Localizing Landmarks

At a glance

Project structure

Source bundle/
├── End/
│   └── Landmarks/
│       ├── LandmarksApp.swift
│       └── Views/
│           ├── Landmarks/
│           │   ├── Landmark Detail/
│           │   │   ├── LandmarkDetailInspectorView.swift
│           │   │   └── LandmarkDetailView.swift
│           │   └── Landmarks View/
│           │       └── LandmarksView.swift
│           ├── Badges/
│           │   └── BadgesView.swift
│           └── Collections/
│               └── Collections/
│                   └── CollectionsView.swift
└── Start/
    └── Landmarks/
        ├── LandmarksApp.swift
        └── Views/
            ├── Landmarks/
            │   ├── Landmark Detail/
            │   │   ├── LandmarkDetailInspectorView.swift
            │   │   └── LandmarkDetailView.swift
            │   └── Landmarks View/
            │       └── LandmarksView.swift
            ├── Badges/
            │   └── BadgesView.swift
            └── Collections/
                └── Collections/
                    └── CollectionsView.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 7 project/configuration file(s) and 102 source declaration(s).

Overall architecture

flowchart LR
    Bundle["Sample bundle"]
    V1["End"]
    V2["Start"]
    Boundary["SwiftUI / MapKit APIs"]
    Bundle --> V1
    V1 --> Boundary
    Bundle --> V2
    V2 --> Boundary

Reference code

End/Landmarks/LandmarksApp.swift:11 — architecture anchor

@main
struct LandmarksApp: App {
    /// An object that manages the app's data and state.
    @State private var modelData = ModelData()

    var body: some Scene {
        WindowGroup {
            LandmarksSplitView()
                .environment(modelData)
                .frame(minWidth: 375.0, minHeight: 375.0)
                // Keeps the current window's size for use in scrolling header calculations.
                .onGeometryChange(for: CGSize.self) { geometry in
                    geometry.size
                } action: {
                    modelData.windowSize = $0
                }
        }
    }
}

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
    LandmarksApp *-- ModelData : modelData
    Constants *-- CGFloat : cornerRadius
    Constants *-- CGFloat : leadingContentInset
    Constants *-- CGFloat : standardPadding

Ownership evidence

End/Landmarks/LandmarksApp.swift:14 — stored dependency or nearest verified ownership anchor

@main
struct LandmarksApp: App {
    // ...
    @State private var modelData = ModelData()
    // ...
}

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

End/Landmarks/Model/BadgeProgress.swift:11 — representative execution boundary

@MainActor
@Observable
class BadgeProgress {
    // ...
        .drawSketch: false
    // ...
}

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

End/Landmarks/LandmarksApp.swift:12 — representative type boundary

@main
struct LandmarksApp: App {
    // ...
    @State private var modelData = ModelData()
    // ...
}

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

Access control

Reference code

End/DiscoverKit/DiscoverKit.swift:30 — representative boundary

    public var localizedTitle: String {
        switch self {
        case .friend: String(localized: .Discover.sharedByFriends)
        case .curated: String(localized: .Discover.curatedCollection)
        }
    }

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: App: LandmarksApp; View: BadgeProgressView, BadgesView, CollectionDetailDisplayView, CollectionDetailEditingView, CollectionDetailView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: body, showsBadges.
• Files: End/Landmarks/LandmarksApp.swift, Start/Landmarks/LandmarksApp.swift, End/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailInspectorView.swift, Start/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailInspectorView.swift, End/Landmarks/Views/Badges/BadgesView.swift, Start/Landmarks/Views/Badges/BadgesView.swift.

Architecture takeaways

• LandmarksApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, MapKit, CoreLocation, CoreTransferable 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