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,
066: Serializable {
067:
068: /** For serialization. */
069: private static final long serialVersionUID = -2228169345475318082L;
070:
071: /** The default group. */
072: private Comparable defaultGroup;
073:
074: /** The groups. */
075: private List groups;
076:
077: /** A mapping between keys and groups. */
078: private Map keyToGroupMap;
079:
080: /**
081: * Creates a new map with a default group named 'Default Group'.
082: */
083: public KeyToGroupMap() {
084: this ("Default Group");
085: }
086:
087: /**
088: * Creates a new map with the specified default group.
089: *
090: * @param defaultGroup the default group (<code>null</code> not permitted).
091: */
092: public KeyToGroupMap(Comparable defaultGroup) {
093: if (defaultGroup == null) {
094: throw new IllegalArgumentException(
095: "Null 'defaultGroup' argument.");
096: }
097: this .defaultGroup = defaultGroup;
098: this .groups = new ArrayList();
099: this .keyToGroupMap = new HashMap();
100: }
101:
102: /**
103: * Returns the number of groups in the map.
104: *
105: * @return The number of groups in the map.
106: */
107: public int getGroupCount() {
108: return this .groups.size() + 1;
109: }
110:
111: /**
112: * Returns a list of the groups (always including the default group) in the
113: * map. The returned list is independent of the map, so altering the list
114: * will have no effect.
115: *
116: * @return The groups (never <code>null</code>).
117: */
118: public List getGroups() {
119: List result = new ArrayList();
120: result.add(this .defaultGroup);
121: Iterator iterator = this .groups.iterator();
122: while (iterator.hasNext()) {
123: Comparable group = (Comparable) iterator.next();
124: if (!result.contains(group)) {
125: result.add(group);
126: }
127: }
128: return result;
129: }
130:
131: /**
132: * Returns the index for the group.
133: *
134: * @param group the group.
135: *
136: * @return The group index (or -1 if the group is not represented within
137: * the map).
138: */
139: public int getGroupIndex(Comparable group) {
140: int result = this .groups.indexOf(group);
141: if (result < 0) {
142: if (this .defaultGroup.equals(group)) {
143: result = 0;
144: }
145: } else {
146: result = result + 1;
147: }
148: return result;
149: }
150:
151: /**
152: * Returns the group that a key is mapped to.
153: *
154: * @param key the key (<code>null</code> not permitted).
155: *
156: * @return The group (never <code>null</code>, returns the default group if
157: * there is no mapping for the specified key).
158: */
159: public Comparable getGroup(Comparable key) {
160: if (key == null) {
161: throw new IllegalArgumentException("Null 'key' argument.");
162: }
163: Comparable result = this .defaultGroup;
164: Comparable group = (Comparable) this .keyToGroupMap.get(key);
165: if (group != null) {
166: result = group;
167: }
168: return result;
169: }
170:
171: /**
172: * Maps a key to a group.
173: *
174: * @param key the key (<code>null</code> not permitted).
175: * @param group the group (<code>null</code> permitted, clears any
176: * existing mapping).
177: */
178: public void mapKeyToGroup(Comparable key, Comparable group) {
179: if (key == null) {
180: throw new IllegalArgumentException("Null 'key' argument.");
181: }
182: Comparable currentGroup = getGroup(key);
183: if (!currentGroup.equals(this .defaultGroup)) {
184: if (!currentGroup.equals(group)) {
185: int count = getKeyCount(currentGroup);
186: if (count == 1) {
187: this .groups.remove(currentGroup);
188: }
189: }
190: }
191: if (group == null) {
192: this .keyToGroupMap.remove(key);
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
243: .equal(this .defaultGroup, that.defaultGroup)) {
244: return false;
245: }
246: if (!this .keyToGroupMap.equals(that.keyToGroupMap)) {
247: return false;
248: }
249: return true;
250: }
251:
252: /**
253: * Returns a clone of the map.
254: *
255: * @return A clone.
256: *
257: * @throws CloneNotSupportedException if there is a problem cloning the
258: * map.
259: */
260: public Object clone() throws CloneNotSupportedException {
261: KeyToGroupMap result = (KeyToGroupMap) super .clone();
262: result.defaultGroup = (Comparable) KeyToGroupMap
263: .clone(this .defaultGroup);
264: result.groups = (List) KeyToGroupMap.clone(this .groups);
265: result.keyToGroupMap = (Map) KeyToGroupMap
266: .clone(this .keyToGroupMap);
267: return result;
268: }
269:
270: /**
271: * Attempts to clone the specified object using reflection.
272: *
273: * @param object the object (<code>null</code> permitted).
274: *
275: * @return The cloned object, or the original object if cloning failed.
276: */
277: private static Object clone(Object object) {
278: if (object == null) {
279: return null;
280: }
281: Class c = object.getClass();
282: Object result = null;
283: try {
284: Method m = c.getMethod("clone", (Class[]) null);
285: if (Modifier.isPublic(m.getModifiers())) {
286: try {
287: result = m.invoke(object, (Object[]) null);
288: } catch (Exception e) {
289: e.printStackTrace();
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: } catch (Exception e) {
319: throw new CloneNotSupportedException("Exception.");
320: }
321: }
322: return result;
323: }
324:
325: }
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