001 /**
002 * =========================================
003 * LibFormula : a free Java formula library
004 * =========================================
005 *
006 * Project Info: http://reporting.pentaho.org/libformula/
007 *
008 * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
009 *
010 * This library is free software; you can redistribute it and/or modify it under the terms
011 * of the GNU Lesser General Public License as published by the Free Software Foundation;
012 * either version 2.1 of the License, or (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
015 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
016 * See the GNU Lesser General Public License for more details.
017 *
018 * You should have received a copy of the GNU Lesser General Public License along with this
019 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
020 * Boston, MA 02111-1307, USA.
021 *
022 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
023 * in the United States and other countries.]
024 *
025 *
026 * ------------
027 * $Id: IsOddFunction.java 3521 2007-10-16 10:55:14Z tmorgner $
028 * ------------
029 * (C) Copyright 2006-2007, by Pentaho Corporation.
030 */
031 package org.jfree.formula.function.information;
032
033 import org.jfree.formula.EvaluationException;
034 import org.jfree.formula.FormulaContext;
035 import org.jfree.formula.LibFormulaErrorValue;
036 import org.jfree.formula.function.Function;
037 import org.jfree.formula.function.ParameterCallback;
038 import org.jfree.formula.lvalues.TypeValuePair;
039 import org.jfree.formula.typing.Type;
040 import org.jfree.formula.typing.TypeRegistry;
041 import org.jfree.formula.typing.coretypes.LogicalType;
042
043 /**
044 * This function retruns true if the given value is an odd number.
045 *
046 * @author Cedric Pronzato
047 *
048 */
049 public class IsOddFunction implements Function
050 {
051 private static final TypeValuePair RETURN_TRUE = new TypeValuePair(
052 LogicalType.TYPE, Boolean.TRUE);
053
054 private static final TypeValuePair RETURN_FALSE = new TypeValuePair(
055 LogicalType.TYPE, Boolean.FALSE);
056
057 public IsOddFunction()
058 {
059 }
060
061 public TypeValuePair evaluate(final FormulaContext context,
062 final ParameterCallback parameters) throws EvaluationException
063 {
064 final int parameterCount = parameters.getParameterCount();
065 if (parameterCount < 1)
066 {
067 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE);
068 }
069
070 final Type type1 = parameters.getType(0);
071 final Object value = parameters.getValue(0);
072
073 final TypeRegistry typeRegistry = context.getTypeRegistry();
074 final Number number = typeRegistry.convertToNumber(type1, value);
075
076 if (number == null)
077 {
078 throw new EvaluationException(
079 LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
080 }
081
082 int intValue = number.intValue();
083 if (intValue < 0)
084 {
085 intValue *= -1;
086 }
087
088 if (intValue % 2 == 1)
089 {
090 return RETURN_TRUE;
091 }
092
093 return RETURN_FALSE;
094 }
095
096 public String getCanonicalName()
097 {
098 return "ISODD";
099 }
100
101 }