Merge "Prepare to make InputMethodUtils package-private"

7 files changed, 285 insertions, 282 deletions

diff --git a/core/java/android/view/inputmethod/InputMethodSubtype.java b/core/java/android/view/inputmethod/InputMethodSubtype.java
index a7d7a8d67f64..61a697282dcb 100644
--- a/core/java/android/view/inputmethod/InputMethodSubtype.java
+++ b/core/java/android/view/inputmethod/InputMethodSubtype.java
@@ -28,7 +28,7 @@ import android.os.Parcelable;
 import android.text.TextUtils;
 import android.util.Slog;
 
-import com.android.internal.inputmethod.InputMethodUtils;
+import com.android.internal.inputmethod.LocaleUtils;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -384,7 +384,7 @@ public final class InputMethodSubtype implements Parcelable {
             if (!TextUtils.isEmpty(mSubtypeLanguageTag)) {
                 mCachedLocaleObj = Locale.forLanguageTag(mSubtypeLanguageTag);
             } else {
-                mCachedLocaleObj = InputMethodUtils.constructLocaleFromString(mSubtypeLocale);
+                mCachedLocaleObj = LocaleUtils.constructLocaleFromString(mSubtypeLocale);
             }
             return mCachedLocaleObj;
         }
diff --git a/core/java/android/view/textservice/SpellCheckerSubtype.java b/core/java/android/view/textservice/SpellCheckerSubtype.java
index 026610ecb6f9..41b70b61fd4a 100644
--- a/core/java/android/view/textservice/SpellCheckerSubtype.java
+++ b/core/java/android/view/textservice/SpellCheckerSubtype.java
@@ -25,7 +25,7 @@ import android.os.Parcelable;
 import android.text.TextUtils;
 import android.util.Slog;
 
-import com.android.internal.inputmethod.InputMethodUtils;
+import com.android.internal.inputmethod.LocaleUtils;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -228,7 +228,7 @@ public final class SpellCheckerSubtype implements Parcelable {
         if (!TextUtils.isEmpty(mSubtypeLanguageTag)) {
             return Locale.forLanguageTag(mSubtypeLanguageTag);
         }
-        return InputMethodUtils.constructLocaleFromString(mSubtypeLocale);
+        return LocaleUtils.constructLocaleFromString(mSubtypeLocale);
     }
 
     /**
diff --git a/core/java/com/android/internal/inputmethod/InputMethodUtils.java b/core/java/com/android/internal/inputmethod/InputMethodUtils.java
index 1e5b5c80f31b..1410ff9a0813 100644
--- a/core/java/com/android/internal/inputmethod/InputMethodUtils.java
+++ b/core/java/com/android/internal/inputmethod/InputMethodUtils.java
@@ -334,32 +334,6 @@ public class InputMethodUtils {
         return getDefaultEnabledImes(context, imis, false /* onlyMinimum */);
     }
 
-    public static Locale constructLocaleFromString(String localeStr) {
-        if (TextUtils.isEmpty(localeStr)) {
-            return null;
-        }
-        // TODO: Use {@link Locale#toLanguageTag()} and {@link Locale#forLanguageTag(languageTag)}.
-        String[] localeParams = localeStr.split("_", 3);
-        if (localeParams.length >= 1 && "tl".equals(localeParams[0])) {
-             // Convert a locale whose language is "tl" to one whose language is "fil".
-             // For example, "tl_PH" will get converted to "fil_PH".
-             // Versions of Android earlier than Lollipop did not support three letter language
-             // codes, and used "tl" (Tagalog) as the language string for "fil" (Filipino).
-             // On Lollipop and above, the current three letter version must be used.
-             localeParams[0] = "fil";
-        }
-        // The length of localeStr is guaranteed to always return a 1 <= value <= 3
-        // because localeStr is not empty.
-        if (localeParams.length == 1) {
-            return new Locale(localeParams[0]);
-        } else if (localeParams.length == 2) {
-            return new Locale(localeParams[0], localeParams[1]);
-        } else if (localeParams.length == 3) {
-            return new Locale(localeParams[0], localeParams[1], localeParams[2]);
-        }
-        return null;
-    }
-
     public static boolean containsSubtypeOf(final InputMethodInfo imi,
             @Nullable final Locale locale, final boolean checkCountry, final String mode) {
         if (locale == null) {
@@ -1320,133 +1294,7 @@ public class InputMethodUtils {
         }
     }
 
-    // For spell checker service manager.
