1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of 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, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.internal.app; 18 19 import android.annotation.IntRange; 20 import android.icu.text.ListFormatter; 21 import android.icu.util.ULocale; 22 import android.os.LocaleList; 23 import android.text.TextUtils; 24 25 import java.text.Collator; 26 import java.util.Comparator; 27 import java.util.Locale; 28 29 /** 30 * This class implements some handy methods to process with locales. 31 */ 32 public class LocaleHelper { 33 34 /** 35 * Sentence-case (first character uppercased). 36 * 37 * <p>There is no good API available for this, not even in ICU. 38 * We can revisit this if we get some ICU support later.</p> 39 * 40 * <p>There are currently several tickets requesting this feature:</p> 41 * <ul> 42 * <li>ICU needs to provide an easy way to titlecase only one first letter 43 * http://bugs.icu-project.org/trac/ticket/11729</li> 44 * <li>Add "initial case" 45 * http://bugs.icu-project.org/trac/ticket/8394</li> 46 * <li>Add code for initialCase, toTitlecase don't modify after Lt, 47 * avoid 49Ers, low-level language-specific casing 48 * http://bugs.icu-project.org/trac/ticket/10410</li> 49 * <li>BreakIterator.getFirstInstance: Often you need to titlecase just the first 50 * word, and leave the rest of the string alone. (closed as duplicate) 51 * http://bugs.icu-project.org/trac/ticket/8946</li> 52 * </ul> 53 * 54 * <p>A (clunky) option with the current ICU API is:</p> 55 * {{ 56 * BreakIterator breakIterator = BreakIterator.getSentenceInstance(locale); 57 * String result = UCharacter.toTitleCase(locale, 58 * source, breakIterator, UCharacter.TITLECASE_NO_LOWERCASE); 59 * }} 60 * 61 * <p>That also means creating a BreakIterator for each locale. Expensive...</p> 62 * 63 * @param str the string to sentence-case. 64 * @param locale the locale used for the case conversion. 65 * @return the string converted to sentence-case. 66 */ 67 public static String toSentenceCase(String str, Locale locale) { 68 if (str.isEmpty()) { 69 return str; 70 } 71 final int firstCodePointLen = str.offsetByCodePoints(0, 1); 72 return str.substring(0, firstCodePointLen).toUpperCase(locale) 73 + str.substring(firstCodePointLen); 74 } 75 76 /** 77 * Normalizes a string for locale name search. Does case conversion for now, 78 * but might do more in the future. 79 * 80 * <p>Warning: it is only intended to be used in searches by the locale picker. 81 * Don't use it for other things, it is very limited.</p> 82 * 83 * @param str the string to normalize 84 * @param locale the locale that might be used for certain operations (i.e. case conversion) 85 * @return the string normalized for search 86 */ 87 public static String normalizeForSearch(String str, Locale locale) { 88 // TODO: tbd if it needs to be smarter (real normalization, remove accents, etc.) 89 // If needed we might use case folding and ICU/CLDR's collation-based loose searching. 90 // TODO: decide what should the locale be, the default locale, or the locale of the string. 91 // Uppercase is better than lowercase because of things like sharp S, Greek sigma, ... 92 return str.toUpperCase(); 93 } 94 95 // For some locales we want to use a "dialect" form, for instance 96 // "Dari" instead of "Persian (Afghanistan)", or "Moldavian" instead of "Romanian (Moldova)" 97 private static boolean shouldUseDialectName(Locale locale) { 98 final String lang = locale.getLanguage(); 99 return "fa".equals(lang) // Persian 100 || "ro".equals(lang) // Romanian 101 || "zh".equals(lang); // Chinese 102 } 103 104 /** 105 * Returns the locale localized for display in the provided locale. 106 * 107 * @param locale the locale whose name is to be displayed. 108 * @param displayLocale the locale in which to display the name. 109 * @param sentenceCase true if the result should be sentence-cased 110 * @return the localized name of the locale. 111 */ 112 public static String getDisplayName(Locale locale, Locale displayLocale, boolean sentenceCase) { 113 final ULocale displayULocale = ULocale.forLocale(displayLocale); 114 String result = shouldUseDialectName(locale) 115 ? ULocale.getDisplayNameWithDialect(locale.toLanguageTag(), displayULocale) 116 : ULocale.getDisplayName(locale.toLanguageTag(), displayULocale); 117 return sentenceCase ? toSentenceCase(result, displayLocale) : result; 118 } 119 120 /** 121 * Returns the locale localized for display in the default locale. 122 * 123 * @param locale the locale whose name is to be displayed. 124 * @param sentenceCase true if the result should be sentence-cased 125 * @return the localized name of the locale. 126 */ 127 public static String getDisplayName(Locale locale, boolean sentenceCase) { 128 return getDisplayName(locale, Locale.getDefault(), sentenceCase); 129 } 130 131 /** 132 * Returns a locale's country localized for display in the provided locale. 133 * 134 * @param locale the locale whose country will be displayed. 