Experimental automatic language switching support.

With this CL, LatinIME switches the current subtype from its enabled
subtypes based on the first locale in EditorInfo#hintLocales.

This functionality is still experimental, and will be triggered only
when EditorInfo#hintLocales is specified by the application.

Bug: 22859862
Change-Id: Ibd0559b370d8aa0d50d1bada8ecfdac0ed8db898

1 files changed, 41 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/latin/RichInputMethodManager.java b/java/src/com/android/inputmethod/latin/RichInputMethodManager.java
index ef946c8bc..3beb51d68 100644
--- a/java/src/com/android/inputmethod/latin/RichInputMethodManager.java
+++ b/java/src/com/android/inputmethod/latin/RichInputMethodManager.java
@@ -32,6 +32,7 @@ import android.view.inputmethod.InputMethodSubtype;
 
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.compat.InputMethodManagerCompatWrapper;
+import com.android.inputmethod.compat.InputMethodSubtypeCompatUtils;
 import com.android.inputmethod.latin.settings.Settings;
 import com.android.inputmethod.latin.utils.AdditionalSubtypeUtils;
 import com.android.inputmethod.latin.utils.LanguageOnSpacebarUtils;
@@ -428,6 +429,46 @@ public class RichInputMethodManager {
         return null;
     }
 
+    public InputMethodSubtype findSubtypeByLocale(final Locale locale) {
+        // Find the best subtype based on a straightforward matching algorithm.
+        // TODO: Use LocaleList#getFirstMatch() instead.
+        final List<InputMethodSubtype> subtypes =
+                getMyEnabledInputMethodSubtypeList(true /* allowsImplicitlySelectedSubtypes */);
+        final int count = subtypes.size();
+        for (int i = 0; i < count; ++i) {
+            final InputMethodSubtype subtype = subtypes.get(i);
+            final Locale subtypeLocale = InputMethodSubtypeCompatUtils.getLocaleObject(subtype);
+            if (subtypeLocale.equals(locale)) {
+                return subtype;
+            }
+        }
+        for (int i = 0; i < count; ++i) {
+            final InputMethodSubtype subtype = subtypes.get(i);
+            final Locale subtypeLocale = InputMethodSubtypeCompatUtils.getLocaleObject(subtype);
+            if (subtypeLocale.getLanguage().equals(locale.getLanguage()) &&
+                    subtypeLocale.getCountry().equals(locale.getCountry()) &&
+                    subtypeLocale.getVariant().equals(locale.getVariant())) {
+                return subtype;
+            }
+        }
+        for (int i = 0; i < count; ++i) {
+            final InputMethodSubtype subtype = subtypes.get(i);
+            final Locale subtypeLocale = InputMethodSubtypeCompatUtils.getLocaleObject(subtype);
+            if (subtypeLocale.getLanguage().equals(locale.getLanguage()) &&
+                    subtypeLocale.getCountry().equals(locale.getCountry())) {
+                return subtype;
+            }
+        }
+        for (int i = 0; i < count; ++i) {
+            final InputMethodSubtype subtype = subtypes.get(i);
+            final Locale subtypeLocale = InputMethodSubtypeCompatUtils.getLocaleObject(subtype);
+            if (subtypeLocale.getLanguage().equals(locale.getLanguage())) {
+                return subtype;
+            }
+        }
+        return null;
+    }
+
     public void setInputMethodAndSubtype(final IBinder token, final InputMethodSubtype subtype) {
         mImmWrapper.mImm.setInputMethodAndSubtype(
                 token, getInputMethodIdOfThisIme(), subtype);