001 package org.apache.myfaces.tobago.util;
002
003 /*
004 * Licensed to the Apache Software Foundation (ASF) under one or more
005 * contributor license agreements. See the NOTICE file distributed with
006 * this work for additional information regarding copyright ownership.
007 * The ASF licenses this file to You under the Apache License, Version 2.0
008 * (the "License"); you may not use this file except in compliance with
009 * the License. You may obtain a copy of the License at
010 *
011 * http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 */
019
020 import javax.faces.context.FacesContext;
021 import java.util.HashSet;
022 import java.util.Map;
023 import java.util.Locale;
024
025 public class AccessKeyMap {
026
027 private static final char[] KEYS = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
028 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o',
029 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
030
031 private static final String REQUEST_MAP_KEY = "accessKeysRequestMapKey";
032
033 private HashSet set;
034 private StringBuilder duplicated = new StringBuilder();
035
036
037 public static AccessKeyMap getInstance(FacesContext facesContext) {
038 final Map requestMap = facesContext.getExternalContext().getRequestMap();
039 AccessKeyMap keyMap = (AccessKeyMap) requestMap.get(REQUEST_MAP_KEY);
040 if (keyMap == null) {
041 keyMap = new AccessKeyMap();
042 requestMap.put(REQUEST_MAP_KEY, keyMap);
043 }
044 return keyMap;
045 }
046
047 private AccessKeyMap() {
048 set = new HashSet();
049 }
050
051 private HashSet getSet() {
052 return set;
053 }
054
055 private String getDuplicated() {
056 return duplicated.toString();
057 }
058
059 private void addDublicated(char key) {
060 duplicated = duplicated.append(key);
061 }
062
063 public static boolean addAccessKey(FacesContext facesContext, Character key) {
064 key = key.toString().toLowerCase(Locale.ENGLISH).charAt(0);
065 final AccessKeyMap instance = getInstance(facesContext);
066 if (instance.getSet().contains(key)) {
067 instance.addDublicated(key);
068 return false;
069 } else {
070 instance.getSet().add(key);
071 return true;
072 }
073 }
074
075 public static String getDublicatedKeys(FacesContext facesContext) {
076 return getInstance(facesContext).getDuplicated();
077 }
078
079 public static String getUnusedKeys(FacesContext facesContext) {
080 HashSet set = getInstance(facesContext).getSet();
081 StringBuilder sb = new StringBuilder();
082 for (char key : KEYS) {
083 if (!set.contains(Character.valueOf(key))) {
084 sb.append(key);
085 }
086 }
087 return sb.toString();
088 }
089 }