-    // TODO: Should we have TextServicesUtils.java?
-    private static final Locale LOCALE_EN_US = new Locale("en", "US");
-    private static final Locale LOCALE_EN_GB = new Locale("en", "GB");
-
-    /**
-     * Returns a list of {@link Locale} in the order of appropriateness for the default spell
-     * checker service.
-     *
-     * <p>If the system language is English, and the region is also explicitly specified in the
-     * system locale, the following fallback order will be applied.</p>
-     * <ul>
-     * <li>(system-locale-language, system-locale-region, system-locale-variant) (if exists)</li>
-     * <li>(system-locale-language, system-locale-region)</li>
-     * <li>("en", "US")</li>
-     * <li>("en", "GB")</li>
-     * <li>("en")</li>
-     * </ul>
-     *
-     * <p>If the system language is English, but no region is specified in the system locale,
-     * the following fallback order will be applied.</p>
-     * <ul>
-     * <li>("en")</li>
-     * <li>("en", "US")</li>
-     * <li>("en", "GB")</li>
-     * </ul>
-     *
-     * <p>If the system language is not English, the following fallback order will be applied.</p>
-     * <ul>
-     * <li>(system-locale-language, system-locale-region, system-locale-variant) (if exists)</li>
-     * <li>(system-locale-language, system-locale-region) (if exists)</li>
-     * <li>(system-locale-language) (if exists)</li>
-     * <li>("en", "US")</li>
-     * <li>("en", "GB")</li>
-     * <li>("en")</li>
-     * </ul>
-     *
-     * @param systemLocale the current system locale to be taken into consideration.
-     * @return a list of {@link Locale}. The first one is considered to be most appropriate.
-     */
     @VisibleForTesting
-    public static ArrayList<Locale> getSuitableLocalesForSpellChecker(
-            @Nullable final Locale systemLocale) {
-        final Locale systemLocaleLanguageCountryVariant;
-        final Locale systemLocaleLanguageCountry;
-        final Locale systemLocaleLanguage;
-        if (systemLocale != null) {
-            final String language = systemLocale.getLanguage();
-            final boolean hasLanguage = !TextUtils.isEmpty(language);
-            final String country = systemLocale.getCountry();
-            final boolean hasCountry = !TextUtils.isEmpty(country);
-            final String variant = systemLocale.getVariant();
-            final boolean hasVariant = !TextUtils.isEmpty(variant);
-            if (hasLanguage && hasCountry && hasVariant) {
-                systemLocaleLanguageCountryVariant = new Locale(language, country, variant);
-            } else {
-                systemLocaleLanguageCountryVariant = null;
-            }
-            if (hasLanguage && hasCountry) {
-                systemLocaleLanguageCountry = new Locale(language, country);
-            } else {
-                systemLocaleLanguageCountry = null;
-            }
-            if (hasLanguage) {
-                systemLocaleLanguage = new Locale(language);
-            } else {
-                systemLocaleLanguage = null;
-            }
-        } else {
-            systemLocaleLanguageCountryVariant = null;
-            systemLocaleLanguageCountry = null;
-            systemLocaleLanguage = null;
-        }
-
-        final ArrayList<Locale> locales = new ArrayList<>();
-        if (systemLocaleLanguageCountryVariant != null) {
-            locales.add(systemLocaleLanguageCountryVariant);
-        }
-
-        if (Locale.ENGLISH.equals(systemLocaleLanguage)) {
-            if (systemLocaleLanguageCountry != null) {
-                // If the system language is English, and the region is also explicitly specified,
-                // following fallback order will be applied.
-                // - systemLocaleLanguageCountry [if systemLocaleLanguageCountry is non-null]
-                // - en_US [if systemLocaleLanguageCountry is non-null and not en_US]
-                // - en_GB [if systemLocaleLanguageCountry is non-null and not en_GB]
-                // - en
-                if (systemLocaleLanguageCountry != null) {
-                    locales.add(systemLocaleLanguageCountry);
-                }
-                if (!LOCALE_EN_US.equals(systemLocaleLanguageCountry)) {
-                    locales.add(LOCALE_EN_US);
-                }
-                if (!LOCALE_EN_GB.equals(systemLocaleLanguageCountry)) {
-                    locales.add(LOCALE_EN_GB);
-                }
-                locales.add(Locale.ENGLISH);
-            } else {
-                // If the system language is English, but no region is specified, following
-                // fallback order will be applied.
