001 /** 002 * ======================================== 003 * JFreeReport : a free Java report library 004 * ======================================== 005 * 006 * Project Info: http://reporting.pentaho.org/ 007 * 008 * (C) Copyright 2000-2007, by Object Refinery Limited, 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 * $Id: GroupByExpression.java 3525 2007-10-16 11:43:48Z tmorgner $ 027 * ------------ 028 * (C) Copyright 2000-2005, by Object Refinery Limited. 029 * (C) Copyright 2005-2007, by Pentaho Corporation. 030 */ 031 package org.jfree.report.expressions.sys; 032 033 import java.util.ArrayList; 034 import java.util.Arrays; 035 036 import org.jfree.report.DataFlags; 037 import org.jfree.report.DataRow; 038 import org.jfree.report.DataSourceException; 039 import org.jfree.report.expressions.AbstractExpression; 040 041 /** 042 * Creation-Date: 08.10.2006, 16:28:37 043 * 044 * @author Thomas Morgner 045 */ 046 public class GroupByExpression extends AbstractExpression 047 { 048 private ArrayList fields; 049 private transient String[] fieldsCached; 050 051 public GroupByExpression() 052 { 053 this.fields = new ArrayList(); 054 } 055 056 /** 057 * Return the current expression value. <P> The value depends (obviously) on 058 * the expression implementation. 059 * 060 * @return the value of the function. 061 */ 062 public Object computeValue() throws DataSourceException 063 { 064 final DataRow dr = getDataRow(); 065 final String[] columns = getField(); 066 for (int i = 0; i < columns.length; i++) 067 { 068 final String column = columns[i]; 069 final DataFlags df = dr.getFlags(column); 070 if (df == null) 071 { 072 // invalid column or invalid implementation ... 073 continue; 074 } 075 if (df.isChanged()) 076 { 077 //Log.debug ("Field: " + df.getName() + " has changed to " + df.getValue()); 078 return Boolean.TRUE; 079 } 080 } 081 return Boolean.FALSE; 082 } 083 084 public void setField (final int index, final String field) 085 { 086 if (fields.size() == index) 087 { 088 fields.add(field); 089 } 090 else 091 { 092 fields.set(index, field); 093 } 094 fieldsCached = null; 095 } 096 097 public String getField (final int index) 098 { 099 return (String) fields.get(index); 100 } 101 102 public int getFieldCount () 103 { 104 return fields.size(); 105 } 106 107 public String[] getField () 108 { 109 if (fieldsCached == null) 110 { 111 fieldsCached = (String[]) fields.toArray(new String[fields.size()]); 112 } 113 return (String[]) fieldsCached.clone(); 114 } 115 116 public void setField (final String[] fields) 117 { 118 this.fields.clear(); 119 this.fields.addAll(Arrays.asList(fields)); 120 this.fieldsCached = (String[]) fields.clone(); 121 } 122 123 public Object clone() throws CloneNotSupportedException 124 { 125 final GroupByExpression co = (GroupByExpression) super.clone(); 126 co.fields = (ArrayList) fields.clone(); 127 co.fieldsCached = fieldsCached; 128 return co; 129 } 130 }