Move util classes to the latin/utils directory

Change-Id: I1c5b27c8edf231680edb8d96f63b9d04cfc6a6fa

1 files changed, 261 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/latin/utils/LocaleUtils.java b/java/src/com/android/inputmethod/latin/utils/LocaleUtils.java
new file mode 100644
index 000000000..58d062bbd
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/utils/LocaleUtils.java
@@ -0,0 +1,261 @@
+/*
+ * 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.latin.utils;
+
+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 in the dictionary pack. They need to be kept synchronized; for any
+ * update/bugfix to this file, consider also updating/fixing the version in the
+ * dictionary pack.
+ */
+public final class LocaleUtils {
+    private static final HashMap<String, Long> EMPTY_LT_HASH_MAP = CollectionUtils.newHashMap();
+    private static final String LOCALE_AND_TIME_STR_SEPARATER = ",";
+
+    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(String referenceLocale, String testedLocale) {
+        if (TextUtils.isEmpty(referenceLocale)) {
+            return TextUtils.isEmpty(testedLocale) ? LOCALE_FULL_MATCH : LOCALE_ANY_MATCH;
+        }
+        if (null == testedLocale) return LOCALE_NO_MATCH;
+        String[] referenceParams = referenceLocale.split("_", 3);
+        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(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(int level) {
+        return LOCALE_MATCH <= level;
+    }
+
+    static final Object sLockForRunInLocale = new Object();
+
+    // TODO: Make this an external class
+    public abstract static class RunInLocale<T> {
+        protected abstract T job(Resources res);
+
+        /**
+         * Execute {@link #job(Resources)} method in specified system locale exclusively.
+         *
+         * @param res the resources to use. Pass current resources.
+         * @param newLocale the locale to change to
+         * @return the value returned from {@link #job(Resources)}.
+         */
+        public T runInLocale(final Resources res, final Locale newLocale) {
+            synchronized (sLockForRunInLocale) {
+                final Configuration conf = res.getConfiguration();
+                final Locale oldLocale = conf.locale;
+                final boolean needsChange = (newLocale != null && !newLocale.equals(oldLocale));
+                try {
+                    if (needsChange) {
+                        conf.locale = newLocale;
+                        res.updateConfiguration(conf, null);
+                    }
+                    return job(res);
+                } finally {
+                    if (needsChange) {
+                        conf.locale = oldLocale;
+                        res.updateConfiguration(conf, null);
+                    }
+                }
+            }
+        }
+    }
+
+    private static final HashMap<String, Locale> sLocaleCache = CollectionUtils.newHashMap();
+
+    /**
+     * 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;
+        }
+    }
+
+    public static HashMap<String, Long> localeAndTimeStrToHashMap(String str) {
+        if (TextUtils.isEmpty(str)) {
+            return EMPTY_LT_HASH_MAP;
+        }
+        final String[] ss = str.split(LOCALE_AND_TIME_STR_SEPARATER);
+        final int N = ss.length;
+        if (N < 2 || N % 2 != 0) {
+            return EMPTY_LT_HASH_MAP;
+        }
+        final HashMap<String, Long> retval = CollectionUtils.newHashMap();
+        for (int i = 0; i < N / 2; ++i) {
+            final String localeStr = ss[i * 2];
+            final long time = Long.valueOf(ss[i * 2 + 1]);
+            retval.put(localeStr, time);
+        }
+        return retval;
+    }
+
+    public static String localeAndTimeHashMapToStr(HashMap<String, Long> map) {
+        if (map == null || map.isEmpty()) {
+            return "";
+        }
+        final StringBuilder builder = new StringBuilder();
+        for (String localeStr : map.keySet()) {
+            if (builder.length() > 0) {
+                builder.append(LOCALE_AND_TIME_STR_SEPARATER);
+            }
+            final Long time = map.get(localeStr);
+            builder.append(localeStr).append(LOCALE_AND_TIME_STR_SEPARATER);
+            builder.append(String.valueOf(time));
+        }
+        return builder.toString();
+    }
+}