Sample CodeiOS, iPadOS, Mac Catalyst, watchOSReviewed 2026-07-21View on Apple Developer

Create accessible experiences for watchOS

At a glance

Item Summary
Purpose Learn how to make your watchOS app more accessible.
App architecture A Swift sample with the source-visible chain PlantCareAppPlantContentViewSwiftUI / ClockKit APIs.
Main patterns View-controller organization, Delegate or data-source callbacks, SwiftUI environment injection, Binding-based state propagation, Publisher-backed observable state
Project style 6 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.

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

Reference code

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

@main
struct PlantCareApp: 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 watchOS-Apps.

Ownership and state

Ownership evidence

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

    @EnvironmentObject var plantData: PlantData
    @State var isShowingEditView = false
    var plant: Plant
    
    var plantIndex: Int {
        plantData.plants.firstIndex(where: { $0.id == plant.id })!
    }
Owner Object or state Relationship Mutation authority
PlantCellView PlantData (plantData) receives environment-provided state The environment provider is authoritative
PlantCellView Plant (plant) stores or receives App/module collaborators
PlantContainerView Plant (plant) borrows mutable state The upstream binding owner is authoritative
PlantViewHorizontal Plant (plant) borrows mutable state The upstream binding owner is authoritative

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

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

struct PlantCareApp: App {
    // ...
}
Type Responsibility Depends on or conforms to
PlantCareApp Application entry and top-level composition App
PlantCellView User-interface presentation and input forwarding View
PlantContainerView User-interface presentation and input forwarding View
PlantEditView User-interface presentation and input forwarding View
PlantContentView User-interface presentation and input forwarding View
ComplicationController View lifecycle, callbacks, and feature coordination NSObject, CLKComplicationDataSource
PlantViewHorizontal Represents a feature value or composable behavior View
PlantViewVertical Represents a feature value or composable behavior View
PlantImage Represents a feature value or composable behavior View
PlantTaskLabel Represents a feature value or composable behavior View

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
createTimelineEntry (PlantCare/PlantCare WatchKit Extension/ComplicationController.swift:78) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: hide an implementation step that is not part of the collaboration surface.
createTemplate (PlantCare/PlantCare WatchKit Extension/ComplicationController.swift:83) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: hide an implementation step that is not part of the collaboration surface.
createModularSmallTemplate (PlantCare/PlantCare WatchKit Extension/ComplicationController.swift:118) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: hide an implementation step that is not part of the collaboration surface.
createModularLargeTemplate (PlantCare/PlantCare WatchKit Extension/ComplicationController.swift:133) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: hide an implementation step that is not part of the collaboration surface.

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

Logic Owning type or file Placement rationale
Application entry and top-level composition PlantCareApp The source’s App suffix makes this role explicit.
View lifecycle, callbacks, and feature coordination ComplicationController The source’s Controller suffix makes this role explicit.
User-interface presentation and input forwarding PlantCellView, PlantContainerView, PlantContentView, PlantEditView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
View-controller organization PlantCare/PlantCare WatchKit Extension/ComplicationController.swift:9 A controller is the verified coordination boundary; this is MVC-style only where a separate model is present.
Delegate or data-source callbacks PlantCare/PlantCare WatchKit Extension/ComplicationController.swift:9 Callback protocols invert event delivery back into the sample’s owner.
SwiftUI environment injection PlantCare/PlantCare WatchKit Extension/PlantCellView.swift:11 The environment supplies state or a capability without threading it through every initializer.
Binding-based state propagation PlantCare/PlantCare WatchKit Extension/PlantCellView.swift:36 A binding exposes controlled read/write access while the upstream owner remains authoritative.
Publisher-backed observable state PlantCare/PlantCare WatchKit Extension/PlantData.swift:159 Published properties notify observers while mutation remains with the state object.

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

Source file Relevant symbols
PlantCare/PlantCare WatchKit Extension/PlantCareApp.swift PlantCareApp
PlantCare/PlantCare WatchKit Extension/PlantCellView.swift PlantCellView, PlantContainerView, PlantViewHorizontal, PlantViewVertical, PlantImage, PlantTaskLabel, PlantButton, PlantTaskList, PlantTaskButtons, PlantCellView_Previews
PlantCare/PlantCare WatchKit Extension/PlantEditView.swift PlantEditView, PlantTaskFrequency, CustomCounter, PlantEditView_Previews
PlantCare/PlantCare WatchKit Extension/PlantContentView.swift PlantContentView, ContentView_Previews
PlantCare/PlantCare WatchKit Extension/ComplicationController.swift ComplicationController
PlantCare/PlantCare WatchKit Extension/PlantData.swift SunlightLevel, Plant, PlantTask, PlantData