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sfshaza2 merged 6 commits into from
Jul 20, 2026
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[ios]update uiscene adoption #13560

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[ios]update uiscene adoption
hellohuanlin Jul 7, 2026
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hellohuanlin Jul 14, 2026
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hellohuanlin Jul 17, 2026
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hellohuanlin Jul 17, 2026
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call out nil vc and highlight registrar.vc API
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remove multi scene mentions
hellohuanlin Jul 17, 2026
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278 changes: 133 additions & 145 deletions sites/docs/src/content/release/breaking-changes/uiscenedelegate.md
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Original file line number Diff line number Diff line change
@@ -1,8 +1,8 @@
---
title: UISceneDelegate adoption
title: UIScene adoption
description: >-
Learn how to migrate your Flutter iOS app, add-to-app integration, or plugin
to Apple's required UIScene lifecycle using FlutterSceneDelegate.
to Apple's required UIScene lifecycle.
---

{% render "docs/breaking-changes.md" %}
Expand Down Expand Up @@ -595,143 +595,8 @@ forward scene lifecycle events to Flutter.

### If your app supports multiple scenes

When multiple scenes are enabled (`UIApplicationSupportsMultipleScenes`),
Flutter can't automatically connect a `FlutterEngine` to its
corresponding `UIScene` during the initial scene connection phase.

To ensure that Flutter plugins can receive the initial scene setup options
(such as deep link URLs or shortcut items passed inside the
`UIScene.ConnectionOptions` payload), you must manually register the
`FlutterEngine` with either your `FlutterSceneDelegate` or your
`FlutterPluginSceneLifeCycleDelegate` inside the
`scene:willConnectToSession:options:` method.

If you don't perform this manual registration,
the `FlutterEngine` still registers itself automatically once the view
created by the `FlutterViewController` is added to the active view hierarchy.
However, by that point, the engine and its plugins have already missed
any launch connection events passed during `willConnectToSession:`.

<Tabs key="ios-language-switcher">
<Tab name="Swift">

```swift title="SceneDelegate.swift"
import Flutter
import FlutterPluginRegistrant
import UIKit

class SceneDelegate: FlutterSceneDelegate {
let flutterEngine = FlutterEngine(name: "my flutter engine")

override func scene(
_ scene: UIScene,
willConnectTo session: UISceneSession,
options connectionOptions: UIScene.ConnectionOptions
) {
guard let windowScene = scene as? UIWindowScene else { return }
window = UIWindow(windowScene: windowScene)

flutterEngine.run()
GeneratedPluginRegistrant.register(with: flutterEngine)

// If using FlutterSceneDelegate:
self.registerSceneLifeCycle(with: flutterEngine)

// If using FlutterSceneLifeCycleProvider:
// sceneLifeCycleDelegate.registerSceneLifeCycle(with: flutterEngine)

let viewController = ViewController(engine: flutterEngine)
window?.rootViewController = viewController
window?.makeKeyAndVisible()
super.scene(scene, willConnectTo: session, options: connectionOptions)
}
}
```

</Tab>
<Tab name="Objective-C">

```objc title="SceneDelegate.h"
#import <UIKit/UIKit.h>
#import <Flutter/Flutter.h>
#import <FlutterPluginRegistrant/GeneratedPluginRegistrant.h>

@interface SceneDelegate : FlutterSceneDelegate
@property(nonatomic, strong) FlutterEngine *flutterEngine;
@end
```

```objc title="SceneDelegate.m"
#import "SceneDelegate.h"
#import "ViewController.h"

@implementation SceneDelegate

- (instancetype)init {
if (self = [super init]) {
_flutterEngine = [[FlutterEngine alloc] initWithName:@"my flutter engine"];
}
return self;
}

- (void)scene:(UIScene *)scene
willConnectToSession:(UISceneSession *)session
options:(UISceneConnectionOptions *)connectionOptions {
if (![scene isKindOfClass:[UIWindowScene class]]) {
return;
}
UIWindowScene *windowScene = (UIWindowScene *)scene;
self.window = [[UIWindow alloc] initWithWindowScene:windowScene];

[self.flutterEngine run];
[GeneratedPluginRegistrant registerWithRegistry:self.flutterEngine];

// If using FlutterSceneDelegate:
[self registerSceneLifeCycleWithFlutterEngine:self.flutterEngine];

// If using FlutterSceneLifeCycleProvider:
// [self.sceneLifeCycleDelegate registerSceneLifeCycleWithFlutterEngine:self.flutterEngine];

ViewController *viewController = [[ViewController alloc] initWithEngine:self.flutterEngine];
self.window.rootViewController = viewController;
[self.window makeKeyAndVisible];
[super scene:scene willConnectToSession:session options:connectionOptions];
}

@end
```

</Tab>
</Tabs>

If you manually register a `FlutterEngine` with a scene,
you must also unregister it if the view
created by the `FlutterEngine` changes scenes.

