[UI] android.app.NativeActivity > WindowedAppActivity + code style

.clang-format

@@ -6,3 +6,8 @@ SortIncludes: true
 
 # Regroup causes unnecessary noise due to clang-format bug.
 IncludeBlocks: Preserve
+
+---
+Language: Java
+DisableFormat: true
+SortIncludes: false

android/android_studio_project/app/src/main/AndroidManifest.xml

@@ -2,12 +2,23 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="jp.xenia.emulator">
 
-    <uses-feature android:name="android.hardware.vulkan.level" android:version="0" android:required="true" />
-    <uses-feature android:name="android.hardware.vulkan.version" android:version="0x400000" android:required="true" />
-    <!-- Granted automatically - guest sockets -->
+    <uses-feature
+        android:name="android.hardware.vulkan.level"
+        android:required="true"
+        android:version="0" />
+
+    <uses-feature
+        android:name="android.hardware.vulkan.version"
+        android:required="true"
+        android:version="0x400000" />
+
+    <!-- Granted automatically - guest sockets. -->
     <uses-permission android:name="android.permission.INTERNET" />
-    <!-- Needs to be requested - loading games from outside the app data directory -->
-    <!-- WRITE_EXTERNAL_STORAGE is not required to write to the external app data directory since API 19 -->
+
+    <!--
+    Needs to be requested - loading games from outside the app data directory.
+    WRITE_EXTERNAL_STORAGE is not required to write to the external app data directory since API 19.
+    -->
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
 
     <application
@@ -17,12 +28,14 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@android:style/Theme.Material.Light">
-        <activity android:name="jp.xenia.emulator.DemoActivity">
+
+        <activity android:name="jp.xenia.emulator.WindowDemoActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
     </application>
 
 </manifest>

android/android_studio_project/app/src/main/java/jp/xenia/emulator/DemoActivity.java

@@ -1,12 +0,0 @@
-package jp.xenia.emulator;
-
-import android.app.Activity;
-import android.os.Bundle;
-
-public class DemoActivity extends Activity {
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_demo);
-    }
-}

android/android_studio_project/app/src/main/java/jp/xenia/emulator/WindowDemoActivity.java

@@ -0,0 +1,8 @@
+package jp.xenia.emulator;
+
+public class WindowDemoActivity extends WindowedAppActivity {
+    @Override
+    protected String getWindowedAppIdentifier() {
+        return "xenia_ui_window_vulkan_demo";
+    }
+}

android/android_studio_project/app/src/main/java/jp/xenia/emulator/WindowedAppActivity.java

@@ -0,0 +1,45 @@
+package jp.xenia.emulator;
+
+import android.app.Activity;
+import android.content.res.AssetManager;
+import android.os.Bundle;
+import android.util.Log;
+
+public abstract class WindowedAppActivity extends Activity {
+    private static final String TAG = "WindowedAppActivity";
+
+    static {
+        // TODO(Triang3l): Move all demos to libxenia.so.
+        System.loadLibrary("xenia-ui-window-vulkan-demo");
+    }
+
+    private long mAppContext;
+
+    private native long initializeWindowedAppOnCreateNative(
+            String windowedAppIdentifier, AssetManager assetManager);
+
+    private native void onDestroyNative(long appContext);
+
+    protected abstract String getWindowedAppIdentifier();
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        mAppContext = initializeWindowedAppOnCreateNative(getWindowedAppIdentifier(), getAssets());
+        if (mAppContext == 0) {
+            Log.e(TAG, "Error initializing the windowed app");
+            finish();
+            return;
+        }
+    }
+
+    @Override
+    protected void onDestroy() {
+        if (mAppContext != 0) {
+            onDestroyNative(mAppContext);
+        }
+        mAppContext = 0;
+        super.onDestroy();
+    }
+}

android/android_studio_project/app/src/main/res/layout/activity_window_demo.xml

@@ -3,6 +3,6 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context="jp.xenia.emulator.DemoActivity">
+    tools:context="jp.xenia.emulator.WindowDemoActivity">
 
