From ea31a75bd4a7ce5801ebfc74114bc14d8462c15b Mon Sep 17 00:00:00 2001
From: cg021 <40409839+cg021@users.noreply.github.com>
Date: Fri, 12 Jun 2020 16:21:25 -0500
Subject: [PATCH] onEndFrame JNI (flutter/engine#18867)

* onEndFrame JNI

* beginFrame brief change
---
 .../flutter/embedding/engine/FlutterJNI.java  | 11 +++++++++
 .../platform/PlatformViewsController.java     |  4 ++++
 .../android/jni/platform_view_android_jni.h   |  8 +++++++
 .../android/platform_view_android_jni_impl.cc | 23 +++++++++++++++++++
 .../android/platform_view_android_jni_impl.h  |  2 ++
 .../embedding/engine/FlutterJNITest.java      | 15 ++++++++++++
 6 files changed, 63 insertions(+)

diff --git a/engine/src/flutter/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java b/engine/src/flutter/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
index c6678ef478c..8ce1e014610 100644
--- a/engine/src/flutter/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
+++ b/engine/src/flutter/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
@@ -810,6 +810,17 @@ public class FlutterJNI {
     }
     platformViewsController.onBeginFrame();
   }
+
+  @SuppressWarnings("unused")
+  @UiThread
+  public void onEndFrame() {
+    ensureRunningOnMainThread();
+    if (platformViewsController == null) {
+      throw new RuntimeException(
+          "platformViewsController must be set before attempting to end the frame");
+    }
+    platformViewsController.onEndFrame();
+  }
   // ----- End Engine Lifecycle Support ----
 
   // @SuppressWarnings("unused")
diff --git a/engine/src/flutter/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java b/engine/src/flutter/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java
index ff5747bd5dc..8a394fa43fd 100644
--- a/engine/src/flutter/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java
+++ b/engine/src/flutter/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java
@@ -545,4 +545,8 @@ public class PlatformViewsController implements PlatformViewsAccessibilityDelega
   public void onBeginFrame() {
     // TODO: Implement this method. https://github.com/flutter/flutter/issues/58288
   }
+
+  public void onEndFrame() {
+    // TODO: Implement this method. https://github.com/flutter/flutter/issues/58288
+  }
 }
diff --git a/engine/src/flutter/shell/platform/android/jni/platform_view_android_jni.h b/engine/src/flutter/shell/platform/android/jni/platform_view_android_jni.h
index ff87ee382cb..5d00ef13b1f 100644
--- a/engine/src/flutter/shell/platform/android/jni/platform_view_android_jni.h
+++ b/engine/src/flutter/shell/platform/android/jni/platform_view_android_jni.h
@@ -137,6 +137,14 @@ class PlatformViewAndroidJNI {
   /// @note       Must be called from the platform thread.
   ///
   virtual void FlutterViewBeginFrame() = 0;
+
+  //----------------------------------------------------------------------------
+  /// @brief      Indicates that the current frame ended.
+  ///             It's used to clean up state.
+  ///
+  /// @note       Must be called from the platform thread.
+  ///
+  virtual void FlutterViewEndFrame() = 0;
 };
 
 }  // namespace flutter
diff --git a/engine/src/flutter/shell/platform/android/platform_view_android_jni_impl.cc b/engine/src/flutter/shell/platform/android/platform_view_android_jni_impl.cc
index b89820227dc..6de577e833e 100644
--- a/engine/src/flutter/shell/platform/android/platform_view_android_jni_impl.cc
+++ b/engine/src/flutter/shell/platform/android/platform_view_android_jni_impl.cc
@@ -82,6 +82,8 @@ static jmethodID g_on_engine_restart_method = nullptr;
 
 static jmethodID g_on_begin_frame_method = nullptr;
 
+static jmethodID g_on_end_frame_method = nullptr;
+
 static jmethodID g_attach_to_gl_context_method = nullptr;
 
 static jmethodID g_update_tex_image_method = nullptr;
@@ -717,6 +719,14 @@ bool PlatformViewAndroid::Register(JNIEnv* env) {
     return false;
   }
 
+  g_on_end_frame_method =
+      env->GetMethodID(g_flutter_jni_class->obj(), "onEndFrame", "()V");
+
+  if (g_on_end_frame_method == nullptr) {
+    FML_LOG(ERROR) << "Could not locate onEndFrame method";
+    return false;
+  }
+
   g_on_display_overlay_surface_method = env->GetMethodID(
       g_flutter_jni_class->obj(), "onDisplayOverlaySurface", "(IIIII)V");
 
@@ -1046,4 +1056,17 @@ void PlatformViewAndroidJNIImpl::FlutterViewBeginFrame() {
   FML_CHECK(CheckException(env));
 }
 
+void PlatformViewAndroidJNIImpl::FlutterViewEndFrame() {
+  JNIEnv* env = fml::jni::AttachCurrentThread();
+
+  auto java_object = java_object_.get(env);
+  if (java_object.is_null()) {
+    return;
+  }
+
+  env->CallVoidMethod(java_object.obj(), g_on_end_frame_method);
+
+  FML_CHECK(CheckException(env));
+}
+
 }  // namespace flutter
diff --git a/engine/src/flutter/shell/platform/android/platform_view_android_jni_impl.h b/engine/src/flutter/shell/platform/android/platform_view_android_jni_impl.h
index 2a53e307ca1..0ab94a28c68 100644
--- a/engine/src/flutter/shell/platform/android/platform_view_android_jni_impl.h
+++ b/engine/src/flutter/shell/platform/android/platform_view_android_jni_impl.h
@@ -64,6 +64,8 @@ class PlatformViewAndroidJNIImpl final : public PlatformViewAndroidJNI {
 
   void FlutterViewBeginFrame() override;
 
+  void FlutterViewEndFrame() override;
+
  private:
   // Reference to FlutterJNI object.
   const fml::jni::JavaObjectWeakGlobalRef java_object_;
diff --git a/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java b/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
index cee3e985d42..8918e4102aa 100644
--- a/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
+++ b/engine/src/flutter/shell/platform/android/test/io/flutter/embedding/engine/FlutterJNITest.java
@@ -96,4 +96,19 @@ public class FlutterJNITest {
     // --- Verify Results ---
     verify(platformViewsController, times(1)).onBeginFrame();
   }
+
+  @Test
+  public void onEndFrame__callsPlatformViewsController() {
+    PlatformViewsController platformViewsController = mock(PlatformViewsController.class);
+
+    // --- Test Setup ---
+    FlutterJNI flutterJNI = new FlutterJNI();
+    flutterJNI.setPlatformViewsController(platformViewsController);
+
+    // --- Execute Test ---
+    flutterJNI.onEndFrame();
+
+    // --- Verify Results ---
+    verify(platformViewsController, times(1)).onEndFrame();
+  }
 }