Add SubtypeLocaleUtils.isRtlLanguage method

Change-Id: I2e399ae9ca111638b583c5681de08b0e6db86e3a

1 files changed, 21 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/latin/utils/SubtypeLocaleUtils.java b/java/src/com/android/inputmethod/latin/utils/SubtypeLocaleUtils.java
index fdbe81ab6..fb1be30f1 100644
--- a/java/src/com/android/inputmethod/latin/utils/SubtypeLocaleUtils.java
+++ b/java/src/com/android/inputmethod/latin/utils/SubtypeLocaleUtils.java
@@ -25,9 +25,11 @@ import android.os.Build;
 import android.util.Log;
 import android.view.inputmethod.InputMethodSubtype;
 
+import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.DictionaryFactory;
 import com.android.inputmethod.latin.R;
 
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Locale;
 
@@ -334,4 +336,23 @@ public final class SubtypeLocaleUtils {
         final Locale locale = getSubtypeLocale(subtype);
         return StringUtils.capitalizeFirstCodePoint(locale.getLanguage(), locale);
     }
+
+    // TODO: Get this information from the framework instead of maintaining here by ourselves.
+    // Sorted list of known Right-To-Left language codes.
+    private static final String[] SORTED_RTL_LANGUAGES = {
+        "ar", // Arabic
+        "fa", // Persian
+        "iw", // Hebrew
+    };
+    static {
+        Arrays.sort(SORTED_RTL_LANGUAGES);
+    }
+
+    // TODO: Remove @UsedForTesting annotation.
+    @UsedForTesting
+    public static boolean isRtlLanguage(final InputMethodSubtype subtype) {
+        final Locale locale = getSubtypeLocale(subtype);
+        final String language = locale.getLanguage();
+        return Arrays.binarySearch(SORTED_RTL_LANGUAGES, language) >= 0;
+    }
 }