1 /*
2 * Copyright (c) 1998, 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
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 @SuppressWarnings("serial") // Same-version serialization only
47 public class TabSet implements Serializable
48 {
49 /** TabStops this TabSet contains. */
50 private TabStop[] tabs;
51 /**
52 * Since this class is immutable the hash code could be
53 * calculated once. MAX_VALUE means that it was not initialized
54 * yet. Hash code shouldn't has MAX_VALUE value.
55 */
56 private int hashCode = Integer.MAX_VALUE;
57
58 /**
59 * Creates and returns an instance of TabSet. The array of Tabs
60 * passed in must be sorted in ascending order.
61 */
62 public TabSet(TabStop[] tabs) {
63 // PENDING(sky): If this becomes a problem, make it sort.
64 if(tabs != null) {
65 int tabCount = tabs.length;
66
67 this.tabs = new TabStop[tabCount];
68 System.arraycopy(tabs, 0, this.tabs, 0, tabCount);
69 }
70 else
71 this.tabs = null;
72 }
73
74 /**
75 * Returns the number of Tab instances the receiver contains.
76 */
77 public int getTabCount() {
78 return (tabs == null) ? 0 : tabs.length;
79 }
80
81 /**
82 * Returns the TabStop at index <code>index</code>. This will throw an
83 * IllegalArgumentException if <code>index</code> is outside the range
84 * of tabs.
85 */
86 public TabStop getTab(int index) {
87 int numTabs = getTabCount();
88
89 if(index < 0 || index >= numTabs)
90 throw new IllegalArgumentException(index +
91 " is outside the range of tabs");
92 return tabs[index];
93 }
94
95 /**
96 * Returns the Tab instance after <code>location</code>. This will
97 * return null if there are no tabs after <code>location</code>.
98 */
99 public TabStop getTabAfter(float location) {
100 int index = getTabIndexAfter(location);
101
102 return (index == -1) ? null : tabs[index];
103 }
104
105 /**
106 * @return the index of the TabStop <code>tab</code>, or -1 if
107 * <code>tab</code> is not contained in the receiver.
108 */
109 public int getTabIndex(TabStop tab) {
110 for(int counter = getTabCount() - 1; counter >= 0; counter--)
111 // should this use .equals?
112 if(getTab(counter) == tab)
113 return counter;
114 return -1;
115 }
116
117 /**
118 * Returns the index of the Tab to be used after <code>location</code>.
119 * This will return -1 if there are no tabs after <code>location</code>.
120 */
121 public int getTabIndexAfter(float location) {
122 int current, min, max;
123
124 min = 0;
125 max = getTabCount();
126 while(min != max) {
127 current = (max - min) / 2 + min;
128 if(location > tabs[current].getPosition()) {
129 if(min == current)
130 min = max;
131 else
132 min = current;
133 }
134 else {
135 if(current == 0 || location > tabs[current - 1].getPosition())
136 return current;
137 max = current;
138 }
139 }
140 // no tabs after the passed in location.
141 return -1;
142 }
143
144 /**
145 * Indicates whether this <code>TabSet</code> is equal to another one.
146 * @param o the <code>TabSet</code> instance which this instance
147 * should be compared to.
148 * @return <code>true</code> if <code>o</code> is the instance of
149 * <code>TabSet</code>, has the same number of <code>TabStop</code>s
150 * and they are all equal, <code>false</code> otherwise.
151 *
152 * @since 1.5
153 */
154 public boolean equals(Object o) {
155 if (o == this) {
156 return true;
157 }
158 if (o instanceof TabSet) {
159 TabSet ts = (TabSet) o;
160 int count = getTabCount();
161 if (ts.getTabCount() != count) {
162 return false;
163 }
164 for (int i=0; i < count; i++) {
165 TabStop ts1 = getTab(i);
166 TabStop ts2 = ts.getTab(i);
167 if ((ts1 == null && ts2 != null) ||
168 (ts1 != null && !getTab(i).equals(ts.getTab(i)))) {
169 return false;
170 }
171 }
172 return true;
173 }
174 return false;
175 }
176
177 /**
178 * Returns a hashcode for this set of TabStops.
179 * @return a hashcode value for this set of TabStops.
180 *
181 * @since 1.5
182 */
183 public int hashCode() {
184 if (hashCode == Integer.MAX_VALUE) {
185 hashCode = 0;
186 int len = getTabCount();
187 for (int i = 0; i < len; i++) {
188 TabStop ts = getTab(i);
189 hashCode ^= ts != null ? getTab(i).hashCode() : 0;
190 }
191 if (hashCode == Integer.MAX_VALUE) {
192 hashCode -= 1;
193 }
194 }
195 return hashCode;
196 }
197
198 /**
199 * Returns the string representation of the set of tabs.
200 */
201 public String toString() {
202 int tabCount = getTabCount();
203 StringBuilder buffer = new StringBuilder("[ ");
204
205 for(int counter = 0; counter < tabCount; counter++) {
206 if(counter > 0)
207 buffer.append(" - ");
208 buffer.append(getTab(counter).toString());
209 }
210 buffer.append(" ]");
211 return buffer.toString();
212 }
213 }