 </RelativeLayout>

src/xenia/ui/windowed_app.cc

@@ -0,0 +1,25 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2021 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#include "xenia/ui/windowed_app.h"
+
+#include <string>
+#include <unordered_map>
+
+namespace xe {
+namespace ui {
+
+#if XE_UI_WINDOWED_APPS_IN_LIBRARY
+// A zero-initialized pointer to remove dependence on the initialization order
+// of the map relatively to the app creator proxies.
+std::unordered_map<std::string, WindowedApp::Creator>* WindowedApp::creators_;
+#endif  // XE_UI_WINDOWED_APPS_IN_LIBRARY
+
+}  // namespace ui
+}  // namespace xe

src/xenia/ui/windowed_app.h

@@ -13,15 +13,17 @@
 #include <cstddef>
 #include <memory>
 #include <string>
+#include <unordered_map>
+#include <utility>
 #include <vector>
 
+#include "xenia/base/assert.h"
 #include "xenia/base/platform.h"
 #include "xenia/ui/windowed_app_context.h"
 
 #if XE_PLATFORM_ANDROID
-#include <android/native_activity.h>
-
-#include "xenia/ui/windowed_app_context_android.h"
+// Multiple apps in a single library instead of separate executables.
+#define XE_UI_WINDOWED_APPS_IN_LIBRARY 1
 #endif
 
 namespace xe {
@@ -36,6 +38,9 @@ class WindowedApp {
   // initialization of platform-specific parts, should preferably be as simple
   // as possible).
 
+  using Creator = std::unique_ptr<xe::ui::WindowedApp> (*)(
+      xe::ui::WindowedAppContext& app_context);
+
   WindowedApp(const WindowedApp& app) = delete;
   WindowedApp& operator=(const WindowedApp& app) = delete;
   virtual ~WindowedApp() = default;
@@ -101,27 +106,67 @@ class WindowedApp {
   std::string name_;
   std::string positional_options_usage_;
   std::vector<std::string> positional_options_;
+
+#if XE_UI_WINDOWED_APPS_IN_LIBRARY
+ public:
+  class CreatorRegistration {
+   public:
+    CreatorRegistration(const std::string_view identifier, Creator creator) {
+      if (!creators_) {
+        // Will be deleted by the last creator registration's destructor, no
+        // need for a library destructor.
+        creators_ = new std::unordered_map<std::string, WindowedApp::Creator>;
+      }
+      iterator_inserted_ = creators_->emplace(identifier, creator);
+      assert_true(iterator_inserted_.second);
+    }
+
+    ~CreatorRegistration() {
+      if (iterator_inserted_.second) {
+        creators_->erase(iterator_inserted_.first);
+        if (creators_->empty()) {
+          delete creators_;
+        }
+      }
+    }
+
+   private:
+    std::pair<std::unordered_map<std::string, Creator>::iterator, bool>
+        iterator_inserted_;
   };
 
-#if XE_PLATFORM_ANDROID
-// Multiple apps in a single library. ANativeActivity_onCreate chosen via
-// android.app.func_name of the NativeActivity of each app.
-#define XE_DEFINE_WINDOWED_APP(export_name, creator)                           \
-  __attribute__((visibility("default"))) extern "C" void export_name(          \
-      ANativeActivity* activity, void* saved_state, size_t saved_state_size) { \
-    xe::ui::AndroidWindowedAppContext::StartAppOnActivityCreate(               \
-        activity, saved_state, saved_state_size, creator);                     \
+  static Creator GetCreator(const std::string& identifier) {
+    if (!creators_) {
+      return nullptr;
+    }
+    auto it = creators_->find(identifier);
+    return it != creators_->end() ? it->second : nullptr;
+  }
+
+ private:
+  static std::unordered_map<std::string, Creator>* creators_;
+#endif  // XE_UI_WINDOWED_APPS_IN_LIBRARY
+};
+
+#if XE_UI_WINDOWED_APPS_IN_LIBRARY
+// Multiple apps in a single library.
+#define XE_DEFINE_WINDOWED_APP(identifier, creator)                          \
+  namespace xe {                                                             \
+  namespace ui {                                                             \
+  namespace windowed_app_creator_registrations {                             \
+  xe::ui::WindowedApp::CreatorRegistration identifier(#identifier, creator); \
+  }                                                                          \
+  }                                                                          \
   }
 #else
 // Separate executables for each app.
 std::unique_ptr<WindowedApp> (*GetWindowedAppCreator())(
     WindowedAppContext& app_context);
-#define XE_DEFINE_WINDOWED_APP(export_name, creator)                       \
-  std::unique_ptr<xe::ui::WindowedApp> (*xe::ui::GetWindowedAppCreator())( \
-      xe::ui::WindowedAppContext & app_context) {                          \
+#define XE_DEFINE_WINDOWED_APP(identifier, creator)              \
+  xe::ui::WindowedApp::Creator xe::ui::GetWindowedAppCreator() { \
     return creator;                                              \
   }
-#endif
+#endif  // XE_UI_WINDOWED_APPS_IN_LIBRARY
 
