import com.android.internal.annotations.VisibleForTesting;
-import android.annotation.IntRange;
import android.annotation.NonNull;
import android.annotation.Nullable;
-import android.icu.util.ULocale;
+import android.text.TextUtils;
import android.util.LocaleList;
import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashMap;
import java.util.List;
import java.util.Locale;
+import java.util.Objects;
public final class LocaleUtils {
Locale get(@Nullable T source);
}
- /**
- * Calculates a matching score for the single desired locale.
- *
- * <p>See {@link LocaleUtils#calculateMatchingScore(ULocale, LocaleList, byte[])} for
- * details.</p>
- */
- @IntRange(from=1, to=3)
- private static byte calculateMatchingSubScore(@NonNull final ULocale supported,
- @NonNull final ULocale desired) {
-
- // Assuming supported/desired is fully expanded.
- if (supported.equals(desired)) {
- return 3; // Exact match.
- }
-
- // Skip language matching since it was already done in calculateMatchingScore.
-
- final String supportedScript = supported.getScript();
- if (supportedScript.isEmpty() || !supportedScript.equals(desired.getScript())) {
- // TODO: Need subscript matching. For example, Hanb should match with Bopo.
- return 1;
- }
-
- final String supportedCountry = supported.getCountry();
- if (supportedCountry.isEmpty() || !supportedCountry.equals(desired.getCountry())) {
- return 2;
- }
-
- // Ignore others e.g. variants, extensions.
- return 3;
- }
-
- /**
- * Calculates a matching score for the desired locale list.
- *
- * <p>The supported locale gets a matching score of 3 if all language, script and country of the
- * supported locale matches with the desired locale. The supported locale gets a matching
- * score of 2 if the language and script of the supported locale matches with the desired
- * locale. The supported locale gets a matching score of 1 if only language of the supported
- * locale matches with the desired locale. The supported locale gets a matching score of 0 if
- * the language of the supported locale doesn't match with the desired locale.</p>
- *
- * <p>This function returns {@code false} if supported locale doesn't match with any desired
- * locale list. Otherwise, this function returns {@code true}.</p>
- */
- private static boolean calculateMatchingScore(@NonNull final ULocale supported,
- @NonNull final LocaleList desired, @NonNull byte[] out) {
- if (desired.isEmpty()) {
- return false;
- }
-
- boolean allZeros = true;
- for (int i = 0; i < desired.size(); ++i) {
- final Locale loc = desired.get(i);
-
- if (!loc.getLanguage().equals(supported.getLanguage())) {
- // TODO: cache the result of addLikelySubtags if it is slow.
- out[i] = 0;
- } else {
- out[i] = calculateMatchingSubScore(
- supported, ULocale.addLikelySubtags(ULocale.forLocale(loc)));
- if (allZeros && out[i] != 0) {
- allZeros = false;
- }
- }
- }
- return !allZeros;
- }
-
- private static final class ScoreEntry implements Comparable<ScoreEntry> {
- public int index = -1;
- @NonNull public byte[] score; // matching score of the i-th system languages.
-
- ScoreEntry(int capacity) {
- score = new byte[capacity];
- }
-
- /**
- * Update score and index if the given score is better than this.
- */
- public void updateIfBetter(@NonNull byte[] newScore, int newIndex) {
- if (isBetterThan(score) != 1) {
- return;
- }
-
- for (int i = 0; i < score.length; ++i) {
- score[i] = newScore[i];
- }
- index = newIndex;
- }
-
- /**
- * Determines given score is better than current.
- *
- * <p>Compares the matching score for the first priority locale. If the given score has
- * higher score than current score, returns 1. If the current score has higher score than
- * given score, returns -1. Otherwise, do the same comparison for the next priority locale.
