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1: /** 2: * ========================================= 3: * LibFormula : a free Java formula library 4: * ========================================= 5: * 6: * Project Info: http://reporting.pentaho.org/libformula/ 7: * 8: * (C) Copyright 2006-2007, by Pentaho Corporation and Contributors. 9: * 10: * This library is free software; you can redistribute it and/or modify it under the terms 11: * of the GNU Lesser General Public License as published by the Free Software Foundation; 12: * either version 2.1 of the License, or (at your option) any later version. 13: * 14: * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 15: * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 16: * See the GNU Lesser General Public License for more details. 17: * 18: * You should have received a copy of the GNU Lesser General Public License along with this 19: * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, 20: * Boston, MA 02111-1307, USA. 21: * 22: * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 23: * in the United States and other countries.] 24: * 25: * 26: * ------------ 27: * $Id: TrimFunction.java,v 1.7 2007/04/01 13:51:53 taqua Exp $ 28: * ------------ 29: * (C) Copyright 2006-2007, by Pentaho Corporation. 30: */ 31: package org.jfree.formula.function.text; 32: 33: import org.jfree.formula.EvaluationException; 34: import org.jfree.formula.FormulaContext; 35: import org.jfree.formula.LibFormulaErrorValue; 36: import org.jfree.formula.function.Function; 37: import org.jfree.formula.function.ParameterCallback; 38: import org.jfree.formula.lvalues.TypeValuePair; 39: import org.jfree.formula.typing.Type; 40: import org.jfree.formula.typing.coretypes.TextType; 41: 42: /** 43: * This function returns the given text free of leading spaces. 44: * Removes all leading and trailing spaces and all extra spaces inside the text. 45: * 46: * @author Cedric Pronzato 47: * @see http://mercury.ccil.org/%7Ecowan/OF/textfuncs.html 48: */ 49: public class TrimFunction implements Function 50: { 51: public TrimFunction() 52: { 53: } 54: 55: public TypeValuePair evaluate(FormulaContext context, ParameterCallback parameters) throws EvaluationException 56: { 57: final int parameterCount = parameters.getParameterCount(); 58: if (parameterCount < 1) 59: { 60: throw new EvaluationException(LibFormulaErrorValue.ERROR_ARGUMENTS_VALUE); 61: } 62: final Type type1 = parameters.getType(0); 63: final Object value1 = parameters.getValue(0); 64: final String result = context.getTypeRegistry().convertToText(type1, value1); 65: 66: if(result == null) 67: { 68: throw new EvaluationException(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE); 69: } 70: 71: // remove all unnecessary spaces .. 72: // we dont use regexps, because they are JDK 1.4, but this library is aimed 73: // for JDK 1.2.2 74: 75: final char[] chars = result.toCharArray(); 76: final StringBuffer b = new StringBuffer(chars.length); 77: boolean removeNextWs = true; 78: 79: for (int i = 0; i < chars.length; i++) 80: { 81: final char c = chars[i]; 82: if (Character.isWhitespace(c)) 83: { 84: if (removeNextWs) 85: { 86: continue; 87: } 88: b.append(c); 89: removeNextWs = true; 90: continue; 91: } 92: 93: b.append(c); 94: removeNextWs = false; 95: } 96: 97: // now check whether the last char is a whitespace and remove that one 98: // if neccessary 99: final String trimmedResult; 100: if (removeNextWs) 101: { 102: trimmedResult = b.substring(0, b.length() - 1); 103: } 104: else 105: { 106: trimmedResult = b.toString(); 107: } 108: 109: return new TypeValuePair(TextType.TYPE, trimmedResult); 110: } 111: 112: public String getCanonicalName() 113: { 114: return "TRIM"; 115: } 116: 117: }