-                // - en
-                // - en_US
-                // - en_GB
-                locales.add(Locale.ENGLISH);
-                locales.add(LOCALE_EN_US);
-                locales.add(LOCALE_EN_GB);
-            }
-        } else {
-            // If the system language is not English, the fallback order will be
-            // - systemLocaleLanguageCountry  [if non-null]
-            // - systemLocaleLanguage  [if non-null]
-            // - en_US
-            // - en_GB
-            // - en
-            if (systemLocaleLanguageCountry != null) {
-                locales.add(systemLocaleLanguageCountry);
-            }
-            if (systemLocaleLanguage != null) {
-                locales.add(systemLocaleLanguage);
-            }
-            locales.add(LOCALE_EN_US);
-            locales.add(LOCALE_EN_GB);
-            locales.add(Locale.ENGLISH);
-        }
-        return locales;
-    }
-
     public static boolean isSoftInputModeStateVisibleAllowed(
             int targetSdkVersion, int controlFlags) {
         if (targetSdkVersion < Build.VERSION_CODES.P) {
@@ -1461,5 +1309,4 @@ public class InputMethodUtils {
         }
         return true;
     }
-
 }
diff --git a/core/java/com/android/internal/inputmethod/LocaleUtils.java b/core/java/com/android/internal/inputmethod/LocaleUtils.java
index eeb3854bcc55..f7360eb0fe13 100644
--- a/core/java/com/android/internal/inputmethod/LocaleUtils.java
+++ b/core/java/com/android/internal/inputmethod/LocaleUtils.java
@@ -16,8 +16,6 @@
 
 package com.android.internal.inputmethod;
 
-import com.android.internal.annotations.VisibleForTesting;
-
 import android.annotation.IntRange;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -25,6 +23,8 @@ import android.icu.util.ULocale;
 import android.os.LocaleList;
 import android.text.TextUtils;
 
+import com.android.internal.annotations.VisibleForTesting;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -208,4 +208,151 @@ public final class LocaleUtils {
             dest.add(sources.get(entry.mIndex));
         }
     }
+
+    public static Locale constructLocaleFromString(String localeStr) {
+        if (TextUtils.isEmpty(localeStr)) {
+            return null;
+        }
+        // TODO: Use {@link Locale#toLanguageTag()} and {@link Locale#forLanguageTag(languageTag)}.
+        String[] localeParams = localeStr.split("_", 3);
+        if (localeParams.length >= 1 && "tl".equals(localeParams[0])) {
+            // Convert a locale whose language is "tl" to one whose language is "fil".
+            // For example, "tl_PH" will get converted to "fil_PH".
+            // Versions of Android earlier than Lollipop did not support three letter language
+            // codes, and used "tl" (Tagalog) as the language string for "fil" (Filipino).
+            // On Lollipop and above, the current three letter version must be used.
+            localeParams[0] = "fil";
+        }
+        // The length of localeStr is guaranteed to always return a 1 <= value <= 3
+        // because localeStr is not empty.
+        if (localeParams.length == 1) {
+            return new Locale(localeParams[0]);
+        } else if (localeParams.length == 2) {
+            return new Locale(localeParams[0], localeParams[1]);
+        } else if (localeParams.length == 3) {
+            return new Locale(localeParams[0], localeParams[1], localeParams[2]);
+        }
+        return null;
+    }
+
+    /**
+     * Returns a list of {@link Locale} in the order of appropriateness for the default spell
+     * checker service.
+     *
+     * <p>If the system language is English, and the region is also explicitly specified in the
+     * system locale, the following fallback order will be applied.</p>
+     * <ul>
+     * <li>(system-locale-language, system-locale-region, system-locale-variant) (if exists)</li>
+     * <li>(system-locale-language, system-locale-region)</li>
+     * <li>("en", "US")</li>
+     * <li>("en", "GB")</li>
+     * <li>("en")</li>
+     * </ul>
+     *
+     * <p>If the system language is English, but no region is specified in the system locale,
+     * the following fallback order will be applied.</p>
+     * <ul>
+     * <li>("en")</li>
+     * <li>("en", "US")</li>
+     * <li>("en", "GB")</li>
+     * </ul>
+     *
+     * <p>If the system language is not English, the following fallback order will be applied.</p>
+     * <ul>
+     * <li>(system-locale-language, system-locale-region, system-locale-variant) (if exists)</li>
+     * <li>(system-locale-language, system-locale-region) (if exists)</li>
+     * <li>(system-locale-language) (if exists)</li>
+     * <li>("en", "US")</li>
+     * <li>("en", "GB")</li>
+     * <li>("en")</li>
+     * </ul>
+     *
+     * @param systemLocale the current system locale to be taken into consideration.
