001/* ChoiceCallback.java -- callback for a choice of values. 002 Copyright (C) 2003, Free Software Foundation, Inc. 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. */ 037 038 039package javax.security.auth.callback; 040 041import java.io.Serializable; 042 043/** 044 * Underlying security services instantiate and pass a 045 * <code>ChoiceCallback</code> to the <code>handle()</code> method of a 046 * {@link CallbackHandler} to display a list of choices and to retrieve the 047 * selected choice(s). 048 * 049 * @see CallbackHandler 050 */ 051public class ChoiceCallback implements Callback, Serializable 052{ 053 054 // Constants and variables 055 // ------------------------------------------------------------------------- 056 057 /** 058 * @serial 059 * @since 1.4 060 */ 061 private String prompt; 062 063 /** 064 * @serial the list of choices. 065 * @since 1.4 066 */ 067 private String[] choices; 068 069 /** 070 * @serial the choice to be used as the default choice. 071 * @since 1.4 072 */ 073 private int defaultChoice; 074 075 /** 076 * @serial whether multiple selections are allowed from the list of choices. 077 * @since 1.4 078 */ 079 private boolean multipleSelectionsAllowed; 080 081 /** 082 * @serial the selected choices, represented as indexes into the choices list. 083 * @since 1.4 084 */ 085 private int[] selections; 086 087 // Constructor(s) 088 //-------------------------------------------------------------------------- 089 090 /** 091 * Construct a <code>ChoiceCallback</code> with a prompt, a list of choices, 092 * a default choice, and a boolean specifying whether or not multiple 093 * selections from the list of choices are allowed. 094 * 095 * @param prompt the prompt used to describe the list of choices. 096 * @param choices the list of choices. 097 * @param defaultChoice the choice to be used as the default choice when the 098 * list of choices are displayed. This value is represented as an index into 099 * the <code>choices</code> array. 100 * @param multipleSelectionsAllowed boolean specifying whether or not 101 * multiple selections can be made from the list of choices. 102 * @throws IllegalArgumentException if <code>prompt</code> is <code>null</code>, 103 * if <code>prompt</code> has a length of <code>0</code>, if <code>choices</code> 104 * is <code>null</code>, if <code>choices</code> has a length of <code>0</code>, 105 * if any element from <code>choices</code> is <code>null</code>, if any 106 * element from <code>choices</code> has a length of <code>0</code> or if 107 * <code>defaultChoice</code> does not fall within the array boundaries of 108 * <code>choices</code>. 109 */ 110 public ChoiceCallback(String prompt, String[] choices, int defaultChoice, 111 boolean multipleSelectionsAllowed) 112 { 113 super(); 114 115 setPrompt(prompt); 116 setChoices(choices); 117 if (defaultChoice < 0 || defaultChoice >= this.choices.length) 118 { 119 throw new IllegalArgumentException("default choice is out of bounds"); 120 } 121 this.defaultChoice = defaultChoice; 122 this.multipleSelectionsAllowed = multipleSelectionsAllowed; 123 } 124 125 // Instance methods 126 // ------------------------------------------------------------------------- 127 128 /** 129 * Get the prompt. 130 * 131 * @return the prompt. 132 */ 133 public String getPrompt() 134 { 135 return prompt; 136 } 137 138 /** 139 * Get the list of choices. 140 * 141 * @return the list of choices. 142 */ 143 public String[] getChoices() 144 { 145 return choices; 146 } 147 148 /** 149 * Get the defaultChoice. 150 * 151 * @return the defaultChoice, represented as an index into the choices list. 152 */ 153 public int getDefaultChoice() 154 { 155 return defaultChoice; 156 } 157 158 /** 159 * Get the boolean determining whether multiple selections from the choices 160 * list are allowed. 161 * 162 * @return whether multiple selections are allowed. 163 */ 164 public boolean allowMultipleSelections() 165 { 166 return multipleSelectionsAllowed; 167 } 168 169 /** 170 * Set the selected choice. 171 * 172 * @param selection the selection represented as an index into the choices 173 * list. 174 * @see #getSelectedIndexes() 175 */ 176 public void setSelectedIndex(int selection) 177 { 178 this.selections = new int[1]; 179 this.selections[0] = selection; 180 } 181 182 /** 183 * Set the selected choices. 184 * 185 * @param selections the selections represented as indexes into the choices 186 * list. 187 * @throws UnsupportedOperationException if multiple selections are not 188 * allowed, as determined by <code>allowMultipleSelections</code>. 189 * @see #getSelectedIndexes() 190 */ 191 public void setSelectedIndexes(int[] selections) 192 { 193 if (!multipleSelectionsAllowed) 194 { 195 throw new UnsupportedOperationException("not allowed"); 196 } 197 198 this.selections = selections; 199 } 200 201 /** 202 * Get the selected choices. 203 * 204 * @return the selected choices, represented as indexes into the choices list. 205 * @see #setSelectedIndexes(int[]) 206 */ 207 public int[] getSelectedIndexes() 208 { 209 return selections; 210 } 211 212 private void setPrompt(String prompt) throws IllegalArgumentException 213 { 214 if ((prompt == null) || (prompt.length() == 0)) 215 { 216 throw new IllegalArgumentException("invalid prompt"); 217 } 218 this.prompt = prompt; 219 } 220 221 private void setChoices(String[] choices) throws IllegalArgumentException 222 { 223 if (choices == null || choices.length == 0) 224 { 225 throw new IllegalArgumentException("invalid choices"); 226 } 227 for (int i = 0; i < choices.length; i++) 228 { 229 if (choices[i] == null || choices[i].length() == 0) 230 { 231 throw new IllegalArgumentException("invalid choice at index #"+i); 232 } 233 } 234 this.choices = choices; 235 } 236}