Revert "Adding app lifecycle notification for macOS and Linux, add hidden state." (flutter/engine#42384)

engine/src/flutter/ci/licenses_golden/licenses_flutter

@@ -2463,7 +2463,6 @@ ORIGIN: ../../../flutter/shell/platform/common/accessibility_bridge.cc + ../../.
 ORIGIN: ../../../flutter/shell/platform/common/accessibility_bridge.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/common/alert_platform_node_delegate.cc + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/common/alert_platform_node_delegate.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/common/app_lifecycle_state.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/common/client_wrapper/binary_messenger_impl.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/common/client_wrapper/byte_buffer_streams.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/common/client_wrapper/core_implementations.cc + ../../../flutter/LICENSE
@@ -2681,7 +2680,6 @@ ORIGIN: ../../../flutter/shell/platform/darwin/ios/platform_view_ios.mm + ../../
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/rendering_api_selection.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/ios/rendering_api_selection.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppDelegate.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppLifecycleDelegate.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterEngine.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterMacOS.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterPlatformViews.h + ../../../flutter/LICENSE
@@ -2693,8 +2691,6 @@ ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Source/Accessibil
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Source/AccessibilityBridgeMacTest.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterAppDelegate.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterAppDelegate_Internal.h + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterAppLifecycleDelegate.mm + ../../../flutter/LICENSE
-ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterAppLifecycleDelegateTest.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterBackingStore.h + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterBackingStore.mm + ../../../flutter/LICENSE
 ORIGIN: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterChannelKeyResponder.h + ../../../flutter/LICENSE
@@ -5134,7 +5130,6 @@ FILE: ../../../flutter/shell/platform/common/accessibility_bridge.cc
 FILE: ../../../flutter/shell/platform/common/accessibility_bridge.h
 FILE: ../../../flutter/shell/platform/common/alert_platform_node_delegate.cc
 FILE: ../../../flutter/shell/platform/common/alert_platform_node_delegate.h
-FILE: ../../../flutter/shell/platform/common/app_lifecycle_state.h
 FILE: ../../../flutter/shell/platform/common/client_wrapper/binary_messenger_impl.h
 FILE: ../../../flutter/shell/platform/common/client_wrapper/byte_buffer_streams.h
 FILE: ../../../flutter/shell/platform/common/client_wrapper/core_implementations.cc
@@ -5354,7 +5349,6 @@ FILE: ../../../flutter/shell/platform/darwin/ios/platform_view_ios.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/rendering_api_selection.h
 FILE: ../../../flutter/shell/platform/darwin/ios/rendering_api_selection.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppDelegate.h
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppLifecycleDelegate.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterEngine.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterMacOS.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Headers/FlutterPlatformViews.h
@@ -5367,8 +5361,6 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/Accessibilit
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/AccessibilityBridgeMacTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterAppDelegate.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterAppDelegate_Internal.h
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterAppLifecycleDelegate.mm
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterAppLifecycleDelegateTest.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterBackingStore.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterBackingStore.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterChannelKeyResponder.h

engine/src/flutter/lib/ui/platform_dispatcher.dart

@@ -1679,15 +1679,13 @@ class FrameTiming {
   }
 }
 
-/// States that an application can be in once it is running.
+/// States that an application can be in.
 ///
-/// States not supported on a platform will be synthesized by the framework when
+/// The values below describe notifications from the operating system.
-/// transitioning between states which are supported, so that all
+/// Applications should not expect to always receive all possible notifications.
-/// implementations share the same state machine.
+/// For example, if the users pulls out the battery from the device, no
-///
+/// notification will be sent before the application is suddenly terminated,
-/// The initial value for the state is the [detached] state, updated to the
+/// along with the rest of the operating system.
-/// current state (usually [resumed]) as soon as the first lifecycle update is
-/// received from the platform.
 ///
 /// For historical and name collision reasons, Flutter's application state names
 /// do not correspond one to one with the state names on all platforms. On
@@ -1698,52 +1696,15 @@ class FrameTiming {
 /// Flutter enters the [paused] state. See the individual state's documentation
 /// for descriptions of what they mean on each platform.
 ///
-/// The current application state can be obtained from
-/// [SchedulerBinding.instance.lifecycleState], and changes to the state can be
-/// observed by creating an [AppLifecycleListener], or by using a
-/// [WidgetsBindingObserver] by overriding the
-/// [WidgetsBindingObserver.didChangeAppLifecycleState] method.
-///
-/// Applications should not rely on always receiving all possible notifications.
-///
-/// For example, if the application is killed with a task manager, a kill
-/// signal, the user pulls the power from the device, or there is a rapid
-/// unscheduled disassembly of the device, no notification will be sent before
-/// the application is suddenly terminated, and some states may be skipped.
-///
 /// See also:
 ///
-/// * [AppLifecycleListener], an object used observe the lifecycle state that
-///   provides state transition callbacks.
 /// * [WidgetsBindingObserver], for a mechanism to observe the lifecycle state
 ///   from the widgets layer.
-/// * iOS's [IOKit activity
+/// * iOS's [IOKit activity lifecycle](https://developer.apple.com/documentation/uikit/app_and_environment/managing_your_app_s_life_cycle?language=objc) documentation.
-///   lifecycle](https://developer.apple.com/documentation/uikit/app_and_environment/managing_your_app_s_life_cycle?language=objc)
+/// * Android's [activity lifecycle](https://developer.android.com/guide/components/activities/activity-lifecycle) documentation.
-///   documentation.
+/// * macOS's [AppKit activity lifecycle](https://developer.apple.com/documentation/appkit/nsapplicationdelegate?language=objc) documentation.
-/// * Android's [activity
-///   lifecycle](https://developer.android.com/guide/components/activities/activity-lifecycle)
-///   documentation.
-/// * macOS's [AppKit activity
-///   lifecycle](https://developer.apple.com/documentation/appkit/nsapplicationdelegate?language=objc)
-///   documentation.
 enum AppLifecycleState {
-  /// The application is still hosted by a Flutter engine but is detached from
+  /// The application is visible and responsive to user input.
-  /// any host views.
-  ///
-  /// The application defaults to this state before it initializes, and can be
-  /// in this state (on Android and iOS only) after all views have been
-  /// detached.
-  ///
-  /// When the application is in this state, the engine is running without a
-  /// view.
-  ///
-  /// This state is only entered on iOS and Android, although on all platforms
-  /// it is the default state before the application begins running.
-  detached,
-
-  /// On all platforms, this state indicates that the application is in the
-  /// default running mode for a running application that has input focus and is
-  /// visible.
   ///
   /// On Android, this state corresponds to the Flutter host view having focus
   /// ([`Activity.onWindowFocusChanged`](https://developer.android.com/reference/android/app/Activity#onWindowFocusChanged(boolean))
@@ -1756,71 +1717,54 @@ enum AppLifecycleState {
   /// was called with false), but hasn't had
   /// [`Activity.onPause`](https://developer.android.com/reference/android/app/Activity#onPause())
   /// called on it.
-  ///
-  /// On iOS and macOS, this corresponds to the app running in the foreground
-  /// active state.
   resumed,
 
-  /// At least one view of the application is visible, but none have input
+  /// The application is in an inactive state and is not receiving user input.
-  /// focus. The application is otherwise running normally.
   ///
-  /// On non-web desktop platforms, this corresponds to an application that is
+  /// On iOS, this state corresponds to an app or the Flutter host view running
-  /// not in the foreground, but still has visible windows.
+  /// in the foreground inactive state. Apps transition to this state when in a
+  /// phone call, responding to a TouchID request, when entering the app
+  /// switcher or the control center, or when the UIViewController hosting the
+  /// Flutter app is transitioning.
   ///
-  /// On the web, this corresponds to an application that is running in a
+  /// On Android, this corresponds to an app or the Flutter host view running in
-  /// window or tab that does not have input focus.
+  /// Android's paused state (i.e.
-  ///
-  /// On iOS and macOS, this state corresponds to the Flutter host view running in the
-  /// foreground inactive state. Apps transition to this state when in a phone
-  /// call, when responding to a TouchID request, when entering the app switcher
-  /// or the control center, or when the UIViewController hosting the Flutter
-  /// app is transitioning.
-  ///
-  /// On Android, this corresponds to the Flutter host view running in Android's
-  /// paused state (i.e.
   /// [`Activity.onPause`](https://developer.android.com/reference/android/app/Activity#onPause())
   /// has been called), or in Android's "resumed" state (i.e.
   /// [`Activity.onResume`](https://developer.android.com/reference/android/app/Activity#onResume())
-  /// has been called) but does not have window focus. Examples of when apps
+  /// has been called) but it has lost window focus. Examples of when apps
   /// transition to this state include when the app is partially obscured or
-  /// another activity is focused, a app running in a split screen that isn't
+  /// another activity is focused, such as: a split-screen app, a phone call, a
-  /// the current app, an app interrupted by a phone call, a picture-in-picture
+  /// picture-in-picture app, a system dialog, another view, when the
-  /// app, a system dialog, another view. It will also be inactive when the
   /// notification window shade is down, or the application switcher is visible.
   ///
-  /// On Android and iOS, apps in this state should assume that they may be
+  /// Apps in this state should assume that they may be [paused] at any time.
-  /// [hidden] and [paused] at any time.
   inactive,
 