+     * @return a list of {@link Locale}. The first one is considered to be most appropriate.
+     */
+    public static ArrayList<Locale> getSuitableLocalesForSpellChecker(
+            @Nullable final Locale systemLocale) {
+        final Locale systemLocaleLanguageCountryVariant;
+        final Locale systemLocaleLanguageCountry;
+        final Locale systemLocaleLanguage;
+        if (systemLocale != null) {
+            final String language = systemLocale.getLanguage();
+            final boolean hasLanguage = !TextUtils.isEmpty(language);
+            final String country = systemLocale.getCountry();
+            final boolean hasCountry = !TextUtils.isEmpty(country);
+            final String variant = systemLocale.getVariant();
+            final boolean hasVariant = !TextUtils.isEmpty(variant);
+            if (hasLanguage && hasCountry && hasVariant) {
+                systemLocaleLanguageCountryVariant = new Locale(language, country, variant);
+            } else {
+                systemLocaleLanguageCountryVariant = null;
+            }
+            if (hasLanguage && hasCountry) {
+                systemLocaleLanguageCountry = new Locale(language, country);
+            } else {
+                systemLocaleLanguageCountry = null;
+            }
+            if (hasLanguage) {
+                systemLocaleLanguage = new Locale(language);
+            } else {
+                systemLocaleLanguage = null;
+            }
+        } else {
+            systemLocaleLanguageCountryVariant = null;
+            systemLocaleLanguageCountry = null;
+            systemLocaleLanguage = null;
+        }
+
+        final ArrayList<Locale> locales = new ArrayList<>();
+        if (systemLocaleLanguageCountryVariant != null) {
+            locales.add(systemLocaleLanguageCountryVariant);
+        }
+
+        if (Locale.ENGLISH.equals(systemLocaleLanguage)) {
+            if (systemLocaleLanguageCountry != null) {
+                // If the system language is English, and the region is also explicitly specified,
+                // following fallback order will be applied.
+                // - systemLocaleLanguageCountry [if systemLocaleLanguageCountry is non-null]
+                // - en_US [if systemLocaleLanguageCountry is non-null and not en_US]
+                // - en_GB [if systemLocaleLanguageCountry is non-null and not en_GB]
+                // - en
+                if (systemLocaleLanguageCountry != null) {
+                    locales.add(systemLocaleLanguageCountry);
+                }
+                if (!Locale.US.equals(systemLocaleLanguageCountry)) {
+                    locales.add(Locale.US);
+                }
+                if (!Locale.UK.equals(systemLocaleLanguageCountry)) {
+                    locales.add(Locale.UK);
+                }
+                locales.add(Locale.ENGLISH);
+            } else {
+                // If the system language is English, but no region is specified, following
+                // fallback order will be applied.
