/* * Copyright (C) 2011 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package com.android.inputmethod.dictionarypack; import android.content.res.Configuration; import android.content.res.Resources; import android.text.TextUtils; import java.util.HashMap; import java.util.Locale; /** * A class to help with handling Locales in string form. * * This file has the same meaning and features (and shares all of its code) with the one with the * same name in Latin IME. They need to be kept synchronized; for any update/bugfix to * this file, consider also updating/fixing the version in Latin IME. */ public final class LocaleUtils { private LocaleUtils() { // Intentional empty constructor for utility class. } // Locale match level constants. // A higher level of match is guaranteed to have a higher numerical value. // Some room is left within constants to add match cases that may arise necessary // in the future, for example differentiating between the case where the countries // are both present and different, and the case where one of the locales does not // specify the countries. This difference is not needed now. // Nothing matches. public static final int LOCALE_NO_MATCH = 0; // The languages matches, but the country are different. Or, the reference locale requires a // country and the tested locale does not have one. public static final int LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER = 3; // The languages and country match, but the variants are different. Or, the reference locale // requires a variant and the tested locale does not have one. public static final int LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER = 6; // The required locale is null or empty so it will accept anything, and the tested locale // is non-null and non-empty. public static final int LOCALE_ANY_MATCH = 10; // The language matches, and the tested locale specifies a country but the reference locale // does not require one. public static final int LOCALE_LANGUAGE_MATCH = 15; // The language and the country match, and the tested locale specifies a variant but the // reference locale does not require one. public static final int LOCALE_LANGUAGE_AND_COUNTRY_MATCH = 20; // The compared locales are fully identical. This is the best match level. public static final int LOCALE_FULL_MATCH = 30; // The level at which a match is "normally" considered a locale match with standard algorithms. // Don't use this directly, use #isMatch to test. private static final int LOCALE_MATCH = LOCALE_ANY_MATCH; // Make this match the maximum match level. If this evolves to have more than 2 digits // when written in base 10, also adjust the getMatchLevelSortedString method. private static final int MATCH_LEVEL_MAX = 30; /** * Return how well a tested locale matches a reference locale. * * This will check the tested locale against the reference locale and return a measure of how * a well it matches the reference. The general idea is that the tested locale has to match * every specified part of the required locale. A full match occur when they are equal, a * partial match when the tested locale agrees with the reference locale but is more specific, * and a difference when the tested locale does not comply with all requirements from the * reference locale. * In more detail, if the reference locale specifies at least a language and the testedLocale * does not specify one, or specifies a different one, LOCALE_NO_MATCH is returned. If the * reference locale is empty or null, it will match anything - in the form of LOCALE_FULL_MATCH * if the tested locale is empty or null, and LOCALE_ANY_MATCH otherwise. If the reference and * tested locale agree on the language, but not on the country, * LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER is returned if the reference locale specifies a country, * and LOCALE_LANGUAGE_MATCH otherwise. * If they agree on both the language and the country, but not on the variant, * LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER is returned if the reference locale * specifies a variant, and LOCALE_LANGUAGE_AND_COUNTRY_MATCH otherwise. If everything matches, * LOCALE_FULL_MATCH is returned. * Examples: * en <=> en_US => LOCALE_LANGUAGE_MATCH * en_US <=> en => LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER * en_US_POSIX <=> en_US_Android => LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER * en_US <=> en_US_Android => LOCALE_LANGUAGE_AND_COUNTRY_MATCH * sp_US <=> en_US => LOCALE_NO_MATCH * de <=> de => LOCALE_FULL_MATCH * en_US <=> en_US => LOCALE_FULL_MATCH * "" <=> en_US => LOCALE_ANY_MATCH * * @param referenceLocale the reference locale to test against. * @param testedLocale the locale to test. * @return a constant that measures how well the tested locale matches the reference locale. */ public static int getMatchLevel(final String referenceLocale, final String testedLocale) { if (TextUtils.isEmpty(referenceLocale)) { return TextUtils.isEmpty(testedLocale) ? LOCALE_FULL_MATCH : LOCALE_ANY_MATCH; } if (null == testedLocale) return LOCALE_NO_MATCH; final String[] referenceParams = referenceLocale.split("_", 3); final String[] testedParams = testedLocale.split("_", 3); // By spec of String#split, [0] cannot be null and length cannot be 0. if (!referenceParams[0].equals(testedParams[0])) return LOCALE_NO_MATCH; switch (referenceParams.length) { case 1: return 1 == testedParams.length ? LOCALE_FULL_MATCH : LOCALE_LANGUAGE_MATCH; case 2: if (1 == testedParams.length) return LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER; if (!referenceParams[1].equals(testedParams[1])) return LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER; if (3 == testedParams.length) return LOCALE_LANGUAGE_AND_COUNTRY_MATCH; return LOCALE_FULL_MATCH; case 3: if (1 == testedParams.length) return LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER; if (!referenceParams[1].equals(testedParams[1])) return LOCALE_LANGUAGE_MATCH_COUNTRY_DIFFER; if (2 == testedParams.length) return LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER; if (!referenceParams[2].equals(testedParams[2])) return LOCALE_LANGUAGE_AND_COUNTRY_MATCH_VARIANT_DIFFER; return LOCALE_FULL_MATCH; } // It should be impossible to come here return LOCALE_NO_MATCH; } /** * Return a string that represents this match level, with better matches first. * * The strings are sorted in lexicographic order: a better match will always be less than * a worse match when compared together. */ public static String getMatchLevelSortedString(final int matchLevel) { // This works because the match levels are 0~99 (actually 0~30) // Ideally this should use a number of digits equals to the 1og10 of the greater matchLevel return String.format(Locale.ROOT, "%02d", MATCH_LEVEL_MAX - matchLevel); } /** * Find out whether a match level should be considered a match. * * This method takes a match level as returned by the #getMatchLevel method, and returns whether * it should be considered a match in the usual sense with standard Locale functions. * * @param level the match level, as returned by getMatchLevel. * @return whether this is a match or not. */ public static boolean isMatch(final int level) { return LOCALE_MATCH <= level; } /** * Sets the system locale for this process. * * @param res the resources to use. Pass current resources. * @param newLocale the locale to change to. * @return the old locale. */ public static Locale setSystemLocale(final Resources res, final Locale newLocale) { final Configuration conf = res.getConfiguration(); final Locale saveLocale = conf.locale; conf.locale = newLocale; res.updateConfiguration(conf, res.getDisplayMetrics()); return saveLocale; } private static final HashMap sLocaleCache = new HashMap(); /** * Creates a locale from a string specification. */ public static Locale constructLocaleFromString(final String localeStr) { if (localeStr == null) return null; synchronized (sLocaleCache) { if (sLocaleCache.containsKey(localeStr)) return sLocaleCache.get(localeStr); Locale retval = null; String[] localeParams = localeStr.split("_", 3); if (localeParams.length == 1) { retval = new Locale(localeParams[0]); } else if (localeParams.length == 2) { retval = new Locale(localeParams[0], localeParams[1]); } else if (localeParams.length == 3) { retval = new Locale(localeParams[0], localeParams[1], localeParams[2]); } if (retval != null) { sLocaleCache.put(localeStr, retval); } return retval; } } }