- * If given score and current score is same for the all system locale, returns 0.</p>
- */
- private int isBetterThan(@NonNull byte[] other) {
- for (int i = 0; i < score.length; ++i) {
- if (score[i] < other[i]) {
- return 1;
- } else if (score[i] > other[i]) {
- return -1;
- }
- }
- return 0;
- }
-
- @Override
- public int compareTo(ScoreEntry other) {
- return isBetterThan(score);
+ @Nullable
+ private static String getLanguage(@Nullable Locale locale) {
+ if (locale == null) {
+ return null;
}
+ return locale.getLanguage();
}
/**
* {@code "en-GB", "ja", "en-AU", "fr-CA", "en-IN"} is specified to {@code preferredLanguages},
* this method tries to copy at most one English locale, at most one Japanese, and at most one
* French locale from {@code source} to {@code dest}. Here the best matching English locale
- * will be searched from {@code source} based on matching score. For the score design, see
- * {@link LocaleUtils#calculateMatchingScore(ULocale, LocaleList, byte[])}</p>
+ * will be searched from {@code source} as follows.
+ * <ol>
+ * <li>The first instance in {@code sources} that exactly matches {@code "en-GB"}</li>
+ * <li>The first instance in {@code sources} that exactly matches {@code "en-AU"}</li>
+ * <li>The first instance in {@code sources} that exactly matches {@code "en-IN"}</li>
+ * <li>The first instance in {@code sources} that partially matches {@code "en"}</li>
+ * </ol>
+ * <p>Then this method iterates the same algorithm for Japanese then French.</p>
*
* @param sources Source items to be filtered.
* @param extractor Type converter from the source items to {@link Locale} object.
@NonNull LocaleExtractor<T> extractor,
@NonNull LocaleList preferredLanguages,
@NonNull ArrayList<T> dest) {
- final HashMap<String, ScoreEntry> scoreboard = new HashMap<>();
- final byte[] score = new byte[preferredLanguages.size()];
-
- for (int i = 0; i < sources.size(); ++i) {
- final Locale loc = extractor.get(sources.get(i));
- if (loc == null ||
- !calculateMatchingScore(ULocale.addLikelySubtags(ULocale.forLocale(loc)),
- preferredLanguages, score)) {
- continue;
+ final Locale[] availableLocales = new Locale[sources.size()];
+ for (int i = 0; i < availableLocales.length; ++i) {
+ availableLocales[i] = extractor.get(sources.get(i));
+ }
+ final Locale[] sortedPreferredLanguages = new Locale[preferredLanguages.size()];
+ if (sortedPreferredLanguages.length > 0) {
+ int nextIndex = 0;
+ final int N = preferredLanguages.size();
+ languageLoop:
+ for (int i = 0; i < N; ++i) {
+ final String language = getLanguage(preferredLanguages.get(i));
+ for (int j = 0; j < nextIndex; ++j) {
+ if (TextUtils.equals(getLanguage(sortedPreferredLanguages[j]), language)) {
+ continue languageLoop;
+ }
+ }
+ for (int j = i; j < N; ++j) {
+ final Locale locale = preferredLanguages.get(j);
+ if (TextUtils.equals(language, getLanguage(locale))) {
+ sortedPreferredLanguages[nextIndex] = locale;
+ ++nextIndex;
+ }
+ }
}
+ }
+
- final String lang = loc.getLanguage();
- ScoreEntry bestScore = scoreboard.get(lang);
- if (bestScore == null) {
- bestScore = new ScoreEntry(score.length);
- scoreboard.put(lang, bestScore);
+ for (int languageIndex = 0; languageIndex < sortedPreferredLanguages.length;) {
+ // Finding the range.
+ final String language = getLanguage(sortedPreferredLanguages[languageIndex]);
+ int nextLanguageIndex = languageIndex;
+ for (; nextLanguageIndex < sortedPreferredLanguages.length; ++nextLanguageIndex) {
+ final Locale locale = sortedPreferredLanguages[nextLanguageIndex];
+ if (!TextUtils.equals(getLanguage(locale), language)) {
+ break;
+ }
}
- bestScore.updateIfBetter(score, i);
- }
+ // Check exact match
+ boolean found = false;
+ for (int i = languageIndex; !found && i < nextLanguageIndex; ++i) {
+ final Locale locale = sortedPreferredLanguages[i];
+ for (int j = 0; j < availableLocales.length; ++j) {
+ if (!Objects.equals(locale, availableLocales[j])) {
+ continue;
+ }
+ dest.add(sources.get(j));
+ found = true;
+ break;
+ }
+ }
- final ScoreEntry[] result = scoreboard.values().toArray(new ScoreEntry[scoreboard.size()]);
- Arrays.sort(result);
- for (final ScoreEntry entry : result) {
- dest.add(sources.get(entry.index));
+ if (!found) {
+ // No exact match. Use language match.