 }  // namespace ui
 }  // namespace xe

src/xenia/ui/windowed_app_context_android.cc

@@ -9,10 +9,12 @@
 
 #include "xenia/ui/windowed_app_context_android.h"
 
+#include <android/asset_manager_jni.h>
 #include <android/configuration.h>
+#include <android/log.h>
 #include <android/looper.h>
-#include <android/native_activity.h>
 #include <fcntl.h>
+#include <jni.h>
 #include <unistd.h>
 #include <array>
 #include <cstdint>
@@ -25,30 +27,6 @@
 namespace xe {
 namespace ui {
 
-void AndroidWindowedAppContext::StartAppOnActivityCreate(
-    ANativeActivity* activity, [[maybe_unused]] void* saved_state,
-    [[maybe_unused]] size_t saved_state_size,
-    std::unique_ptr<WindowedApp> (*app_creator)(
-        WindowedAppContext& app_context)) {
-  // TODO(Triang3l): Pass the launch options from the Intent or the saved
-  // instance state.
-  AndroidWindowedAppContext* app_context = new AndroidWindowedAppContext;
-  if (!app_context->Initialize(activity)) {
-    delete app_context;
-    ANativeActivity_finish(activity);
-    return;
-  }
-  // The pointer is now held by the Activity as its ANativeActivity::instance,
-  // until the destruction.
-  if (!app_context->InitializeApp(app_creator)) {
-    // InitializeApp might have sent commands to the UI thread looper callback
-    // pipe, perform deferred destruction.
-    app_context->RequestDestruction();
-    ANativeActivity_finish(activity);
-    return;
-  }
-}
-
 void AndroidWindowedAppContext::NotifyUILoopOfPendingFunctions() {
   // Don't check ui_thread_looper_callback_registered_, as it's owned
   // exclusively by the UI thread, while this may be called by any, and in case
@@ -69,22 +47,145 @@ void AndroidWindowedAppContext::NotifyUILoopOfPendingFunctions() {
 
 void AndroidWindowedAppContext::PlatformQuitFromUIThread() {
   // All the shutdown will be done in onDestroy of the activity.
-  ANativeActivity_finish(activity_);
+  if (activity_ && activity_method_finish_) {
+    ui_thread_jni_env_->CallVoidMethod(activity_, activity_method_finish_);
+  }
+}
+
+AndroidWindowedAppContext*
+AndroidWindowedAppContext::JniActivityInitializeWindowedAppOnCreate(
+    JNIEnv* jni_env, jobject activity, jstring windowed_app_identifier,
+    jobject asset_manager) {
+  WindowedApp::Creator app_creator;
+  {
+    const char* windowed_app_identifier_c_str =
+        jni_env->GetStringUTFChars(windowed_app_identifier, nullptr);
+    if (!windowed_app_identifier_c_str) {
+      __android_log_write(
+          ANDROID_LOG_ERROR, "AndroidWindowedAppContext",
+          "Failed to get the UTF-8 string for the windowed app identifier");
+      return nullptr;
+    }
+    app_creator = WindowedApp::GetCreator(windowed_app_identifier_c_str);
+    if (!app_creator) {
+      __android_log_print(ANDROID_LOG_ERROR, "AndroidWindowedAppContext",
+                          "Failed to get the creator for the windowed app %s",
+                          windowed_app_identifier_c_str);
+      jni_env->ReleaseStringUTFChars(windowed_app_identifier,
+                                     windowed_app_identifier_c_str);
+      return nullptr;
+    }
+    jni_env->ReleaseStringUTFChars(windowed_app_identifier,
+                                   windowed_app_identifier_c_str);
+  }
+
+  AndroidWindowedAppContext* app_context = new AndroidWindowedAppContext;
+  if (!app_context->Initialize(jni_env, activity, asset_manager)) {
+    delete app_context;
+    return nullptr;
+  }
+
+  if (!app_context->InitializeApp(app_creator)) {
+    // InitializeApp might have sent commands to the UI thread looper callback
+    // pipe, perform deferred destruction.
+    app_context->RequestDestruction();
+    return nullptr;
+  }
+
+  return app_context;
+}
+
+void AndroidWindowedAppContext::JniActivityOnDestroy() {
+  if (app_) {
+    app_->InvokeOnDestroy();
+    app_.reset();
+  }
+  RequestDestruction();
 }
 
