add prefered result language argument

android/src/main/java/com/aloisdeniel/geocoder/GeocoderPlugin.java

@@ -2,6 +2,7 @@
 
 import java.util.List;
 import java.util.ArrayList;
+import java.util.Locale;
 import java.util.Map;
 import java.util.HashMap;
 import java.io.IOException;
@@ -31,11 +32,11 @@ class NotAvailableException extends Exception {
  */
 public class GeocoderPlugin implements MethodCallHandler {
 
-  private Geocoder geocoder;
+  private Context context;
 
   public GeocoderPlugin(Context context) {
 
-    this.geocoder = new Geocoder(context);
+    this.context = context;
   }
 
   /**
@@ -102,26 +103,27 @@ public void onMethodCall(MethodCall call, Result rawResult) {
     else if (call.method.equals("findAddressesFromCoordinates")) {
       float latitude = ((Number) call.argument("latitude")).floatValue();
       float longitude = ((Number) call.argument("longitude")).floatValue();
-      findAddressesFromCoordinates(latitude,longitude, result);
+      String language = ((String) call.argument("language"));
+      findAddressesFromCoordinates(latitude, longitude, language, result);
     } else {
       result.notImplemented();
     }
   }
 
-  private void assertPresent() throws NotAvailableException {
+  private void assertPresent(Geocoder geocoder) throws NotAvailableException {
     if (!geocoder.isPresent()) {
       throw new NotAvailableException();
     }
   }
 
   private void findAddressesFromQuery(final String address, final Result result) {
-
     final GeocoderPlugin plugin = this;
+    final Geocoder geocoder = new Geocoder(context);
     new AsyncTask<Void, Void, List<Address>>() {
         @Override
         protected List<Address> doInBackground(Void... params) {
             try {
-                plugin.assertPresent();
+                plugin.assertPresent(geocoder);
                 return geocoder.getFromLocationName(address, 20);
             } catch (IOException ex) {
                 return null;
@@ -143,13 +145,14 @@ protected void onPostExecute(List<Address> addresses) {
     }.execute();
   }
 
-  private void findAddressesFromCoordinates(final float latitude, final float longitude, final Result result) {
+  private void findAddressesFromCoordinates(final float latitude, final float longitude, final String language, final Result result) {
     final GeocoderPlugin plugin = this;
+    final Geocoder geocoder = language == null ? new Geocoder(context) : new Geocoder(context, new Locale(language));
     new AsyncTask<Void, Void, List<Address>>() {
         @Override
         protected List<Address> doInBackground(Void... params) {
             try {
-                plugin.assertPresent();
+                plugin.assertPresent(geocoder);
                 return geocoder.getFromLocation(latitude, longitude, 20);
             } catch (IOException ex) {
                 return null;

ios/Classes/GeocoderPlugin.m

@@ -27,14 +27,25 @@ - (void) handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result
   if ([@"findAddressesFromCoordinates" isEqualToString:call.method]) {
       NSNumber *longitude = call.arguments[@"longitude"];
       NSNumber *latitude = call.arguments[@"latitude"];
+      NSString *language = call.arguments[@"language"];
       CLLocation * location = [[CLLocation alloc] initWithLatitude:latitude.doubleValue longitude:longitude.doubleValue];
       [self initializeGeocoder];
-      [self.geocoder reverseGeocodeLocation:location completionHandler:^(NSArray *placemarks, NSError *error) {
-          if (error) {
-              return result(error.flutterError);
-          }
-          result([self placemarksToDictionary:placemarks]);
-      }];
+      if (language != (id)[NSNull null] && @available(iOS 11.0, *)) {
+          NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:language];
+          [self.geocoder reverseGeocodeLocation:location preferredLocale:locale completionHandler:^(NSArray *placemarks, NSError *error) {
+              if (error) {
+                  return result(error.flutterError);
+              }
+              result([self placemarksToDictionary:placemarks]);
+          }];
+      } else {
+          [self.geocoder reverseGeocodeLocation:location completionHandler:^(NSArray *placemarks, NSError *error) {
+              if (error) {
+                  return result(error.flutterError);
+              }
+              result([self placemarksToDictionary:placemarks]);
+          }];
+      }
   }
   else if ([@"findAddressesFromQuery" isEqualToString:call.method]) {
       NSString *address = call.arguments[@"address"];

lib/geocoder.dart

@@ -6,5 +6,6 @@ export 'model.dart';
 
 class Geocoder {
   static final Geocoding local = LocalGeocoding();
+  static Geocoding withLanguage(String language) => LocalGeocoding(language: language);
   static Geocoding google(String apiKey, { String language }) => GoogleGeocoding(apiKey, language: language);
 }

lib/services/local.dart

@@ -7,10 +7,18 @@ import 'package:geocoder/services/base.dart';
 
 /// Geocoding and reverse geocoding through built-lin local platform services.
 class LocalGeocoding implements Geocoding {
+  final String language;
+
+  LocalGeocoding({ this.language });
+
   static const MethodChannel _channel = MethodChannel('github.com/aloisdeniel/geocoder');
 
   Future<List<Address>> findAddressesFromCoordinates(Coordinates coordinates) async  {
-    Iterable addresses = await _channel.invokeMethod('findAddressesFromCoordinates', coordinates.toMap());
+    Iterable addresses = await _channel.invokeMethod('findAddressesFromCoordinates', {
+      "latitude": coordinates.latitude,
+      "longitude": coordinates.longitude,
+      "language": language,
+    });
     return addresses.map((x) => Address.fromMap(x)).toList();
   }