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: MinusSignOperator.java 2887 2007-06-06 17:07:52Z taqua $
028 * ------------
029 * (C) Copyright 2006-2007, by Pentaho Corporation.
030 */
031 package org.jfree.formula.operators;
032
033 import java.math.BigDecimal;
034
035 import org.jfree.formula.EvaluationException;
036 import org.jfree.formula.FormulaContext;
037 import org.jfree.formula.LibFormulaErrorValue;
038 import org.jfree.formula.lvalues.TypeValuePair;
039 import org.jfree.formula.typing.Type;
040 import org.jfree.formula.typing.TypeRegistry;
041
042 /**
043 * Creation-Date: 02.11.2006, 10:27:03
044 *
045 * @author Thomas Morgner
046 */
047 public class MinusSignOperator implements PrefixOperator
048 {
049 private static final BigDecimal ZERO = new BigDecimal(0);
050
051
052 public MinusSignOperator()
053 {
054 }
055
056 public TypeValuePair evaluate(final FormulaContext context,
057 final TypeValuePair value1)
058 throws EvaluationException
059 {
060 final Type type = value1.getType();
061 final Object val = value1.getValue();
062 if (val == null)
063 {
064 throw new EvaluationException(LibFormulaErrorValue.ERROR_NA_VALUE);
065 }
066
067 if (type.isFlagSet(Type.NUMERIC_TYPE))
068 {
069 final TypeRegistry typeRegistry = context.getTypeRegistry();
070 // return the same as zero minus value.
071 final Number number = typeRegistry.convertToNumber(type, val);
072 final BigDecimal value = getAsBigDecimal(number);
073 return new TypeValuePair(type, ZERO.subtract(value));
074 }
075
076 if(val instanceof Number)
077 {
078 final BigDecimal value = getAsBigDecimal((Number)val);
079 return new TypeValuePair(type, ZERO.subtract(value));
080 }
081
082 throw new EvaluationException
083 (LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
084 }
085
086 private BigDecimal getAsBigDecimal(final Number number)
087 {
088 if (number instanceof BigDecimal)
089 {
090 return (BigDecimal) number;
091 }
092 return new BigDecimal(number.toString());
093 }
094
095 public String toString()
096 {
097 return "-";
098 }
099 }