1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 5 * use this file except in compliance with the License. You may obtain a copy of 6 * the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations under 14 * the License. 15 */ 16 17 package com.android.inputmethod.dictionarypack; 18 19 import android.content.res.Configuration; 20 import android.content.res.Resources; 21 import android.text.TextUtils; 22 23 import java.util.HashMap; 24 import java.util.Locale; 25 26 /** 27 * A class to help with handling Locales in string form. 28 * 29 * This file has the same meaning and features (and shares all of its code) with the one with the 30 * same name in Latin IME. They need to be kept synchronized; for any update/bugfix to 31 * this file, consider also updating/fixing the version in Latin IME. 32 */ 33 public final class LocaleUtils { 34 private LocaleUtils() { 35 // Intentional empty constructor for utility class. 36 } 37 38 // Locale match level constants. 39 // A higher level of match is guaranteed to have a higher numerical value. 40 // Some room is left within constants to add match cases that may arise necessary 41 // in the future, for example differentiating between the case where the countries 42 // are both present and different, and the case where one of the locales does not 43 // specify the countries. This difference is not needed now. 44 45 // Nothing matches. 46 public static final int LOCALE_NO_MATCH = 0; 47 // The languages matches, but the country are different. Or, the reference locale requires a 48 // country and the tested locale does not have one. 49 public static final int LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER = 3; 50 // The languages and country match, but the variants are different. Or, the reference locale 51 // requires a variant and the tested locale does not have one. 52 public static final int LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER = 6; 53 // The required locale is null or empty so it will accept anything, and the tested locale 54 // is non-null and non-empty. 55 public static final int LOCALE_ANY_MATCH = 10; 56 // The language matches, and the tested locale specifies a country but the reference locale 57 // does not require one. 58 public static final int LOCALE_LANGUAGE_MATCH = 15; 59 // The language and the country match, and the tested locale specifies a variant but the 60 // reference locale does not require one. 61 public static final int LOCALE_LANGUAGE_AND_COUNTRY_MATCH = 20; 62 // The compared locales are fully identical. This is the best match level. 63 public static final int LOCALE_FULL_MATCH = 30; 64 65 // The level at which a match is "normally" considered a locale match with standard algorithms. 66 // Don't use this directly, use #isMatch to test. 67 private static final int LOCALE_MATCH = LOCALE_ANY_MATCH; 68 69 // Make this match the maximum match level. If this evolves to have more than 2 digits 70 // when written in base 10, also adjust the getMatchLevelSortedString method. 71 private static final int MATCH_LEVEL_MAX = 30; 72 73 /** 74 * Return how well a tested locale matches a reference locale. 75 * 76 * This will check the tested locale against the reference locale and return a measure of how 77 * a well it matches the reference. The general idea is that the tested locale has to match 78 * every specified part of the required locale. A full match occur when they are equal, a 79 * partial match when the tested locale agrees with the reference locale but is more specific, 80 * and a difference when the tested locale does not comply with all requirements from the 81 * reference locale. 82 * In more detail, if the reference locale specifies at least a language and the testedLocale 83 * does not specify one, or specifies a different one, LOCALE_NO_MATCH is returned. If the 84 * reference locale is empty or null, it will match anything - in the form of LOCALE_FULL_MATCH 85 * if the tested locale is empty or null, and LOCALE_ANY_MATCH otherwise. If the reference and 86 * tested locale agree on the language, but not on the country, 87 * LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER is returned if the reference locale specifies a country, 88 * and LOCALE_LANGUAGE_MATCH otherwise. 89 * If they agree on both the language and the country, but not on the variant, 90 * LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER is returned if the reference locale 91 * specifies a variant, and LOCALE_LANGUAGE_AND_COUNTRY_MATCH otherwise. If everything matches, 92 * LOCALE_FULL_MATCH is returned. 