001 /*
002 $Id: Sequence.java 4098 2006-10-10 16:09:48Z blackdrag $
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 import org.codehaus.groovy.runtime.typehandling.DefaultTypeTransformation;
055
056 /**
057 * Represents a sequence of objects which represents zero or many instances of
058 * of objects of a given type. The type can be ommitted in which case any type of
059 * object can be added.
060 *
061 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
062 * @version $Revision: 4098 $
063 */
064 public class Sequence extends ArrayList implements GroovyObject {
065
066 private MetaClass metaClass = InvokerHelper.getMetaClass(this);
067 private Class type;
068 private int hashCode;
069
070 public Sequence() {
071 this(null);
072 }
073
074 public Sequence(Class type) {
075 this.type = type;
076 }
077
078 public Sequence(Class type, List content) {
079 super(content.size());
080 this.type = type;
081 addAll(content);
082 }
083
084 /**
085 * Sets the contents of this sequence to that
086 * of the given collection.
087 */
088 public void set(Collection collection) {
089 checkCollectionType(collection);
090 clear();
091 addAll(collection);
092 }
093
094 public boolean equals(Object that) {
095 if (that instanceof Sequence) {
096 return equals((Sequence) that);
097 }
098 return false;
099 }
100
101 public boolean equals(Sequence that) {
102 if (size() == that.size()) {
103 for (int i = 0; i < size(); i++) {
104 if (!DefaultTypeTransformation.compareEqual(this.get(i), that.get(i))) {
105 return false;
106 }
107 }
108 return true;
109 }
110 return false;
111 }
112
113 public int hashCode() {
114 if (hashCode == 0) {
115 for (int i = 0; i < size(); i++) {
116 Object value = get(i);
117 int hash = (value != null) ? value.hashCode() : 0xbabe;
118 hashCode ^= hash;
119 }
120 if (hashCode == 0) {
121 hashCode = 0xbabe;
122 }
123 }
124 return hashCode;
125 }
126
127 public int minimumSize() {
128 return 0;
129 }
130
131 /**
132 * @return the type of the elements in the sequence or null if there is no
133 * type constraint on this sequence
134 */
135 public Class type() {
136 return type;
137 }
138
139 public void add(int index, Object element) {
140 checkType(element);
141 hashCode = 0;
142 super.add(index, element);
143 }
144
145 public boolean add(Object element) {
146 checkType(element);
147 hashCode = 0;
148 return super.add(element);
149 }
150
151 public boolean addAll(Collection c) {
152 checkCollectionType(c);
153 hashCode = 0;
154 return super.addAll(c);
155 }
156
157 public boolean addAll(int index, Collection c) {
158 checkCollectionType(c);
159 hashCode = 0;
160 return super.addAll(index, c);
161 }
162
163 public void clear() {
164 hashCode = 0;
165 super.clear();
166 }
167
168 public Object remove(int index) {
169 hashCode = 0;
170 return super.remove(index);
171 }
172
173 protected void removeRange(int fromIndex, int toIndex) {
174 hashCode = 0;
175 super.removeRange(fromIndex, toIndex);
176 }
177
178 public Object set(int index, Object element) {
179 hashCode = 0;
180 return super.set(index, element);
181 }
182
183 // GroovyObject interface
184 //-------------------------------------------------------------------------
185 public Object invokeMethod(String name, Object args) {
186 try {
187 return getMetaClass().invokeMethod(this, name, args);
188 }
189 catch (MissingMethodException e) {
190 // lets apply the method to each item in the collection
191 List answer = new ArrayList(size());
192 for (Iterator iter = iterator(); iter.hasNext(); ) {
193 Object element = iter.next();
194 Object value = InvokerHelper.invokeMethod(element, name, args);
195 answer.add(value);
196 }
197 return answer;
198 }
199 }
200
201 public Object getProperty(String property) {
202 return getMetaClass().getProperty(this, property);
203 }
204
205 public void setProperty(String property, Object newValue) {
206 getMetaClass().setProperty(this, property, newValue);
207 }
208
209 public MetaClass getMetaClass() {
210 return metaClass;
211 }
212
213 public void setMetaClass(MetaClass metaClass) {
214 this.metaClass = metaClass;
215 }
216
217 // Implementation methods
218 //-------------------------------------------------------------------------
219
220 /**
221 * Checks that each member of the given collection are of the correct
222 * type
223 */
224 protected void checkCollectionType(Collection c) {
225 if (type != null) {
226 for (Iterator iter = c.iterator(); iter.hasNext(); ) {
227 Object element = iter.next();
228 checkType(element);
229 }
230 }
231 }
232
233
234 /**
235 * Checks that the given object instance is of the correct type
236 * otherwise a runtime exception is thrown
237 */
238 protected void checkType(Object object) {
239 if (object == null) {
240 throw new NullPointerException("Sequences cannot contain null, use a List instead");
241 }
242 if (type != null) {
243 if (!type.isInstance(object)) {
244 throw new IllegalArgumentException(
245 "Invalid type of argument for sequence of type: "
246 + type.getName()
247 + " cannot add object: "
248 + object);
249 }
250 }
251 }
252 }