 AndroidWindowedAppContext::~AndroidWindowedAppContext() { Shutdown(); }
 
-bool AndroidWindowedAppContext::Initialize(ANativeActivity* activity) {
-  int32_t api_level;
-  {
-    AConfiguration* configuration = AConfiguration_new();
-    AConfiguration_fromAssetManager(configuration, activity->assetManager);
-    api_level = AConfiguration_getSdkVersion(configuration);
-    AConfiguration_delete(configuration);
+bool AndroidWindowedAppContext::Initialize(JNIEnv* ui_thread_jni_env,
+                                           jobject activity,
+                                           jobject asset_manager) {
+  // Xenia logging is not initialized yet - use __android_log_write or
+  // __android_log_print until InitializeAndroidAppFromMainThread is done.
+
+  ui_thread_jni_env_ = ui_thread_jni_env;
+
+  // Initialize the asset manager for retrieving the current configuration.
+  asset_manager_jobject_ = ui_thread_jni_env_->NewGlobalRef(asset_manager);
+  if (!asset_manager_jobject_) {
+    __android_log_write(
+        ANDROID_LOG_ERROR, "AndroidWindowedAppContext",
+        "Failed to create a global reference to the asset manager");
+    Shutdown();
+    return false;
   }
-  xe::InitializeAndroidAppFromMainThread(api_level);
+  asset_manager_ =
+      AAssetManager_fromJava(ui_thread_jni_env_, asset_manager_jobject_);
+  if (!asset_manager_) {
+    __android_log_write(ANDROID_LOG_ERROR, "AndroidWindowedAppContext",
+                        "Failed to create get the AAssetManager");
+    Shutdown();
+    return false;
+  }
+
+  // Get the initial configuration.
+  configuration_ = AConfiguration_new();
+  if (!configuration_) {
+    __android_log_write(ANDROID_LOG_ERROR, "AndroidWindowedAppContext",
+                        "Failed to create an AConfiguration");
+    Shutdown();
+    return false;
+  }
+  AConfiguration_fromAssetManager(configuration_, asset_manager_);
+
+  // Initialize Xenia globals that may depend on the API level, as well as
+  // logging.
+  xe::InitializeAndroidAppFromMainThread(
+      AConfiguration_getSdkVersion(configuration_));
   android_base_initialized_ = true;
 
+  // Initialize interfacing with the WindowedAppActivity.
+  activity_ = ui_thread_jni_env_->NewGlobalRef(activity);
+  if (!activity_) {
+    XELOGE(
+        "AndroidWindowedAppContext: Failed to create a global reference to the "
+        "activity");
+    Shutdown();
+    return false;
+  }
+  {
+    jclass activity_class_local_ref =
+        ui_thread_jni_env_->GetObjectClass(activity);
+    if (!activity_class_local_ref) {
+      XELOGE("AndroidWindowedAppContext: Failed to get the activity class");
+      Shutdown();
+      return false;
+    }
+    activity_class_ = reinterpret_cast<jclass>(ui_thread_jni_env_->NewGlobalRef(
+        reinterpret_cast<jobject>(activity_class_local_ref)));
+    ui_thread_jni_env_->DeleteLocalRef(
+        reinterpret_cast<jobject>(activity_class_local_ref));
+  }
+  if (!activity_class_) {
+    XELOGE(
+        "AndroidWindowedAppContext: Failed to create a global reference to the "
+        "activity class");
+    Shutdown();
+    return false;
+  }
+  bool activity_ids_obtained = true;
+  activity_ids_obtained &=
+      (activity_method_finish_ = ui_thread_jni_env_->GetMethodID(
+           activity_class_, "finish", "()V")) != nullptr;
+  if (!activity_ids_obtained) {
+    XELOGE("AndroidWindowedAppContext: Failed to get the activity class IDs");
+    Shutdown();
+    return false;
+  }
+
   // Initialize sending commands to the UI thread looper callback, for
   // requesting function calls in the UI thread.
   ui_thread_looper_ = ALooper_forThread();
@@ -117,10 +218,6 @@ bool AndroidWindowedAppContext::Initialize(ANativeActivity* activity) {
   }
   ui_thread_looper_callback_registered_ = true;
 
