001 /* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2008, 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 2004-2008, by Object Refinery Limited and Contributors.
031 *
032 * Original Author: David Gilbert (for Object Refinery Limited);
033 * Contributor(s): -;
034 *
035 * Changes
036 * -------
037 * 29-Apr-2004 : Version 1 (DG);
038 * 07-Jul-2004 : Added a group list to ensure group index is consistent, fixed
039 * cloning problem (DG);
040 * 18-Aug-2005 : Added casts in clone() method to suppress 1.5 compiler
041 * warnings - see patch 1260587 (DG);
042 *
043 */
044
045 package org.jfree.data;
046
047 import java.io.Serializable;
048 import java.lang.reflect.Method;
049 import java.lang.reflect.Modifier;
050 import java.util.ArrayList;
051 import java.util.Collection;
052 import java.util.HashMap;
053 import java.util.Iterator;
054 import java.util.List;
055 import java.util.Map;
056
057 import org.jfree.util.ObjectUtilities;
058 import org.jfree.util.PublicCloneable;
059
060 /**
061 * A class that maps keys (instances of <code>Comparable</code>) to groups.
062 */
063 public class KeyToGroupMap implements Cloneable, PublicCloneable, Serializable {
064
065 /** For serialization. */
066 private static final long serialVersionUID = -2228169345475318082L;
067
068 /** The default group. */
069 private Comparable defaultGroup;
070
071 /** The groups. */
072 private List groups;
073
074 /** A mapping between keys and groups. */
075 private Map keyToGroupMap;
076
077 /**
078 * Creates a new map with a default group named 'Default Group'.
079 */
080 public KeyToGroupMap() {
081 this("Default Group");
082 }
083
084 /**
085 * Creates a new map with the specified default group.
086 *
087 * @param defaultGroup the default group (<code>null</code> not permitted).
088 */
089 public KeyToGroupMap(Comparable defaultGroup) {
090 if (defaultGroup == null) {
091 throw new IllegalArgumentException("Null 'defaultGroup' argument.");
092 }
093 this.defaultGroup = defaultGroup;
094 this.groups = new ArrayList();
095 this.keyToGroupMap = new HashMap();
096 }
097
098 /**
099 * Returns the number of groups in the map.
100 *
101 * @return The number of groups in the map.
102 */
103 public int getGroupCount() {
104 return this.groups.size() + 1;
105 }
106
107 /**
108 * Returns a list of the groups (always including the default group) in the
109 * map. The returned list is independent of the map, so altering the list
110 * will have no effect.
111 *
112 * @return The groups (never <code>null</code>).
113 */
114 public List getGroups() {
115 List result = new ArrayList();
116 result.add(this.defaultGroup);
117 Iterator iterator = this.groups.iterator();
118 while (iterator.hasNext()) {
119 Comparable group = (Comparable) iterator.next();
120 if (!result.contains(group)) {
121 result.add(group);
122 }
123 }
124 return result;
125 }
126
127 /**
128 * Returns the index for the group.
129 *
130 * @param group the group.
131 *
132 * @return The group index (or -1 if the group is not represented within
133 * the map).
134 */
135 public int getGroupIndex(Comparable group) {
136 int result = this.groups.indexOf(group);
137 if (result < 0) {
138 if (this.defaultGroup.equals(group)) {
139 result = 0;
140 }
141 }
142 else {
143 result = result + 1;
144 }
145 return result;
146 }
147
148 /**
149 * Returns the group that a key is mapped to.
150 *
151 * @param key the key (<code>null</code> not permitted).
152 *
153 * @return The group (never <code>null</code>, returns the default group if
154 * there is no mapping for the specified key).
155 */
156 public Comparable getGroup(Comparable key) {
157 if (key == null) {
158 throw new IllegalArgumentException("Null 'key' argument.");
159 }
160 Comparable result = this.defaultGroup;
161 Comparable group = (Comparable) this.keyToGroupMap.get(key);
162 if (group != null) {
163 result = group;
164 }
165 return result;
166 }
167
168 /**
169 * Maps a key to a group.
170 *
171 * @param key the key (<code>null</code> not permitted).
172 * @param group the group (<code>null</code> permitted, clears any
173 * existing mapping).
