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 java.util.Locale;
041 import java.util.Vector;
042
043 /**
044 * Describes all elements of an accessible object's state. For example, an
045 * object may be enabled and have focus.
046 *
047 * @author Eric Blake (ebb9@email.byu.edu)
048 * @see AccessibleState
049 * @since 1.2
050 * @status updated to 1.4
051 */
052 public class AccessibleStateSet
053 {
054 /**
055 * The list of states, should be instances of AccessibleState. Don't set
056 * this to null.
057 *
058 * @see #add(AccessibleState)
059 * @see #addAll(AccessibleState[])
060 * @see #remove(AccessibleState)
061 * @see #contains(AccessibleState)
062 * @see #toArray()
063 * @see #clear()
064 */
065 protected Vector<AccessibleState> states = new Vector<AccessibleState>();
066
067 /**
068 * Create an empty state set.
069 */
070 public AccessibleStateSet()
071 {
072 }
073
074 /**
075 * Create a state set initialized with the given states, duplicates are
076 * ignored.
077 *
078 * @param states the states to insert
079 * @throws NullPointerException if states is null
080 */
081 public AccessibleStateSet(AccessibleState[] states)
082 {
083 addAll(states);
084 }
085
086 /**
087 * Add a new state to the current set. Return true if the state was added,
088 * as duplicates are ignored. Entering a null state will cause problems
089 * later, so don't do it.
090 *
091 * @param state the state to add
092 * @return true if the state was added
093 */
094 public boolean add(AccessibleState state)
095 {
096 return states.contains(state) ? false : states.add(state);
097 }
098
099 /**
100 * Add all of the states to the current set. Duplicates are ignored.
101 * Entering a null state will cause problems later, so don't do it.
102 *
103 * @param array the array of states to add
104 * @throws NullPointerException if array is null
105 */
106 public void addAll(AccessibleState[] array)
107 {
108 int i = array.length;
109 while (--i >= 0)
110 add(array[i]);
111 }
112
113 /**
114 * Remove a state from the set. If a state was removed, return true.
115 *
116 * @param state the state to remove
117 * @return true if the set changed
118 */
119 public boolean remove(AccessibleState state)
120 {
121 return states.remove(state);
122 }
123
124 /**
125 * Clear all states in the set.
126 */
127 public void clear()
128 {
129 states.clear();
130 }
131
132 /**
133 * Check if the current state is in the set.
134 *
135 * @param state the state to locate
136 * @return true if it is in the set
137 */
138 public boolean contains(AccessibleState state)
139 {
140 return states.contains(state);
141 }
142
143 /**
144 * Return the state set as an array.
145 *
146 * @return an array of the current states
147 */
148 public AccessibleState[] toArray()
149 {
150 AccessibleState[] result = new AccessibleState[states.size()];
151 states.toArray(result);
152 return result;
153 }
154
155 /**
156 * Return a localized, comma-separated string representing all states
157 * in the set. This is in arbitrary order.
158 *
159 * @return the string representation
160 * @see AccessibleBundle#toDisplayString(String, Locale)
161 */
162 public String toString()
163 {
164 int i = states.size();
165 if (i == 0)
166 return "";
167 // Pre-allocate an average of 10 chars per state.
168 StringBuffer b = new StringBuffer(i * 10);
169 while (--i >= 0)
170 b.append(states.get(i)).append(',');
171 return b.substring(0, b.length() - 1);
172 }
173 } // class AccessibleStateSet