-  /// All views of an application are hidden, either because the application is
+  /// The application is not currently visible to the user, not responding to
-  /// about to be paused (on iOS and Android), or because it has been minimized
+  /// user input, and running in the background.
-  /// or placed on a desktop that is no longer visible (on non-web desktop), or
-  /// is running in a window or tab that is no longer visible (on the web).
-  ///
-  /// On iOS and Android, in order to keep the state machine the same on all
-  /// platforms, a transition to this state is synthesized before the [paused]
-  /// state is entered when coming from [inactive], and before the [inactive]
-  /// state is entered when coming from [paused]. This allows cross-platform
-  /// implementations that want to know when an app is conceptually "hidden" to
-  /// only write one handler.
-  hidden,
-
-  /// The application is not currently visible to the user, and not responding
-  /// to user input.
   ///
   /// When the application is in this state, the engine will not call the
   /// [PlatformDispatcher.onBeginFrame] and [PlatformDispatcher.onDrawFrame]
   /// callbacks.
-  ///
-  /// This state is only entered on iOS and Android.
   paused,
+
+  /// The application is still hosted on a flutter engine but is detached from
+  /// any host views.
+  ///
+  /// When the application is in this state, the engine is running without
+  /// a view. It can either be in the progress of attaching a view when engine
+  /// was first initializes, or after the view being destroyed due to a Navigator
+  /// pop.
+  detached,
 }
 
 /// The possible responses to a request to exit the application.
 ///
-/// The request is typically responded to by creating an [AppLifecycleListener]
+/// The request is typically responded to by a [WidgetsBindingObserver].
-/// and supplying an [AppLifecycleListener.onExitRequested] callback, or by
+// TODO(gspencergoog): Insert doc references here to AppLifecycleListener and to
-/// overriding [WidgetsBindingObserver.didRequestAppExit].
+// the actual function called on WidgetsBindingObserver once those have landed
+// in the framework. https://github.com/flutter/flutter/issues/121721
 enum AppExitResponse {
   /// Exiting the application can proceed.
   exit,
@@ -1829,7 +1773,10 @@ enum AppExitResponse {
 }
 
 /// The type of application exit to perform when calling
-/// [ServicesBinding.exitApplication].
+/// `ServicesBinding.exitApplication`.
+// TODO(gspencergoog): Insert doc references here to
+// ServicesBinding.exitApplication that has landed in the framework.
+// https://github.com/flutter/flutter/issues/121721
 enum AppExitType {
   /// Requests that the application start an orderly exit, sending a request
   /// back to the framework through the [WidgetsBinding]. If that responds

engine/src/flutter/lib/web_ui/lib/platform_dispatcher.dart

@@ -104,7 +104,7 @@ abstract class PlatformDispatcher {
   VoidCallback? get onLocaleChanged;
   set onLocaleChanged(VoidCallback? callback);
 
-  String get initialLifecycleState => '';
+  String get initialLifecycleState => 'AppLifecycleState.resumed';
 
   bool get alwaysUse24HourFormat;
 
@@ -247,11 +247,10 @@ class FrameTiming {
 }
 
 enum AppLifecycleState {
-  detached,
   resumed,
   inactive,
-  hidden,
   paused,
+  detached,
 }
 
 enum AppExitResponse {

engine/src/flutter/lib/web_ui/lib/src/engine/platform_dispatcher.dart

@@ -104,7 +104,6 @@ class EnginePlatformDispatcher extends ui.PlatformDispatcher {
     _addFontSizeObserver();
     _addLocaleChangedListener();
     registerHotRestartListener(dispose);
-    _setAppLifecycleState(ui.AppLifecycleState.resumed);
   }
 
   /// The [EnginePlatformDispatcher] singleton.
@@ -1006,14 +1005,6 @@ class EnginePlatformDispatcher extends ui.PlatformDispatcher {
     _fontSizeObserver = null;
   }
 
-  void _setAppLifecycleState(ui.AppLifecycleState state) {
-    sendPlatformMessage(
-      'flutter/lifecycle',
-      Uint8List.fromList(utf8.encode(state.toString())).buffer.asByteData(),
-      null,
-    );
-  }
-
   /// A callback that is invoked whenever [textScaleFactor] changes value.
   ///
   /// The framework invokes this callback in the same zone in which the

engine/src/flutter/shell/platform/android/io/flutter/embedding/engine/systemchannels/LifecycleChannel.java

@@ -22,21 +22,14 @@ public class LifecycleChannel {
   private static final String TAG = "LifecycleChannel";
   private static final String CHANNEL_NAME = "flutter/lifecycle";
 
-  // This enum should match the Dart enum of the same name.
+  // These should stay in sync with the AppLifecycleState enum in the framework.
-  //
+  private static final String RESUMED = "AppLifecycleState.resumed";
-  // HIDDEN isn't used on Android (it's synthesized in the Framework code). It's
+  private static final String INACTIVE = "AppLifecycleState.inactive";
-  // only listed here so that apicheck_test.dart can make sure that the states here
+  private static final String PAUSED = "AppLifecycleState.paused";
-  // match the Dart code.
+  private static final String DETACHED = "AppLifecycleState.detached";
-  private enum AppLifecycleState {
-    DETACHED,
-    RESUMED,
-    INACTIVE,
-    HIDDEN,
-    PAUSED,
-  };
 
-  private AppLifecycleState lastAndroidState = null;
+  private String lastAndroidState = "";
-  private AppLifecycleState lastFlutterState = null;
+  private String lastFlutterState = "";
   private boolean lastFocus = true;
 
   @NonNull private final BasicMessageChannel<String> channel;
@@ -62,39 +55,21 @@ public class LifecycleChannel {
   // | Stopped       |     false      |    paused     |
   // | Detached      |     true       |    detached   |
   // | Detached      |     false      |    detached   |
-  //
+  private void sendState(String state, boolean hasFocus) {
-  // The hidden state isn't used on Android, it's synthesized in the Framework
-  // code when transitioning between paused and inactive in either direction.
-  private void sendState(AppLifecycleState state, boolean hasFocus) {
     if (lastAndroidState == state && hasFocus == lastFocus) {
       // No inputs changed, so Flutter state could not have changed.
       return;
     }
-    if (state == null && lastAndroidState == null) {
+    String newState;
-      // If we're responding to a focus change before the state is set, just
+    if (state == RESUMED) {
-      // keep the last reported focus state and don't send anything to the
+      // Focus is only taken into account when the Android state is "Resumed".
-      // framework. This could happen if focus events and lifecycle events are
+      // In all other states, focus is ignored, because we can't know what order
-      // delivered out of the expected order.
+      // Android lifecycle notifications and window focus notifications events
-      lastFocus = hasFocus;
+      // will arrive in, and those states don't send input events anyhow.
-      return;
+      newState = hasFocus ? RESUMED : INACTIVE;
+    } else {
+      newState = state;
     }
-    AppLifecycleState newState = null;
-    switch (state) {
-      case RESUMED:
-        // Focus is only taken into account when the Android state is "Resumed".
-        // In all other states, focus is ignored, because we can't know what order
-        // Android lifecycle notifications and window focus notifications events
-        // will arrive in, and those states don't send input events anyhow.
-        newState = hasFocus ? AppLifecycleState.RESUMED : AppLifecycleState.INACTIVE;
-        break;
-      case INACTIVE:
-      case HIDDEN:
-      case PAUSED:
-      case DETACHED:
-        newState = state;
-        break;
-    }
-
     // Keep the last reported values for future updates.
     lastAndroidState = state;
     lastFocus = hasFocus;
@@ -102,14 +77,12 @@ public class LifecycleChannel {
       // No change in the resulting Flutter state, so don't report anything.
       return;
     }
-    String message = "AppLifecycleState." + newState.name().toLowerCase();
+    Log.v(TAG, "Sending " + newState + " message.");
-    Log.v(TAG, "Sending " + message + " message.");
+    channel.send(newState);
-    channel.send(message);
     lastFlutterState = newState;
   }
 
-  // Called if at least one window in the app has focus, even if the focused
+  // Called if at least one window in the app has focus.
-  // window doesn't contain a Flutter view.
   public void aWindowIsFocused() {
     sendState(lastAndroidState, true);
   }
@@ -120,18 +93,18 @@ public class LifecycleChannel {
   }
 
   public void appIsResumed() {
-    sendState(AppLifecycleState.RESUMED, lastFocus);
+    sendState(RESUMED, lastFocus);
   }
 
   public void appIsInactive() {
-    sendState(AppLifecycleState.INACTIVE, lastFocus);
+    sendState(INACTIVE, lastFocus);
   }
 
   public void appIsPaused() {
-    sendState(AppLifecycleState.PAUSED, lastFocus);
+    sendState(PAUSED, lastFocus);
   }
 
   public void appIsDetached() {
-    sendState(AppLifecycleState.DETACHED, lastFocus);
+    sendState(DETACHED, lastFocus);
   }
 }

engine/src/flutter/shell/platform/common/BUILD.gn

@@ -58,10 +58,7 @@ source_set("common_cpp_input") {
 }
 
 source_set("common_cpp_enums") {
-  public = [
+  public = [ "platform_provided_menu.h" ]
-    "app_lifecycle_state.h",
-    "platform_provided_menu.h",
-  ]
 