+                // - en
+                // - en_US
+                // - en_GB
+                locales.add(Locale.ENGLISH);
+                locales.add(Locale.US);
+                locales.add(Locale.UK);
+            }
+        } else {
+            // If the system language is not English, the fallback order will be
+            // - systemLocaleLanguageCountry  [if non-null]
+            // - systemLocaleLanguage  [if non-null]
+            // - en_US
+            // - en_GB
+            // - en
+            if (systemLocaleLanguageCountry != null) {
+                locales.add(systemLocaleLanguageCountry);
+            }
+            if (systemLocaleLanguage != null) {
+                locales.add(systemLocaleLanguage);
+            }
+            locales.add(Locale.US);
+            locales.add(Locale.UK);
+            locales.add(Locale.ENGLISH);
+        }
+        return locales;
+    }
 }
diff --git a/core/tests/coretests/src/com/android/internal/inputmethod/InputMethodUtilsTest.java b/core/tests/coretests/src/com/android/internal/inputmethod/InputMethodUtilsTest.java
index 3064afaeaab1..f731a4affb87 100644
--- a/core/tests/coretests/src/com/android/internal/inputmethod/InputMethodUtilsTest.java
+++ b/core/tests/coretests/src/com/android/internal/inputmethod/InputMethodUtilsTest.java
@@ -71,15 +71,11 @@ public class InputMethodUtilsTest {
     private static final Locale LOCALE_FR = new Locale("fr");
     private static final Locale LOCALE_FR_CA = new Locale("fr", "CA");
     private static final Locale LOCALE_HI = new Locale("hi");
-    private static final Locale LOCALE_JA = new Locale("ja");
     private static final Locale LOCALE_JA_JP = new Locale("ja", "JP");
     private static final Locale LOCALE_ZH_CN = new Locale("zh", "CN");
     private static final Locale LOCALE_ZH_TW = new Locale("zh", "TW");
     private static final Locale LOCALE_IN = new Locale("in");
     private static final Locale LOCALE_ID = new Locale("id");
-    private static final Locale LOCALE_TH = new Locale("ht");
-    private static final Locale LOCALE_TH_TH = new Locale("ht", "TH");
-    private static final Locale LOCALE_TH_TH_TH = new Locale("ht", "TH", "TH");
     private static final String SUBTYPE_MODE_KEYBOARD = "keyboard";
     private static final String SUBTYPE_MODE_VOICE = "voice";
     private static final String SUBTYPE_MODE_HANDWRITING = "handwriting";
@@ -1087,122 +1083,6 @@ public class InputMethodUtilsTest {
     }
 
     @Test
-    public void testGetSuitableLocalesForSpellChecker() throws Exception {
-        {
-            final ArrayList<Locale> locales =
-                    InputMethodUtils.getSuitableLocalesForSpellChecker(LOCALE_EN_US);
-            assertEquals(3, locales.size());
-            assertEquals(LOCALE_EN_US, locales.get(0));
-            assertEquals(LOCALE_EN_GB, locales.get(1));
-            assertEquals(LOCALE_EN, locales.get(2));
-        }
-
-        {
-            final ArrayList<Locale> locales =
-                    InputMethodUtils.getSuitableLocalesForSpellChecker(LOCALE_EN_GB);
-            assertEquals(3, locales.size());
-            assertEquals(LOCALE_EN_GB, locales.get(0));
-            assertEquals(LOCALE_EN_US, locales.get(1));
-            assertEquals(LOCALE_EN, locales.get(2));
-        }
-
-        {
-            final ArrayList<Locale> locales =
-                    InputMethodUtils.getSuitableLocalesForSpellChecker(LOCALE_EN);
-            assertEquals(3, locales.size());
-            assertEquals(LOCALE_EN, locales.get(0));
-            assertEquals(LOCALE_EN_US, locales.get(1));
-            assertEquals(LOCALE_EN_GB, locales.get(2));
-        }
-
-        {
-            final ArrayList<Locale> locales =
-                    InputMethodUtils.getSuitableLocalesForSpellChecker(LOCALE_EN_IN);
-            assertEquals(4, locales.size());
-            assertEquals(LOCALE_EN_IN, locales.get(0));
-            assertEquals(LOCALE_EN_US, locales.get(1));
-            assertEquals(LOCALE_EN_GB, locales.get(2));
-            assertEquals(LOCALE_EN, locales.get(3));
-        }
-
-        {
-            final ArrayList<Locale> locales =
-                    InputMethodUtils.getSuitableLocalesForSpellChecker(LOCALE_JA_JP);
-            assertEquals(5, locales.size());
-            assertEquals(LOCALE_JA_JP, locales.get(0));
-            assertEquals(LOCALE_JA, locales.get(1));
-            assertEquals(LOCALE_EN_US, locales.get(2));
-            assertEquals(LOCALE_EN_GB, locales.get(3));
-            assertEquals(Locale.ENGLISH, locales.get(4));
-        }
-
-        // Test 3-letter language code.
-        {
-            final ArrayList<Locale> locales =
-                    InputMethodUtils.getSuitableLocalesForSpellChecker(LOCALE_FIL_PH);
-            assertEquals(5, locales.size());
-            assertEquals(LOCALE_FIL_PH, locales.get(0));
-            assertEquals(LOCALE_FIL, locales.get(1));
-            assertEquals(LOCALE_EN_US, locales.get(2));
-            assertEquals(LOCALE_EN_GB, locales.get(3));
-            assertEquals(Locale.ENGLISH, locales.get(4));
-        }
-
-        // Test variant.