174 */
175 public void mapKeyToGroup(Comparable key, Comparable group) {
176 if (key == null) {
177 throw new IllegalArgumentException("Null 'key' argument.");
178 }
179 Comparable currentGroup = getGroup(key);
180 if (!currentGroup.equals(this.defaultGroup)) {
181 if (!currentGroup.equals(group)) {
182 int count = getKeyCount(currentGroup);
183 if (count == 1) {
184 this.groups.remove(currentGroup);
185 }
186 }
187 }
188 if (group == null) {
189 this.keyToGroupMap.remove(key);
190 }
191 else {
192 if (!this.groups.contains(group)) {
193 if (!this.defaultGroup.equals(group)) {
194 this.groups.add(group);
195 }
196 }
197 this.keyToGroupMap.put(key, group);
198 }
199 }
200
201 /**
202 * Returns the number of keys mapped to the specified group. This method
203 * won't always return an accurate result for the default group, since
204 * explicit mappings are not required for this group.
205 *
206 * @param group the group (<code>null</code> not permitted).
207 *
208 * @return The key count.
209 */
210 public int getKeyCount(Comparable group) {
211 if (group == null) {
212 throw new IllegalArgumentException("Null 'group' argument.");
213 }
214 int result = 0;
215 Iterator iterator = this.keyToGroupMap.values().iterator();
216 while (iterator.hasNext()) {
217 Comparable g = (Comparable) iterator.next();
218 if (group.equals(g)) {
219 result++;
220 }
221 }
222 return result;
223 }
224
225 /**
226 * Tests the map for equality against an arbitrary object.
227 *
228 * @param obj the object to test against (<code>null</code> permitted).
229 *
230 * @return A boolean.
231 */
232 public boolean equals(Object obj) {
233 if (obj == this) {
234 return true;
235 }
236 if (!(obj instanceof KeyToGroupMap)) {
237 return false;
238 }
239 KeyToGroupMap that = (KeyToGroupMap) obj;
240 if (!ObjectUtilities.equal(this.defaultGroup, that.defaultGroup)) {
241 return false;
242 }
243 if (!this.keyToGroupMap.equals(that.keyToGroupMap)) {
244 return false;
245 }
246 return true;
247 }
248
249 /**
250 * Returns a clone of the map.
251 *
252 * @return A clone.
253 *
254 * @throws CloneNotSupportedException if there is a problem cloning the
255 * map.
256 */
257 public Object clone() throws CloneNotSupportedException {
258 KeyToGroupMap result = (KeyToGroupMap) super.clone();
259 result.defaultGroup
260 = (Comparable) KeyToGroupMap.clone(this.defaultGroup);
261 result.groups = (List) KeyToGroupMap.clone(this.groups);
262 result.keyToGroupMap = (Map) KeyToGroupMap.clone(this.keyToGroupMap);
263 return result;
264 }
265
266 /**
267 * Attempts to clone the specified object using reflection.
268 *
269 * @param object the object (<code>null</code> permitted).
270 *
271 * @return The cloned object, or the original object if cloning failed.
272 */
273 private static Object clone(Object object) {
274 if (object == null) {
275 return null;
276 }
277 Class c = object.getClass();
278 Object result = null;
279 try {
280 Method m = c.getMethod("clone", (Class[]) null);
281 if (Modifier.isPublic(m.getModifiers())) {
282 try {
283 result = m.invoke(object, (Object[]) null);
284 }
285 catch (Exception e) {
286 e.printStackTrace();
287 }
288 }
289 }
290 catch (NoSuchMethodException e) {
291 result = object;
292 }
293 return result;
294 }
295
296 /**
297 * Returns a clone of the list.
298 *
299 * @param list the list.
300 *
301 * @return A clone of the list.
302 *
303 * @throws CloneNotSupportedException if the list could not be cloned.
304 */
305 private static Collection clone(Collection list)
306 throws CloneNotSupportedException {
307 Collection result = null;
308 if (list != null) {
309 try {
310 List clone = (List) list.getClass().newInstance();
311 Iterator iterator = list.iterator();
312 while (iterator.hasNext()) {
313 clone.add(KeyToGroupMap.clone(iterator.next()));
314 }
315 result = clone;
316 }
317 catch (Exception e) {
318 throw new CloneNotSupportedException("Exception.");
319 }
320 }
321 return result;
322 }
323
324 }