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: RightFunction.java 2752 2007-04-10 14:10:41Z taqua $ 028 * ------------ 029 * (C) Copyright 2006-2007, by Pentaho Corporation. 030 */ 031 package org.jfree.formula.function.text; 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.TextType; 042 043 /** 044 * This function returns a selected number of text characters from the right.<br/> 045 * This function depends on <code>MidFunction</code>. 046 * 047 * @see MidFunction 048 * 049 * @author Cedric Pronzato 050 * 051 */ 052 public class RightFunction implements Function 053 { 054 public RightFunction() 055 { 056 } 057 058 public TypeValuePair evaluate(final FormulaContext context, 059 final ParameterCallback parameters) throws EvaluationException 060 { 061 final int parameterCount = parameters.getParameterCount(); 062 if (parameterCount < 1 || parameterCount > 2) 063 { 064 throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE); 065 } 066 final TypeRegistry typeRegistry = context.getTypeRegistry(); 067 068 final Type textType = parameters.getType(0); 069 final Object textValue = parameters.getValue(0); 070 071 final String text = typeRegistry.convertToText(textType, textValue); 072 final int length; 073 if(parameterCount == 2) 074 { 075 final Number lengthVal = typeRegistry.convertToNumber(parameters.getType(1), parameters.getValue(1)); 076 if (lengthVal.doubleValue() < 0) 077 { 078 throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 079 } 080 length = lengthVal.intValue(); 081 } 082 else 083 { 084 length = 1; 085 } 086 087 if(text == null || length < 0) 088 { 089 throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 090 } 091 092 int s = text.length()-length +1; 093 if(s < 1) 094 { 095 s = 1; 096 } 097 final MidFunction function = new MidFunction(); 098 return new TypeValuePair(TextType.TYPE, function.process(text, new Integer(s), new Integer(length))); 099 } 100 101 public String getCanonicalName() 102 { 103 return "RIGHT"; 104 } 105 106 }