Integrating accessibility into your app

At a glance

Project structure

AccessibilityUIExamples/
├── Application/           # catalog, split shell, dynamic detail host
├── Buttons/ Text/ Images/
├── Checkbox/ Slider/ Stepper/ Switches/
├── Table/ Outline/ LayoutArea/
├── CustomRotors/
└── TransientUI/ SearchField/ RadioButtons/

Folder names are the architectural index: each is a focused demo with its own controller and custom view.

Overall architecture

flowchart LR
    App["AppDelegate"] --> Split["SplitViewController"]
    Split --> Main["MainViewController"]
    Main --> Catalog["[Example] metadata"]
    Main --> Split
    Split --> Detail["DetailViewController"]
    Detail --> Storyboard["Feature storyboard"]
    Storyboard --> Demo["Independent example controller + view"]
    Demo --> AppKit["NSAccessibility roles / protocols"]

Reference code

AccessibilityUIExamples/Application/DetailViewController.swift:35 — metadata selects and embeds a feature controller (abridged).

let storyboard = NSStoryboard(
    name: detailItemRecord.viewControllerIdentifier,
    bundle: nil
)
let controller = storyboard.instantiateController(
    withIdentifier: detailItemRecord.viewControllerIdentifier
) as? NSViewController
insertChild(controller, at: 0)
view.addSubview(controller.view)

Ownership and state

classDiagram
    SplitViewController *-- MainViewController
    SplitViewController *-- DetailViewController
    MainViewController *-- Example : examplesArrayBacking
    MainViewController o-- MainViewControllerDelegate : weak
    DetailViewController *-- NSViewController : current child
    CustomControl *-- AccessibilityState : feature-local

Ownership evidence

AccessibilityUIExamples/Application/SplitViewController.swift:26 — the split controller wires and retains the two shell children.

mainViewController = splitViewItems[0].viewController as? MainViewController
mainViewController.delegate = self

self.detailViewController = splitViewItems[1].viewController as? DetailViewController

func didChangeExampleSelection(...) {
    detailViewController.detailItemRecord = selection
}

The shell owns the current example lifecycle. Feature controls own only their drawing, input, and accessibility state; there is no shared domain store.

Class and protocol design

MainViewControllerDelegate: AnyObject is the app-defined selection boundary at AccessibilityUIExamples/Application/MainViewController.swift:263. Feature types mostly adopt framework contracts directly—for example, CustomSliderView: NSView, NSAccessibilitySlider at AccessibilityUIExamples/Slider/CustomSliderView.swift:18. Custom rotor views add small delegate protocols when they must ask a controller for elements.

Access control

Here fileprivate is purposeful: a base declaration and same-file extensions share helpers. public does not make this a library; it is used for framework-facing methods.

Logic ownership and placement

Design patterns

Naming conventions

• Feature folders and controllers share nouns (Slider/CustomSliderViewController).
• Custom implementations use Custom or a precise control role, while shell types use Main, Detail, and Split.
• Delegate protocols name the producer (MainViewControllerDelegate) and callbacks begin with did....

Architecture takeaways

• Read the archive as a host plus independent recipes, not a monolithic production architecture.
• Use the shell to own navigation and feature controllers to own their accessibility semantics.
• Same-file fileprivate helpers can support extension-based organization without widening target-wide access.
• Mixed Swift/Objective-C files are parallel demonstrations, not duplicated layers of one subsystem.

Source map

• Official Apple documentation