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: PercentageOperator.java 4100 2007-11-26 21:04:25Z dkincade $
028     * ------------
029     * (C) Copyright 2006-2007, by Pentaho Corporation.
030     */
031    package org.jfree.formula.operators;
032    
033    import org.jfree.formula.EvaluationException;
034    import org.jfree.formula.FormulaContext;
035    import org.jfree.formula.LibFormulaErrorValue;
036    import org.jfree.formula.lvalues.TypeValuePair;
037    import org.jfree.formula.typing.Type;
038    import org.jfree.formula.typing.TypeRegistry;
039    import org.jfree.formula.typing.coretypes.NumberType;
040    
041    import java.math.BigDecimal;
042    
043    /**
044     * Creation-Date: 02.11.2006, 10:27:03
045     *
046     * @author Thomas Morgner
047     */
048    public class PercentageOperator implements PostfixOperator
049    {
050      private static final BigDecimal HUNDRED = new BigDecimal(100);
051    
052    
053      public PercentageOperator()
054      {
055      }
056    
057    
058      public TypeValuePair evaluate(final FormulaContext context, final TypeValuePair value1)
059          throws EvaluationException
060      {
061        final Object rawValue = value1.getValue();
062        if (rawValue == null)
063        {
064          throw new EvaluationException(LibFormulaErrorValue.ERROR_NA_VALUE);
065        }
066    
067        final Type type = value1.getType();
068        final TypeRegistry typeRegistry = context.getTypeRegistry();
069    
070        if (type.isFlagSet(Type.NUMERIC_TYPE) == false &&
071            type.isFlagSet(Type.ANY_TYPE) == false)
072        {
073          throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
074        }
075    
076        // return the same as zero minus value.
077        final Number number = typeRegistry.convertToNumber(type, rawValue);
078        final BigDecimal value = OperatorUtility.getAsBigDecimal(number);
079        final BigDecimal divide = value.divide(HUNDRED, value.scale()+2,BigDecimal.ROUND_HALF_UP);
080        return new TypeValuePair(NumberType.GENERIC_NUMBER, divide);
081      }
082    
083      public String toString()
084      {
085        return "%";
086      }
087    
088    }
089