   public_configs = [
     "//flutter:config",

engine/src/flutter/shell/platform/common/app_lifecycle_state.h

@@ -1,89 +0,0 @@
-// Copyright 2013 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef FLUTTER_SHELL_PLATFORM_COMMON_APP_LIFECYCLE_STATE_H_
-#define FLUTTER_SHELL_PLATFORM_COMMON_APP_LIFECYCLE_STATE_H_
-
-namespace flutter {
-
-/**
- * These constants describe the possible lifecycle states of the application.
- * They must be kept up to date with changes in the framework's
- * AppLifecycleState enum. They are passed to the embedder's |SetLifecycleState|
- * function.
- *
- * States not supported on a platform will be synthesized by the framework when
- * transitioning between states which are supported, so that all implementations
- * share the same state machine.
- *
- * Here is the state machine:
- *
- *     +-----------+                               +-----------+
- *     | detached  |------------------------------>|  resumed  |
- *     +-----------+                               +-----------+
- *          ^                                              ^
- *          |                                              |
- *          |                                              v
- *     +-----------+        +--------------+       +-----------+
- *     | paused    |<------>|    hidden    |<----->|  inactive |
- *     +-----------+        +--------------+       +-----------+
- */
-enum class AppLifecycleState {
-  /**
-   * Corresponds to the Framework's AppLifecycleState.detached: The initial
-   * state of the state machine. On Android and iOS, also the final state of the
-   * state machine when all views are detached. Other platforms do not enter
-   * this state again after initially leaving it.
-   */
-  kDetached,
-
-  /**
-   * Corresponds to the Framework's AppLifecycleState.resumed: The nominal
-   * "running" state of the application. The application is visible, has input
-   * focus, and is running.
-   */
-  kResumed,
-
-  /**
-   * Corresponds to the Framework's AppLifecycleState.inactive: At least one
-   * view of the application is visible, but none have input focus. The
-   * application is otherwise running normally.
-   */
-  kInactive,
-
-  /**
-   * Corresponds to the Framework's AppLifecycleState.hidden: All views of an
-   * application are hidden, either because the application is being stopped (on
-   * iOS and Android), or because it is being minimized or on a desktop that is
-   * no longer visible (on desktop), or on a tab that is no longer visible (on
-   * web).
-   */
-  kHidden,
-
-  /**
-   * Corresponds to the Framework's AppLifecycleState.paused: The application is
-   * not running, and can be detached or started again at any time. This state
-   * is typically only entered into on iOS and Android.
-   */
-  kPaused,
-};
-
-constexpr const char* AppLifecycleStateToString(AppLifecycleState state) {
-  switch (state) {
-    case AppLifecycleState::kDetached:
-      return "AppLifecycleState.detached";
-    case AppLifecycleState::kResumed:
-      return "AppLifecycleState.resumed";
-    case AppLifecycleState::kInactive:
-      return "AppLifecycleState.inactive";
-    case AppLifecycleState::kHidden:
-      return "AppLifecycleState.hidden";
-    case AppLifecycleState::kPaused:
-      return "AppLifecycleState.paused";
-  }
-}
-
-}  // namespace flutter
-
-#endif  // FLUTTER_SHELL_PLATFORM_COMMON_APP_LIFECYCLE_STATE_H_

engine/src/flutter/shell/platform/darwin/macos/BUILD.gn

@@ -38,7 +38,6 @@ _framework_binary_subpath = "Versions/A/$_flutter_framework_name"
 # the Flutter engine source root.
 _flutter_framework_headers = [
   "framework/Headers/FlutterAppDelegate.h",
-  "framework/Headers/FlutterAppLifecycleDelegate.h",
   "framework/Headers/FlutterEngine.h",
   "framework/Headers/FlutterMacOS.h",
   "framework/Headers/FlutterPlatformViews.h",
@@ -57,7 +56,6 @@ source_set("flutter_framework_source") {
     "framework/Source/AccessibilityBridgeMac.h",
     "framework/Source/AccessibilityBridgeMac.mm",
     "framework/Source/FlutterAppDelegate.mm",
-    "framework/Source/FlutterAppLifecycleDelegate.mm",
     "framework/Source/FlutterBackingStore.h",
     "framework/Source/FlutterBackingStore.mm",
     "framework/Source/FlutterChannelKeyResponder.h",
@@ -169,7 +167,6 @@ executable("flutter_desktop_darwin_unittests") {
 
   sources = [
     "framework/Source/AccessibilityBridgeMacTest.mm",
-    "framework/Source/FlutterAppLifecycleDelegateTest.mm",
     "framework/Source/FlutterChannelKeyResponderTest.mm",
     "framework/Source/FlutterCompositorTest.mm",
     "framework/Source/FlutterEmbedderExternalTextureTest.mm",

engine/src/flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppDelegate.h

@@ -7,11 +7,10 @@
 
 #import <Cocoa/Cocoa.h>
 
-#import "FlutterAppLifecycleDelegate.h"
 #import "FlutterMacros.h"
 
 /**
- * |NSApplicationDelegate| subclass for simple apps that want default behavior.
+ * `NSApplicationDelegate` subclass for simple apps that want default behavior.
  *
  * This class implements the following behaviors:
  *   * Updates the application name of items in the application menu to match the name in
@@ -34,23 +33,11 @@ FLUTTER_DARWIN_EXPORT
 @property(weak, nonatomic) IBOutlet NSMenu* applicationMenu;
 
 /**
- * The primary application window containing a FlutterViewController. This is
+ * The primary application window containing a FlutterViewController. This is primarily intended
- * primarily intended for use in single-window applications.
+ * for use in single-window applications.
  */
 @property(weak, nonatomic) IBOutlet NSWindow* mainFlutterWindow;
 
-/**
- * Adds an object implementing |FlutterAppLifecycleDelegate| to the list of
- * delegates to be informed of application lifecycle events.
- */
-- (void)addApplicationLifecycleDelegate:(NSObject<FlutterAppLifecycleDelegate>*)delegate;
-
-/**
- * Removes an object implementing |FlutterAppLifecycleDelegate| to the list of
- * delegates to be informed of application lifecycle events.
- */
-- (void)removeApplicationLifecycleDelegate:(NSObject<FlutterAppLifecycleDelegate>*)delegate;
-
 @end
 
 #endif  // FLUTTER_FLUTTERAPPDELEGATE_H_

engine/src/flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppLifecycleDelegate.h

@@ -1,137 +0,0 @@
-// Copyright 2013 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef FLUTTER_FLUTTERAPPLIFECYCLEDELEGATE_H_
-#define FLUTTER_FLUTTERAPPLIFECYCLEDELEGATE_H_
-
-#import <Cocoa/Cocoa.h>
-#include <Foundation/Foundation.h>
-
-#import "FlutterMacros.h"
-#import "FlutterPluginMacOS.h"
-
-NS_ASSUME_NONNULL_BEGIN
-
-#pragma mark -
-/**
- * Protocol for listener of lifecycle events from the NSApplication, typically a
- * FlutterPlugin.
- */
-@protocol FlutterAppLifecycleDelegate <NSObject>
-
-@optional
-/**
- * Called when the |FlutterAppDelegate| gets the applicationWillFinishLaunching
- * notification.
- */
-- (void)handleWillFinishLaunching:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationDidFinishLaunching
- * notification.
- */
-- (void)handleDidFinishLaunching:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationWillBecomeActive
- * notification.
- */
-- (void)handleWillBecomeActive:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationDidBecomeActive
- * notification.
- */
-- (void)handleDidBecomeActive:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationWillResignActive
- * notification.
- */
-- (void)handleWillResignActive:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationWillResignActive
- * notification.
- */
-- (void)handleDidResignActive:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationWillHide
- * notification.
- */
-- (void)handleWillHide:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationDidHide
- * notification.
- */
-- (void)handleDidHide:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationWillUnhide
- * notification.
- */
-- (void)handleWillUnhide:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationDidUnhide
- * notification.
- */
-- (void)handleDidUnhide:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationDidUnhide
- * notification.
- */
-- (void)handleDidChangeScreenParameters:(NSNotification*)notification;
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationDidUnhide
- * notification.
- */
-- (void)handleDidChangeOcclusionState:(NSNotification*)notification API_AVAILABLE(macos(10.9));
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationWillTerminate
- * notification.
- *
- * Applications should not rely on always receiving all possible notifications.
- *
- * For example, if the application is killed with a task manager, a kill signal,
- * the user pulls the power from the device, or there is a rapid unscheduled
- * disassembly of the device, no notification will be sent before the
- * application is suddenly terminated, and this notification may be skipped.
- */
-- (void)handleWillTerminate:(NSNotification*)notification;
-@end
-
-#pragma mark -
-
-/**
- * Propagates `NSAppDelegate` callbacks to registered delegates.
- */
-FLUTTER_DARWIN_EXPORT
-@interface FlutterAppLifecycleRegistrar : NSObject <FlutterAppLifecycleDelegate>
-
-/**
- * Registers `delegate` to receive lifecycle callbacks via this
- * FlutterAppLifecycleDelegate as long as it is alive.
- *
- * `delegate` will only be referenced weakly.
- */
-- (void)addDelegate:(NSObject<FlutterAppLifecycleDelegate>*)delegate;
-
-/**
- * Unregisters `delegate` so that it will no longer receive life cycle callbacks
- * via this FlutterAppLifecycleDelegate.
- *
- * `delegate` will only be referenced weakly.
- */
-- (void)removeDelegate:(NSObject<FlutterAppLifecycleDelegate>*)delegate;
-@end
-
-NS_ASSUME_NONNULL_END
-
-#endif  // FLUTTER_FLUTTERAPPLIFECYCLEDELEGATE_H_

engine/src/flutter/shell/platform/darwin/macos/framework/Headers/FlutterEngine.h

@@ -9,7 +9,6 @@
 
 #include <stdint.h>
 
-#import "FlutterAppLifecycleDelegate.h"
 #import "FlutterBinaryMessenger.h"
 #import "FlutterDartProject.h"
 #import "FlutterMacros.h"
@@ -27,8 +26,7 @@
  * code.
  */
 FLUTTER_DARWIN_EXPORT
-@interface FlutterEngine
+@interface FlutterEngine : NSObject <FlutterTextureRegistry, FlutterPluginRegistry>
-    : NSObject <FlutterTextureRegistry, FlutterPluginRegistry, FlutterAppLifecycleDelegate>
 
 /**
  * Initializes an engine with the given project.

engine/src/flutter/shell/platform/darwin/macos/framework/Headers/FlutterMacOS.h

@@ -3,7 +3,6 @@
 // found in the LICENSE file.
 
