Creating a collaborative photo gallery with SharePlay

At a glance

Project structure

Source bundle/
├── GroupActivities-PhotoLibrary/
│   ├── GroupActivities_PhotoLibraryApp.swift
│   ├── Models/
│   │   ├── AppModel.swift
│   │   ├── SessionController.swift
│   │   ├── DisplayImage.swift
│   │   ├── PhotoShareActivity.swift
│   │   └── PhotosPickerItemExtension.swift
│   └── Views/
│       ├── ContentView.swift
│       ├── ImageCellView.swift
│       ├── ImageView.swift
│       ├── PhotoGalleryView.swift
│       └── SharePlayButton.swift
└── Configuration/
    └── SampleCode.xcconfig

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 5 project/configuration file(s) and 10 source declaration(s).

Overall architecture

flowchart LR
    N1["GroupActivities_PhotoLibraryApp"]
    N2["ContentView"]
    N3["AppModel"]
    N4["GroupActivities APIs"]
    N1 --> N2
    N2 --> N3
    N3 --> N4

Reference code

GroupActivities-PhotoLibrary/GroupActivities_PhotoLibraryApp.swift:10 — architecture anchor

@main
struct PhotoLibraryApp: App {
    // ...
}

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 Group Activities.

Ownership and state

classDiagram
    PhotoLibraryApp *-- AppModel : appModel
    AppModel *-- Logger : logger
    AppModel *-- String : name
    AppModel o-- SessionController : sessionController

Ownership evidence

GroupActivities-PhotoLibrary/GroupActivities_PhotoLibraryApp.swift:12 — stored dependency or nearest verified ownership anchor

    @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.

Class and protocol design

GroupActivities-PhotoLibrary/GroupActivities_PhotoLibraryApp.swift:11 — representative type boundary

struct PhotoLibraryApp: App {
    // ...
}

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

Access control

Reference code

GroupActivities-PhotoLibrary/GroupActivities_PhotoLibraryApp.swift:12 — representative boundary

    @State private var appModel = AppModel()

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: PhotoLibraryApp; Controller: SessionController; Model: AppModel; View: ContentView, ImageCellView, ImageView, PhotoGalleryView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: endSession, removeItem, shareExistingImages, observeGroupSessions, updateImagesFromSelection, addImagesFromPhotoPicker, removeImagesFromPhotoPicker, loadImage.
• Files: GroupActivities-PhotoLibrary/Models/AppModel.swift, GroupActivities-PhotoLibrary/Models/SessionController.swift, GroupActivities-PhotoLibrary/Views/ContentView.swift, GroupActivities-PhotoLibrary/Views/ImageCellView.swift, GroupActivities-PhotoLibrary/Views/ImageView.swift, GroupActivities-PhotoLibrary/Views/PhotoGalleryView.swift.

Architecture takeaways

• GroupActivities_PhotoLibraryApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, GroupActivities, PhotosUI, QuickLook 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