1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package javax.swing.text;
26
27 import java.util.Hashtable;
28 import java.util.Enumeration;
29 import java.util.Collections;
30 import java.io.IOException;
31 import java.io.ObjectInputStream;
32 import java.io.Serializable;
33 import java.util.AbstractMap;
34 import java.util.LinkedHashMap;
35
36 /**
37 * A straightforward implementation of MutableAttributeSet using a
38 * hash table.
39 * <p>
40 * <strong>Warning:</strong>
41 * Serialized objects of this class will not be compatible with
42 * future Swing releases. The current serialization support is
43 * appropriate for short term storage or RMI between applications running
44 * the same version of Swing. As of 1.4, support for long term storage
45 * of all JavaBeans™
46 * has been added to the <code>java.beans</code> package.
47 * Please see {@link java.beans.XMLEncoder}.
48 *
49 * @author Tim Prinzing
50 */
51 @SuppressWarnings("serial") // Same-version serialization only
52 public class SimpleAttributeSet implements MutableAttributeSet, Serializable, Cloneable
53 {
54 private static final long serialVersionUID = -6631553454711782652L;
55
56 /**
57 * An empty attribute set.
58 */
59 public static final AttributeSet EMPTY = new EmptyAttributeSet();
60
61 private transient LinkedHashMap<Object, Object> table = new LinkedHashMap<>(3);
62
63 /**
64 * Creates a new attribute set.
65 */
66 public SimpleAttributeSet() {
67 }
68
69 /**
70 * Creates a new attribute set based on a supplied set of attributes.
71 *
72 * @param source the set of attributes
73 */
74 public SimpleAttributeSet(AttributeSet source) {
75 addAttributes(source);
76 }
77
78 /**
79 * Checks whether the set of attributes is empty.
80 *
81 * @return true if the set is empty else false
82 */
83 public boolean isEmpty()
84 {
85 return table.isEmpty();
86 }
87
88 /**
89 * Gets a count of the number of attributes.
90 *
91 * @return the count
92 */
93 public int getAttributeCount() {
94 return table.size();
95 }
96
97 /**
98 * Tells whether a given attribute is defined.
99 *
100 * @param attrName the attribute name
101 * @return true if the attribute is defined
102 */
103 public boolean isDefined(Object attrName) {
104 return table.containsKey(attrName);
105 }
106
107 /**
108 * Compares two attribute sets.
109 *
110 * @param attr the second attribute set
111 * @return true if the sets are equal, false otherwise
112 */
113 public boolean isEqual(AttributeSet attr) {
114 return ((getAttributeCount() == attr.getAttributeCount()) &&
115 containsAttributes(attr));
116 }
117
118 /**
119 * Makes a copy of the attributes.
120 *
121 * @return the copy
122 */
123 public AttributeSet copyAttributes() {
124 return (AttributeSet) clone();
125 }
126
127 /**
128 * Gets the names of the attributes in the set.
129 *
130 * @return the names as an <code>Enumeration</code>
131 */
132 public Enumeration<?> getAttributeNames() {
133 return Collections.enumeration(table.keySet());
134 }
135
136 /**
137 * Gets the value of an attribute.
138 *
139 * @param name the attribute name
140 * @return the value
141 */
142 public Object getAttribute(Object name) {
143 Object value = table.get(name);
144 if (value == null) {
145 AttributeSet parent = getResolveParent();
146 if (parent != null) {
147 value = parent.getAttribute(name);
148 }
149 }
150 return value;
151 }
152
153 /**
154 * Checks whether the attribute list contains a
155 * specified attribute name/value pair.
156 *
157 * @param name the name
158 * @param value the value
159 * @return true if the name/value pair is in the list
160 */
161 public boolean containsAttribute(Object name, Object value) {
162 return value.equals(getAttribute(name));
163 }
164
165 /**
166 * Checks whether the attribute list contains all the
167 * specified name/value pairs.
168 *
169 * @param attributes the attribute list
170 * @return true if the list contains all the name/value pairs
171 */
172 public boolean containsAttributes(AttributeSet attributes) {
173 boolean result = true;
174
175 Enumeration<?> names = attributes.getAttributeNames();
176 while (result && names.hasMoreElements()) {
177 Object name = names.nextElement();
178 result = attributes.getAttribute(name).equals(getAttribute(name));
179 }
180
181 return result;
182 }
183
184 /**
185 * Adds an attribute to the list.
186 *
187 * @param name the attribute name
188 * @param value the attribute value
189 */
190 public void addAttribute(Object name, Object value) {
191 table.put(name, value);
192 }
193
194 /**
195 * Adds a set of attributes to the list.
196 *
197 * @param attributes the set of attributes to add
198 */
199 public void addAttributes(AttributeSet attributes) {
200 Enumeration<?> names = attributes.getAttributeNames();
201 while (names.hasMoreElements()) {
202 Object name = names.nextElement();
203 addAttribute(name, attributes.getAttribute(name));
204 }
205 }
206
207 /**
208 * Removes an attribute from the list.
