Fix some serious lifecycle bugs with Android embedding code (#22203)

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

@@ -405,11 +405,11 @@ public class FlutterActivity extends Activity
 
     super.onCreate(savedInstanceState);
 
-    lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_CREATE);
-
     delegate = new FlutterActivityAndFragmentDelegate(this);
     delegate.onAttach(this);
-    delegate.onActivityCreated(savedInstanceState);
+    delegate.onRestoreInstanceState(savedInstanceState);
+
+    lifecycle.handleLifecycleEvent(Lifecycle.Event.ON_CREATE);
 
     configureWindowForTransparency();
     setContentView(createFlutterView());

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

@@ -307,8 +307,10 @@ import java.util.Arrays;
     return flutterSplashView;
   }
 
-  void onActivityCreated(@Nullable Bundle bundle) {
-    Log.v(TAG, "onActivityCreated. Giving framework and plugins an opportunity to restore state.");
+  void onRestoreInstanceState(@Nullable Bundle bundle) {
+    Log.v(
+        TAG,
+        "onRestoreInstanceState. Giving framework and plugins an opportunity to restore state.");
     ensureAlive();
 
     Bundle pluginState = null;
@@ -900,10 +902,11 @@ import java.util.Arrays;
     /**
      * Whether state restoration is enabled.
      *
-     * <p>When this returns true, the instance state provided to {@code onActivityCreated(Bundle)}
-     * will be forwarded to the framework via the {@code RestorationChannel} and during {@code
-     * onSaveInstanceState(Bundle)} the current framework instance state obtained from {@code
-     * RestorationChannel} will be stored in the provided bundle.
+     * <p>When this returns true, the instance state provided to {@code
+     * onRestoreInstanceState(Bundle)} will be forwarded to the framework via the {@code
+     * RestorationChannel} and during {@code onSaveInstanceState(Bundle)} the current framework
+     * instance state obtained from {@code RestorationChannel} will be stored in the provided
+     * bundle.
      *
      * <p>This defaults to true, unless a cached engine is used.
      */

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

@@ -608,6 +608,12 @@ public class FlutterFragment extends Fragment implements FlutterActivityAndFragm
     delegate.onAttach(context);
   }
 
+  @Override
+  public void onCreate(@Nullable Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    delegate.onRestoreInstanceState(savedInstanceState);
+  }
+
   @Nullable
   @Override
   public View onCreateView(
@@ -615,12 +621,6 @@ public class FlutterFragment extends Fragment implements FlutterActivityAndFragm
     return delegate.onCreateView(inflater, container, savedInstanceState);
   }
 
-  @Override
-  public void onActivityCreated(@Nullable Bundle savedInstanceState) {
-    super.onActivityCreated(savedInstanceState);
-    delegate.onActivityCreated(savedInstanceState);
-  }
-
   @Override
   public void onStart() {
     super.onStart();

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

@@ -810,8 +810,8 @@ import java.util.Set;
 
     /**
      * Invoked by the {@link FlutterEngine} that owns this {@code ActivityPluginBinding} when its
-     * associated {@link Activity} has its {@code onCreate(Bundle)} method invoked, or its
-     * associated {@code Fragment} has its {@code onActivityCreated(Bundle)} method invoked.
+     * associated {@link Activity} or {@code Fragment} has its {@code onCreate(Bundle)} method
+     * invoked.
      */
     void onRestoreInstanceState(@Nullable Bundle bundle) {
       for (OnSaveInstanceStateListener listener : onSaveInstanceStateListeners) {

shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityControlSurface.java

@@ -142,8 +142,7 @@ public interface ActivityControlSurface {
   /**
    * Call this method from the {@link Activity} or {@code Fragment} that is attached to this {@code
    * ActivityControlSurface}'s {@link FlutterEngine} when {@link Activity#onCreate(Bundle)} or
-   * {@code Fragment#onActivityCreated(Bundle)} is invoked in the {@link Activity} or {@code
-   * Fragment}.
+   * {@code Fragment#onCreate(Bundle)} is invoked in the {@link Activity} or {@code Fragment}.
    */
   void onRestoreInstanceState(@Nullable Bundle bundle);
 }

shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityPluginBinding.java

@@ -112,7 +112,7 @@ public interface ActivityPluginBinding {
 
     /**
      * Invoked when the associated {@code Activity} executes {@link Activity#onCreate(Bundle)} or
-     * associated {@code Fragment} executes {@code Fragment#onActivityCreated(Bundle)}.
+     * associated {@code Fragment} executes {@code Fragment#onCreate(Bundle)}.
      */
     void onRestoreInstanceState(@Nullable Bundle bundle);
   }

shell/platform/android/test/io/flutter/embedding/android/FlutterActivityTest.java

@@ -19,11 +19,17 @@ import android.content.pm.PackageManager;
 import android.os.Bundle;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.lifecycle.DefaultLifecycleObserver;
+import androidx.lifecycle.LifecycleOwner;
 import io.flutter.embedding.android.FlutterActivityLaunchConfigs.BackgroundMode;
 import io.flutter.embedding.engine.FlutterEngine;
 import io.flutter.embedding.engine.FlutterEngineCache;
 import io.flutter.embedding.engine.FlutterJNI;
 import io.flutter.embedding.engine.loader.FlutterLoader;
+import io.flutter.embedding.engine.plugins.FlutterPlugin;
+import io.flutter.embedding.engine.plugins.activity.ActivityAware;
+import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
+import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding.OnSaveInstanceStateListener;
 import io.flutter.plugins.GeneratedPluginRegistrant;
 import java.util.List;
 import org.junit.After;
@@ -251,6 +257,24 @@ public class FlutterActivityTest {
     verify(mockDelegate, times(1)).onDetach();
   }
 