<Tabs key="ios-language-switcher">
<Tab name="Swift">

```swift
// If using FlutterSceneDelegate:
self.unregisterSceneLifeCycle(with: flutterEngine)

// If using FlutterSceneLifeCycleProvider:
sceneLifeCycleDelegate.unregisterSceneLifeCycle(with: flutterEngine)
```

</Tab>
<Tab name="Objective-C">

```objc
// If using FlutterSceneDelegate:
[self unregisterSceneLifeCycleWithFlutterEngine:self.flutterEngine];

// If using FlutterSceneLifeCycleProvider:
[self.sceneLifeCycleDelegate unregisterSceneLifeCycleWithFlutterEngine:self.flutterEngine];
```

</Tab>
</Tabs>
Flutter doesn't fully support multiple scenes yet,
but support is in progress.

<a id="migration-guide-for-flutter-plugins" aria-hidden="true"></a>

Expand Down Expand Up @@ -821,7 +686,6 @@ migrate it to UIKit's scene-based lifecycle as follows:
| [`application:continueUserActivity:restorationHandler:`][] | [`scene:continueUserActivity:`][] |
| [`application:performActionForShortcutItem:completionHandler:`][] | [`windowScene:performActionForShortcutItem:completionHandler:`][] |
| [`application:openURL:options:`][] | [`scene:openURLContexts:`][] |
| [`application:performFetchWithCompletionHandler:`][] | [`BGAppRefreshTask`][] |
| [`application:willFinishLaunchingWithOptions:`][] | [`scene:willConnectToSession:options:`][] |
| [`application:didFinishLaunchingWithOptions:`][] | [`scene:willConnectToSession:options:`][] |

Expand Down Expand Up @@ -911,7 +775,127 @@ migrate it to UIKit's scene-based lifecycle as follows:
Move any logic that relies on the launch options to the
`scene:willConnectToSession:options:` event.

1. Optional: Migrate other deprecated APIs to support
1. If your plugin uses an API that must be called before
`application:didFinishLaunchingWithOptions:` completes,
you should expose a public method that app developers
can call directly in their AppDelegate.

The following Apple APIs must be configured before app launch finishes:

- [`BGTaskScheduler.registerForTaskWithIdentifier:usingQueue:launchHandler:`][]
- [`UNUserNotificationCenterDelegate`][]
- [`HKHealthStore.enableBackgroundDeliveryForType:frequency:withCompletion:`][]

For example, to support `BGTaskScheduler`:

<Tabs key="ios-language-switcher">
Comment thread
sfshaza2 marked this conversation as resolved.
<Tab name="Swift">

```swift diff
// Plugin

public class BGTaskPlugin: NSObject, FlutterPlugin {
public static let shared = BGTaskPlugin()
public static func register(with registrar: FlutterPluginRegistrar) {
let channel = ...
registrar.addMethodCallDelegate(shared, channel: channel)
registrar.addApplicationDelegate(shared)
}
+ // A new API for apps to call in their `AppDelegate`'s `application:didFinishLaunchingWithOptions:`
+ public func registerBackgroundHandler(identifier: String) {
+ BGTaskScheduler.register(forTaskWithIdentifier: identifier, using: .main) { task in
+ // Handle background task execution
+ }
+ }
- public func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [AnyHashable : Any] = [:]) -> Bool {
- BGTaskScheduler.register(forTaskWithIdentifier: identifier, using: .main) { task in
- // Handle background task execution
- }
- return true
- }
}

// App

class AppDelegate: FlutterAppDelegate {
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
+ BGTaskPlugin.shared.registerBackgroundHandler(identifier: "com.example.task")
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
}
```

</Tab>
<Tab name="Objective-C">

```objc diff
// Plugin

@interface BGTaskPlugin : NSObject <FlutterPlugin>
+ + (instancetype)sharedInstance;
+ - (void)registerBackgroundHandlerWithIdentifier:(NSString *)identifier;
@end

@implementation BGTaskPlugin

+ + (instancetype)sharedInstance {
+ static BGTaskPlugin *sharedInstance = nil;
+ static dispatch_once_t onceToken;
+ dispatch_once(&onceToken, ^{
+ sharedInstance = [[BGTaskPlugin alloc] init];
+ });
+ return sharedInstance;
+ }

+ (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
FlutterMethodChannel *channel = ...
[registrar addMethodCallDelegate:[BGTaskPlugin sharedInstance] channel:channel];
[registrar addApplicationDelegate:[BGTaskPlugin sharedInstance]];
}

+ // A new API for apps to call in their `AppDelegate`'s `application:didFinishLaunchingWithOptions:`
+ - (void)registerBackgroundHandlerWithIdentifier:(NSString *)identifier {
+ [[BGTaskScheduler sharedScheduler] registerForTaskWithIdentifier:identifier
+ usingQueue:dispatch_get_main_queue()
+ launchHandler:^(BGTask *task) {
+ // Handle background task execution
+ }];
+ }

- - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
- [[BGTaskScheduler sharedScheduler] registerForTaskWithIdentifier:identifier
- usingQueue:dispatch_get_main_queue()
- launchHandler:^(BGTask *task) {
- // Handle background task execution
- }];
- return YES;
- }
@end

// App

@implementation AppDelegate
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+ [[BGTaskPlugin sharedInstance] registerBackgroundHandlerWithIdentifier:@"com.example.task"];
return [super application:application didFinishLaunchingWithOptions:launchOptions];
}
@end
```

