1 /* AccessibleRelationSet.java -- the combined relations of an accessible object
2 Copyright (C) 2002, 2005 Free Software Foundation
4 This file is part of GNU Classpath.
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
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12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
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18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
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35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
38 package javax.accessibility;
40 import java.util.Locale;
41 import java.util.Vector;
44 * Describes all relations of an accessible object. For example, an object
45 * by labeled by one object and control another.
47 * @author Eric Blake (ebb9@email.byu.edu)
48 * @see AccessibleRelation
50 * @status updated to 1.4
52 public class AccessibleRelationSet
55 * The list of relations, should be instances of AccessibleRelation. Don't
58 * @see #add(AccessibleRelation)
59 * @see #addAll(AccessibleRelation[])
60 * @see #remove(AccessibleRelation)
61 * @see #contains(String)
67 protected Vector<AccessibleRelation> relations
68 = new Vector<AccessibleRelation>();
71 * Create an empty relation set.
73 public AccessibleRelationSet()
78 * Create a relation set initialized with the given relations, duplicates are
81 * @param relations the relations to insert
82 * @throws NullPointerException if relations is null
84 public AccessibleRelationSet(AccessibleRelation[] relations)
90 * Add a new relation to the current set. If the relation is already in
91 * the set, the targets are merged with the existing relation, possibly
92 * resulting in an object being in the target list more than once. Do not
93 * add a relation with a null key, as it will cause problems later.
95 * @param relation the relation to add
96 * @return true if the set was modified, which is always the case
97 * @throws NullPointerException if relation is null
99 public boolean add(AccessibleRelation relation)
101 AccessibleRelation old = get(relation.key);
103 return relations.add(relation);
104 if (old.targets.length == 0)
105 old.targets = relation.targets;
106 else if (relation.targets.length != 0)
108 Object[] t = new Object[old.targets.length + relation.targets.length];
109 System.arraycopy(old.targets, 0, t, 0, old.targets.length);
110 System.arraycopy(relation.targets, 0, t, old.targets.length,
111 relation.targets.length);
118 * Add all of the relations to the current set. Duplicates are ignored.
120 * @param array the array of relations to add
121 * @throws NullPointerException if array is null or has null entries
123 public void addAll(AccessibleRelation[] array)
125 int i = array.length;
131 * Remove a relation from the set. If a relation was removed, return true.
132 * Note that this uses AccessibleRelation.equals, which defaults to ==, so a
133 * relation with the same key may still exist in the set afterwords.
135 * @param relation the state to remove
136 * @return true if the set changed
138 public boolean remove(AccessibleRelation relation)
140 return relations.remove(relation);
144 * Clear all relations in the set.
152 * Return the number of relations in the set.
154 * @return the set size
158 return relations.size();
162 * Check if the relation key is in the set.
164 * @param key the relation to locate
165 * @return true if it is in the set
167 public boolean contains(String key)
169 int i = relations.size();
171 if (((AccessibleRelation) relations.get(i)).key.equals(key))
177 * Get the relation that matches the key.
179 * @param key the relation to locate
180 * @return the relation in the set, or null
182 public AccessibleRelation get(String key)
184 int i = relations.size();
187 AccessibleRelation r = (AccessibleRelation) relations.get(i);
188 if (r.key.equals(key))
195 * Return the relation set as an array.
197 * @return an array of the current relations
199 public AccessibleRelation[] toArray()
201 AccessibleRelation[] result = new AccessibleRelation[relations.size()];
202 relations.toArray(result);
207 * Return a localized, comma-separated string representing all relations
208 * in the set. This is in arbitrary order.
210 * @return the string representation
211 * @see AccessibleBundle#toDisplayString(String, Locale)
213 public String toString()
215 int i = relations.size();
218 // Pre-allocate an average of 10 chars per state.
219 StringBuffer b = new StringBuffer(i * 10);
221 b.append(relations.get(i)).append(',');
222 return b.substring(0, b.length() - 1);
224 } // class AccessibleRelationSet