001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
006 *
007 * Project Info: http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
022 * USA.
023 *
024 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
025 * in the United States and other countries.]
026 *
027 * ------------------
028 * KeyToGroupMap.java
029 * ------------------
030 * (C) Copyright 2004, 2005, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * $Id: KeyToGroupMap.java,v 1.7.2.2 2005/10/25 21:29:13 mungady Exp $
036 *
037 * Changes
038 * -------
039 * 29-Apr-2004 : Version 1 (DG);
040 * 07-Jul-2004 : Added a group list to ensure group index is consistent, fixed
041 * cloning problem (DG);
042 * 18-Aug-2005 : Added casts in clone() method to suppress 1.5 compiler
043 * warnings - see patch 1260587 (DG);
044 *
045 */
046
047 package org.jfree.data;
048
049 import java.io.Serializable;
050 import java.lang.reflect.Method;
051 import java.lang.reflect.Modifier;
052 import java.util.ArrayList;
053 import java.util.Collection;
054 import java.util.HashMap;
055 import java.util.Iterator;
056 import java.util.List;
057 import java.util.Map;
058
059 import org.jfree.util.ObjectUtilities;
060 import org.jfree.util.PublicCloneable;
061
062 /**
063 * A class that maps keys (instances of <code>Comparable</code>) to groups.
064 */
065 public class KeyToGroupMap implements Cloneable, PublicCloneable, Serializable {
066
067 /** For serialization. */
068 private static final long serialVersionUID = -2228169345475318082L;
069
070 /** The default group. */
071 private Comparable defaultGroup;
072
073 /** The groups. */
074 private List groups;
075
076 /** A mapping between keys and groups. */
077 private Map keyToGroupMap;
078
079 /**
080 * Creates a new map with a default group named 'Default Group'.
081 */
082 public KeyToGroupMap() {
083 this("Default Group");
084 }
085
086 /**
087 * Creates a new map with the specified default group.
088 *
089 * @param defaultGroup the default group (<code>null</code> not permitted).
090 */
091 public KeyToGroupMap(Comparable defaultGroup) {
092 if (defaultGroup == null) {
093 throw new IllegalArgumentException("Null 'defaultGroup' argument.");
094 }
095 this.defaultGroup = defaultGroup;
096 this.groups = new ArrayList();
097 this.keyToGroupMap = new HashMap();
098 }
099
100 /**
101 * Returns the number of groups in the map.
102 *
103 * @return The number of groups in the map.
104 */
105 public int getGroupCount() {
106 return this.groups.size() + 1;
107 }
108
109 /**
110 * Returns a list of the groups (always including the default group) in the
111 * map. The returned list is independent of the map, so altering the list
112 * will have no effect.
113 *
114 * @return The groups (never <code>null</code>).
115 */
116 public List getGroups() {
117 List result = new ArrayList();
118 result.add(this.defaultGroup);
119 Iterator iterator = this.groups.iterator();
120 while (iterator.hasNext()) {
121 Comparable group = (Comparable) iterator.next();
122 if (!result.contains(group)) {
123 result.add(group);
124 }
125 }
126 return result;
127 }
128
129 /**
130 * Returns the index for the group.
131 *
132 * @param group the group.
133 *
134 * @return The group index (or -1 if the group is not represented within
135 * the map).
136 */
137 public int getGroupIndex(Comparable group) {
138 int result = this.groups.indexOf(group);
139 if (result < 0) {
140 if (this.defaultGroup.equals(group)) {
141 result = 0;
142 }
143 }
144 else {
145 result = result + 1;
146 }
147 return result;
148 }
149
150 /**
151 * Returns the group that a key is mapped to.
152 *
153 * @param key the key (<code>null</code> not permitted).
154 *
155 * @return The group (never <code>null</code>, returns the default group if
156 * there is no mapping for the specified key).
157 */
158 public Comparable getGroup(Comparable key) {
159 if (key == null) {
160 throw new IllegalArgumentException("Null 'key' argument.");
161 }
162 Comparable result = this.defaultGroup;
163 Comparable group = (Comparable) this.keyToGroupMap.get(key);
164 if (group != null) {
165 result = group;
166 }
167 return result;
168 }
169
170 /**
171 * Maps a key to a group.
172 *
173 * @param key the key (<code>null</code> not permitted).
174 * @param group the group (<code>null</code> permitted, clears any
175 * existing mapping).