+ for (int j = 0; j < availableLocales.length; ++j) {
+ if (!TextUtils.equals(language, getLanguage(availableLocales[j]))) {
+ continue;
+ }
+ dest.add(sources.get(j));
+ break;
+ }
+ }
+ languageIndex = nextLanguageIndex;
}
}
-}
+}
\ No newline at end of file
assertEquals(availableLocales.get(1), dest.get(0)); // "en-CA"
}
}
-
- @SmallTest
- public void testFilterByLanguageFallbackRules() throws Exception {
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr-Latn-RS");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-BA"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-CS"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-ME"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-RS"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-BA"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-CS"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-ME"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-RS"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(7), dest.get(0)); // "sr-Latn-RS"
- }
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr-Latn-RS-x-android");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-BA"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-CS"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-ME"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-RS"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-BA"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-CS"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-ME"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-RS"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(7), dest.get(0)); // "sr-Latn-RS"
- }
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr-Latn-RS");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-BA-x-android"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-CS-x-android"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-ME-x-android"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-RS-x-android"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-BA-x-android"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-CS-x-android"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-ME-x-android"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-RS-x-android"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(7), dest.get(0)); // "sr-Latn-RS-x-android"
- }
-
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr-Latn-RS");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(2), dest.get(0)); // "sr-Latn"
- }
-
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr-RS");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr"));
- availableLocales.add(Locale.forLanguageTag("sr-RS"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(0), dest.get(0)); // "sr"
- }
-
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr-Latn");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr"));
- availableLocales.add(Locale.forLanguageTag("sr-RS"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(2), dest.get(0)); // "sr-Latn"
- }
-
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr"));
- availableLocales.add(Locale.forLanguageTag("sr-RS"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(0), dest.get(0)); // "sr"
- }
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr-Latn"));
- availableLocales.add(Locale.forLanguageTag("sr-RS"));
- availableLocales.add(Locale.forLanguageTag("sr"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(1), dest.get(0)); // "sr-RS"
- }
-
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-RS"));
- availableLocales.add(Locale.forLanguageTag("sr-Latn-RS"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(0), dest.get(0)); // "sr-Cyrl-RS"
- }
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("sr-Latn");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("sr-Latn-RS"));
- availableLocales.add(Locale.forLanguageTag("sr-Cyrl-RS"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- assertEquals(availableLocales.get(0), dest.get(0)); // "sr-Latn-RS"
- }
- }
-
- public void testFilterKnownLimitation() throws Exception {
- // Following test cases are not for intentional behavior but checks for preventing the
- // behavior from becoming worse.
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("ja-Hrkt");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("ja-Jpan"));
- availableLocales.add(Locale.forLanguageTag("ja-Hrkt"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- // Should be ja-Jpan since it supports ja-Hrkt and listed before ja-Hrkt.
- assertEquals(availableLocales.get(1), dest.get(0));
- }
- {
- final LocaleList preferredLocales = LocaleList.forLanguageTags("zh-Hani");
- final ArrayList<Locale> availableLocales = new ArrayList<>();
- availableLocales.add(Locale.forLanguageTag("zh-Hans"));
- availableLocales.add(Locale.forLanguageTag("zh-Hant"));
- availableLocales.add(Locale.forLanguageTag("zh-Hanb"));
- availableLocales.add(Locale.forLanguageTag("zh-Hani"));
- final ArrayList<Locale> dest = new ArrayList<>();
- LocaleUtils.filterByLanguage(availableLocales, sIdentityMapper, preferredLocales, dest);
- assertEquals(1, dest.size());
- // Should be zh-Hans since it supports zh-Hani. Also zh-Hant, zh-Hanb supports zh-Hani.
- assertEquals(availableLocales.get(3), dest.get(0));
- }
- }
}
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