Configuring a Wi-Fi accessory to join a network

At a glance

Project structure

Source bundle/
├── BrandXAccessory/
│   ├── AppDelegate.swift
│   └── UI/
│       └── ViewControllers/
│           ├── BrandXAccessoryBaseViewController.swift
│           ├── BrandXAccessoryConfigureViewController.swift
│           ├── BrandXAccessoryDoneViewController.swift
│           └── BrandXAccessorySetupViewController.swift
└── BrandXAccessorySetup/
    ├── AppDelegate.swift
    ├── Network/
    │   ├── AccessoryNetworkManager.swift
    │   └── DeviceNetworkManager.swift
    ├── UI/
    │   └── ViewControllers/
    │       ├── QRScanningViewController.swift
    │       └── SetupBaseViewController.swift
    ├── Location/
    │   └── LocationManager.swift
    └── SceneDelegate.swift

Structure observations

• Architecturally prominent files are ranked from entry points and role-named declarations; resource-only paths are omitted.
• Primary languages: Swift.
• The verified tree contains 10 project/configuration file(s) and 30 source declaration(s).

Overall architecture

flowchart LR
    Bundle["Sample bundle"]
    V1["BrandXAccessory"]
    V2["BrandXAccessorySetup"]
    Boundary["Network / NetworkExtension APIs"]
    Bundle --> V1
    V1 --> Boundary
    Bundle --> V2
    V2 --> Boundary

Reference code

BrandXAccessory/AppDelegate.swift:10 — architecture anchor

@NSApplicationMain
class AppDelegate: NSObject, NSApplicationDelegate {

    func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
        return true
    }
}

Interpretation

The branches represent separate entry-bearing project variants in the downloaded bundle, not runtime calls between those variants. Each branch is intentionally collapsed at the documented framework boundary; the detailed target-local flow remains in the cited files. Ownership is claimed only where the next section cites a stored property or assignment.

Ownership and state

classDiagram
    AccessoryNetworkManager o-- Delegate : delegate
    AccessoryNetworkManager *-- Bool : isReady
    AccessoryNetworkManager *-- String : status
    QRScanningViewController o-- QRScanningDelegate : delegate

Ownership evidence

BrandXAccessorySetup/Network/AccessoryNetworkManager.swift:17 — stored dependency or nearest verified ownership anchor

final class AccessoryNetworkManager {
    // ...
    public weak var delegate: Delegate?
    // ...
}

Composition arrows indicate a source-visible construction expression or locally owned value state; aggregation means the owner stores or receives a dependency without proving exclusive lifetime ownership.

Concurrency, scheduling, and thread safety

Evidence limit: actor isolation, async/await, or Task creation does not by itself prove background-thread execution; Sendable conformance alone does not prove thread-safe mutation.

@MainActor/MainActor.run, DispatchQueue.main, and RunLoop.main are reported as distinct isolation, queue, and event-loop mechanisms. A plain Task is kept separate from Task.detached; neither is labeled as a background thread.

Reference code

BrandXAccessory/UI/ViewControllers/BrandXAccessoryConfigureViewController.swift:53 — representative execution boundary

            DispatchQueue.main.async {
                // Notice the prepended WebSocket secure protocol.
                self.urlComponents.host = "\(ipAddr)"
                self.serviceNameValue.stringValue = "\(self.urlComponents.scheme!)://\(self.urlComponents.host!):\(self.urlComponents.port!)"
                self.updateQRCode()
            }

State propagation, frameworks, and dependencies

Evidence limit: an import proves a source-level compilation dependency at the cited line; it does not prove runtime use, architectural adoption, or whether a Swift package is a direct application dependency.

receive(on:) describes downstream delivery scheduling, while subscribe(on:) describes upstream subscription/request/cancel scheduling. An import Combine alone establishes neither behavior nor a Store, reducer, Redux, or other application architecture.

Class and protocol design

BrandXAccessorySetup/Network/AccessoryNetworkManager.swift:54 — representative type boundary

protocol AccessoryNetworkManagerDelegate: AnyObject {
    func accessoryNetworkManagerDidUpdate(acessoryNetworkManager: AccessoryNetworkManager)
}

The source explicitly defines local protocol relationships: BrandXAccessoryConfigureViewController → WebSocketListenerDelegate, BrandXAccessoryConfigureViewController → WebSocketConnectionDelegate, SetupHotspotConnectViewController → AccessoryNetworkManagerDelegate, SetupQRCodeViewController → QRScanningDelegate, SetupSendDataViewController → WebSocketConnectionDelegate.

Access control

Reference code

BrandXAccessory/Network/WebSocketListener.swift:15 — representative boundary

class WebSocketListener {
    // ...
    private var websocketListener: NWListener?
    // ...
}

Swift declarations without a modifier are internal; explicit private, fileprivate, private(set), public, or open entries above are interpreted by language semantics. Objective-C/C samples instead rely on header and implementation boundaries, which are not equivalent to Swift lexical privacy.

Logic ownership and placement

Design patterns

Naming conventions

• Types: Controller: BrandXAccessoryBaseViewController, BrandXAccessoryConfigureViewController, BrandXAccessoryDoneViewController, BrandXAccessorySetupViewController, QRScanningViewController; Delegate: AccessoryNetworkManagerDelegate, AppDelegate, QRScanningDelegate, SceneDelegate, WebSocketConnectionDelegate; Manager: AccessoryNetworkManager, DeviceNetworkManager, LocationManager.
• Protocols: AccessoryNetworkManagerDelegate, QRScanningDelegate, WebSocketListenerDelegate, WebSocketConnectionDelegate.
• Methods: applicationShouldTerminateAfterLastWindowClosed, removeConfiguration, applyConfiguration, accessoryNetworkManagerDidUpdate, viewDidLoad, viewWillAppear, viewWillDisappear, viewDidLayoutSubviews.
• Files: BrandXAccessory/AppDelegate.swift, BrandXAccessorySetup/AppDelegate.swift, BrandXAccessorySetup/Network/AccessoryNetworkManager.swift, BrandXAccessorySetup/UI/ViewControllers/QRScanningViewController.swift, BrandXAccessory/UI/ViewControllers/BrandXAccessoryBaseViewController.swift, BrandXAccessory/UI/ViewControllers/BrandXAccessoryConfigureViewController.swift.

Architecture takeaways

• AppDelegate is the main source-visible entry or composition anchor for this sample.
• Framework work reaches UIKit, Cocoa, Network, NetworkExtension through a deliberately small high-level chain; the detailed API graph remains inside the cited implementation files.
• Stored-property evidence identifies lifecycle collaboration; it does not by itself prove exclusive object ownership.
• Access-control conclusions separate verified language visibility from the likely design rationale.
• Local protocol relationships provide an explicit substitution boundary.

Source map

• Official Apple documentation