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1: /** 2: * ======================================== 3: * JFreeReport : a free Java report library 4: * ======================================== 5: * 6: * Project Info: http://reporting.pentaho.org/ 7: * 8: * (C) Copyright 2000-2007, by Object Refinery Limited, 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: * $Id: GroupByExpression.java 3525 2007-10-16 11:43:48Z tmorgner $ 27: * ------------ 28: * (C) Copyright 2000-2005, by Object Refinery Limited. 29: * (C) Copyright 2005-2007, by Pentaho Corporation. 30: */ 31: package org.jfree.report.expressions.sys; 32: 33: import java.util.ArrayList; 34: import java.util.Arrays; 35: 36: import org.jfree.report.DataFlags; 37: import org.jfree.report.DataRow; 38: import org.jfree.report.DataSourceException; 39: import org.jfree.report.expressions.AbstractExpression; 40: 41: /** 42: * Creation-Date: 08.10.2006, 16:28:37 43: * 44: * @author Thomas Morgner 45: */ 46: public class GroupByExpression extends AbstractExpression 47: { 48: private ArrayList fields; 49: private transient String[] fieldsCached; 50: 51: public GroupByExpression() 52: { 53: this.fields = new ArrayList(); 54: } 55: 56: /** 57: * Return the current expression value. <P> The value depends (obviously) on 58: * the expression implementation. 59: * 60: * @return the value of the function. 61: */ 62: public Object computeValue() throws DataSourceException 63: { 64: final DataRow dr = getDataRow(); 65: final String[] columns = getField(); 66: for (int i = 0; i < columns.length; i++) 67: { 68: final String column = columns[i]; 69: final DataFlags df = dr.getFlags(column); 70: if (df == null) 71: { 72: // invalid column or invalid implementation ... 73: continue; 74: } 75: if (df.isChanged()) 76: { 77: //Log.debug ("Field: " + df.getName() + " has changed to " + df.getValue()); 78: return Boolean.TRUE; 79: } 80: } 81: return Boolean.FALSE; 82: } 83: 84: public void setField (final int index, final String field) 85: { 86: if (fields.size() == index) 87: { 88: fields.add(field); 89: } 90: else 91: { 92: fields.set(index, field); 93: } 94: fieldsCached = null; 95: } 96: 97: public String getField (final int index) 98: { 99: 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: }