001/* AccessibleStateSet.java -- the combined state of an accessible object
002   Copyright (C) 2002, 2005 Free Software Foundation
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package javax.accessibility;
039
040import gnu.java.lang.CPStringBuilder;
041
042import java.util.Locale;
043import 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 */
054public 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