Send locales to Flutter in FlutterEngine initialization instead of Fl…

…utterView (flutter#34243)

shell/platform/android/io/flutter/embedding/android/FlutterView.java

@@ -1210,7 +1210,6 @@ public void attachToFlutterEngine(@NonNull FlutterEngine flutterEngine) {
             false,
             systemSettingsObserver);
 
-    localizationPlugin.sendLocalesToFlutter(getResources().getConfiguration());
     sendViewportMetricsToFlutter();
 
     flutterEngine.getPlatformViewsController().attachToView(this);

shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java

@@ -349,6 +349,8 @@ public FlutterEngine(
     this.pluginRegistry =
         new FlutterEngineConnectionRegistry(context.getApplicationContext(), this, flutterLoader);
 
+    localizationPlugin.sendLocalesToFlutter(context.getResources().getConfiguration());
+
     // Only automatically register plugins if both constructor parameter and
     // loaded AndroidManifest config turn this feature on.
     if (automaticallyRegisterPlugins && flutterLoader.automaticallyRegisterPlugins()) {

shell/platform/android/test/io/flutter/embedding/engine/FlutterEngineTest.java

@@ -7,6 +7,8 @@
 import static org.mockito.Mockito.anyInt;
 import static org.mockito.Mockito.atLeast;
 import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
@@ -15,6 +17,9 @@
 
 import android.content.Context;
 import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.res.Configuration;
+import android.content.res.Resources;
+import android.os.LocaleList;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import io.flutter.FlutterInjector;
@@ -41,12 +46,20 @@
 @RunWith(AndroidJUnit4.class)
 public class FlutterEngineTest {
   private final Context ctx = ApplicationProvider.getApplicationContext();
+  private final Context mockContext = mock(Context.class);
   @Mock FlutterJNI flutterJNI;
   boolean jniAttached;
 
   @Before
   public void setUp() {
     MockitoAnnotations.openMocks(this);
+
+    Resources mockResources = mock(Resources.class);
+    Configuration mockConfiguration = mock(Configuration.class);
+    doReturn(mockResources).when(mockContext).getResources();
+    doReturn(mockConfiguration).when(mockResources).getConfiguration();
+    doReturn(LocaleList.getEmptyLocaleList()).when(mockConfiguration).getLocales();
+
     jniAttached = false;
     when(flutterJNI.isAttached()).thenAnswer(invocation -> jniAttached);
     doAnswer(
@@ -82,6 +95,20 @@ public void itAutomaticallyRegistersPluginsByDefault() {
     assertEquals(flutterEngine, registeredEngines.get(0));
   }
 
+  @Test
+  public void itSendLocalesOnEngineInit() {
+    FlutterJNI mockFlutterJNI = mock(FlutterJNI.class);
+    when(mockFlutterJNI.isAttached()).thenReturn(true);
+
+    assertTrue(GeneratedPluginRegistrant.getRegisteredEngines().isEmpty());
+    FlutterLoader mockFlutterLoader = mock(FlutterLoader.class);
+    when(mockFlutterLoader.automaticallyRegisterPlugins()).thenReturn(true);
+    FlutterEngine flutterEngine = new FlutterEngine(ctx, mockFlutterLoader, mockFlutterJNI);
+
+    verify(mockFlutterJNI, times(1))
+        .dispatchPlatformMessage(eq("flutter/localization"), any(), anyInt(), anyInt());
+  }
+
   // Helps show the root cause of MissingPluginException type errors like
   // https://github.com/flutter/flutter/issues/78625.
   @Test
@@ -194,36 +221,34 @@ public void itNotifiesPlatformViewsControllerAboutJNILifecycle() {
 
   @Test
   public void itUsesApplicationContext() throws NameNotFoundException {
-    Context context = mock(Context.class);
     Context packageContext = mock(Context.class);
 