176 */
177 public void mapKeyToGroup(Comparable key, Comparable group) {
178 if (key == null) {
179 throw new IllegalArgumentException("Null 'key' argument.");
180 }
181 Comparable currentGroup = getGroup(key);
182 if (!currentGroup.equals(this.defaultGroup)) {
183 if (!currentGroup.equals(group)) {
184 int count = getKeyCount(currentGroup);
185 if (count == 1) {
186 this.groups.remove(currentGroup);
187 }
188 }
189 }
190 if (group == null) {
191 this.keyToGroupMap.remove(key);
192 }
193 else {
194 if (!this.groups.contains(group)) {
195 if (!this.defaultGroup.equals(group)) {
196 this.groups.add(group);
197 }
198 }
199 this.keyToGroupMap.put(key, group);
200 }
201 }
202
203 /**
204 * Returns the number of keys mapped to the specified group. This method
205 * won't always return an accurate result for the default group, since
206 * explicit mappings are not required for this group.
207 *
208 * @param group the group (<code>null</code> not permitted).
209 *
210 * @return The key count.
211 */
212 public int getKeyCount(Comparable group) {
213 if (group == null) {
214 throw new IllegalArgumentException("Null 'group' argument.");
215 }
216 int result = 0;
217 Iterator iterator = this.keyToGroupMap.values().iterator();
218 while (iterator.hasNext()) {
219 Comparable g = (Comparable) iterator.next();
220 if (group.equals(g)) {
221 result++;
222 }
223 }
224 return result;
225 }
226
227 /**
228 * Tests the map for equality against an arbitrary object.
229 *
230 * @param obj the object to test against (<code>null</code> permitted).
231 *
232 * @return A boolean.
233 */
234 public boolean equals(Object obj) {
235 if (obj == this) {
236 return true;
237 }
238 if (!(obj instanceof KeyToGroupMap)) {
239 return false;
240 }
241 KeyToGroupMap that = (KeyToGroupMap) obj;
242 if (!ObjectUtilities.equal(this.defaultGroup, that.defaultGroup)) {
243 return false;
244 }
245 if (!this.keyToGroupMap.equals(that.keyToGroupMap)) {
246 return false;
247 }
248 return true;
249 }
250
251 /**
252 * Returns a clone of the map.
253 *
254 * @return A clone.
255 *
256 * @throws CloneNotSupportedException if there is a problem cloning the
257 * map.
258 */
259 public Object clone() throws CloneNotSupportedException {
260 KeyToGroupMap result = (KeyToGroupMap) super.clone();
261 result.defaultGroup
262 = (Comparable) KeyToGroupMap.clone(this.defaultGroup);
263 result.groups = (List) KeyToGroupMap.clone(this.groups);
264 result.keyToGroupMap = (Map) KeyToGroupMap.clone(this.keyToGroupMap);
265 return result;
266 }
267
268 /**
269 * Attempts to clone the specified object using reflection.
270 *
271 * @param object the object (<code>null</code> permitted).
272 *
273 * @return The cloned object, or the original object if cloning failed.
274 */
275 private static Object clone(Object object) {
276 if (object == null) {
277 return null;
278 }
279 Class c = object.getClass();
280 Object result = null;
281 try {
282 Method m = c.getMethod("clone", (Class[]) null);
283 if (Modifier.isPublic(m.getModifiers())) {
284 try {
285 result = m.invoke(object, (Object[]) null);
286 }
287 catch (Exception e) {
288 e.printStackTrace();
289 }
290 }
291 }
292 catch (NoSuchMethodException e) {
293 result = object;
294 }
295 return result;
296 }
297
298 /**
299 * Returns a clone of the list.
300 *
301 * @param list the list.
302 *
303 * @return A clone of the list.
304 *
305 * @throws CloneNotSupportedException if the list could not be cloned.
306 */
307 private static Collection clone(Collection list)
308 throws CloneNotSupportedException {
309 Collection result = null;
310 if (list != null) {
311 try {
312 List clone = (List) list.getClass().newInstance();
313 Iterator iterator = list.iterator();
314 while (iterator.hasNext()) {
315 clone.add(KeyToGroupMap.clone(iterator.next()));
316 }
317 result = clone;
318 }
319 catch (Exception e) {
320 throw new CloneNotSupportedException("Exception.");
321 }
322 }
323 return result;
324 }
325
326 }