 #import "FlutterAppDelegate.h"
-#import "FlutterAppLifecycleDelegate.h"
 #import "FlutterBinaryMessenger.h"
 #import "FlutterChannels.h"
 #import "FlutterCodecs.h"

engine/src/flutter/shell/platform/darwin/macos/framework/Headers/FlutterPluginMacOS.h

@@ -8,7 +8,8 @@
 #import "FlutterCodecs.h"
 #import "FlutterMacros.h"
 
-NS_ASSUME_NONNULL_BEGIN
+// TODO: Merge this file and FlutterPluginRegistrarMacOS.h with the iOS FlutterPlugin.h, sharing
+// all but the platform-specific methods.
 
 @protocol FlutterPluginRegistrar;
 
@@ -28,7 +29,7 @@ FLUTTER_DARWIN_EXPORT
  * Creates an instance of the plugin to register with |registrar| using the desired
  * FlutterPluginRegistrar methods.
  */
-+ (void)registerWithRegistrar:(id<FlutterPluginRegistrar>)registrar;
++ (void)registerWithRegistrar:(nonnull id<FlutterPluginRegistrar>)registrar;
 
 @optional
 
@@ -43,8 +44,6 @@ FLUTTER_DARWIN_EXPORT
  * - Any other value (including nil) to indicate success. The value will
  *   be returned to the Flutter caller, and must be serializable to JSON.
  */
-- (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result;
+- (void)handleMethodCall:(nonnull FlutterMethodCall*)call result:(nonnull FlutterResult)result;
-
-NS_ASSUME_NONNULL_END
 
 @end

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterAppDelegate.mm

@@ -8,7 +8,6 @@
 #import <AppKit/AppKit.h>
 
 #include "flutter/fml/logging.h"
-#import "flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppLifecycleDelegate.h"
 #include "flutter/shell/platform/embedder/embedder.h"
 
 @interface FlutterAppDelegate ()
@@ -18,15 +17,17 @@
  */
 - (NSString*)applicationName;
 
-@property(nonatomic) FlutterAppLifecycleRegistrar* lifecycleRegistrar;
 @end
 
 @implementation FlutterAppDelegate
 
+// TODO(gspencergoog): Implement application lifecycle forwarding to plugins here, as is done
+// on iOS. Currently macOS plugins don't have access to lifecycle messages.
+// https://github.com/flutter/flutter/issues/30735
+
 - (instancetype)init {
   if (self = [super init]) {
     _terminationHandler = nil;
-    _lifecycleRegistrar = [[FlutterAppLifecycleRegistrar alloc] init];
   }
   return self;
 }
@@ -41,16 +42,6 @@
   }
 }
 
-#pragma mark - Delegate handling
-
-- (void)addApplicationLifecycleDelegate:(NSObject<FlutterAppLifecycleDelegate>*)delegate {
-  [[self lifecycleRegistrar] addDelegate:delegate];
-}
-
-- (void)removeApplicationLifecycleDelegate:(NSObject<FlutterAppLifecycleDelegate>*)delegate {
-  [[self lifecycleRegistrar] removeDelegate:delegate];
-}
-
 #pragma mark Private Methods
 
 - (NSString*)applicationName {

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterAppLifecycleDelegate.mm

@@ -1,130 +0,0 @@
-// Copyright 2013 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#import "flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppLifecycleDelegate.h"
-
-#include <AppKit/AppKit.h>
-#include <AppKit/NSApplication.h>
-#include <Foundation/Foundation.h>
-#include <objc/message.h>
-
-#include "flutter/fml/logging.h"
-#include "flutter/fml/paths.h"
-
-@interface FlutterAppLifecycleRegistrar ()
-@end
-
-@implementation FlutterAppLifecycleRegistrar {
-  NSMutableArray* _notificationUnsubscribers;
-
-  // Weak references to registered plugins.
-  NSPointerArray* _delegates;
-}
-
-- (void)addObserverFor:(NSString*)name selector:(SEL)selector {
-  [[NSNotificationCenter defaultCenter] addObserver:self selector:selector name:name object:nil];
-  __block NSObject* blockSelf = self;
-  dispatch_block_t unsubscribe = ^{
-    [[NSNotificationCenter defaultCenter] removeObserver:blockSelf name:name object:nil];
-  };
-  [_notificationUnsubscribers addObject:[unsubscribe copy]];
-}
-
-- (instancetype)init {
-  if (self = [super init]) {
-    _notificationUnsubscribers = [[NSMutableArray alloc] init];
-
-// Using a macro to avoid errors where the notification doesn't match the
-// selector.
-#ifdef OBSERVE_NOTIFICATION
-#error OBSERVE_NOTIFICATION ALREADY DEFINED!
-#else
-#define OBSERVE_NOTIFICATION(SELECTOR) \
-  [self addObserverFor:NSApplication##SELECTOR##Notification selector:@selector(handle##SELECTOR:)]
-#endif
-
-    OBSERVE_NOTIFICATION(WillFinishLaunching);
-    OBSERVE_NOTIFICATION(DidFinishLaunching);
-    OBSERVE_NOTIFICATION(WillBecomeActive);
-    OBSERVE_NOTIFICATION(DidBecomeActive);
-    OBSERVE_NOTIFICATION(WillResignActive);
-    OBSERVE_NOTIFICATION(DidResignActive);
-    OBSERVE_NOTIFICATION(WillTerminate);
-    OBSERVE_NOTIFICATION(WillHide);
-    OBSERVE_NOTIFICATION(DidHide);
-    OBSERVE_NOTIFICATION(WillUnhide);
-    OBSERVE_NOTIFICATION(DidUnhide);
-    OBSERVE_NOTIFICATION(DidChangeScreenParameters);
-    OBSERVE_NOTIFICATION(DidChangeOcclusionState);
-
-#undef OBSERVE_NOTIFICATION
-
-    _delegates = [NSPointerArray weakObjectsPointerArray];
-  }
-  return self;
-}
-
-- (void)dealloc {
-  for (dispatch_block_t unsubscribe in _notificationUnsubscribers) {
-    unsubscribe();
-  }
-  [_notificationUnsubscribers removeAllObjects];
-  _delegates = nil;
-  _notificationUnsubscribers = nil;
-}
-
-static BOOL IsPowerOfTwo(NSUInteger x) {
-  return x != 0 && (x & (x - 1)) == 0;
-}
-
-- (void)addDelegate:(NSObject<FlutterAppLifecycleDelegate>*)delegate {
-  [_delegates addPointer:(__bridge void*)delegate];
-  if (IsPowerOfTwo([_delegates count])) {
-    [_delegates compact];
-  }
-}
-
-- (void)removeDelegate:(NSObject<FlutterAppLifecycleDelegate>*)delegate {
-  NSUInteger index = [[_delegates allObjects] indexOfObject:delegate];
-  if (index >= 0) {
-    [_delegates removePointerAtIndex:index];
-  }
-}
-
-// This isn't done via performSelector because that can cause leaks due to the
-// selector not being known. Using a macro to avoid mismatch errors between the
-// notification and the selector.
-#ifdef DISTRIBUTE_NOTIFICATION
-#error DISTRIBUTE_NOTIFICATION ALREADY DEFINED!
-#else
-#define DISTRIBUTE_NOTIFICATION(SELECTOR)                                  \
-  -(void)handle##SELECTOR : (NSNotification*)notification {                \
-    for (NSObject<FlutterAppLifecycleDelegate> * delegate in _delegates) { \
-      if (!delegate) {                                                     \
-        continue;                                                          \
-      }                                                                    \
-      if ([delegate respondsToSelector:@selector(handle##SELECTOR:)]) {    \
-        [delegate handle##SELECTOR:notification];                          \
-      }                                                                    \
-    }                                                                      \
-  }
-#endif
-
-DISTRIBUTE_NOTIFICATION(WillFinishLaunching)
-DISTRIBUTE_NOTIFICATION(DidFinishLaunching)
-DISTRIBUTE_NOTIFICATION(WillBecomeActive)
-DISTRIBUTE_NOTIFICATION(DidBecomeActive)
-DISTRIBUTE_NOTIFICATION(WillResignActive)
-DISTRIBUTE_NOTIFICATION(DidResignActive)
-DISTRIBUTE_NOTIFICATION(WillTerminate)
-DISTRIBUTE_NOTIFICATION(WillHide)
-DISTRIBUTE_NOTIFICATION(WillUnhide)
-DISTRIBUTE_NOTIFICATION(DidHide)
-DISTRIBUTE_NOTIFICATION(DidUnhide)
-DISTRIBUTE_NOTIFICATION(DidChangeScreenParameters)
-DISTRIBUTE_NOTIFICATION(DidChangeOcclusionState)
-
-#undef DISTRIBUTE_NOTIFICATION
-
-@end