209 *
210 * @param name the attribute name
211 */
212 public void removeAttribute(Object name) {
213 table.remove(name);
214 }
215
216 /**
217 * Removes a set of attributes from the list.
218 *
219 * @param names the set of names to remove
220 */
221 public void removeAttributes(Enumeration<?> names) {
222 while (names.hasMoreElements())
223 removeAttribute(names.nextElement());
224 }
225
226 /**
227 * Removes a set of attributes from the list.
228 *
229 * @param attributes the set of attributes to remove
230 */
231 public void removeAttributes(AttributeSet attributes) {
232 if (attributes == this) {
233 table.clear();
234 }
235 else {
236 Enumeration<?> names = attributes.getAttributeNames();
237 while (names.hasMoreElements()) {
238 Object name = names.nextElement();
239 Object value = attributes.getAttribute(name);
240 if (value.equals(getAttribute(name)))
241 removeAttribute(name);
242 }
243 }
244 }
245
246 /**
247 * Gets the resolving parent. This is the set
248 * of attributes to resolve through if an attribute
249 * isn't defined locally. This is null if there
250 * are no other sets of attributes to resolve
251 * through.
252 *
253 * @return the parent
254 */
255 public AttributeSet getResolveParent() {
256 return (AttributeSet) table.get(StyleConstants.ResolveAttribute);
257 }
258
259 /**
260 * Sets the resolving parent.
261 *
262 * @param parent the parent
263 */
264 public void setResolveParent(AttributeSet parent) {
265 addAttribute(StyleConstants.ResolveAttribute, parent);
266 }
267
268 // --- Object methods ---------------------------------
269
270 /**
271 * Clones a set of attributes.
272 *
273 * @return the new set of attributes
274 */
275 @SuppressWarnings("unchecked") // Cast of result of clone
276 public Object clone() {
277 SimpleAttributeSet attr;
278 try {
279 attr = (SimpleAttributeSet) super.clone();
280 attr.table = (LinkedHashMap) table.clone();
281 } catch (CloneNotSupportedException cnse) {
282 attr = null;
283 }
284 return attr;
285 }
286
287 /**
288 * Returns a hashcode for this set of attributes.
289 * @return a hashcode value for this set of attributes.
290 */
291 public int hashCode() {
292 return table.hashCode();
293 }
294
295 /**
296 * Compares this object to the specified object.
297 * The result is <code>true</code> if the object is an equivalent
298 * set of attributes.
299 * @param obj the object to compare this attribute set with
300 * @return <code>true</code> if the objects are equal;
301 * <code>false</code> otherwise
302 */
303 public boolean equals(Object obj) {
304 if (this == obj) {
305 return true;
306 }
307 if (obj instanceof AttributeSet) {
308 AttributeSet attrs = (AttributeSet) obj;
309 return isEqual(attrs);
310 }
311 return false;
312 }
313
314 /**
315 * Converts the attribute set to a String.
316 *
317 * @return the string
318 */
319 public String toString() {
320 String s = "";
321 Enumeration<?> names = getAttributeNames();
322 while (names.hasMoreElements()) {
323 Object key = names.nextElement();
324 Object value = getAttribute(key);
325 if (value instanceof AttributeSet) {
326 // don't go recursive
327 s = s + key + "=**AttributeSet** ";
328 } else {
329 s = s + key + "=" + value + " ";
330 }
331 }
332 return s;
333 }
334
335 private void writeObject(java.io.ObjectOutputStream s) throws IOException {
336 s.defaultWriteObject();
337 StyleContext.writeAttributeSet(s, this);
338 }
339
340 private void readObject(ObjectInputStream s)
341 throws ClassNotFoundException, IOException {
342 s.defaultReadObject();
343 table = new LinkedHashMap<>(3);
344 StyleContext.readAttributeSet(s, this);
345 }
346
347 /**
348 * An AttributeSet that is always empty.
349 */
350 static class EmptyAttributeSet implements AttributeSet, Serializable {
351 static final long serialVersionUID = -8714803568785904228L;
352
353 public int getAttributeCount() {
354 return 0;
355 }
356 public boolean isDefined(Object attrName) {
357 return false;
358 }
359 public boolean isEqual(AttributeSet attr) {
360 return (attr.getAttributeCount() == 0);
361 }
362 public AttributeSet copyAttributes() {
363 return this;
364 }
365 public Object getAttribute(Object key) {
366 return null;
367 }
368 public Enumeration<?> getAttributeNames() {
369 return Collections.emptyEnumeration();
370 }
371 public boolean containsAttribute(Object name, Object value) {
372 return false;
373 }
374 public boolean containsAttributes(AttributeSet attributes) {
375 return (attributes.getAttributeCount() == 0);
376 }
377 public AttributeSet getResolveParent() {
378 return null;
379 }
380 public boolean equals(Object obj) {
381 if (this == obj) {
382 return true;
383 }
384 return ((obj instanceof AttributeSet) &&
385 (((AttributeSet)obj).getAttributeCount() == 0));
386 }
387 public int hashCode() {
388 return 0;
389 }
390 }
391 }