001 /* AccessibleStateSet.java -- the combined state of an accessible object
002 Copyright (C) 2002, 2005 Free Software Foundation
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package javax.accessibility;
039
040 import gnu.java.lang.CPStringBuilder;
041
042 import java.util.Locale;
043 import java.util.Vector;
044
045 /**
046 * Describes all elements of an accessible object's state. For example, an
047 * object may be enabled and have focus.
048 *
049 * @author Eric Blake (ebb9@email.byu.edu)
050 * @see AccessibleState
051 * @since 1.2
052 * @status updated to 1.4
053 */
054 public class AccessibleStateSet
055 {
056 /**
057 * The list of states, should be instances of AccessibleState. Don't set
058 * this to null.
059 *
060 * @see #add(AccessibleState)
061 * @see #addAll(AccessibleState[])
062 * @see #remove(AccessibleState)
063 * @see #contains(AccessibleState)
064 * @see #toArray()
065 * @see #clear()
066 */
067 protected Vector<AccessibleState> states = new Vector<AccessibleState>();
068
069 /**
070 * Create an empty state set.
071 */
072 public AccessibleStateSet()
073 {
074 }
075
076 /**
077 * Create a state set initialized with the given states, duplicates are
078 * ignored.
079 *
080 * @param states the states to insert
081 * @throws NullPointerException if states is null
082 */
083 public AccessibleStateSet(AccessibleState[] states)
084 {
085 addAll(states);
086 }
087
088 /**
089 * Add a new state to the current set. Return true if the state was added,
090 * as duplicates are ignored. Entering a null state will cause problems
091 * later, so don't do it.
092 *
093 * @param state the state to add
094 * @return true if the state was added
095 */
096 public boolean add(AccessibleState state)
097 {
098 return states.contains(state) ? false : states.add(state);
099 }
100
101 /**
102 * Add all of the states to the current set. Duplicates are ignored.
103 * Entering a null state will cause problems later, so don't do it.
104 *
105 * @param array the array of states to add
106 * @throws NullPointerException if array is null
107 */
108 public void addAll(AccessibleState[] array)
109 {
110 int i = array.length;
111 while (--i >= 0)
112 add(array[i]);
113 }
114
115 /**
116 * Remove a state from the set. If a state was removed, return true.
117 *
118 * @param state the state to remove
119 * @return true if the set changed
120 */
121 public boolean remove(AccessibleState state)
122 {
123 return states.remove(state);
124 }
125
126 /**
127 * Clear all states in the set.
128 */
129 public void clear()
130 {
131 states.clear();
132 }
133
134 /**
135 * Check if the current state is in the set.
136 *
137 * @param state the state to locate
138 * @return true if it is in the set
139 */
140 public boolean contains(AccessibleState state)
141 {
142 return states.contains(state);
143 }
144
145 /**
146 * Return the state set as an array.
147 *
148 * @return an array of the current states
149 */
150 public AccessibleState[] toArray()
151 {
152 AccessibleState[] result = new AccessibleState[states.size()];
153 states.toArray(result);
154 return result;
155 }
156
157 /**
158 * Return a localized, comma-separated string representing all states
159 * in the set. This is in arbitrary order.
160 *
161 * @return the string representation
162 * @see AccessibleBundle#toDisplayString(String, Locale)
163 */
164 public String toString()
165 {
166 int i = states.size();
167 if (i == 0)
168 return "";
169 // Pre-allocate an average of 10 chars per state.
170 CPStringBuilder b = new CPStringBuilder(i * 10);
171 while (--i >= 0)
172 b.append(states.get(i)).append(',');
173 return b.substring(0, b.length() - 1);
174 }
175 } // class AccessibleStateSet