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterAppLifecycleDelegateTest.mm

@@ -1,223 +0,0 @@
-// Copyright 2013 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#import "flutter/shell/platform/darwin/macos/framework/Headers/FlutterAppLifecycleDelegate.h"
-
-#import "flutter/testing/testing.h"
-#include "third_party/googletest/googletest/include/gtest/gtest.h"
-
-@interface TestFlutterAppLifecycleDelegate : NSObject <FlutterAppLifecycleDelegate>
-@property(nonatomic, readwrite, nullable) NSNotification* lastNotification;
-@end
-
-@implementation TestFlutterAppLifecycleDelegate
-
-- (void)setNotification:(NSNotification*)notification {
-  self.lastNotification = notification;
-}
-
-- (void)handleWillFinishLaunching:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleDidFinishLaunching:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleWillBecomeActive:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleDidBecomeActive:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleWillResignActive:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleDidResignActive:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleWillHide:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleDidHide:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleWillUnhide:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleDidUnhide:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleDidChangeScreenParameters:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-- (void)handleDidChangeOcclusionState:(NSNotification*)notification API_AVAILABLE(macos(10.9)) {
-  [self setNotification:notification];
-}
-
-- (void)handleWillTerminate:(NSNotification*)notification {
-  [self setNotification:notification];
-}
-
-@end
-
-namespace flutter::testing {
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToWillFinishLaunching) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* willFinishLaunching =
-      [NSNotification notificationWithName:NSApplicationWillFinishLaunchingNotification object:nil];
-  [registrar handleWillFinishLaunching:willFinishLaunching];
-  EXPECT_EQ([delegate lastNotification], willFinishLaunching);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToDidFinishLaunching) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* didFinishLaunching =
-      [NSNotification notificationWithName:NSApplicationDidFinishLaunchingNotification object:nil];
-  [registrar handleDidFinishLaunching:didFinishLaunching];
-  EXPECT_EQ([delegate lastNotification], didFinishLaunching);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToWillBecomeActive) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* willBecomeActive =
-      [NSNotification notificationWithName:NSApplicationWillBecomeActiveNotification object:nil];
-  [registrar handleWillBecomeActive:willBecomeActive];
-  EXPECT_EQ([delegate lastNotification], willBecomeActive);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToDidBecomeActive) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* didBecomeActive =
-      [NSNotification notificationWithName:NSApplicationDidBecomeActiveNotification object:nil];
-  [registrar handleDidBecomeActive:didBecomeActive];
-  EXPECT_EQ([delegate lastNotification], didBecomeActive);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToWillResignActive) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* willResignActive =
-      [NSNotification notificationWithName:NSApplicationWillResignActiveNotification object:nil];
-  [registrar handleWillResignActive:willResignActive];
-  EXPECT_EQ([delegate lastNotification], willResignActive);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToDidResignActive) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* didResignActive =
-      [NSNotification notificationWithName:NSApplicationDidResignActiveNotification object:nil];
-  [registrar handleDidResignActive:didResignActive];
-  EXPECT_EQ([delegate lastNotification], didResignActive);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToWillTerminate) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* applicationWillTerminate =
-      [NSNotification notificationWithName:NSApplicationWillTerminateNotification object:nil];
-  [registrar handleWillTerminate:applicationWillTerminate];
-  EXPECT_EQ([delegate lastNotification], applicationWillTerminate);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToWillHide) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* willHide = [NSNotification notificationWithName:NSApplicationWillHideNotification
-                                                           object:nil];
-  [registrar handleWillHide:willHide];
-  EXPECT_EQ([delegate lastNotification], willHide);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToWillUnhide) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* willUnhide =
-      [NSNotification notificationWithName:NSApplicationWillUnhideNotification object:nil];
-  [registrar handleWillUnhide:willUnhide];
-  EXPECT_EQ([delegate lastNotification], willUnhide);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToDidHide) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* didHide = [NSNotification notificationWithName:NSApplicationDidHideNotification
-                                                          object:nil];
-  [registrar handleDidHide:didHide];
-  EXPECT_EQ([delegate lastNotification], didHide);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToDidUnhide) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* didUnhide =
-      [NSNotification notificationWithName:NSApplicationDidUnhideNotification object:nil];
-  [registrar handleDidUnhide:didUnhide];
-  EXPECT_EQ([delegate lastNotification], didUnhide);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToDidChangeScreenParameters) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* didChangeScreenParameters =
-      [NSNotification notificationWithName:NSApplicationDidChangeScreenParametersNotification
-                                    object:nil];
-  [registrar handleDidChangeScreenParameters:didChangeScreenParameters];
-  EXPECT_EQ([delegate lastNotification], didChangeScreenParameters);
-}
-
-TEST(FlutterAppLifecycleDelegateTest, RespondsToDidChangeOcclusionState) {
-  FlutterAppLifecycleRegistrar* registrar = [[FlutterAppLifecycleRegistrar alloc] init];
-  TestFlutterAppLifecycleDelegate* delegate = [[TestFlutterAppLifecycleDelegate alloc] init];
-  [registrar addDelegate:delegate];
-
-  NSNotification* didChangeOcclusionState =
-      [NSNotification notificationWithName:NSApplicationDidChangeOcclusionStateNotification
-                                    object:nil];
-  if ([registrar respondsToSelector:@selector(handleDidChangeOcclusionState:)]) {
-    [registrar handleDidChangeOcclusionState:didChangeOcclusionState];
-    EXPECT_EQ([delegate lastNotification], didChangeOcclusionState);
-  }
-}
-
-}  // namespace flutter::testing

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine.mm

@@ -9,7 +9,6 @@
 #include <iostream>
 #include <vector>
 
-#include "flutter/shell/platform/common/app_lifecycle_state.h"
 #include "flutter/shell/platform/common/engine_switches.h"
 #include "flutter/shell/platform/embedder/embedder.h"
 
@@ -25,8 +24,6 @@
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterViewEngineProvider.h"
 
 NSString* const kFlutterPlatformChannel = @"flutter/platform";
-NSString* const kFlutterSettingsChannel = @"flutter/settings";
-NSString* const kFlutterLifecycleChannel = @"flutter/lifecycle";
 
 /**
  * Constructs and returns a FlutterLocale struct corresponding to |locale|, which must outlive
@@ -176,7 +173,8 @@ constexpr char kTextPlainFormat[] = "text/plain";
   _terminator = terminator ? terminator : ^(id sender) {
     // Default to actually terminating the application. The terminator exists to
     // allow tests to override it so that an actual exit doesn't occur.
-    [[NSApplication sharedApplication] terminate:sender];
+    NSApplication* flutterApp = [NSApplication sharedApplication];
+    [flutterApp terminate:sender];
   };
   FlutterAppDelegate* appDelegate =
       (FlutterAppDelegate*)[[NSApplication sharedApplication] delegate];
@@ -392,14 +390,7 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
 
   FlutterThreadSynchronizer* _threadSynchronizer;
 
-  // The next available view ID.
   int _nextViewId;
-
-  // Whether the application is currently the active application.
-  BOOL _active;
-
-  // Whether any portion of the application is currently visible.
-  BOOL _visible;
 }
 
 - (instancetype)initWithName:(NSString*)labelPrefix project:(FlutterDartProject*)project {
@@ -411,8 +402,7 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
       allowHeadlessExecution:(BOOL)allowHeadlessExecution {
   self = [super init];
   NSAssert(self, @"Super init cannot be nil");
-  _active = NO;
+
-  _visible = NO;
   _project = project ?: [[FlutterDartProject alloc] init];
   _messengerHandlers = [[NSMutableDictionary alloc] init];
   _currentMessengerConnection = 1;
@@ -443,19 +433,11 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
   [self setUpPlatformViewChannel];
   [self setUpAccessibilityChannel];
   [self setUpNotificationCenterListeners];
-  FlutterAppDelegate* appDelegate =
-      reinterpret_cast<FlutterAppDelegate*>([[NSApplication sharedApplication] delegate]);
-  [appDelegate addApplicationLifecycleDelegate:self];
 
   return self;
 }
 
 - (void)dealloc {
-  FlutterAppDelegate* appDelegate =
-      reinterpret_cast<FlutterAppDelegate*>([[NSApplication sharedApplication] delegate]);
-  if (appDelegate != nil) {
-    [appDelegate removeApplicationLifecycleDelegate:self];
-  }
   @synchronized(_isResponseValid) {
     [_isResponseValid removeAllObjects];
     [_isResponseValid addObject:@NO];
@@ -1015,11 +997,11 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
   [FlutterMouseCursorPlugin registerWithRegistrar:[self registrarForPlugin:@"mousecursor"]];
   [FlutterMenuPlugin registerWithRegistrar:[self registrarForPlugin:@"menu"]];
   _settingsChannel =
-      [FlutterBasicMessageChannel messageChannelWithName:kFlutterSettingsChannel
+      [FlutterBasicMessageChannel messageChannelWithName:@"flutter/settings"
                                          binaryMessenger:self.binaryMessenger
                                                    codec:[FlutterJSONMessageCodec sharedInstance]];
   _platformChannel =
-      [FlutterMethodChannel methodChannelWithName:kFlutterPlatformChannel
+      [FlutterMethodChannel methodChannelWithName:@"flutter/platform"
                                   binaryMessenger:self.binaryMessenger
                                             codec:[FlutterJSONMethodCodec sharedInstance]];
   [_platformChannel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
@@ -1077,7 +1059,7 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
 }
 - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
   if ([call.method isEqualToString:@"SystemNavigator.pop"]) {
-    [[NSApplication sharedApplication] terminate:self];
+    [NSApp terminate:self];
     result(nil);
   } else if ([call.method isEqualToString:@"SystemSound.play"]) {
     [self playSystemSound:call.arguments];
@@ -1139,60 +1121,6 @@ static void OnPlatformMessage(const FlutterPlatformMessage* message, FlutterEngi
   return _threadSynchronizer;
 }
 