+  @Test
+  public void itRestoresPluginStateBeforePluginOnCreate() {
+    FlutterLoader mockFlutterLoader = mock(FlutterLoader.class);
+    FlutterJNI mockFlutterJni = mock(FlutterJNI.class);
+    when(mockFlutterJni.isAttached()).thenReturn(true);
+    FlutterEngine cachedEngine =
+        new FlutterEngine(RuntimeEnvironment.application, mockFlutterLoader, mockFlutterJni);
+    FakeFlutterPlugin fakeFlutterPlugin = new FakeFlutterPlugin();
+    cachedEngine.getPlugins().add(fakeFlutterPlugin);
+    FlutterEngineCache.getInstance().put("my_cached_engine", cachedEngine);
+
+    Intent intent =
+        FlutterActivity.withCachedEngine("my_cached_engine").build(RuntimeEnvironment.application);
+    Robolectric.buildActivity(FlutterActivity.class, intent).setup();
+    assertTrue(
+        "Expected FakeFlutterPlugin onCreateCalled to be true", fakeFlutterPlugin.onCreateCalled);
+  }
+
   static class FlutterActivityWithProvidedEngine extends FlutterActivity {
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
@@ -272,6 +296,7 @@ public class FlutterActivityTest {
   // This is just a compile time check to ensure that it's possible for FlutterActivity subclasses
   // to provide their own intent builders which builds their own runtime types.
   static class FlutterActivityWithIntentBuilders extends FlutterActivity {
+
     public static NewEngineIntentBuilder withNewEngine() {
       return new NewEngineIntentBuilder(FlutterActivityWithIntentBuilders.class);
     }
@@ -280,4 +305,59 @@ public class FlutterActivityTest {
       return new CachedEngineIntentBuilder(FlutterActivityWithIntentBuilders.class, cachedEngineId);
     }
   }
+
+  private static final class FakeFlutterPlugin
+      implements FlutterPlugin,
+          ActivityAware,
+          OnSaveInstanceStateListener,
+          DefaultLifecycleObserver {
+
+    private ActivityPluginBinding activityPluginBinding;
+    private boolean stateRestored = false;
+    private boolean onCreateCalled = false;
+
+    @Override
+    public void onAttachedToEngine(@NonNull FlutterPluginBinding binding) {}
+
+    @Override
+    public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {}
+
+    @Override
+    public void onAttachedToActivity(@NonNull ActivityPluginBinding binding) {
+      activityPluginBinding = binding;
+      binding.addOnSaveStateListener(this);
+      ((FlutterActivity) binding.getActivity()).getLifecycle().addObserver(this);
+    }
+
+    @Override
+    public void onDetachedFromActivityForConfigChanges() {
+      onDetachedFromActivity();
+    }
+
+    @Override
+    public void onReattachedToActivityForConfigChanges(@NonNull ActivityPluginBinding binding) {
+      onAttachedToActivity(binding);
+    }
+
+    @Override
+    public void onDetachedFromActivity() {
+      ((FlutterActivity) activityPluginBinding.getActivity()).getLifecycle().removeObserver(this);
+      activityPluginBinding.removeOnSaveStateListener(this);
+      activityPluginBinding = null;
+    }
+
+    @Override
+    public void onSaveInstanceState(@NonNull Bundle bundle) {}
+
+    @Override
+    public void onRestoreInstanceState(@Nullable Bundle bundle) {
+      stateRestored = true;
+    }
+
+    @Override
+    public void onCreate(@NonNull LifecycleOwner lifecycleOwner) {
+      assertTrue("State was restored before onCreate", stateRestored);
+      onCreateCalled = true;
+    }
+  }
 }

shell/platform/android/test/io/flutter/embedding/android/FlutterAndroidComponentTest.java

@@ -81,7 +81,7 @@ public class FlutterAndroidComponentTest {
     assertNotNull(binding.getTextureRegistry());
     assertNotNull(binding.getPlatformViewRegistry());
 
-    delegate.onActivityCreated(null);
+    delegate.onRestoreInstanceState(null);
     delegate.onCreateView(null, null, null);
     delegate.onStart();
     delegate.onResume();
@@ -151,7 +151,7 @@ public class FlutterAndroidComponentTest {
     assertNotNull(binding.getActivity());
     assertNotNull(binding.getLifecycle());
 
-    delegate.onActivityCreated(null);
+    delegate.onRestoreInstanceState(null);
 
     // Verify that after Activity creation, the plugin was allowed to restore state.
     verify(mockSaveStateListener, times(1)).onRestoreInstanceState(any(Bundle.class));
@@ -194,7 +194,7 @@ public class FlutterAndroidComponentTest {
     // --- Execute the behavior under test ---
     // Push the delegate through all lifecycle methods all the way to destruction.
     delegate.onAttach(RuntimeEnvironment.application);
-    delegate.onActivityCreated(null);
+    delegate.onRestoreInstanceState(null);
     delegate.onCreateView(null, null, null);
     delegate.onStart();
     delegate.onResume();