fix(ios): adopt FlutterSceneLifeCycleDelegate for UIScene deep link support

[Kobikg78]

Summary

Fixes deep link breakage on iOS apps using Flutter 3.41+ (DELIVERY-114618).

Problem

Flutter 3.41 auto-migrates apps to UIScene by default. When UIScene is active, UIKit routes deep links through the scene delegate (scene:openURLContexts:, scene:willConnectToSession:options:) rather than the traditional AppDelegate methods (application:openURL:options:). The plugin only implemented the AppDelegate path, causing deep links to be silently dropped.

Fix

AppsflyerSdkPlugin now conforms to FlutterSceneLifeCycleDelegate and registers via [registrar addSceneDelegate:instance] (iOS 13+). Three new methods added:

• scene:willConnectToSession:options: — cold-start URI-scheme deep links
• scene:openURLContexts: — warm-start URI-scheme deep links
• scene:continueUserActivity: — Universal Links via UIScene

No app-side changes required.

Testing

• Reproduced the bug on iOS 18.4 simulator + Flutter 3.41.4 (confirmed broken delegate chain via system logs)
• Verified fix: scene:willConnectToSession:options: fires before startSDK, onDeepLinking Status.FOUND delivered correctly
• Full E2E: 40/40 checks passed (Android + iOS 18.4, all 3 phases)

Fixes: DELIVERY-114618

[Dani-Koza-AF]

Deprecated getViewController not fixed - ios/Classes/AppsflyerSdkPlugin.m
Line 908-912 still uses UIApplication.delegate.window which returns nil under UIScene:

+ (FlutterViewController*) getViewController{
    UIViewController *topMostViewControllerObj =  [[[UIApplication sharedApplication] delegate] window].rootViewController;
    FlutterViewController *flutterViewController = (FlutterViewController *)topMostViewControllerObj;
    return flutterViewController;
}

While not directly related to deep linking, this is a ticking time bomb for any code path that calls it under UIScene.

[Dani-Koza-AF]

Per the Flutter migration guide for plugins, the minimum Flutter SDK should be bumped to >=3.38.0 (or the protocol adoption must be compile-time guarded). Currently i see it's flutter: ">=1.10.0" you might have to take care of it too.

[Kobikg78]

Fixed in commit 2317776. getViewController now iterates [UIApplication sharedApplication].connectedScenes to find the foreground-active UIWindowScene, then falls back to delegate.window on iOS < 13.

[Kobikg78]

Addressed in commit 783530c with a compile-time #if __has_include guard instead of raising the minimum Flutter version. The pubspec.yaml stays at flutter: ">=1.10.0" — Flutter <3.38 builds silently skip the UIScene delegate adoption, while Flutter >=3.38 gets the full fix. No breaking change for existing users.

[Kobikg78]

Replying to #438 (comment) —

Deprecated getViewController not fixed — still uses UIApplication.delegate.window which returns nil under UIScene.

Fixed. getViewController now uses UIWindowScene.connectedScenes to find the foreground-active scene on iOS 13+, and falls back to delegate.window only on older iOS:

+ (FlutterViewController*) getViewController {
    UIWindow *window = nil;
    if (@available(iOS 13.0, *)) {
        for (UIWindowScene *scene in [UIApplication sharedApplication].connectedScenes) {
            if (scene.activationState == UISceneActivationStateForegroundActive) {
                window = scene.windows.firstObject;
                break;
            }
        }
    }
    if (window == nil) {
        window = [[[UIApplication sharedApplication] delegate] window];
    }
    UIViewController *topMostViewControllerObj = window.rootViewController;
    return (FlutterViewController *)topMostViewControllerObj;
}

[Dani-Koza-AF]

Great work @Kobikg78 !