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