Creating a multiview video playback experience in visionOS

At a glance

Project structure

Source bundle/
└── MultiviewVideoPlayback/
    ├── MultiviewVideoPlaybackApp.swift
    ├── Helpers/
    │   └── SceneDelegate.swift
    ├── Models/
    │   ├── MultiviewStateModel.swift
    │   ├── VideoModel.swift
    │   └── Video.swift
    └── Views/
        ├── VideoItemSelectionView.swift
        ├── ContentView.swift
        ├── ItemVideoPlayer.swift
        ├── MultiviewVideoSelectionView.swift
        ├── SystemVideoPlayer.swift
        ├── ThumbnailView.swift
        └── VideoHomeView.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 14 source declaration(s).

Overall architecture

flowchart LR
    N1["MultiviewVideoPlaybackApp"]
    N2["ContentView"]
    N3["MultiviewStateModel"]
    N4["ItemVideoPlayer"]
    N5["AVKit APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4
    N4 --> N5

Reference code

MultiviewVideoPlayback/MultiviewVideoPlaybackApp.swift:10 — architecture anchor

@main
struct MultiviewVideoPlaybackApp: App {
    @UIApplicationDelegateAdaptor private var appDelegate: CustomApplicationDelegate

    var body: some Scene {
        WindowGroup {
            ContentView()
                .frame(minWidth: 1200, minHeight: 600)
        }
        .windowResizability(.contentSize)
    }
}

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 AVKit.

Ownership and state

classDiagram
    MultiviewVideoPlaybackApp o-- CustomApplicationDelegate : appDelegate
    CustomSceneDelegate o-- UIScene : scene
    MultiviewStateModel *-- Array : videoModels
    MultiviewStateModel o-- VideoModel : embeddedVideo

Ownership evidence

MultiviewVideoPlayback/MultiviewVideoPlaybackApp.swift:12 — stored dependency or nearest verified ownership anchor

@main
struct MultiviewVideoPlaybackApp: App {
    @UIApplicationDelegateAdaptor private var appDelegate: CustomApplicationDelegate
    // ...
}

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

MultiviewVideoPlayback/Models/MultiviewStateModel.swift:11 — representative execution boundary

@Observable @MainActor
final class MultiviewStateModel: AVExperienceController.Delegate {
    // ...
    var videoModels: [VideoModel] = []
    // ...
}

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

MultiviewVideoPlayback/MultiviewVideoPlaybackApp.swift:11 — representative type boundary

@main
struct MultiviewVideoPlaybackApp: App {
    @UIApplicationDelegateAdaptor private var appDelegate: CustomApplicationDelegate
    // ...
}

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

Access control

Reference code

MultiviewVideoPlayback/Models/Video.swift:35 — representative boundary

    fileprivate static func metadataItem(key identifier: AVMetadataIdentifier, value: Any) -> AVMetadataItem {
        let item = AVMutableMetadataItem()
        // ...
    }

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
    actor User
    participant View as Selection view
    participant State as State model
    participant Exp as Experience controller
    User->>View: Add/remove video
    View->>State: videoSelected(item, inMultiview)
    State->>Exp: grouped transition
    Exp-->>State: transition context delegate callback
    State->>State: update isAddedToMultiview/embeddedVideo
    State-->>View: observable state rerenders

Reference code

MultiviewVideoPlayback/Views/MultiviewVideoSelectionView.swift:24 — source excerpt

                ForEach(multiviewStateModel.videoModels, id: \.video) { videoModel in
                    Button {
                        Task {
                            await multiviewStateModel.videoSelected(
                                videoModel: videoModel,
                                inMultiview: fromMultiviewContentSelection
                            )
                        }
                    } label: {
                        VideoItemSelectionView(
                            videoModel: videoModel,
                            inMultiviewContentSelection: fromMultiviewContentSelection
                        )
                        .padding(.vertical, 5)
                    }
                    .buttonBorderShape(.roundedRectangle(radius: 25.0))
                }

Naming conventions

• Types: App: MultiviewVideoPlaybackApp; Delegate: CustomApplicationDelegate, CustomSceneDelegate; Model: MultiviewStateModel, VideoModel; Player: ItemVideoPlayer, SystemVideoPlayer; View: ContentView, MultiviewVideoSelectionView, ThumbnailView, VideoHomeView, VideoItemSelectionView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: sceneWillEnterForeground, sceneDidBecomeActive, sceneDidDisconnect, application, populate, videoSelected, experienceController, setFallbackScene.
• Files: MultiviewVideoPlayback/MultiviewVideoPlaybackApp.swift, MultiviewVideoPlayback/Models/MultiviewStateModel.swift, MultiviewVideoPlayback/Models/VideoModel.swift, MultiviewVideoPlayback/Views/VideoItemSelectionView.swift, MultiviewVideoPlayback/Views/ContentView.swift, MultiviewVideoPlayback/Views/ItemVideoPlayer.swift.

Architecture takeaways

• MultiviewVideoPlaybackApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, AVKit, UIKit, AVFoundation 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