</Tab>
</Tabs>

This change is required due to UIScene changing the app launch
sequence. For apps that adopt `UIScene`, Flutter calls
`application:willFinishLaunchingWithOptions:` and
`application:didFinishLaunchingWithOptions:` during the
`scene:willConnectToSession:options:` callback.

1. Migrate other deprecated APIs to support
multiple scenes in the future.

@vashworth vashworth Jul 17, 2026 •
edited
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Maybe change to

"Migrate other deprecated APIs to properly access the viewController, screen, or window."


| Deprecated API | UIScene replacement |
Expand All @@ -923,8 +907,11 @@ migrate it to UIKit's scene-based lifecycle as follows:

{:.table}

Instead of accessing these APIs,
access the `windowScene` through the `viewController`,
Because `UIApplication.shared.delegate.window` is `nil`
after adopting `UIScene`,
you should access the `viewController`
via the plugin registrar's `viewController` property
and retrieve the window or `windowScene` from there,
as shown in the following examples.

<Tabs key="ios-language-switcher">
Expand Down Expand Up @@ -1022,7 +1009,6 @@ migrate it to UIKit's scene-based lifecycle as follows:
[`application:continueUserActivity:restorationHandler:`]: {{site.apple-dev}}/documentation/uikit/uiapplicationdelegate/1623072-application
[`application:performActionForShortcutItem:completionHandler:`]: {{site.apple-dev}}/documentation/uikit/uiapplicationdelegate/application(_:performactionfor:completionhandler:)
[`application:openURL:options:`]: {{site.apple-dev}}/documentation/uikit/uiapplicationdelegate/1623112-application
[`application:performFetchWithCompletionHandler:`]: {{site.apple-dev}}/documentation/uikit/uiapplicationdelegate/1623125-application
[`application:willFinishLaunchingWithOptions:`]: {{site.apple-dev}}/documentation/uikit/uiapplicationdelegate/1623032-application
[`application:didFinishLaunchingWithOptions:`]: {{site.apple-dev}}/documentation/uikit/uiapplicationdelegate/1622921-application
[`sceneDidBecomeActive`]: {{site.apple-dev}}/documentation/uikit/uiscenedelegate/3197915-scenedidbecomeactive
Expand All @@ -1032,7 +1018,6 @@ migrate it to UIKit's scene-based lifecycle as follows:
[`scene:continueUserActivity:`]: {{site.apple-dev}}/documentation/uikit/uiscenedelegate/scene(_:continue:)
[`windowScene:performActionForShortcutItem:completionHandler:`]: {{site.apple-dev}}/documentation/uikit/uiwindowscenedelegate/3238088-windowscene
[`scene:openURLContexts:`]: {{site.apple-dev}}/documentation/uikit/uiscenedelegate/3238059-scene
[`BGAppRefreshTask`]: {{site.apple-dev}}/documentation/backgroundtasks/bgapprefreshtask
[`scene:willConnectToSession:options:`]: {{site.apple-dev}}/documentation/uikit/uiscenedelegate/3197914-scene
[`UIScreen mainScreen`]: {{site.apple-dev}}/documentation/uikit/uiscreen/1617815-mainscreen
[`UIWindowScene screen`]: {{site.apple-dev}}/documentation/uikit/uiwindowscene/screen?language=objc
Expand All @@ -1042,6 +1027,9 @@ migrate it to UIKit's scene-based lifecycle as follows:
[`UIWindowScene windows`]: {{site.apple-dev}}/documentation/uikit/uiwindowscene/windows?language=objc
[`UIApplicationDelegate window`]: {{site.apple-dev}}/documentation/uikit/uiapplicationdelegate/window
[`UIView window`]: {{site.apple-dev}}/documentation/uikit/uiview/window?language=objc
[`BGTaskScheduler.registerForTaskWithIdentifier:usingQueue:launchHandler:`]: <{{site.apple-dev}}/documentation/backgroundtasks/bgtaskscheduler/register(fortaskwithidentifier:using:launchhandler:)?language=objc>
[`UNUserNotificationCenterDelegate`]: {{site.apple-dev}}/documentation/usernotifications/unusernotificationcenterdelegate?language=objc
[`HKHealthStore.enableBackgroundDeliveryForType:frequency:withCompletion:`]: <{{site.apple-dev}}/documentation/healthkit/hkhealthstore/enablebackgrounddelivery(for:frequency:withcompletion:)?language=objc>

## Bespoke FlutterViewController usage

Expand Down
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