-#pragma mark - FlutterAppLifecycleDelegate
-
-- (void)setApplicationState:(flutter::AppLifecycleState)state {
-  NSString* nextState =
-      [[NSString alloc] initWithCString:flutter::AppLifecycleStateToString(state)];
-  [self sendOnChannel:kFlutterLifecycleChannel
-              message:[nextState dataUsingEncoding:NSUTF8StringEncoding]];
-}
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationWillBecomeActive
- * notification.
- */
-- (void)handleWillBecomeActive:(NSNotification*)notification {
-  _active = YES;
-  if (!_visible) {
-    [self setApplicationState:flutter::AppLifecycleState::kHidden];
-  } else {
-    [self setApplicationState:flutter::AppLifecycleState::kResumed];
-  }
-}
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationWillResignActive
- * notification.
- */
-- (void)handleWillResignActive:(NSNotification*)notification {
-  _active = NO;
-  if (!_visible) {
-    [self setApplicationState:flutter::AppLifecycleState::kHidden];
-  } else {
-    [self setApplicationState:flutter::AppLifecycleState::kInactive];
-  }
-}
-
-/**
- * Called when the |FlutterAppDelegate| gets the applicationDidUnhide
- * notification.
- */
-- (void)handleDidChangeOcclusionState:(NSNotification*)notification API_AVAILABLE(macos(10.9)) {
-  NSApplicationOcclusionState occlusionState = [[NSApplication sharedApplication] occlusionState];
-  if (occlusionState & NSApplicationOcclusionStateVisible) {
-    _visible = YES;
-    if (_active) {
-      [self setApplicationState:flutter::AppLifecycleState::kResumed];
-    } else {
-      [self setApplicationState:flutter::AppLifecycleState::kInactive];
-    }
-  } else {
-    _visible = NO;
-    [self setApplicationState:flutter::AppLifecycleState::kHidden];
-  }
-}
-
 #pragma mark - FlutterBinaryMessenger
 
 - (void)sendOnChannel:(nonnull NSString*)channel message:(nullable NSData*)message {

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterEngineTest.mm

@@ -805,75 +805,55 @@ TEST_F(FlutterEngineTest, HandleAccessibilityEvent) {
   EXPECT_TRUE(announced);
 }
 
-TEST_F(FlutterEngineTest, HandleLifecycleStates) API_AVAILABLE(macos(10.9)) {
+TEST_F(FlutterEngineTest, RunWithEntrypointUpdatesDisplayConfig) {
-  __block flutter::AppLifecycleState sentState;
+  BOOL updated = NO;
-  id engineMock = CreateMockFlutterEngine(nil);
+  FlutterEngine* engine = GetFlutterEngine();
-
+  auto original_update_displays = engine.embedderAPI.NotifyDisplayUpdate;
-  // Have to enumerate all the values because OCMStub can't capture
+  engine.embedderAPI.NotifyDisplayUpdate = MOCK_ENGINE_PROC(
-  // non-Objective-C object arguments.
+      NotifyDisplayUpdate, ([&updated, &original_update_displays](
-  OCMStub([engineMock setApplicationState:flutter::AppLifecycleState::kDetached])
+                                auto engine, auto update_type, auto* displays, auto display_count) {
-      .andDo((^(NSInvocation* invocation) {
+        updated = YES;
-        sentState = flutter::AppLifecycleState::kDetached;
+        return original_update_displays(engine, update_type, displays, display_count);
-      }));
-  OCMStub([engineMock setApplicationState:flutter::AppLifecycleState::kResumed])
-      .andDo((^(NSInvocation* invocation) {
-        sentState = flutter::AppLifecycleState::kResumed;
-      }));
-  OCMStub([engineMock setApplicationState:flutter::AppLifecycleState::kInactive])
-      .andDo((^(NSInvocation* invocation) {
-        sentState = flutter::AppLifecycleState::kInactive;
-      }));
-  OCMStub([engineMock setApplicationState:flutter::AppLifecycleState::kHidden])
-      .andDo((^(NSInvocation* invocation) {
-        sentState = flutter::AppLifecycleState::kHidden;
-      }));
-  OCMStub([engineMock setApplicationState:flutter::AppLifecycleState::kPaused])
-      .andDo((^(NSInvocation* invocation) {
-        sentState = flutter::AppLifecycleState::kPaused;
       }));
 
-  __block NSApplicationOcclusionState visibility = NSApplicationOcclusionStateVisible;
+  EXPECT_TRUE([engine runWithEntrypoint:@"main"]);
-  id mockApplication = OCMPartialMock([NSApplication sharedApplication]);
+  EXPECT_TRUE(updated);
-  OCMStub((NSApplicationOcclusionState)[mockApplication occlusionState])
-      .andDo(^(NSInvocation* invocation) {
-        [invocation setReturnValue:&visibility];
-      });
 
-  NSNotification* willBecomeActive =
+  updated = NO;
-      [[NSNotification alloc] initWithName:NSApplicationWillBecomeActiveNotification
+  [[NSNotificationCenter defaultCenter]
-                                    object:nil
+      postNotificationName:NSApplicationDidChangeScreenParametersNotification
-                                  userInfo:nil];
+                    object:nil];
-  NSNotification* willResignActive =
+  EXPECT_TRUE(updated);
-      [[NSNotification alloc] initWithName:NSApplicationWillResignActiveNotification
+}
-                                    object:nil
-                                  userInfo:nil];
 
-  NSNotification* didChangeOcclusionState;
+TEST_F(FlutterEngineTest, NotificationsUpdateDisplays) {
-  didChangeOcclusionState =
+  BOOL updated = NO;
-      [[NSNotification alloc] initWithName:NSApplicationDidChangeOcclusionStateNotification
+  FlutterEngine* engine = GetFlutterEngine();
-                                    object:nil
+  auto original_set_viewport_metrics = engine.embedderAPI.SendWindowMetricsEvent;
-                                  userInfo:nil];
+  engine.embedderAPI.SendWindowMetricsEvent = MOCK_ENGINE_PROC(
+      SendWindowMetricsEvent,
+      ([&updated, &original_set_viewport_metrics](auto engine, auto* window_metrics) {
+        updated = YES;
+        return original_set_viewport_metrics(engine, window_metrics);
+      }));
 
-  [engineMock handleDidChangeOcclusionState:didChangeOcclusionState];
+  EXPECT_TRUE([engine runWithEntrypoint:@"main"]);
-  EXPECT_EQ(sentState, flutter::AppLifecycleState::kInactive);
 
-  [engineMock handleWillBecomeActive:willBecomeActive];
+  updated = NO;
-  EXPECT_EQ(sentState, flutter::AppLifecycleState::kResumed);
+  [[NSNotificationCenter defaultCenter] postNotificationName:NSWindowDidChangeScreenNotification
+                                                      object:nil];
+  // No VC.
+  EXPECT_FALSE(updated);
 
-  [engineMock handleWillResignActive:willResignActive];
+  FlutterViewController* viewController = [[FlutterViewController alloc] initWithEngine:engine
-  EXPECT_EQ(sentState, flutter::AppLifecycleState::kInactive);
+                                                                                nibName:nil
+                                                                                 bundle:nil];
+  [viewController loadView];
+  viewController.flutterView.frame = CGRectMake(0, 0, 800, 600);
 
-  visibility = 0;
+  [[NSNotificationCenter defaultCenter] postNotificationName:NSWindowDidChangeScreenNotification
-  [engineMock handleDidChangeOcclusionState:didChangeOcclusionState];
+                                                      object:nil];
-  EXPECT_EQ(sentState, flutter::AppLifecycleState::kHidden);
+  EXPECT_TRUE(updated);
-
-  [engineMock handleWillBecomeActive:willBecomeActive];
-  EXPECT_EQ(sentState, flutter::AppLifecycleState::kHidden);
-
-  [engineMock handleWillResignActive:willResignActive];
-  EXPECT_EQ(sentState, flutter::AppLifecycleState::kHidden);
-
-  [mockApplication stopMocking];
 }
 
 }  // namespace flutter::testing

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine_Internal.h

@@ -8,8 +8,6 @@
 
 #include <memory>
 
-#include "flutter/shell/platform/common/app_lifecycle_state.h"
-
 #import "flutter/shell/platform/darwin/macos/framework/Source/AccessibilityBridgeMac.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterCompositor.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterPlatformViewController.h"
@@ -174,14 +172,6 @@ typedef NS_ENUM(NSInteger, FlutterAppExitResponse) {
 
 - (nonnull FlutterPlatformViewController*)platformViewController;
 
-/**
- * Handles changes to the application state, sending them to the framework.
- *
- * @param state One of the lifecycle constants in app_lifecycle_state.h,
- *              corresponding to the Dart enum AppLifecycleState.
- */
-- (void)setApplicationState:(flutter::AppLifecycleState)state;
-
 // Accessibility API.
 
