Working with generic spatial accessories

At a glance

Project structure

Source bundle/
└── WorkingWithGenericSpatialAccessories/
    └── WorkingWithGenericSpatialAccessories/
        ├── WorkingWithGenericSpatialAccessoriesApp.swift
        ├── Models/
        │   ├── AppModel.swift
        │   ├── HapticModel.swift
        │   ├── AccessoryModel.swift
        │   └── AccessoryModel+Haptics.swift
        ├── Views/
        │   ├── ContentView.swift
        │   ├── ImmersiveView.swift
        │   ├── VolumeView.swift
        │   ├── ToggleImmersiveSpaceButton.swift
        │   └── ToggleVolumeButton.swift
        └── Extensions/
            ├── Entity.swift
            └── Logger.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 4 project/configuration file(s) and 13 source declaration(s).

Overall architecture

flowchart LR
    N1["WorkingWithGenericSpatialAccessoriesApp"]
    N2["ContentView"]
    N3["AccessoryModel"]
    N4["SwiftUI / RealityKit APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4

Reference code

WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessoriesApp.swift:10 — architecture anchor

@main
struct WorkingWithGenericSpatialAccessoriesApp: App {
    @State private var appModel = AppModel()
    // ...
}

Interpretation

The arrows summarize the source-visible entry, role-named types or folders, and framework direction; when nodes come from structural folders, the sequence is a high-level interpretation rather than proof that every adjacent node calls the next. Ownership is claimed only where the next section cites a stored property or assignment. The diagram is intentionally limited to the dominant path into visionOS.

Ownership and state

classDiagram
    WorkingWithGenericSpatialAccessoriesApp *-- AppModel : appModel
    AppModel *-- AccessoryModel : accessoryModel
    HapticModel o-- CHHapticEngine : hapticEngine
    HapticModel *-- Logger : logger

Ownership evidence

WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessoriesApp.swift:12 — stored dependency or nearest verified ownership anchor

@main
struct WorkingWithGenericSpatialAccessoriesApp: App {
    @State private var appModel = AppModel()
    // ...
}

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

WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/Models/AccessoryModel.swift:40 — representative execution boundary

                authChangeTask?.cancel()
                authChangeTask = Task {
                    await handleAuthorizationStatusChange()
                }

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

WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessoriesApp.swift:11 — representative type boundary

@main
struct WorkingWithGenericSpatialAccessoriesApp: App {
    @State private var appModel = AppModel()
    // ...
}

No local protocol conformance is claimed as protocol-oriented design; external framework conformances are listed only as dependencies.

Access control

Reference code

WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/Extensions/Entity.swift:46 — representative boundary

    private static func createSegment(height: Float, radius: Float, color: UIColor) -> Entity {
        let material = SimpleMaterial(color: color, isMetallic: false)
        let mesh = MeshResource.generateCylinder(height: height, radius: radius)
        return ModelEntity(mesh: mesh, materials: [material])
    }

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

Main application flow

sequenceDiagram
    participant AccessoryModel
    participant Task
    participant AnchoringComponent
    participant HapticModel
    AccessoryModel->>Task: Start asynchronous work
    AccessoryModel->>AccessoryModel: updateAccessoryTrackingProvider()
    AccessoryModel->>Task: Start asynchronous work
    AccessoryModel->>AnchoringComponent: AccessoryAnchoringSource()
    AccessoryModel->>AccessoryModel: loadReferenceEntity()
    AccessoryModel->>HapticModel: HapticModel()

Reference code

WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/Models/AccessoryModel.swift:282 — handleAccessoryDeviceChange()

    private func handleAccessoryDeviceChange() {
        // ...
        availableLocations = []
        hapticModel = nil
        referenceEntity = nil
        resetAnchorObservationState()
        deviceChangeTask?.cancel()
        Task {
            await updateAccessoryTrackingProvider()
        }
        guard let accessoryDevice else {
            return
        }
        accessoryDevice.input?.elementValueDidChangeHandler = { [weak self] (_, element) in
            guard let self else { return }
            if let button = element as? GCButtonElement,
               button.pressedInput.isPressed {
                logger.info("Button pressed: \(element.localizedName ?? "Unnamed element")")
                initiateDigitalReplicaPlacement()
            }
        }
        deviceChangeTask = Task {
            do {
                let anchoringSource = try await AnchoringComponent.AccessoryAnchoringSource(device: accessoryDevice)
                guard !Task.isCancelled else { return }
                availableLocations = anchoringSource.accessoryLocations
                await loadReferenceEntity(from: anchoringSource)
            } catch is CancellationError {
                return
            } catch {
                logger.error("Failed to create anchoring source: \(error)")
            }
            hapticModel = await HapticModel(accessory: accessoryDevice)
        }
    }

Naming conventions

• Types: App: WorkingWithGenericSpatialAccessoriesApp; Model: AccessoryModel, AppModel, HapticModel; View: ContentView, ImmersiveView, VolumeView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: play, createEvents, createPulseEvent, makeAnchoringSource, toggleAccessoryLocation, initiateDigitalReplicaPlacement, queryLatestAccessoryAnchor, observeAccessoryTrackingProvider.
• Files: WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessoriesApp.swift, WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/Models/AppModel.swift, WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/Models/HapticModel.swift, WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/Models/AccessoryModel.swift, WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/Views/ContentView.swift, WorkingWithGenericSpatialAccessories/WorkingWithGenericSpatialAccessories/Views/ImmersiveView.swift.

Architecture takeaways

• WorkingWithGenericSpatialAccessoriesApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, RealityKit, ARKit, CoreHaptics 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.
• The source does not justify labeling the design protocol-oriented.

Source map

• Official Apple documentation