-        {
-            final ArrayList<Locale> locales =
-                    InputMethodUtils.getSuitableLocalesForSpellChecker(LOCALE_TH_TH_TH);
-            assertEquals(6, locales.size());
-            assertEquals(LOCALE_TH_TH_TH, locales.get(0));
-            assertEquals(LOCALE_TH_TH, locales.get(1));
-            assertEquals(LOCALE_TH, locales.get(2));
-            assertEquals(LOCALE_EN_US, locales.get(3));
-            assertEquals(LOCALE_EN_GB, locales.get(4));
-            assertEquals(Locale.ENGLISH, locales.get(5));
-        }
-
-        // Test Locale extension.
-        {
-            final Locale localeWithoutVariant = LOCALE_JA_JP;
-            final Locale localeWithVariant = new Locale.Builder()
-                    .setLocale(LOCALE_JA_JP)
-                    .setExtension('x', "android")
-                    .build();
-            assertFalse(localeWithoutVariant.equals(localeWithVariant));
-
-            final ArrayList<Locale> locales =
-                    InputMethodUtils.getSuitableLocalesForSpellChecker(localeWithVariant);
-            assertEquals(5, locales.size());
-            assertEquals(LOCALE_JA_JP, locales.get(0));
-            assertEquals(LOCALE_JA, locales.get(1));
-            assertEquals(LOCALE_EN_US, locales.get(2));
-            assertEquals(LOCALE_EN_GB, locales.get(3));
-            assertEquals(Locale.ENGLISH, locales.get(4));
-        }
-    }
-
-    @Test
-    public void testConstructLocaleFromString() throws Exception {
-        assertEquals(new Locale("en"), InputMethodUtils.constructLocaleFromString("en"));
-        assertEquals(new Locale("en", "US"), InputMethodUtils.constructLocaleFromString("en_US"));
-        assertEquals(new Locale("en", "US", "POSIX"),
-                InputMethodUtils.constructLocaleFromString("en_US_POSIX"));
-
-        // Special rewrite rule for "tl" for versions of Android earlier than Lollipop that did not
-        // support three letter language codes, and used "tl" (Tagalog) as the language string for
-        // "fil" (Filipino).
-        assertEquals(new Locale("fil"), InputMethodUtils.constructLocaleFromString("tl"));
-        assertEquals(new Locale("fil", "PH"), InputMethodUtils.constructLocaleFromString("tl_PH"));
-        assertEquals(new Locale("fil", "PH", "POSIX"),
-                InputMethodUtils.constructLocaleFromString("tl_PH_POSIX"));
-
-        // So far rejecting an invalid/unexpected locale string is out of the scope of this method.
-        assertEquals(new Locale("a"), InputMethodUtils.constructLocaleFromString("a"));
-        assertEquals(new Locale("a b c"), InputMethodUtils.constructLocaleFromString("a b c"));
-        assertEquals(new Locale("en-US"), InputMethodUtils.constructLocaleFromString("en-US"));
-    }
-
-    @Test
     public void testIsSoftInputModeStateVisibleAllowed() {
         // On pre-P devices, SOFT_INPUT_STATE_VISIBLE/SOFT_INPUT_STATE_ALWAYS_VISIBLE are always
         // allowed, regardless of the focused view state.
