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: RunningExpressionSlot.java,v 1.5 2007/04/01 18:49:24 taqua Exp $
027 * ------------
028 * (C) Copyright 2000-2005, by Object Refinery Limited.
029 * (C) Copyright 2005-2007, by Pentaho Corporation.
030 */
031
032 package org.jfree.report.data;
033
034 import org.jfree.report.DataRow;
035 import org.jfree.report.DataSourceException;
036 import org.jfree.report.ReportData;
037 import org.jfree.report.expressions.Expression;
038 import org.jfree.report.expressions.ExpressionRuntime;
039 import org.jfree.report.expressions.Function;
040 import org.jfree.report.flow.ReportContext;
041 import org.jfree.report.i18n.ResourceBundleFactory;
042 import org.jfree.util.Configuration;
043
044 /**
045 * Creation-Date: 25.11.2006, 15:18:58
046 *
047 * @author Thomas Morgner
048 */
049 public class RunningExpressionSlot
050 implements ExpressionSlot, ExpressionRuntime
051 {
052 private StaticExpressionRuntimeData staticRuntimeData;
053 private Expression expression;
054 private Object value;
055 private String name;
056 private boolean queried;
057 private DataRow dataRow;
058
059 public RunningExpressionSlot(final Expression expression,
060 final StaticExpressionRuntimeData runtimeData,
061 final PrecomputeNode precomputeNode)
062 {
063 this.staticRuntimeData = runtimeData;
064 this.expression = expression;
065 this.name = expression.getName();
066 this.expression.setRuntime(this);
067 this.expression.setRuntime(null);
068 }
069
070 public Expression getExpression()
071 {
072 return expression;
073 }
074
075 public Object getValue() throws DataSourceException
076 {
077 if (queried == false)
078 {
079 //noinspection SynchronizeOnNonFinalField
080 synchronized (expression)
081 {
082 expression.setRuntime(this);
083 value = expression.computeValue();
084 expression.setRuntime(null);
085 }
086 queried = true;
087 }
088 return value;
089 }
090
091 public String getName()
092 {
093 return name;
094 }
095
096 public DataRow getDataRow()
097 {
098 return dataRow;
099 }
100
101 public Object clone() throws CloneNotSupportedException
102 {
103 return super.clone();
104 }
105
106 public void updateDataRow(final DataRow dataRow)
107 {
108 this.dataRow = dataRow;
109 }
110
111 /**
112 * Returns the report data used in this section. If subreports are used, this
113 * does not reflect the complete report data.
114 * <p/>
115 * All access to the report data must be properly synchronized. Failure to do
116 * so may result in funny results. Do not assume that the report data will be
117 * initialized on the current cursor positon.
118 *
119 * @return
120 */
121 public ReportData getData()
122 {
123 return staticRuntimeData.getData();
124 }
125
126 public Object getDeclaringParent()
127 {
128 return staticRuntimeData.getDeclaringParent();
129 }
130
131 public Configuration getConfiguration()
132 {
133 return staticRuntimeData.getConfiguration();
134 }
135
136 public ResourceBundleFactory getResourceBundleFactory()
137 {
138 return staticRuntimeData.getResourceBundleFactory();
139 }
140
141 public void advance() throws DataSourceException
142 {
143 if (expression instanceof Function)
144 {
145 Function f = (Function) expression;
146 expression.setRuntime(this);
147 expression = f.advance();
148 f.setRuntime(null);
149 expression.setRuntime(null);
150 }
151 value = null;
152 queried = false;
153 }
154
155 public boolean isDeepTraversing()
156 {
157 return expression.isDeepTraversing();
158 }
159
160 public int getCurrentRow()
161 {
162 return staticRuntimeData.getCurrentRow();
163 }
164
165 public ReportContext getReportContext()
166 {
167 return staticRuntimeData.getReportContext();
168 }
169
170 public boolean isPreserve()
171 {
172 return expression.isPreserve();
173 }
174 }