Sharing Your Location to Find a Park

At a glance

Project structure

Source bundle/
├── Park Finder (UIKit)/
│   └── Park Finder/
│       ├── main.m
│       ├── AppDelegate.h
│       ├── AppDelegate.m
│       ├── SceneDelegate.m
│       ├── ViewController.m
│       ├── SceneDelegate.h
│       └── ViewController.h
├── Park Finder (SwiftUI)/
│   └── Park Finder/
│       ├── ParkFinder.swift
│       ├── ContentView.swift
│       ├── Coordinator.swift
│       └── MapView.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: C/Objective-C header, Objective-C, Swift.
• The verified tree contains 8 project/configuration file(s) and 7 source declaration(s).

Overall architecture

flowchart LR
    Bundle["Sample bundle"]
    V1["Park Finder (SwiftUI)"]
    V2["Park Finder (UIKit)"]
    Boundary["CoreLocation APIs"]
    Bundle --> V1
    V1 --> Boundary
    Bundle --> V2
    V2 --> Boundary

Reference code

Park Finder (UIKit)/Park Finder/main.m:11 — architecture anchor

int main(int argc, char * argv[]) {
    NSString * appDelegateClassName;
    @autoreleasepool {
        appDelegateClassName = NSStringFromClass([AppDelegate class]);
    }
    return UIApplicationMain(argc, argv, nil, appDelegateClassName);
}

Interpretation

The branches represent separate entry-bearing project variants in the downloaded bundle, not runtime calls between those variants. Each branch is intentionally collapsed at the documented framework boundary; the detailed target-local flow remains in the cited files. Ownership is claimed only where the next section cites a stored property or assignment.

Ownership and state

classDiagram
    ContentView *-- CLLocationManager : manager
    Coordinator o-- MapView : parent
    MapView o-- CLLocationManager : manager
    MapView *-- MKMapView : map

Ownership evidence

Park Finder (SwiftUI)/Park Finder/ContentView.swift:13 — stored dependency or nearest verified ownership anchor

struct ContentView: View {
    @State var manager = CLLocationManager()
    // ...
}

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.

No source-visible execution, scheduling, or synchronization boundary was found in the indexed source.

@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.

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

Park Finder (UIKit)/Park Finder/AppDelegate.h:10 — representative type boundary

@interface AppDelegate : UIResponder <UIApplicationDelegate>


@end

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

Access control

Reference code

Park Finder (SwiftUI)/Park Finder/Coordinator.swift:19 — representative boundary

    private func addPins(location: CLLocation) {
        // ...
                return
        // ...
    }

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

Main application flow

sequenceDiagram
    participant ViewController
    participant CLGeocoder
    participant geocoder
    participant placemarks
    participant mapview
    participant MKLocalSearchRequest
    participant searchRequest
    ViewController->>CLGeocoder: alloc()
    ViewController->>geocoder: completionHandler
    ViewController->>placemarks: objectAtIndex()
    ViewController->>mapview: regionThatFits()
    ViewController->>mapview: setRegion()
    ViewController->>MKLocalSearchRequest: alloc()
    ViewController->>searchRequest: setNaturalLanguageQuery()
    ViewController->>mapview: addAnnotation()

Reference code

Park Finder (UIKit)/Park Finder/ViewController.m:69 — addPins()

- (void)addPins:(CLLocation *)location {
    CLGeocoder *geocoder = [[CLGeocoder alloc] init];
    [geocoder reverseGeocodeLocation:location completionHandler:^(NSArray<CLPlacemark*> *placemarks, NSError *error) {
        if (!placemarks) {
            return;
        } else if (placemarks && placemarks.count > 0) {
            CLPlacemark *placemark = [placemarks objectAtIndex:0];
            MKCoordinateRegion viewRegion = MKCoordinateRegionMakeWithDistance(placemark.location.coordinate, 1500, 1500);
            MKCoordinateRegion adjustedRegion = [self.mapview regionThatFits:viewRegion];
            [self.mapview setRegion:adjustedRegion animated:NO];

            MKLocalSearchRequest *searchRequest = [[MKLocalSearchRequest alloc] init];
            [searchRequest setNaturalLanguageQuery:@"Park"];
            [searchRequest setRegion:self.mapview.region];
            [searchRequest setRegion:viewRegion];

            MKLocalSearch *localSearch = [[MKLocalSearch alloc] initWithRequest:searchRequest];
            [localSearch startWithCompletionHandler:^(MKLocalSearchResponse *response, NSError *searcherror) {
                if (!searcherror) {
                    [self.mapview removeAnnotations: self.mapview.annotations];
                    for (MKMapItem *item in [response mapItems]) {
                        MKPointAnnotation *annotation = [[MKPointAnnotation alloc] init];
                        [annotation setCoordinate: item.placemark.coordinate];
                        [annotation setTitle: item.placemark.name];
                        [self.mapview addAnnotation:annotation];
                    }
                }
            }];
        }
    }];
}

Naming conventions

• Types: Controller: ViewController; Coordinator: Coordinator; Delegate: AppDelegate, SceneDelegate; View: ContentView, MapView.
• Protocols: no local protocol declaration in the scanned source.
• Methods: application, scene, sceneDidDisconnect, sceneDidBecomeActive, sceneWillResignActive, sceneWillEnterForeground, sceneDidEnterBackground, viewDidLoad.
• Files: Park Finder (SwiftUI)/Park Finder/ParkFinder.swift, Park Finder (UIKit)/Park Finder/AppDelegate.h, Park Finder (SwiftUI)/Park Finder/ContentView.swift, Park Finder (UIKit)/Park Finder/AppDelegate.m, Park Finder (UIKit)/Park Finder/SceneDelegate.m, Park Finder (UIKit)/Park Finder/ViewController.m.

Architecture takeaways

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