 /**

engine/src/flutter/shell/platform/linux/BUILD.gn

@@ -158,7 +158,6 @@ source_set("flutter_linux_sources") {
   ]
 
   deps = [
-    "//flutter/shell/platform/common:common_cpp_enums",
     "//flutter/shell/platform/common:common_cpp_input",
     "//flutter/shell/platform/common:common_cpp_switches",
     "//flutter/shell/platform/embedder:embedder_headers",
@@ -258,7 +257,6 @@ executable("flutter_linux_unittests") {
     ":flutter_linux_gschemas",
     ":flutter_linux_sources",
     "//flutter/runtime:libdart",
-    "//flutter/shell/platform/common:common_cpp_enums",
     "//flutter/shell/platform/embedder:embedder_headers",
     "//flutter/shell/platform/embedder:embedder_test_utils",
     "//flutter/testing",

engine/src/flutter/shell/platform/linux/fl_engine.cc

@@ -10,7 +10,6 @@
 #include <string>
 #include <vector>
 
-#include "flutter/shell/platform/common/app_lifecycle_state.h"
 #include "flutter/shell/platform/common/engine_switches.h"
 #include "flutter/shell/platform/embedder/embedder.h"
 #include "flutter/shell/platform/linux/fl_binary_messenger_private.h"
@@ -24,7 +23,6 @@
 #include "flutter/shell/platform/linux/fl_texture_gl_private.h"
 #include "flutter/shell/platform/linux/fl_texture_registrar_private.h"
 #include "flutter/shell/platform/linux/public/flutter_linux/fl_plugin_registry.h"
-#include "flutter/shell/platform/linux/public/flutter_linux/fl_string_codec.h"
 
 // Unique number associated with platform tasks.
 static constexpr size_t kPlatformTaskRunnerIdentifier = 1;
@@ -34,8 +32,6 @@ static constexpr size_t kPlatformTaskRunnerIdentifier = 1;
 static constexpr int32_t kMousePointerDeviceId = 0;
 static constexpr int32_t kPointerPanZoomDeviceId = 1;
 
-static constexpr const char* kFlutterLifecycleChannel = "flutter/lifecycle";
-
 struct _FlEngine {
   GObject parent_instance;
 
@@ -126,25 +122,6 @@ static void parse_locale(const gchar* locale,
   }
 }
 
-static void set_app_lifecycle_state(FlEngine* self,
-                                    const flutter::AppLifecycleState state) {
-  FlBinaryMessenger* binary_messenger = fl_engine_get_binary_messenger(self);
-
-  g_autoptr(FlValue) value =
-      fl_value_new_string(flutter::AppLifecycleStateToString(state));
-  g_autoptr(FlStringCodec) codec = fl_string_codec_new();
-  g_autoptr(GBytes) message =
-      fl_message_codec_encode_message(FL_MESSAGE_CODEC(codec), value, nullptr);
-
-  if (message == nullptr) {
-    return;
-  }
-
-  fl_binary_messenger_send_on_channel(binary_messenger,
-                                      kFlutterLifecycleChannel, message,
-                                      nullptr, nullptr, nullptr);
-}
-
 // Passes locale information to the Flutter engine.
 static void setup_locales(FlEngine* self) {
   const gchar* const* languages = g_get_language_names();
@@ -744,18 +721,6 @@ GBytes* fl_engine_send_platform_message_finish(FlEngine* self,
   return static_cast<GBytes*>(g_task_propagate_pointer(G_TASK(result), error));
 }
 
-void fl_engine_send_window_state_event(FlEngine* self,
-                                       gboolean visible,
-                                       gboolean focused) {
-  if (visible && focused) {
-    set_app_lifecycle_state(self, flutter::AppLifecycleState::kResumed);
-  } else if (visible) {
-    set_app_lifecycle_state(self, flutter::AppLifecycleState::kInactive);
-  } else {
-    set_app_lifecycle_state(self, flutter::AppLifecycleState::kHidden);
-  }
-}
-
 void fl_engine_send_window_metrics_event(FlEngine* self,
                                          size_t width,
                                          size_t height,

engine/src/flutter/shell/platform/linux/fl_engine_private.h

@@ -167,18 +167,6 @@ void fl_engine_send_window_metrics_event(FlEngine* engine,
                                          size_t height,
                                          double pixel_ratio);
 
-/**
- * fl_engine_send_window_state_event:
- * @engine: an #FlEngine.
- * @visible: whether the window is currently visible or not.
- * @focused: whether the window is currently focused or not.
- *
- * Sends a window state event to the engine.
- */
-void fl_engine_send_window_state_event(FlEngine* engine,
-                                       gboolean visible,
-                                       gboolean focused);
-
 /**
  * fl_engine_send_mouse_pointer_event:
  * @engine: an #FlEngine.

engine/src/flutter/shell/platform/linux/fl_engine_test.cc

@@ -5,12 +5,10 @@
 // Included first as it collides with the X11 headers.
 #include "gtest/gtest.h"
 
-#include "flutter/shell/platform/common/app_lifecycle_state.h"
 #include "flutter/shell/platform/embedder/test_utils/proc_table_replacement.h"
 #include "flutter/shell/platform/linux/fl_engine_private.h"
 #include "flutter/shell/platform/linux/public/flutter_linux/fl_engine.h"
 #include "flutter/shell/platform/linux/public/flutter_linux/fl_json_message_codec.h"
-#include "flutter/shell/platform/linux/public/flutter_linux/fl_string_codec.h"
 #include "flutter/shell/platform/linux/testing/fl_test.h"
 
 // MOCK_ENGINE_PROC is leaky by design
@@ -425,42 +423,6 @@ TEST(FlEngineTest, SwitchesEmpty) {
   EXPECT_EQ(switches->len, 0U);
 }
 
-TEST(FlEngineTest, SendWindowStateEvent) {
-  g_autoptr(FlEngine) engine = make_mock_engine();
-  FlutterEngineProcTable* embedder_api = fl_engine_get_embedder_api(engine);
-
-  bool called = false;
-  std::string state;
-  embedder_api->SendPlatformMessage = MOCK_ENGINE_PROC(
-      SendPlatformMessage,
-      ([&called, &state](auto engine, const FlutterPlatformMessage* message) {
-        EXPECT_STREQ(message->channel, "flutter/lifecycle");
-        called = true;
-        g_autoptr(FlStringCodec) codec = fl_string_codec_new();
-        g_autoptr(GBytes) data =
-            g_bytes_new(message->message, message->message_size);
-        g_autoptr(GError) error = nullptr;
-        g_autoptr(FlValue) parsed_state = fl_message_codec_decode_message(
-            FL_MESSAGE_CODEC(codec), data, &error);
-
-        state = fl_value_get_string(parsed_state);
-        return kSuccess;
-      }));
-  fl_engine_send_window_state_event(engine, false, false);
-  EXPECT_STREQ(state.c_str(), flutter::AppLifecycleStateToString(
-                                  flutter::AppLifecycleState::kHidden));
-  fl_engine_send_window_state_event(engine, false, true);
-  EXPECT_STREQ(state.c_str(), flutter::AppLifecycleStateToString(
-                                  flutter::AppLifecycleState::kHidden));
-  fl_engine_send_window_state_event(engine, true, false);
-  EXPECT_STREQ(state.c_str(), flutter::AppLifecycleStateToString(
-                                  flutter::AppLifecycleState::kInactive));
-  fl_engine_send_window_state_event(engine, true, true);
-  EXPECT_STREQ(state.c_str(), flutter::AppLifecycleStateToString(
-                                  flutter::AppLifecycleState::kResumed));
-  EXPECT_TRUE(called);
-}
-
 #ifndef FLUTTER_RELEASE
 TEST(FlEngineTest, Switches) {
   g_autoptr(FlEngine) engine = make_mock_engine();

engine/src/flutter/shell/platform/linux/fl_view.cc

@@ -42,9 +42,6 @@ struct _FlView {
   // Pointer button state recorded for sending status updates.
   int64_t button_state;
 
-  // Current state information for the window associated with this view.
-  GdkWindowState window_state;
-
   // Flutter system channel handlers.
   FlAccessibilityPlugin* accessibility_plugin;
   FlKeyboardManager* keyboard_manager;
@@ -62,9 +59,7 @@ struct _FlView {
   /* FlKeyboardViewDelegate related properties */
   KeyboardLayoutNotifier keyboard_layout_notifier;
   GdkKeymap* keymap;
-  gulong keymap_keys_changed_cb_id;  // Signal connection ID for
+  gulong keymap_keys_changed_cb_id;  // Signal connection ID.
-                                     // keymap-keys-changed
-  gulong window_state_cb_id;  // Signal connection ID for window-state-changed
 };
 
 enum { kPropFlutterProject = 1, kPropLast };
@@ -240,8 +235,6 @@ static void on_pre_engine_restart_cb(FlEngine* engine, gpointer user_data) {
   g_clear_object(&self->scrolling_manager);
   init_keyboard(self);
   init_scrolling(self);
-  self->window_state =
-      gdk_window_get_state(gtk_widget_get_window(GTK_WIDGET(self)));
 }
 