diff --git a/core/tests/coretests/src/com/android/internal/inputmethod/LocaleUtilsTest.java b/core/tests/coretests/src/com/android/internal/inputmethod/LocaleUtilsTest.java
index 549511a420eb..7d0e646181c0 100644
--- a/core/tests/coretests/src/com/android/internal/inputmethod/LocaleUtilsTest.java
+++ b/core/tests/coretests/src/com/android/internal/inputmethod/LocaleUtilsTest.java
@@ -17,6 +17,7 @@
 package com.android.internal.inputmethod;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 
 import android.os.LocaleList;
 import android.support.test.filters.SmallTest;
@@ -34,6 +35,18 @@ public class LocaleUtilsTest {
 
     private static final LocaleUtils.LocaleExtractor<Locale> sIdentityMapper = source -> source;
 
+    private static final Locale LOCALE_EN = new Locale("en");
+    private static final Locale LOCALE_EN_US = new Locale("en", "US");
+    private static final Locale LOCALE_EN_GB = new Locale("en", "GB");
+    private static final Locale LOCALE_EN_IN = new Locale("en", "IN");
+    private static final Locale LOCALE_FIL = new Locale("fil");
+    private static final Locale LOCALE_FIL_PH = new Locale("fil", "PH");
+    private static final Locale LOCALE_JA = new Locale("ja");
+    private static final Locale LOCALE_JA_JP = new Locale("ja", "JP");
+    private static final Locale LOCALE_TH = new Locale("ht");
+    private static final Locale LOCALE_TH_TH = new Locale("ht", "TH");
+    private static final Locale LOCALE_TH_TH_TH = new Locale("ht", "TH", "TH");
+
     @Test
     public void testFilterByLanguageEmptyLanguageList() throws Exception {
         final ArrayList<Locale> availableLocales = new ArrayList<>();
@@ -385,4 +398,120 @@ public class LocaleUtilsTest {
             assertEquals(availableLocales.get(3), dest.get(0));
         }
     }
+
+    @Test
+    public void testGetSuitableLocalesForSpellChecker() throws Exception {
+        {
+            final ArrayList<Locale> locales =
+                    LocaleUtils.getSuitableLocalesForSpellChecker(LOCALE_EN_US);
+            assertEquals(3, locales.size());
+            assertEquals(LOCALE_EN_US, locales.get(0));
+            assertEquals(LOCALE_EN_GB, locales.get(1));
+            assertEquals(LOCALE_EN, locales.get(2));
+        }
+
+        {
+            final ArrayList<Locale> locales =
+                    LocaleUtils.getSuitableLocalesForSpellChecker(LOCALE_EN_GB);
+            assertEquals(3, locales.size());
+            assertEquals(LOCALE_EN_GB, locales.get(0));
+            assertEquals(LOCALE_EN_US, locales.get(1));
+            assertEquals(LOCALE_EN, locales.get(2));
+        }
+
+        {
+            final ArrayList<Locale> locales =
+                    LocaleUtils.getSuitableLocalesForSpellChecker(LOCALE_EN);
+            assertEquals(3, locales.size());
+            assertEquals(LOCALE_EN, locales.get(0));
+            assertEquals(LOCALE_EN_US, locales.get(1));
+            assertEquals(LOCALE_EN_GB, locales.get(2));
+        }
+
+        {
+            final ArrayList<Locale> locales =
+                    LocaleUtils.getSuitableLocalesForSpellChecker(LOCALE_EN_IN);
+            assertEquals(4, locales.size());
+            assertEquals(LOCALE_EN_IN, locales.get(0));
+            assertEquals(LOCALE_EN_US, locales.get(1));
+            assertEquals(LOCALE_EN_GB, locales.get(2));
+            assertEquals(LOCALE_EN, locales.get(3));
+        }
+
+        {
+            final ArrayList<Locale> locales =
+                    LocaleUtils.getSuitableLocalesForSpellChecker(LOCALE_JA_JP);
+            assertEquals(5, locales.size());
+            assertEquals(LOCALE_JA_JP, locales.get(0));
+            assertEquals(LOCALE_JA, locales.get(1));
+            assertEquals(LOCALE_EN_US, locales.get(2));
+            assertEquals(LOCALE_EN_GB, locales.get(3));
+            assertEquals(Locale.ENGLISH, locales.get(4));
+        }
+
+        // Test 3-letter language code.
+        {
+            final ArrayList<Locale> locales =
+                    LocaleUtils.getSuitableLocalesForSpellChecker(LOCALE_FIL_PH);
+            assertEquals(5, locales.size());
+            assertEquals(LOCALE_FIL_PH, locales.get(0));
+            assertEquals(LOCALE_FIL, locales.get(1));
+            assertEquals(LOCALE_EN_US, locales.get(2));
+            assertEquals(LOCALE_EN_GB, locales.get(3));
+            assertEquals(Locale.ENGLISH, locales.get(4));
+        }
+
+        // Test variant.
+        {
+            final ArrayList<Locale> locales =
+                    LocaleUtils.getSuitableLocalesForSpellChecker(LOCALE_TH_TH_TH);
+            assertEquals(6, locales.size());
+            assertEquals(LOCALE_TH_TH_TH, locales.get(0));
+            assertEquals(LOCALE_TH_TH, locales.get(1));
+            assertEquals(LOCALE_TH, locales.get(2));
+            assertEquals(LOCALE_EN_US, locales.get(3));
+            assertEquals(LOCALE_EN_GB, locales.get(4));
+            assertEquals(Locale.ENGLISH, locales.get(5));
+        }
+
+        // Test Locale extension.