93 * Examples: 94 * en <=> en_US => LOCALE_LANGUAGE_MATCH 95 * en_US <=> en => LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER 96 * en_US_POSIX <=> en_US_Android => LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER 97 * en_US <=> en_US_Android => LOCALE_LANGUAGE_AND_COUNTRY_MATCH 98 * sp_US <=> en_US => LOCALE_NO_MATCH 99 * de <=> de => LOCALE_FULL_MATCH 100 * en_US <=> en_US => LOCALE_FULL_MATCH 101 * "" <=> en_US => LOCALE_ANY_MATCH 102 * 103 * @param referenceLocale the reference locale to test against. 104 * @param testedLocale the locale to test. 105 * @return a constant that measures how well the tested locale matches the reference locale. 106 */ 107 public static int getMatchLevel(final String referenceLocale, final String testedLocale) { 108 if (TextUtils.isEmpty(referenceLocale)) { 109 return TextUtils.isEmpty(testedLocale) ? LOCALE_FULL_MATCH : LOCALE_ANY_MATCH; 110 } 111 if (null == testedLocale) return LOCALE_NO_MATCH; 112 final String[] referenceParams = referenceLocale.split("_", 3); 113 final String[] testedParams = testedLocale.split("_", 3); 114 // By spec of String#split, [0] cannot be null and length cannot be 0. 115 if (!referenceParams[0].equals(testedParams[0])) return LOCALE_NO_MATCH; 116 switch (referenceParams.length) { 117 case 1: 118 return 1 == testedParams.length ? LOCALE_FULL_MATCH : LOCALE_LANGUAGE_MATCH; 119 case 2: 120 if (1 == testedParams.length) return LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER; 121 if (!referenceParams[1].equals(testedParams[1])) 122 return LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER; 123 if (3 == testedParams.length) return LOCALE_LANGUAGE_AND_COUNTRY_MATCH; 124 return LOCALE_FULL_MATCH; 125 case 3: 126 if (1 == testedParams.length) return LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER; 127 if (!referenceParams[1].equals(testedParams[1])) 128 return LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER; 129 if (2 == testedParams.length) return LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER; 130 if (!referenceParams[2].equals(testedParams[2])) 131 return LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER; 132 return LOCALE_FULL_MATCH; 133 } 134 // It should be impossible to come here 135 return LOCALE_NO_MATCH; 136 } 137 138 /** 139 * Return a string that represents this match level, with better matches first. 140 * 141 * The strings are sorted in lexicographic order: a better match will always be less than 142 * a worse match when compared together. 143 */ 144 public static String getMatchLevelSortedString(final int matchLevel) { 145 // This works because the match levels are 0~99 (actually 0~30) 146 // Ideally this should use a number of digits equals to the 1og10 of the greater matchLevel 147 return String.format(Locale.ROOT, "%02d", MATCH_LEVEL_MAX - matchLevel); 148 } 149 150 /** 151 * Find out whether a match level should be considered a match. 152 * 153 * This method takes a match level as returned by the #getMatchLevel method, and returns whether 154 * it should be considered a match in the usual sense with standard Locale functions. 155 * 156 * @param level the match level, as returned by getMatchLevel. 157 * @return whether this is a match or not. 158 */ 159 public static boolean isMatch(final int level) { 160 return LOCALE_MATCH <= level; 161 } 162 163 /** 164 * Sets the system locale for this process. 165 * 166 * @param res the resources to use. Pass current resources. 167 * @param newLocale the locale to change to. 168 * @return the old locale. 169 */ 170 public static Locale setSystemLocale(final Resources res, final Locale newLocale) { 171 final Configuration conf = res.getConfiguration(); 172 final Locale saveLocale = conf.locale; 173 conf.locale = newLocale; 174 res.updateConfiguration(conf, res.getDisplayMetrics()); 175 return saveLocale; 176 } 177 178 private static final HashMap<String, Locale> sLocaleCache = new HashMap<String, Locale>(); 179 180 /** 181 * Creates a locale from a string specification. 182 */ 183 public static Locale constructLocaleFromString(final String localeStr) { 184 if (localeStr == null) 185 return null; 186 synchronized (sLocaleCache) { 187 if (sLocaleCache.containsKey(localeStr)) 188 return sLocaleCache.get(localeStr); 189 Locale retval = null; 190 String[] localeParams = localeStr.split("_", 3); 191 if (localeParams.length == 1) { 192 retval = new Locale(localeParams[0]); 193 } else if (localeParams.length == 2) { 194 retval = new Locale(localeParams[0], localeParams[1]); 195 } else if (localeParams.length == 3) { 196 retval = new Locale(localeParams[0], localeParams[1], localeParams[2]); 197 } 198 if (retval != null) { 199 sLocaleCache.put(localeStr, retval); 200 } 201 return retval; 202 } 203 } 204 } 205