 // Implements FlPluginRegistry::get_registrar_for_plugin.
@@ -487,42 +480,12 @@ static void gesture_zoom_end_cb(GtkGestureZoom* gesture,
   fl_scrolling_manager_handle_zoom_end(self->scrolling_manager);
 }
 
-static gboolean window_state_event_cb(GtkWidget* widget,
-                                      GdkEvent* event,
-                                      gpointer user_data) {
-  g_return_val_if_fail(FL_IS_VIEW(user_data), FALSE);
-  g_return_val_if_fail(FL_IS_ENGINE(FL_VIEW(user_data)->engine), FALSE);
-  FlView* self = FL_VIEW(user_data);
-  GdkWindowState state = event->window_state.new_window_state;
-  GdkWindowState previous_state = self->window_state;
-  self->window_state = state;
-  bool was_visible = !((previous_state & GDK_WINDOW_STATE_WITHDRAWN) ||
-                       (previous_state & GDK_WINDOW_STATE_ICONIFIED));
-  bool is_visible = !((state & GDK_WINDOW_STATE_WITHDRAWN) ||
-                      (state & GDK_WINDOW_STATE_ICONIFIED));
-  bool was_focused = (previous_state & GDK_WINDOW_STATE_FOCUSED);
-  bool is_focused = (state & GDK_WINDOW_STATE_FOCUSED);
-  if (was_visible != is_visible || was_focused != is_focused) {
-    if (self->engine != nullptr) {
-      fl_engine_send_window_state_event(FL_ENGINE(self->engine), is_visible,
-                                        is_focused);
-    }
-  }
-  return FALSE;
-}
-
 static void realize_cb(GtkWidget* widget) {
   FlView* self = FL_VIEW(widget);
   g_autoptr(GError) error = nullptr;
 
   // Handle requests by the user to close the application.
   GtkWidget* toplevel_window = gtk_widget_get_toplevel(GTK_WIDGET(self));
-
-  // Listen to window state changes.
-  self->window_state_cb_id =
-      g_signal_connect(toplevel_window, "window-state-event",
-                       G_CALLBACK(window_state_event_cb), self);
-
   g_signal_connect(toplevel_window, "delete-event",
                    G_CALLBACK(window_delete_event_cb), self);
 
@@ -661,12 +624,6 @@ static void fl_view_dispose(GObject* object) {
                                                 nullptr);
   }
 
-  if (self->window_state_cb_id != 0) {
-    GtkWidget* toplevel_window = gtk_widget_get_toplevel(GTK_WIDGET(self));
-    g_signal_handler_disconnect(toplevel_window, self->window_state_cb_id);
-    self->window_state_cb_id = 0;
-  }
-
   g_clear_object(&self->project);
   g_clear_object(&self->renderer);
   g_clear_object(&self->engine);
@@ -726,8 +683,6 @@ static void fl_view_class_init(FlViewClass* klass) {
 
 static void fl_view_init(FlView* self) {
   gtk_widget_set_can_focus(GTK_WIDGET(self), TRUE);
-  self->window_state = gdk_window_get_state(
-      gtk_widget_get_window(gtk_widget_get_toplevel(GTK_WIDGET(self))));
 }
 
 G_MODULE_EXPORT FlView* fl_view_new(FlDartProject* project) {

engine/src/flutter/shell/platform/windows/BUILD.gn

@@ -129,7 +129,6 @@ source_set("flutter_windows_source") {
   public_deps = [
     "//flutter/fml:string_conversion",
     "//flutter/shell/platform/common:common_cpp_accessibility",
-    "//flutter/shell/platform/common:common_cpp_enums",
   ]
 
   deps = [

engine/src/flutter/shell/platform/windows/flutter_windows_engine.cc

@@ -397,7 +397,6 @@ bool FlutterWindowsEngine::Run(std::string_view entrypoint) {
                                     displays.data(), displays.size());
 
   SendSystemLocales();
-  SetLifecycleState(flutter::AppLifecycleState::kResumed);
 
   settings_plugin_->StartWatching();
   settings_plugin_->SendSettings();
@@ -563,13 +562,6 @@ void FlutterWindowsEngine::SetNextFrameCallback(fml::closure callback) {
       this);
 }
 
-void FlutterWindowsEngine::SetLifecycleState(flutter::AppLifecycleState state) {
-  const char* state_name = flutter::AppLifecycleStateToString(state);
-  SendPlatformMessage("flutter/lifecycle",
-                      reinterpret_cast<const uint8_t*>(state_name),
-                      strlen(state_name), nullptr, nullptr);
-}
-
 void FlutterWindowsEngine::SendSystemLocales() {
   std::vector<LanguageInfo> languages =
       GetPreferredLanguageInfo(*windows_registry_);

engine/src/flutter/shell/platform/windows/flutter_windows_engine.h

@@ -16,7 +16,6 @@
 #include "flutter/fml/closure.h"
 #include "flutter/fml/macros.h"
 #include "flutter/shell/platform/common/accessibility_bridge.h"
-#include "flutter/shell/platform/common/app_lifecycle_state.h"
 #include "flutter/shell/platform/common/client_wrapper/binary_messenger_impl.h"
 #include "flutter/shell/platform/common/client_wrapper/include/flutter/basic_message_channel.h"
 #include "flutter/shell/platform/common/incoming_message_dispatcher.h"
@@ -307,9 +306,6 @@ class FlutterWindowsEngine {
   // system changes.
   void SendSystemLocales();
 
-  // Sends the current lifecycle state to the framework.
-  void SetLifecycleState(flutter::AppLifecycleState state);
-
   // Create the keyboard & text input sub-systems.
   //
   // This requires that a view is attached to the engine.

engine/src/flutter/tools/api_check/test/apicheck_test.dart

@@ -43,6 +43,10 @@ void checkApiConsistency(String flutterRoot) {
       sourcePath: path.join(flutterRoot, 'lib', 'ui', 'window.dart'),
       className: 'AccessibilityFeatures',
     );
+    final List<String> webuiFields = getDartClassFields(
+      sourcePath: path.join(flutterRoot, 'lib', 'ui', 'window.dart'),
+      className: 'AccessibilityFeatures',
+    );
     // C values: kFlutterAccessibilityFeatureFooBar = 1 << N,
     final List<String> embedderEnumValues = getCppEnumValues(
       sourcePath: path.join(flutterRoot, 'shell', 'platform', 'embedder', 'embedder.h'),
@@ -60,6 +64,7 @@ void checkApiConsistency(String flutterRoot) {
       enumName: 'AccessibilityFeature',
     ).map(allCapsToCamelCase).toList();
 
+    expect(webuiFields, uiFields);
     expect(embedderEnumValues, uiFields);
     expect(internalEnumValues, uiFields);
     expect(javaEnumValues, uiFields);
@@ -72,7 +77,7 @@ void checkApiConsistency(String flutterRoot) {
       className: 'SemanticsAction',
     );
     final List<String> webuiFields = getDartClassFields(
-      sourcePath: path.join(flutterRoot, 'lib', 'web_ui', 'lib', 'semantics.dart'),
+      sourcePath: path.join(flutterRoot, 'lib', 'ui', 'semantics.dart'),
       className: 'SemanticsAction',
     );
     // C values: kFlutterSemanticsActionFooBar = 1 << N.
@@ -98,33 +103,6 @@ void checkApiConsistency(String flutterRoot) {
     expect(javaEnumValues, uiFields);
   });
 
-  test('AppLifecycleState enums match', () {
-    // Dart values: _kFooBarIndex = 1 << N.
-    final List<String> uiFields = getDartClassFields(
-      sourcePath: path.join(flutterRoot, 'lib', 'ui', 'platform_dispatcher.dart'),
-      className: 'AppLifecycleState',
-    );
-    final List<String> webuiFields = getDartClassFields(
-      sourcePath: path.join(flutterRoot, 'lib', 'web_ui', 'lib', 'platform_dispatcher.dart'),
-      className: 'AppLifecycleState',
-    );
-    // C++ values: kFooBar = 1 << N.
-    final List<String> internalEnumValues = getCppEnumClassValues(
-      sourcePath: path.join(flutterRoot, 'shell', 'platform', 'common', 'app_lifecycle_state.h'),
-      enumName: 'AppLifecycleState',
-    );
-    // Java values: FOO_BAR(1 << N).
-    final List<String> javaEnumValues = getJavaEnumValues(
-      sourcePath: path.join(flutterRoot, 'shell', 'platform', 'android', 'io',
-          'flutter', 'embedding', 'engine', 'systemchannels', 'LifecycleChannel.java'),
-      enumName: 'AppLifecycleState',
-    ).map(allCapsToCamelCase).toList();
-
-    expect(webuiFields, uiFields);
-    expect(internalEnumValues, uiFields);
-    expect(javaEnumValues, uiFields);
-  });
-
   test('SemanticsFlag enums match', () {
     // Dart values: _kFooBarIndex = 1 << N.
     final List<String> uiFields = getDartClassFields(