-  activity_ = activity;
-  activity_->instance = this;
-  activity_->callbacks->onDestroy = OnActivityDestroy;
-
   return true;
 }
 
@@ -135,12 +232,6 @@ void AndroidWindowedAppContext::Shutdown() {
   assert_null(activity_window_);
   activity_window_ = nullptr;
 
-  if (activity_) {
-    activity_->callbacks->onDestroy = nullptr;
-    activity_->instance = nullptr;
-    activity_ = nullptr;
-  }
-
   if (ui_thread_looper_callback_registered_) {
     ALooper_removeFd(ui_thread_looper_, ui_thread_looper_callback_pipe_[0]);
     ui_thread_looper_callback_registered_ = false;
@@ -157,10 +248,34 @@ void AndroidWindowedAppContext::Shutdown() {
     ui_thread_looper_ = nullptr;
   }
 
+  activity_method_finish_ = nullptr;
+  if (activity_class_) {
+    ui_thread_jni_env_->DeleteGlobalRef(
+        reinterpret_cast<jobject>(activity_class_));
+    activity_class_ = nullptr;
+  }
+  if (activity_) {
+    ui_thread_jni_env_->DeleteGlobalRef(activity_);
+    activity_ = nullptr;
+  }
+
   if (android_base_initialized_) {
     xe::ShutdownAndroidAppFromMainThread();
     android_base_initialized_ = false;
   }
+
+  if (configuration_) {
+    AConfiguration_delete(configuration_);
+    configuration_ = nullptr;
+  }
+
+  asset_manager_ = nullptr;
+  if (asset_manager_jobject_) {
+    ui_thread_jni_env_->DeleteGlobalRef(asset_manager_jobject_);
+    asset_manager_jobject_ = nullptr;
+  }
+
+  ui_thread_jni_env_ = nullptr;
 }
 
 void AndroidWindowedAppContext::RequestDestruction() {
@@ -260,15 +375,26 @@ bool AndroidWindowedAppContext::InitializeApp(std::unique_ptr<WindowedApp> (
   return true;
 }
 
-void AndroidWindowedAppContext::OnActivityDestroy(ANativeActivity* activity) {
-  auto& app_context =
-      *static_cast<AndroidWindowedAppContext*>(activity->instance);
-  if (app_context.app_) {
-    app_context.app_->InvokeOnDestroy();
-    app_context.app_.reset();
-  }
-  app_context.RequestDestruction();
-}
-
 }  // namespace ui
 }  // namespace xe
+
+extern "C" {
+
+JNIEXPORT jlong JNICALL
+Java_jp_xenia_emulator_WindowedAppActivity_initializeWindowedAppOnCreateNative(
+    JNIEnv* jni_env, jobject activity, jstring windowed_app_identifier,
+    jobject asset_manager) {
+  return reinterpret_cast<jlong>(
+      xe::ui::AndroidWindowedAppContext ::
+          JniActivityInitializeWindowedAppOnCreate(
+              jni_env, activity, windowed_app_identifier, asset_manager));
+}
+
+JNIEXPORT void JNICALL
+Java_jp_xenia_emulator_WindowedAppActivity_onDestroyNative(
+    JNIEnv* jni_env, jobject activity, jlong app_context_ptr) {
+  reinterpret_cast<xe::ui::AndroidWindowedAppContext*>(app_context_ptr)
+      ->JniActivityOnDestroy();
+}
+
+}  // extern "C"

src/xenia/ui/windowed_app_context_android.h

@@ -10,8 +10,10 @@
 #ifndef XENIA_UI_WINDOWED_APP_CONTEXT_ANDROID_H_
 #define XENIA_UI_WINDOWED_APP_CONTEXT_ANDROID_H_
 
+#include <android/asset_manager.h>
+#include <android/configuration.h>
 #include <android/looper.h>
-#include <android/native_activity.h>
+#include <jni.h>
 #include <array>
 #include <memory>
 
