Sample CodevisionOSReviewed 2026-07-21View on Apple Developer

Embedding controls in an immersive space

At a glance

Item Summary
Purpose Keep controls visible throughout an immersive experience by displaying them in a window or a view attachment.
App architecture A Swift sample with the source-visible chain SampleAppContentViewAppModelSwiftUI / RealityKit APIs.
Main patterns No named application pattern supported by the extracted structure
Project style 17 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.
Execution model Source-visible boundaries: @MainActor, await suspension point, Task closure isolated to MainActor, Task; none alone proves a background thread.
State/event model Source-visible mechanisms: @Observable, SwiftUI state property wrapper.
Key frameworks/packages SwiftUI, RealityKit, Foundation, OSLog, RealityKitContent; these are source dependencies, not architecture labels.

Project structure

Source bundle/
├── SampleApp/
│   ├── SampleApp.swift
│   ├── AppModel.swift
│   ├── ScenePhaseMonitor.swift
│   ├── SphereModel.swift
│   ├── ContentView.swift
│   ├── ImmersiveView.swift
│   └── Control Views/
│       ├── ControlsAttachment.swift
│       ├── ControlsWindow.swift
│       ├── DebugMainSceneStates.swift
│       ├── ImmersiveControls.swift
│       └── OpenSpheresMenuButton.swift
└── Packages/
    └── RealityKitContent/
        └── Sources/
            └── RealityKitContent/
                └── RealityKitContent.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 20 source declaration(s).

Overall architecture

Reference code

SampleApp/SampleApp.swift:17 — architecture anchor

@main
struct SampleApp: 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

Ownership evidence

SampleApp/SampleApp.swift:19 — stored dependency or nearest verified ownership anchor

@main
struct SampleApp: App {
    @State private var appModel = AppModel()
    // ...
}
Owner Object or state Relationship Mutation authority
SampleApp AppModel (appModel) owns wrapper-managed state Owning lexical scope
AppModel Dictionary (mainSceneStates) owns value state App/module collaborators
ScenePhaseMonitor Logger (state) creates and retains Initialized by the owner; the binding is immutable
SceneStateWindowViewModifier ReferenceWritableKeyPath (keyPath) stores or receives Initialized by the owner; the binding is immutable

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.

Concern Source mechanism Verified placement or handoff Evidence
Main isolation @MainActor The cited annotation marks its attached declaration or closure as main-actor isolated. SampleApp/AppModel.swift:11
Suspension boundary await suspension point The source declares or crosses an asynchronous boundary; it does not by itself establish background execution. SampleApp/ImmersiveView.swift:49
Main isolation Task closure isolated to MainActor The cited operation explicitly enters a main-actor-isolated region. SampleApp/ToggleImmersiveSpaceButton.swift:51
Task creation Task The source creates an unstructured task; surrounding context determines inherited actor isolation. SampleApp/ToggleImmersiveSpaceButton.swift:51

@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

SampleApp/AppModel.swift:11 — representative execution boundary

@MainActor
@Observable
class AppModel {
    // ...
        case closed
    // ...
}

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.

Category Mechanism or module Verified role Evidence
State propagation @Observable Observation macro publishes source-visible changes. SampleApp/AppModel.swift:12
State propagation SwiftUI state property wrapper A SwiftUI property wrapper supplies or observes UI state. SampleApp/ContentView.swift:13
Source import SwiftUI The cited file imports this module; runtime use and architectural role are not inferred. SampleApp/AppModel.swift:8
Source import RealityKit The cited file imports this module; runtime use and architectural role are not inferred. SampleApp/ContentView.swift:9
Source import Foundation The cited file imports this module; runtime use and architectural role are not inferred. Packages/RealityKitContent/Sources/RealityKitContent/RealityKitContent.swift:8
Source import OSLog The cited file imports this module; runtime use and architectural role are not inferred. SampleApp/SampleApp.swift:8
Source import RealityKitContent The cited file imports this module; runtime use and architectural role are not inferred. SampleApp/ContentView.swift:10
Source import PackageDescription The cited file imports this module; runtime use and architectural role are not inferred. Packages/RealityKitContent/Package.swift:11