135 * @param displayLocale the locale in which to display the name. 136 * @return the localized country name. 137 */ 138 public static String getDisplayCountry(Locale locale, Locale displayLocale) { 139 return ULocale.getDisplayCountry(locale.toLanguageTag(), ULocale.forLocale(displayLocale)); 140 } 141 142 /** 143 * Returns a locale's country localized for display in the default locale. 144 * 145 * @param locale the locale whose country will be displayed. 146 * @return the localized country name. 147 */ 148 public static String getDisplayCountry(Locale locale) { 149 return ULocale.getDisplayCountry(locale.toLanguageTag(), ULocale.getDefault()); 150 } 151 152 /** 153 * Returns the locale list localized for display in the provided locale. 154 * 155 * @param locales the list of locales whose names is to be displayed. 156 * @param displayLocale the locale in which to display the names. 157 * If this is null, it will use the default locale. 158 * @param maxLocales maximum number of locales to display. Generates ellipsis after that. 159 * @return the locale aware list of locale names 160 */ 161 public static String getDisplayLocaleList( 162 LocaleList locales, Locale displayLocale, @IntRange(from=1) int maxLocales) { 163 164 final Locale dispLocale = displayLocale == null ? Locale.getDefault() : displayLocale; 165 166 final boolean ellipsisNeeded = locales.size() > maxLocales; 167 final int localeCount, listCount; 168 if (ellipsisNeeded) { 169 localeCount = maxLocales; 170 listCount = maxLocales + 1; // One extra slot for the ellipsis 171 } else { 172 listCount = localeCount = locales.size(); 173 } 174 final String[] localeNames = new String[listCount]; 175 for (int i = 0; i < localeCount; i++) { 176 localeNames[i] = LocaleHelper.getDisplayName(locales.get(i), dispLocale, false); 177 } 178 if (ellipsisNeeded) { 179 // Theoretically, we want to extract this from ICU's Resource Bundle for 180 // "Ellipsis/final", which seems to have different strings than the normal ellipsis for 181 // Hong Kong Traditional Chinese (zh_Hant_HK) and Dzongkha (dz). But that has two 182 // problems: it's expensive to extract it, and in case the output string becomes 183 // automatically ellipsized, it can result in weird output. 184 localeNames[maxLocales] = TextUtils.ELLIPSIS_STRING; 185 } 186 187 ListFormatter lfn = ListFormatter.getInstance(dispLocale); 188 return lfn.format((Object[]) localeNames); 189 } 190 191 /** 192 * Adds the likely subtags for a provided locale ID. 193 * 194 * @param locale the locale to maximize. 195 * @return the maximized Locale instance. 196 */ 197 public static Locale addLikelySubtags(Locale locale) { 198 return libcore.icu.ICU.addLikelySubtags(locale); 199 } 200 201 /** 202 * Locale-sensitive comparison for LocaleInfo. 203 * 204 * <p>It uses the label, leaving the decision on what to put there to the LocaleInfo. 205 * For instance fr-CA can be shown as "franais" as a generic label in the language selection, 206 * or "franais (Canada)" if it is a suggestion, or "Canada" in the country selection.</p> 207 * 208 * <p>Gives priority to suggested locales (to sort them at the top).</p> 209 */ 210 public static final class LocaleInfoComparator implements Comparator<LocaleStore.LocaleInfo> { 211 private final Collator mCollator; 212 private final boolean mCountryMode; 213 private static final String PREFIX_ARABIC = "\u0627\u0644"; // ALEF-LAM, 214 215 /** 216 * Constructor. 217 * 218 * @param sortLocale the locale to be used for sorting. 219 */ 220 public LocaleInfoComparator(Locale sortLocale, boolean countryMode) { 221 mCollator = Collator.getInstance(sortLocale); 222 mCountryMode = countryMode; 223 } 224 225 /* 226 * The Arabic collation should ignore Alef-Lam at the beginning (b/26277596) 227 * 228 * We look at the label's locale, not the current system locale. 229 * This is because the name of the Arabic language itself is in Arabic, 230 * and starts with Alef-Lam, no matter what the system locale is. 231 */ 232 private String removePrefixForCompare(Locale locale, String str) { 233 if ("ar".equals(locale.getLanguage()) && str.startsWith(PREFIX_ARABIC)) { 234 return str.substring(PREFIX_ARABIC.length()); 235 } 236 return str; 237 } 238 239 /** 240 * Compares its two arguments for order. 241 * 242 * @param lhs the first object to be compared 243 * @param rhs the second object to be compared 244 * @return a negative integer, zero, or a positive integer as the first 245 * argument is less than, equal to, or greater than the second. 246 */ 247 @Override 248 public int compare(LocaleStore.LocaleInfo lhs, LocaleStore.LocaleInfo rhs) { 249 // We don't care about the various suggestion types, just "suggested" (!= 0) 250 // and "all others" (== 0) 251 if (lhs.isSuggested() == rhs.isSuggested()) { 252 // They are in the same "bucket" (suggested / others), so we compare the text 253 return mCollator.compare( 254 removePrefixForCompare(lhs.getLocale(), lhs.getLabel(mCountryMode)), 255 removePrefixForCompare(rhs.getLocale(), rhs.getLabel(mCountryMode))); 256 } else { 257 // One locale is suggested and one is not, so we put them in different "buckets" 258 return lhs.isSuggested() ? -1 : 1; 259 } 260 } 261 } 262 } 263
