001 /*
002 $Id: Sequence.java,v 1.4 2005/04/12 16:38:42 jstrachan Exp $
003
004 Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005
006 Redistribution and use of this software and associated documentation
007 ("Software"), with or without modification, are permitted provided
008 that the following conditions are met:
009
010 1. Redistributions of source code must retain copyright
011 statements and notices. Redistributions must also contain a
012 copy of this document.
013
014 2. Redistributions in binary form must reproduce the
015 above copyright notice, this list of conditions and the
016 following disclaimer in the documentation and/or other
017 materials provided with the distribution.
018
019 3. The name "groovy" must not be used to endorse or promote
020 products derived from this Software without prior written
021 permission of The Codehaus. For written permission,
022 please contact info@codehaus.org.
023
024 4. Products derived from this Software may not be called "groovy"
025 nor may "groovy" appear in their names without prior written
026 permission of The Codehaus. "groovy" is a registered
027 trademark of The Codehaus.
028
029 5. Due credit should be given to The Codehaus -
030 http://groovy.codehaus.org/
031
032 THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS
033 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
034 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
035 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
036 THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
037 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
038 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
039 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
040 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
041 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
042 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
043 OF THE POSSIBILITY OF SUCH DAMAGE.
044
045 */
046 package groovy.lang;
047
048 import java.util.ArrayList;
049 import java.util.Collection;
050 import java.util.Iterator;
051 import java.util.List;
052
053 import org.codehaus.groovy.runtime.InvokerHelper;
054
055 /**
056 * Represents a sequence of objects which represents zero or many instances of
057 * of objects of a given type. The type can be ommitted in which case any type of
058 * object can be added.
059 *
060 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
061 * @version $Revision: 1.4 $
062 */
063 public class Sequence extends ArrayList implements GroovyObject {
064
065 private MetaClass metaClass = InvokerHelper.getMetaClass(this);
066 private Class type;
067 private int hashCode;
068
069 public Sequence() {
070 this(null);
071 }
072
073 public Sequence(Class type) {
074 this.type = type;
075 }
076
077 public Sequence(Class type, List content) {
078 super(content.size());
079 this.type = type;
080 addAll(content);
081 }
082
083 /**
084 * Sets the contents of this sequence to that
085 * of the given collection.
086 */
087 public void set(Collection collection) {
088 checkCollectionType(collection);
089 clear();
090 addAll(collection);
091 }
092
093 public boolean equals(Object that) {
094 if (that instanceof Sequence) {
095 return equals((Sequence) that);
096 }
097 return false;
098 }
099
100 public boolean equals(Sequence that) {
101 if (size() == that.size()) {
102 for (int i = 0; i < size(); i++) {
103 if (!InvokerHelper.compareEqual(this.get(i), that.get(i))) {
104 return false;
105 }
106 }
107 return true;
108 }
109 return false;
110 }
111
112 public int hashCode() {
113 if (hashCode == 0) {
114 for (int i = 0; i < size(); i++) {
115 Object value = get(i);
116 int hash = (value != null) ? value.hashCode() : 0xbabe;
117 hashCode ^= hash;
118 }
119 if (hashCode == 0) {
120 hashCode = 0xbabe;
121 }
122 }
123 return hashCode;
124 }
125
126 public int minimumSize() {
127 return 0;
128 }
129
130 /**
131 * @return the type of the elements in the sequence or null if there is no
132 * type constraint on this sequence
133 */
134 public Class type() {
135 return type;
136 }
137
138 public void add(int index, Object element) {
139 checkType(element);
140 hashCode = 0;
141 super.add(index, element);
142 }
143
144 public boolean add(Object element) {
145 checkType(element);
146 hashCode = 0;
147 return super.add(element);
148 }
149
150 public boolean addAll(Collection c) {
151 checkCollectionType(c);
152 hashCode = 0;
153 return super.addAll(c);
154 }
155
156 public boolean addAll(int index, Collection c) {
157 checkCollectionType(c);
158 hashCode = 0;
159 return super.addAll(index, c);
160 }
161
162 public void clear() {
163 hashCode = 0;
164 super.clear();
165 }
166
167 public Object remove(int index) {
168 hashCode = 0;
169 return super.remove(index);
170 }
171
172 protected void removeRange(int fromIndex, int toIndex) {
173 hashCode = 0;
174 super.removeRange(fromIndex, toIndex);
175 }
176
177 public Object set(int index, Object element) {
178 hashCode = 0;
179 return super.set(index, element);
180 }
181
182 // GroovyObject interface
183 //-------------------------------------------------------------------------
184 public Object invokeMethod(String name, Object args) {
185 try {
186 return getMetaClass().invokeMethod(this, name, args);
187 }
188 catch (MissingMethodException e) {
189 // lets apply the method to each item in the collection
190 List answer = new ArrayList(size());
191 for (Iterator iter = iterator(); iter.hasNext(); ) {
192 Object element = iter.next();
193 Object value = InvokerHelper.invokeMethod(element, name, args);
194 answer.add(value);
195 }
196 return answer;
197 }
198 }
199
200 public Object getProperty(String property) {
201 return getMetaClass().getProperty(this, property);
202 }
203
204 public void setProperty(String property, Object newValue) {
205 getMetaClass().setProperty(this, property, newValue);
206 }
207
208 public MetaClass getMetaClass() {
209 return metaClass;
210 }
211
212 public void setMetaClass(MetaClass metaClass) {
213 this.metaClass = metaClass;
214 }
215
216 // Implementation methods
217 //-------------------------------------------------------------------------
218
219 /**
220 * Checks that each member of the given collection are of the correct
221 * type
222 */
223 protected void checkCollectionType(Collection c) {
224 if (type != null) {
225 for (Iterator iter = c.iterator(); iter.hasNext(); ) {
226 Object element = iter.next();
227 checkType(element);
228 }
229 }
230 }
231
232
233 /**
234 * Checks that the given object instance is of the correct type
235 * otherwise a runtime exception is thrown
236 */
237 protected void checkType(Object object) {
238 if (object == null) {
239 throw new NullPointerException("Sequences cannot contain null, use a List instead");
240 }
241 if (type != null) {
242 if (!type.isInstance(object)) {
243 throw new IllegalArgumentException(
244 "Invalid type of argument for sequence of type: "
245 + type.getName()
246 + " cannot add object: "
247 + object);
248 }
249 }
250 }
251 }