Notes WWDC 2019 : Architecting Your App for Multiple Windows

Référence : Session 258 - Architecting Your App for Multiple Windows

Changes to app lifecycle

App delegate responsibilities:

• iOS 12 and before: process lifecycle and UI lifecycle
• iOS 13: process lifecycle and new scene session lifecycle; the UI lifecycle is handled by the scene delegate

Using the scene delegate

Configuring new sessions

func application(_ application: UIApplication,
configurationForConnecting connectingSceneSession: UISceneSession,
options: UIScene.ConnectionOptions) -> UISceneConfiguration

• Select a scene configuration
• Provides user activities, URLs
• Static and dynamic definition

Scene disconnection

func sceneDidDisconnect(_ scene: UIScene)

• System is releasing the scene
• May be called any time
• Release associated resources
• The scene may return

Cleaning up discarded sessions

func application(_ application: UIApplication,
didDiscardSceneSessions sceneSessions: Set<UISceneSession>)

• For permanently discarded sessions
• Delete associated data
• May be called after next launch

Architecture

Per-scene state restoration

func stateRestorationActivity(for scene: UIScene) -> NSUserActivity?

• Called on scene background
• Encode state via NSUserActivity
• Data protection

Keeping scenes in sync

Different methods to update interface across scenes:

• Delegates
• Notifications
• Combine framework