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

Searching, displaying, and navigating to places

At a glance

Item Summary
Purpose Convert place information between coordinates and user-friendly place names, get cycling directions, and conveniently display formatted addresses.
App architecture A Swift sample with the source-visible chain MapKitFountainsAppContentViewMapKit APIs.
Main patterns No named application pattern supported by the extracted structure
Project style 5 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
├── MapKitFountains/
│   ├── MapKitFountainsApp.swift
│   ├── FountainMapView.swift
│   ├── ContentView.swift
│   ├── GeocodeView.swift
│   └── ReverseGeocodeView.swift
├── Configuration/
│   └── SampleCode.xcconfig
└── MapKitFountains.xcodeproj/
    ├── .xcodesamplecode.plist
    └── project.pbxproj

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 3 project/configuration file(s) and 6 source declaration(s).

Overall architecture

Reference code

MapKitFountains/MapKitFountainsApp.swift:11 — architecture anchor

@main
struct MapKitFountainsApp: App {

    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

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 MapKit.

Ownership and state

Ownership evidence

MapKitFountains/FountainMapView.swift:49 — stored dependency or nearest verified ownership anchor

    @State private var fountains: [MKMapItem] = []
    @State private var selectedItem: MKMapItem?
    @State private var cameraPosition: MapCameraPosition = .automatic
    @State private var mapRoute: MKRoute?
    @State private var lookAroundScene: MKLookAroundScene?
    
    private let locationManager = CLLocationManager()
Owner Object or state Relationship Mutation authority
FountainMapView Array (fountains) owns wrapper-managed state Owning lexical scope
FountainMapView MKMapItem (selectedItem) owns wrapper-managed state Owning lexical scope
FountainMapView MapCameraPosition (cameraPosition) owns wrapper-managed state Owning lexical scope
FountainMapView MKRoute (mapRoute) owns wrapper-managed state Owning lexical scope

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

MapKitFountains/MapKitFountainsApp.swift:12 — representative type boundary

struct MapKitFountainsApp: App {
    // ...
}
Type Responsibility Depends on or conforms to
MapKitFountainsApp Application entry and top-level composition App
FountainMapView User-interface presentation and input forwarding View
ContentView User-interface presentation and input forwarding View
GeocodeView User-interface presentation and input forwarding View
ReverseGeocodeView User-interface presentation and input forwarding View
DublinFountains Represents a feature value or composable behavior Concrete collaborators/imported frameworks

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
fountains (MapKitFountains/FountainMapView.swift:49) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.
selectedItem (MapKitFountains/FountainMapView.swift:50) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.
cameraPosition (MapKitFountains/FountainMapView.swift:51) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.
mapRoute (MapKitFountains/FountainMapView.swift:52) private Use is restricted to the lexical declaration and same-file extensions allowed by Swift. Inference: keep state mutation or dependency lifetime inside the owning implementation.

Reference code

MapKitFountains/FountainMapView.swift:49 — representative boundary

    @State private var fountains: [MKMapItem] = []
    @State private var selectedItem: MKMapItem?
    @State private var cameraPosition: MapCameraPosition = .automatic
    @State private var mapRoute: MKRoute?
    @State private var lookAroundScene: MKLookAroundScene?

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 MapKitFountainsApp The source’s App suffix makes this role explicit.
User-interface presentation and input forwarding ContentView, FountainMapView, GeocodeView, ReverseGeocodeView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
No named application pattern MapKitFountains/MapKitFountainsApp.swift:11 The verified source directly composes concrete framework types; this document avoids forcing a pattern name.

Naming conventions

  • Types: App: MapKitFountainsApp; View: ContentView, FountainMapView, GeocodeView, ReverseGeocodeView.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: fountainMapItems.
  • Files: MapKitFountains/MapKitFountainsApp.swift, MapKitFountains/FountainMapView.swift, MapKitFountains/ContentView.swift, MapKitFountains/GeocodeView.swift, MapKitFountains/ReverseGeocodeView.swift.

Architecture takeaways

  • MapKitFountainsApp is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches SwiftUI, MapKit, CoreLocation, GeoToolbox 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
MapKitFountains/MapKitFountainsApp.swift MapKitFountainsApp
MapKitFountains/FountainMapView.swift DublinFountains, FountainMapView
MapKitFountains/ContentView.swift ContentView
MapKitFountains/GeocodeView.swift GeocodeView
MapKitFountains/ReverseGeocodeView.swift ReverseGeocodeView