-    when(context.createPackageContext(any(), anyInt())).thenReturn(packageContext);
+    when(mockContext.createPackageContext(any(), anyInt())).thenReturn(packageContext);
 
     new FlutterEngine(
-        context,
+        mockContext,
         mock(FlutterLoader.class),
         flutterJNI,
         /*dartVmArgs=*/ new String[] {},
         /*automaticallyRegisterPlugins=*/ false);
 
-    verify(context, atLeast(1)).getApplicationContext();
+    verify(mockContext, atLeast(1)).getApplicationContext();
   }
 
   @Test
   public void itUsesPackageContextForAssetManager() throws NameNotFoundException {
-    Context context = mock(Context.class);
     Context packageContext = mock(Context.class);
-    when(context.createPackageContext(any(), anyInt())).thenReturn(packageContext);
+    when(mockContext.createPackageContext(any(), anyInt())).thenReturn(packageContext);
 
     new FlutterEngine(
-        context,
+        mockContext,
         mock(FlutterLoader.class),
         flutterJNI,
         /*dartVmArgs=*/ new String[] {},
         /*automaticallyRegisterPlugins=*/ false);
 
     verify(packageContext, atLeast(1)).getAssets();
-    verify(context, times(0)).getAssets();
+    verify(mockContext, times(0)).getAssets();
   }
 
   @Test
@@ -232,7 +257,6 @@ public void itCanUseFlutterLoaderInjectionViaFlutterInjector() throws NameNotFou
     FlutterLoader mockFlutterLoader = mock(FlutterLoader.class);
     FlutterInjector.setInstance(
         new FlutterInjector.Builder().setFlutterLoader(mockFlutterLoader).build());
-    Context mockContext = mock(Context.class);
     Context packageContext = mock(Context.class);
 
     when(mockContext.createPackageContext(any(), anyInt())).thenReturn(packageContext);
@@ -246,14 +270,13 @@ public void itCanUseFlutterLoaderInjectionViaFlutterInjector() throws NameNotFou
 
   @Test
   public void itNotifiesListenersForDestruction() throws NameNotFoundException {
-    Context context = mock(Context.class);
     Context packageContext = mock(Context.class);
 
-    when(context.createPackageContext(any(), anyInt())).thenReturn(packageContext);
+    when(mockContext.createPackageContext(any(), anyInt())).thenReturn(packageContext);
 
     FlutterEngine engineUnderTest =
         new FlutterEngine(
-            context,
+            mockContext,
             mock(FlutterLoader.class),
             flutterJNI,
             /*dartVmArgs=*/ new String[] {},
@@ -267,15 +290,14 @@ public void itNotifiesListenersForDestruction() throws NameNotFoundException {
 
   @Test
   public void itDoesNotAttachAgainWhenBuiltWithAnAttachedJNI() throws NameNotFoundException {
-    Context context = mock(Context.class);
     Context packageContext = mock(Context.class);
 
-    when(context.createPackageContext(any(), anyInt())).thenReturn(packageContext);
+    when(mockContext.createPackageContext(any(), anyInt())).thenReturn(packageContext);
     when(flutterJNI.isAttached()).thenReturn(true);
 
     FlutterEngine engineUnderTest =
         new FlutterEngine(
-            context,
+            mockContext,
             mock(FlutterLoader.class),
             flutterJNI,
             /*dartVmArgs=*/ new String[] {},
@@ -286,15 +308,14 @@ public void itDoesNotAttachAgainWhenBuiltWithAnAttachedJNI() throws NameNotFound
 
   @Test
   public void itComesWithARunningDartExecutorIfJNIIsAlreadyAttached() throws NameNotFoundException {
-    Context context = mock(Context.class);
     Context packageContext = mock(Context.class);
 
-    when(context.createPackageContext(any(), anyInt())).thenReturn(packageContext);
+    when(mockContext.createPackageContext(any(), anyInt())).thenReturn(packageContext);
     when(flutterJNI.isAttached()).thenReturn(true);
 
     FlutterEngine engineUnderTest =
         new FlutterEngine(
-            context,
+            mockContext,
             mock(FlutterLoader.class),
             flutterJNI,
             /*dartVmArgs=*/ new String[] {},