import com.android.internal.annotations.VisibleForTesting;
+import android.annotation.IntRange;
import android.annotation.NonNull;
import android.annotation.Nullable;
-import android.text.TextUtils;
+import android.icu.util.ULocale;
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);
}
- @Nullable
- private static String getLanguage(@Nullable Locale locale) {
- if (locale == null) {
- return null;
+ /**
+ * 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);
}
- 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} 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>
+ * will be searched from {@code source} based on matching score. For the score design, see
+ * {@link LocaleUtils#calculateMatchingScore(ULocale, LocaleList, byte[])}</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 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 HashMap<String, ScoreEntry> scoreboard = new HashMap<>();
+ final byte[] score = new byte[preferredLanguages.size()];
- 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;
- }
+ 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;
}
- // 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 String lang = loc.getLanguage();
+ ScoreEntry bestScore = scoreboard.get(lang);
+ if (bestScore == null) {
+ bestScore = new ScoreEntry(score.length);
+ scoreboard.put(lang, bestScore);
}
- 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;
+ bestScore.updateIfBetter(score, i);
+ }
+
+ final ScoreEntry[] result = scoreboard.values().toArray(new ScoreEntry[scoreboard.size()]);
+ Arrays.sort(result);
+ for (final ScoreEntry entry : result) {
+ dest.add(sources.get(entry.index));
}
}
-}
\ 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));
+ }
+ }
}
OSDN Git Service
