1 /*
2 * Copyright (c) 1998, 2010, 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
26 package javax.swing.text;
27
28 import java.io.Serializable;
29
30 /**
31 * A TabSet is comprised of many TabStops. It offers methods for locating the
32 * closest TabStop to a given position and finding all the potential TabStops.
33 * It is also immutable.
34 * <p>
35 * <strong>Warning:</strong>
36 * Serialized objects of this class will not be compatible with
37 * future Swing releases. The current serialization support is
38 * appropriate for short term storage or RMI between applications running
39 * the same version of Swing. As of 1.4, support for long term storage
40 * of all JavaBeans™
41 * has been added to the <code>java.beans</code> package.
42 * Please see {@link java.beans.XMLEncoder}.
43 *
44 * @author Scott Violet
45 */
46 public class TabSet implements Serializable
47 {
48 /** TabStops this TabSet contains. */
49 private TabStop[] tabs;
50 /**
51 * Since this class is immutable the hash code could be
52 * calculated once. MAX_VALUE means that it was not initialized
53 * yet. Hash code shouldn't has MAX_VALUE value.
54 */
55 private int hashCode = Integer.MAX_VALUE;
56
57 /**
58 * Creates and returns an instance of TabSet. The array of Tabs
59 * passed in must be sorted in ascending order.
60 */
61 public TabSet(TabStop[] tabs) {
62 // PENDING(sky): If this becomes a problem, make it sort.
63 if(tabs != null) {
64 int tabCount = tabs.length;
65
66 this.tabs = new TabStop[tabCount];
67 System.arraycopy(tabs, 0, this.tabs, 0, tabCount);
68 }
69 else
70 this.tabs = null;
71 }
72
73 /**
74 * Returns the number of Tab instances the receiver contains.
75 */
76 public int getTabCount() {
77 return (tabs == null) ? 0 : tabs.length;
78 }
79
80 /**
81 * Returns the TabStop at index <code>index</code>. This will throw an
82 * IllegalArgumentException if <code>index</code> is outside the range
83 * of tabs.
84 */
85 public TabStop getTab(int index) {
86 int numTabs = getTabCount();
87
88 if(index < 0 || index >= numTabs)
89 throw new IllegalArgumentException(index +
90 " is outside the range of tabs");
91 return tabs[index];
92 }
93
94 /**
95 * Returns the Tab instance after <code>location</code>. This will
96 * return null if there are no tabs after <code>location</code>.
97 */
98 public TabStop getTabAfter(float location) {
99 int index = getTabIndexAfter(location);
100
101 return (index == -1) ? null : tabs[index];
102 }
103
104 /**
105 * @return the index of the TabStop <code>tab</code>, or -1 if
106 * <code>tab</code> is not contained in the receiver.
107 */
108 public int getTabIndex(TabStop tab) {
109 for(int counter = getTabCount() - 1; counter >= 0; counter--)
110 // should this use .equals?
111 if(getTab(counter) == tab)
112 return counter;
113 return -1;
114 }
115
116 /**
117 * Returns the index of the Tab to be used after <code>location</code>.
118 * This will return -1 if there are no tabs after <code>location</code>.
119 */
120 public int getTabIndexAfter(float location) {
121 int current, min, max;
122
123 min = 0;
124 max = getTabCount();
125 while(min != max) {
126 current = (max - min) / 2 + min;
127 if(location > tabs[current].getPosition()) {
128 if(min == current)
129 min = max;
130 else
131 min = current;
132 }
133 else {
134 if(current == 0 || location > tabs[current - 1].getPosition())
135 return current;
136 max = current;
137 }
138 }
139 // no tabs after the passed in location.
140 return -1;
141 }
142
143 /**
144 * Indicates whether this <code>TabSet</code> is equal to another one.
145 * @param o the <code>TabSet</code> instance which this instance
146 * should be compared to.
147 * @return <code>true</code> if <code>o</code> is the instance of
148 * <code>TabSet</code>, has the same number of <code>TabStop</code>s
149 * and they are all equal, <code>false</code> otherwise.
150 *
151 * @since 1.5
152 */
153 public boolean equals(Object o) {
154 if (o == this) {
155 return true;
156 }
157 if (o instanceof TabSet) {
158 TabSet ts = (TabSet) o;
159 int count = getTabCount();
160 if (ts.getTabCount() != count) {
161 return false;
162 }
163 for (int i=0; i < count; i++) {
164 TabStop ts1 = getTab(i);
165 TabStop ts2 = ts.getTab(i);
166 if ((ts1 == null && ts2 != null) ||
167 (ts1 != null && !getTab(i).equals(ts.getTab(i)))) {
168 return false;
169 }
170 }
171 return true;
172 }
173 return false;
174 }
175
176 /**
177 * Returns a hashcode for this set of TabStops.
178 * @return a hashcode value for this set of TabStops.
179 *
180 * @since 1.5
181 */
182 public int hashCode() {
183 if (hashCode == Integer.MAX_VALUE) {
184 hashCode = 0;
185 int len = getTabCount();
186 for (int i = 0; i < len; i++) {
187 TabStop ts = getTab(i);
188 hashCode ^= ts != null ? getTab(i).hashCode() : 0;
189 }
190 if (hashCode == Integer.MAX_VALUE) {
191 hashCode -= 1;
192 }
193 }
194 return hashCode;
195 }
196
197 /**
198 * Returns the string representation of the set of tabs.
199 */
200 public String toString() {
201 int tabCount = getTabCount();
202 StringBuilder buffer = new StringBuilder("[ ");
203
204 for(int counter = 0; counter < tabCount; counter++) {
205 if(counter > 0)
206 buffer.append(" - ");
207 buffer.append(getTab(counter).toString());
208 }
209 buffer.append(" ]");
210 return buffer.toString();
211 }
212 }