From a1fe1c8ca5294b758b41d5385e4ce6033d8a8f84 Mon Sep 17 00:00:00 2001
From: Ajmal Kunnummal <ajmalknml@google.com>
Date: Wed, 14 Jul 2021 10:51:02 -0700
Subject: [PATCH] Make FlutterFragment usable without requiring it to be
 attached to an Android Activity. (Attempt 2) (flutter/engine#27397)

---
 .../FlutterActivityAndFragmentDelegate.java    |  8 ++++----
 ...FlutterActivityAndFragmentDelegateTest.java | 18 ++++++++++++++----
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/engine/src/flutter/shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java b/engine/src/flutter/shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java
index 18dd0cddb29..0f398ef0fe3 100644
--- a/engine/src/flutter/shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java
+++ b/engine/src/flutter/shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java
@@ -276,15 +276,15 @@ import java.util.Arrays;
     if (host.getRenderMode() == RenderMode.surface) {
       FlutterSurfaceView flutterSurfaceView =
           new FlutterSurfaceView(
-              host.getActivity(), host.getTransparencyMode() == TransparencyMode.transparent);
+              host.getContext(), host.getTransparencyMode() == TransparencyMode.transparent);
 
       // Allow our host to customize FlutterSurfaceView, if desired.
       host.onFlutterSurfaceViewCreated(flutterSurfaceView);
 
       // Create the FlutterView that owns the FlutterSurfaceView.
-      flutterView = new FlutterView(host.getActivity(), flutterSurfaceView);
+      flutterView = new FlutterView(host.getContext(), flutterSurfaceView);
     } else {
-      FlutterTextureView flutterTextureView = new FlutterTextureView(host.getActivity());
+      FlutterTextureView flutterTextureView = new FlutterTextureView(host.getContext());
 
       flutterTextureView.setOpaque(host.getTransparencyMode() == TransparencyMode.opaque);
 
@@ -292,7 +292,7 @@ import java.util.Arrays;
       host.onFlutterTextureViewCreated(flutterTextureView);
 
       // Create the FlutterView that owns the FlutterTextureView.
-      flutterView = new FlutterView(host.getActivity(), flutterTextureView);
+      flutterView = new FlutterView(host.getContext(), flutterTextureView);
     }
 
     // Add listener to be notified when Flutter renders its first frame.
diff --git a/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/android/FlutterActivityAndFragmentDelegateTest.java b/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/android/FlutterActivityAndFragmentDelegateTest.java
index ddad953b64b..c00bd1e6463 100644
--- a/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/android/FlutterActivityAndFragmentDelegateTest.java
+++ b/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/android/FlutterActivityAndFragmentDelegateTest.java
@@ -378,6 +378,9 @@ public class FlutterActivityAndFragmentDelegateTest {
     // Declare that the host does NOT want Flutter to attach to the surrounding Activity.
     when(mockHost.shouldAttachEngineToActivity()).thenReturn(false);
 
+    // getActivity() returns null if the activity is not attached
+    when(mockHost.getActivity()).thenReturn(null);
+
     // Create the real object that we're testing.
     FlutterActivityAndFragmentDelegate delegate = new FlutterActivityAndFragmentDelegate(mockHost);
 
@@ -385,14 +388,21 @@ public class FlutterActivityAndFragmentDelegateTest {
     // Flutter is attached to the surrounding Activity in onAttach.
     delegate.onAttach(RuntimeEnvironment.application);
 
-    // Verify that the ActivityControlSurface was NOT told to attach to an Activity.
-    verify(mockFlutterEngine.getActivityControlSurface(), never())
-        .attachToActivity(any(Activity.class), any(Lifecycle.class));
+    // Make sure all of the other lifecycle methods can run safely as well
+    // without a valid Activity
+    delegate.onCreateView(null, null, null, 0);
+    delegate.onStart();
+    delegate.onResume();
+    delegate.onPause();
+    delegate.onStop();
+    delegate.onDestroyView();
 
     // Flutter is detached from the surrounding Activity in onDetach.
     delegate.onDetach();
 
-    // Verify that the ActivityControlSurface was NOT told to detach from the Activity.
+    // Verify that the ActivityControlSurface was NOT told to attach or detach to an Activity.
+    verify(mockFlutterEngine.getActivityControlSurface(), never())
+        .attachToActivity(any(Activity.class), any(Lifecycle.class));
     verify(mockFlutterEngine.getActivityControlSurface(), never()).detachFromActivity();
   }