@@ -25,13 +27,6 @@ class WindowedApp;
 
 class AndroidWindowedAppContext final : public WindowedAppContext {
  public:
-  // For calling from android.app.func_name exports.
-  static void StartAppOnActivityCreate(
-      ANativeActivity* activity, void* saved_state, size_t saved_state_size,
-      std::unique_ptr<WindowedApp> (*app_creator)(
-          WindowedAppContext& app_context));
-
-  ANativeActivity* activity() const { return activity_; }
   WindowedApp* app() const { return app_.get(); }
 
   void NotifyUILoopOfPendingFunctions() override;
@@ -45,6 +40,12 @@ class AndroidWindowedAppContext final : public WindowedAppContext {
   AndroidWindow* GetActivityWindow() const { return activity_window_; }
   void SetActivityWindow(AndroidWindow* window) { activity_window_ = window; }
 
+  // For calling from WindowedAppActivity native methods.
+  static AndroidWindowedAppContext* JniActivityInitializeWindowedAppOnCreate(
+      JNIEnv* jni_env, jobject activity, jstring windowed_app_identifier,
+      jobject asset_manager);
+  void JniActivityOnDestroy();
+
  private:
   enum class UIThreadLooperCallbackCommand : uint8_t {
     kDestroy,
@@ -55,13 +56,14 @@ class AndroidWindowedAppContext final : public WindowedAppContext {
 
   // Don't delete this object directly externally if successfully initialized as
   // the looper may still execute the callback for pending commands after an
-  // external ANativeActivity_removeFd, and the callback receives a pointer to
-  // the context - deletion must be deferred and done in the callback itself.
+  // external ALooper_removeFd, and the callback receives a pointer to the
+  // context - deletion must be deferred and done in the callback itself.
   // Defined in the translation unit where WindowedApp is complete because of
   // std::unique_ptr.
   ~AndroidWindowedAppContext();
 
-  bool Initialize(ANativeActivity* activity);
+  bool Initialize(JNIEnv* ui_thread_jni_env, jobject activity,
+                  jobject asset_manager);
   void Shutdown();
 
   // Call this function instead of deleting the object directly, so if needed,
@@ -75,10 +77,29 @@ class AndroidWindowedAppContext final : public WindowedAppContext {
   bool InitializeApp(std::unique_ptr<WindowedApp> (*app_creator)(
       WindowedAppContext& app_context));
 
-  static void OnActivityDestroy(ANativeActivity* activity);
+  // Useful notes about JNI usage on Android within Xenia:
+  // - All static libraries defining JNI native functions must be linked to
+  //   shared libraries via LOCAL_WHOLE_STATIC_LIBRARIES.
+  // - If method or field IDs are cached, a global reference to the class needs
+  //   to be held - it prevents the class from being unloaded by the class
+  //   loaders (in a way that would make the IDs invalid when it's reloaded).
+  // - GetStringUTFChars (UTF-8) returns null-terminated strings, GetStringChars
+  //   (UTF-16) does not.
+  JNIEnv* ui_thread_jni_env_ = nullptr;
+
+  // The object reference must be held by the app according to
+  // AAssetManager_fromJava documentation.
+  jobject asset_manager_jobject_ = nullptr;
+  AAssetManager* asset_manager_ = nullptr;
+
+  AConfiguration* configuration_ = nullptr;
 
   bool android_base_initialized_ = false;
 
+  jobject activity_ = nullptr;
+  jclass activity_class_ = nullptr;
+  jmethodID activity_method_finish_ = nullptr;
+
   // May be read by non-UI threads in NotifyUILoopOfPendingFunctions.
   ALooper* ui_thread_looper_ = nullptr;
   // [1] (the write file descriptor) may be referenced as read-only by non-UI
@@ -86,11 +107,6 @@ class AndroidWindowedAppContext final : public WindowedAppContext {
   std::array<int, 2> ui_thread_looper_callback_pipe_{-1, -1};
   bool ui_thread_looper_callback_registered_ = false;
 
-  // TODO(Triang3l): Switch from ANativeActivity to the context itself being the
-  // object for communication with the Java code when NativeActivity isn't used
-  // anymore as its functionality is heavily limited.
-  ANativeActivity* activity_ = nullptr;
-
   AndroidWindow* activity_window_ = nullptr;
 
   std::unique_ptr<WindowedApp> app_;