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