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

SampleApp/SampleApp.swift:18 — representative type boundary

@main
struct SampleApp: App {
    @State private var appModel = AppModel()
    // ...
}
Type Responsibility Depends on or conforms to
SampleApp Application entry and top-level composition App
AppModel Feature data or observable state Concrete collaborators/imported frameworks
SphereModel Feature data or observable state Codable, CustomStringConvertible, Hashable, Identifiable
ContentView User-interface presentation and input forwarding View
ImmersiveView User-interface presentation and input forwarding View
SceneID Defines a closed set of feature states or choices String
ImmersiveSpaceState Represents mutable feature state Equatable
WindowState Represents mutable feature state Equatable
SceneStateWindowViewModifier Represents a feature value or composable behavior ViewModifier
SceneStateWindowGroupViewModifier Represents a feature value or composable behavior Concrete collaborators/imported frameworks

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

Access control

Symbol Access Verified effect Likely rationale
realityKitContentBundle (Packages/RealityKitContent/Sources/RealityKitContent/RealityKitContent.swift:11) public The symbol is visible to importing modules. Inference: make the declaration available across a module or target boundary.
appModel (SampleApp/ContentView.swift:13) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.
selectedSphereID (SampleApp/ContentView.swift:19) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.
navigationPath (SampleApp/ContentView.swift:31) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.

Reference code

Packages/RealityKitContent/Sources/RealityKitContent/RealityKitContent.swift:11 — representative boundary

public let realityKitContentBundle = Bundle.module

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

Logic Owning type or file Placement rationale
Application entry and top-level composition SampleApp The source’s App suffix makes this role explicit.
Feature data or observable state AppModel, SphereModel The source’s Model suffix makes this role explicit.
User-interface presentation and input forwarding ContentView, ImmersiveView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
No named application pattern SampleApp/SampleApp.swift:17 The verified source directly composes concrete framework types; this document avoids forcing a pattern name.

Naming conventions

  • Types: App: SampleApp; Model: AppModel, SphereModel; View: ContentView, ImmersiveView.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: updateWindowState, unregisterWindow, windowState, monitorScenePhase, body.
  • Files: SampleApp/SampleApp.swift, SampleApp/AppModel.swift, SampleApp/SphereModel.swift, SampleApp/ContentView.swift, SampleApp/ImmersiveView.swift, SampleApp/Control Views/ControlsAttachment.swift.

Architecture takeaways

  • SampleApp is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches SwiftUI, RealityKit, RealityKitContent, PackageDescription 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

Source file Relevant symbols
SampleApp/SampleApp.swift Cited implementation, SampleApp, OSLog, SceneID
Packages/RealityKitContent/Sources/RealityKitContent/RealityKitContent.swift Cited implementation, Foundation, Feature implementation
SampleApp/ContentView.swift Cited implementation, SwiftUI state property wrapper, RealityKit, RealityKitContent, ContentView
SampleApp/AppModel.swift @MainActor, @Observable, SwiftUI, AppModel, ImmersiveSpaceState, WindowState
SampleApp/ImmersiveView.swift await suspension point, ImmersiveView
SampleApp/ToggleImmersiveSpaceButton.swift Task closure isolated to MainActor, Task, ToggleImmersiveSpaceButton
Packages/RealityKitContent/Package.swift PackageDescription, Feature implementation
SampleApp/ScenePhaseMonitor.swift SceneStateWindowViewModifier, SceneStateWindowGroupViewModifier
SampleApp/SphereModel.swift SphereModel, ColorOption
SampleApp/Control Views/ControlsAttachment.swift ControlsAttachment
SampleApp/Control Views/ControlsWindow.swift ControlsWindow
SampleApp/Control Views/DebugMainSceneStates.swift DebugMainSceneStates
SampleApp/Control Views/ImmersiveControls.swift ImmersiveControls
SampleApp/Control Views/OpenSpheresMenuButton.swift OpenSpheresMenuButton
SampleApp/SphereDetails.swift SphereDetails
SampleApp/StorableTransform.swift StorableTransform