.setTypeEquals(BaseType.BOOLEAN);
079
080                operation = new StringParameter(this, "Logical operator");
081                operation.addChoice("and");
082                operation.addChoice("or");
083                operation.setExpression("and");
084
085                number = new PortParameter(this, "number");
086                number.setExpression("1");
087        }
088
089        // /////////////////////////////////////////////////////////////////
090        // // ports and parameters ////
091
092        /**
093         * The input port, which contains the booleans.
094         */
095        public TypedIOPort booleans = null;
096        /**
097         * The output port, which contains their combination.
098         */
099        public TypedIOPort combination = null;
100        /**
101         * The parameter, which specifies the logical operator.
102         */
103        public StringParameter operation = null;
104        /**
105         * The port parameter, which specifies the number of booleans in the
106         * sequence and defaults to 1.
107         */
108        public PortParameter number = null;
109
110        // /////////////////////////////////////////////////////////////////
111        // // public methods ////
112
113        /**
114         * Check the validity of the <i>number</i> parameter value, set the
115         * consumption rate of the input port, and, if necessary, invalidate the
116         * current schedule of the director.
117         * 
118         * @param attribute
119         *            The attribute that has changed.
120         * @exception IllegalActionException
121         *                If the parameter is out of range.
122         */
123        public void attributeChanged(Attribute attribute)
124                        throws IllegalActionException {
125                if (attribute == number) {
126                        _length = ((IntToken) number.getToken()).intValue();
127                        if (_length < 0) {
128                                throw new IllegalActionException(this, "Invalid number: "
129                                                + _length);
130                        }
131                } else {
132                        super.attributeChanged(attribute);
133                }
134        }
135
136        /**
137         * Take the booleans and combine them.
138         * 
139         * @exception IllegalActionException
140         *                If there's no director or if the operation is wrong.
141         */
142        public void fire() throws IllegalActionException {
143                super.fire();
144                number.update();
145                _length = ((IntToken) number.getToken()).intValue();
146                _array = booleans.get(0, _length);
147                _logic = operation.stringValue();
148                _sum = (BooleanToken) _array[0];
149                if (_logic.equalsIgnoreCase("and")) {
150                        for (int i = 1; i < _length; i++) {
151                                _sum = _sum.and((BooleanToken) _array[i]);
152                        }
153                } else if (_logic.equalsIgnoreCase("or")) {
154                        for (int i = 1; i < _length; i++) {
155                                _sum = _sum.or((BooleanToken) _array[i]);
156                        }
157                } else {
158                        _sum = null;
159                        throw new IllegalActionException(this, "Invalid operation: "
160                                        + _logic);
161                }
162                combination.send(0, _sum);
163        }
164
165        /**
166         * Post fire the actor. Return false to indicate that the process has
167         * finished. If it returns true, the process will continue indefinitely.
168         */
169        public boolean postfire() {
170                return false;
171        }
172
173        /**
174         * Prefire the actor. Return true if the input port has enough tokens for
175         * this actor to fire. The number of tokens required is determined by the
176         * value of the <i>number</i> parameter.
177         * 
178         * @return boolean True if there are enough tokens at the input port for
179         *         this actor to fire.
180         * @exception IllegalActionException
181         *                If the hasToken() query to the input port throws it.
182         */
183        public boolean prefire() throws IllegalActionException {
184                _length = ((IntToken) number.getToken()).intValue();
185                if (!booleans.hasToken(0, _length)) {
186                        if (_debugging) {
187                                _debug("Called prefire(), which returns false.");
188                        }
189                        return false;
190                } else {
191                        return super.prefire();
192                }
193        }
194
195        // /////////////////////////////////////////////////////////////////
196        // // protected members ////
197
198        // /////////////////////////////////////////////////////////////////
199        // // private methods ////
200
201        // /////////////////////////////////////////////////////////////////
202        // // private members ////
203
204        private int _length;
205        private Token[] _array;
206        private String _logic;
207        private BooleanToken _sum;
208}