Create accessible experiences for watchOS

At a glance

Project structure

Source bundle/
├── PlantCare/
│   ├── PlantCare WatchKit Extension/
│   │   ├── PlantCareApp.swift
│   │   ├── PlantCellView.swift
│   │   ├── PlantEditView.swift
│   │   ├── PlantContentView.swift
│   │   ├── ComplicationController.swift
│   │   ├── PlantData.swift
│   │   └── Info.plist
│   └── PlantCare.xcodeproj/
│       ├── .xcodesamplecode.plist
│       └── project.pbxproj
└── 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 4 project/configuration file(s) and 19 source declaration(s).

Overall architecture

flowchart LR
    N1["PlantCareApp"]
    N2["PlantContentView"]
    N3["SwiftUI / ClockKit APIs"]
    N1 --> N2
    N2 --> N3

Reference code

PlantCare/PlantCare WatchKit Extension/PlantCareApp.swift:10 — architecture anchor

@main
struct PlantCareApp: App {
    @StateObject var plantData = PlantData.shared

    var body: some Scene {
        WindowGroup {
            NavigationView {
                PlantContentView()
                    .environmentObject(plantData)
            }
        }
    }
}

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 watchOS-Apps.

Ownership and state

classDiagram
    PlantCellView o-- PlantData : plantData
    PlantCellView o-- Plant : plant
    PlantContainerView o-- Plant : plant
    PlantViewHorizontal o-- Plant : plant

Ownership evidence

PlantCare/PlantCare WatchKit Extension/PlantCellView.swift:11 — stored dependency or nearest verified ownership anchor

struct PlantCellView: View {
    @EnvironmentObject var plantData: PlantData
    // ...
}

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

PlantCare/PlantCare WatchKit Extension/PlantCellView.swift:116 — representative execution boundary

            self.isTapped.toggle()
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
                self.isTapped.toggle()
            }

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

PlantCare/PlantCare WatchKit Extension/PlantCareApp.swift:11 — representative type boundary

@main
struct PlantCareApp: App {
    @StateObject var plantData = PlantData.shared
    // ...
}

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

Access control

Reference code

PlantCare/PlantCare WatchKit Extension/ComplicationController.swift:78 — representative boundary

    private func createTimelineEntry(forComplication complication: CLKComplication, date: Date) -> CLKComplicationTimelineEntry {
        let template = createTemplate(forComplication: complication, date: date)
        return CLKComplicationTimelineEntry(date: date, complicationTemplate: template)
    }

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: PlantCareApp; Controller: ComplicationController; View: PlantCellView, PlantContainerView, PlantContentView, PlantEditView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: getComplicationDescriptors, handleSharedComplicationDescriptors, getTimelineEndDate, getPrivacyBehavior, getCurrentTimelineEntry, getTimelineEntries, getLocalizableSampleTemplate, createTimelineEntry.
• Files: PlantCare/PlantCare WatchKit Extension/PlantCareApp.swift, PlantCare/PlantCare WatchKit Extension/PlantCellView.swift, PlantCare/PlantCare WatchKit Extension/PlantEditView.swift, PlantCare/PlantCare WatchKit Extension/PlantContentView.swift, PlantCare/PlantCare WatchKit Extension/ComplicationController.swift, PlantCare/PlantCare WatchKit Extension/PlantData.swift.

Architecture takeaways

• PlantCareApp is the main source-visible entry or composition anchor for this sample.
• Framework work reaches SwiftUI, ClockKit 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