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1: /* AccessibleRelationSet.java -- the combined relations of an accessible object 2: Copyright (C) 2002, 2005 Free Software Foundation 3: 4: This file is part of GNU Classpath. 5: 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 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 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. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 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 24: combination. 25: 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 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: package javax.accessibility; 39: 40: import gnu.java.lang.CPStringBuilder; 41: 42: import java.util.Locale; 43: import java.util.Vector; 44: 45: /** 46: * Describes all relations of an accessible object. For example, an object 47: * by labeled by one object and control another. 48: * 49: * @author Eric Blake (ebb9@email.byu.edu) 50: * @see AccessibleRelation 51: * @since 1.2 52: * @status updated to 1.4 53: */ 54: public class AccessibleRelationSet 55: { 56: /** 57: * The list of relations, should be instances of AccessibleRelation. Don't 58: * set this to null. 59: * 60: * @see #add(AccessibleRelation) 61: * @see #addAll(AccessibleRelation[]) 62: * @see #remove(AccessibleRelation) 63: * @see #contains(String) 64: * @see #get(String) 65: * @see #size() 66: * @see #toArray() 67: * @see #clear() 68: */ 69: protected Vector<AccessibleRelation> relations 70: = new Vector<AccessibleRelation>(); 71: 72: /** 73: * Create an empty relation set. 74: */ 75: public AccessibleRelationSet() 76: { 77: } 78: 79: /** 80: * Create a relation set initialized with the given relations, duplicates are 81: * ignored. 82: * 83: * @param relations the relations to insert 84: * @throws NullPointerException if relations is null 85: */ 86: public AccessibleRelationSet(AccessibleRelation[] relations) 87: { 88: addAll(relations); 89: } 90: 91: /** 92: * Add a new relation to the current set. If the relation is already in 93: * the set, the targets are merged with the existing relation, possibly 94: * resulting in an object being in the target list more than once. Do not 95: * add a relation with a null key, as it will cause problems later. 96: * 97: * @param relation the relation to add 98: * @return true if the set was modified, which is always the case 99: * @throws NullPointerException if relation is null 100: */ 101: public boolean add(AccessibleRelation relation) 102: { 103: AccessibleRelation old = get(relation.key); 104: if (old == null) 105: return relations.add(relation); 106: if (old.targets.length == 0) 107: old.targets = relation.targets; 108: else if (relation.targets.length != 0) 109: { 110: Object[] t = new Object[old.targets.length + relation.targets.length]; 111: System.arraycopy(old.targets, 0, t, 0, old.targets.length); 112: System.arraycopy(relation.targets, 0, t, old.targets.length, 113: relation.targets.length); 114: old.targets = t; 115: } 116: return true; 117: } 118: 119: /** 120: * Add all of the relations to the current set. Duplicates are ignored. 121: * 122: * @param array the array of relations to add 123: * @throws NullPointerException if array is null or has null entries 124: */ 125: public void addAll(AccessibleRelation[] array) 126: { 127: int i = array.length; 128: while (--i >= 0) 129: add(array[i]); 130: } 131: 132: /** 133: * Remove a relation from the set. If a relation was removed, return true. 134: * Note that this uses AccessibleRelation.equals, which defaults to ==, so a 135: * relation with the same key may still exist in the set afterwords. 136: * 137: * @param relation the state to remove 138: * @return true if the set changed 139: */ 140: public boolean remove(AccessibleRelation relation) 141: { 142: return relations.remove(relation); 143: } 144: 145: /** 146: * Clear all relations in the set. 147: */ 148: public void clear() 149: { 150: relations.clear(); 151: } 152: 153: /** 154: * Return the number of relations in the set. 155: * 156: * @return the set size 157: */ 158: public int size() 159: { 160: return relations.size(); 161: } 162: 163: /** 164: * Check if the relation key is in the set. 165: * 166: * @param key the relation to locate 167: * @return true if it is in the set 168: */ 169: public boolean contains(String key) 170: { 171: int i = relations.size(); 172: while (--i >= 0) 173: if ((relations.get(i)).key.equals(key)) 174: return true; 175: return false; 176: } 177: 178: /** 179: * Get the relation that matches the key. 180: * 181: * @param key the relation to locate 182: * @return the relation in the set, or null 183: */ 184: public AccessibleRelation get(String key) 185: { 186: int i = relations.size(); 187: while (--i >= 0) 188: { 189: AccessibleRelation r = relations.get(i); 190: if (r.key.equals(key)) 191: return r; 192: } 193: return null; 194: } 195: 196: /** 197: * Return the relation set as an array. 198: * 199: * @return an array of the current relations 200: */ 201: public AccessibleRelation[] toArray() 202: { 203: AccessibleRelation[] result = new AccessibleRelation[relations.size()]; 204: relations.toArray(result); 205: return result; 206: } 207: 208: /** 209: * Return a localized, comma-separated string representing all relations 210: * in the set. This is in arbitrary order. 211: * 212: * @return the string representation 213: * @see AccessibleBundle#toDisplayString(String, Locale) 214: */ 215: public String toString() 216: { 217: int i = relations.size(); 218: if (i == 0) 219: return ""; 220: // Pre-allocate an average of 10 chars per state. 221: CPStringBuilder b = new CPStringBuilder(i * 10); 222: while (--i >= 0) 223: b.append(relations.get(i)).append(','); 224: return b.substring(0, b.length() - 1); 225: } 226: } // class AccessibleRelationSet