+        {
+            final Locale localeWithoutVariant = LOCALE_JA_JP;
+            final Locale localeWithVariant = new Locale.Builder()
+                    .setLocale(LOCALE_JA_JP)
+                    .setExtension('x', "android")
+                    .build();
+            assertFalse(localeWithoutVariant.equals(localeWithVariant));
+
+            final ArrayList<Locale> locales =
+                    LocaleUtils.getSuitableLocalesForSpellChecker(localeWithVariant);
+            assertEquals(5, locales.size());
+            assertEquals(LOCALE_JA_JP, locales.get(0));
+            assertEquals(LOCALE_JA, locales.get(1));
+            assertEquals(LOCALE_EN_US, locales.get(2));
+            assertEquals(LOCALE_EN_GB, locales.get(3));
+            assertEquals(Locale.ENGLISH, locales.get(4));
+        }
+    }
+
+    @Test
+    public void testConstructLocaleFromString() throws Exception {
+        assertEquals(new Locale("en"), LocaleUtils.constructLocaleFromString("en"));
+        assertEquals(new Locale("en", "US"), LocaleUtils.constructLocaleFromString("en_US"));
+        assertEquals(new Locale("en", "US", "POSIX"),
+                LocaleUtils.constructLocaleFromString("en_US_POSIX"));
+
+        // Special rewrite rule for "tl" for versions of Android earlier than Lollipop that did not
+        // support three letter language codes, and used "tl" (Tagalog) as the language string for
+        // "fil" (Filipino).
+        assertEquals(new Locale("fil"), LocaleUtils.constructLocaleFromString("tl"));
+        assertEquals(new Locale("fil", "PH"), LocaleUtils.constructLocaleFromString("tl_PH"));
+        assertEquals(new Locale("fil", "PH", "POSIX"),
+                LocaleUtils.constructLocaleFromString("tl_PH_POSIX"));
+
+        // So far rejecting an invalid/unexpected locale string is out of the scope of this method.
+        assertEquals(new Locale("a"), LocaleUtils.constructLocaleFromString("a"));
+        assertEquals(new Locale("a b c"), LocaleUtils.constructLocaleFromString("a b c"));
+        assertEquals(new Locale("en-US"), LocaleUtils.constructLocaleFromString("en-US"));
+    }
 }
diff --git a/services/core/java/com/android/server/TextServicesManagerService.java b/services/core/java/com/android/server/TextServicesManagerService.java
index 40f81b3c2850..708350d6f174 100644
--- a/services/core/java/com/android/server/TextServicesManagerService.java
+++ b/services/core/java/com/android/server/TextServicesManagerService.java
@@ -20,7 +20,7 @@ import static android.view.textservice.TextServicesManager.DISABLE_PER_PROFILE_S
 
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.content.PackageMonitor;
-import com.android.internal.inputmethod.InputMethodUtils;
+import com.android.internal.inputmethod.LocaleUtils;
 import com.android.internal.textservice.ISpellCheckerService;
 import com.android.internal.textservice.ISpellCheckerServiceCallback;
 import com.android.internal.textservice.ISpellCheckerSession;
@@ -461,7 +461,7 @@ public class TextServicesManagerService extends ITextServicesManager.Stub {
         // is pre-installed or not.
         final Locale systemLocal = mContext.getResources().getConfiguration().locale;
         final ArrayList<Locale> suitableLocales =
-                InputMethodUtils.getSuitableLocalesForSpellChecker(systemLocal);
+                LocaleUtils.getSuitableLocalesForSpellChecker(systemLocal);
         if (DBG) {
             Slog.w(TAG, "findAvailSystemSpellCheckerLocked suitableLocales="
                     + Arrays.toString(suitableLocales.toArray(new Locale[suitableLocales.size()])));
@@ -475,7 +475,7 @@ public class TextServicesManagerService extends ITextServicesManager.Stub {
                 final int subtypeCount = info.getSubtypeCount();
                 for (int subtypeIndex = 0; subtypeIndex < subtypeCount; ++subtypeIndex) {
                     final SpellCheckerSubtype subtype = info.getSubtypeAt(subtypeIndex);
-                    final Locale subtypeLocale = InputMethodUtils.constructLocaleFromString(
+                    final Locale subtypeLocale = LocaleUtils.constructLocaleFromString(
                             subtype.getLocale());
                     if (locale.equals(subtypeLocale)) {
                         // TODO: We may have more spell checkers that fall into this category.