Increasing App Usage with Suggestions Based on User Activities

At a glance

Project structure

Source bundle/
├── ProactiveToolbox/
│   ├── AppDelegate.swift
│   ├── DirectionsRequestViewController.swift
│   ├── KeyboardSuggestionsViewController.swift
│   ├── LocationViewController.swift
│   ├── SearchViewController.swift
│   ├── Base.lproj/
│   │   ├── LaunchScreen.storyboard
│   │   └── Main.storyboard
│   └── Info.plist
├── Configuration/
│   └── SampleCode.xcconfig
└── ProactiveToolbox.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 6 project/configuration file(s) and 5 source declaration(s).

Overall architecture

flowchart LR
    N1["AppDelegate"]
    N2["DirectionsRequestViewController"]
    N3["MapKit / UIKit APIs"]
    N1 --> N2
    N2 --> N3

Reference code

ProactiveToolbox/AppDelegate.swift:21 — architecture anchor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    // ...
}

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 Foundation.

Ownership and state

classDiagram
    AppDelegate o-- UIWindow : window
    DirectionsRequestViewController *-- Bool : validAddressDictionary
    DirectionsRequestViewController *-- Bool : validGeoCoordinates
    DirectionsRequestViewController o-- UIImageView : geoCoordinateIsValidImageView

Ownership evidence

ProactiveToolbox/AppDelegate.swift:23 — stored dependency or nearest verified ownership anchor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    // ...
}

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

ProactiveToolbox/DirectionsRequestViewController.swift:68 — representative execution boundary

class DirectionsRequestViewController: UIViewController {
    // ...
        let semaphore = DispatchSemaphore(value: 0)
    // ...
}

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

ProactiveToolbox/AppDelegate.swift:22 — representative type boundary

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    // ...
}

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

Access control

Reference code

ProactiveToolbox/DirectionsRequestViewController.swift:25 — representative boundary

class DirectionsRequestViewController: UIViewController {
    // ...
    fileprivate let imageNamePass: String = "pass"
    fileprivate let imageNameFail: String = "fail"

    // ...
}

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: Controller: DirectionsRequestViewController, KeyboardSuggestionsViewController, LocationViewController, SearchViewController; Delegate: AppDelegate.
• Protocols: no local protocol declaration in the scanned source.
• Methods: application, viewDidLoad, validateAndDisplayDirectionsRequest, geocodedCoordinatesFromMapItem, updateValidationUI, textFieldShouldReturn, updateUserActivity, updateUserActivityState.
• Files: ProactiveToolbox/AppDelegate.swift, ProactiveToolbox/DirectionsRequestViewController.swift, ProactiveToolbox/KeyboardSuggestionsViewController.swift, ProactiveToolbox/LocationViewController.swift, ProactiveToolbox/SearchViewController.swift.

Architecture takeaways

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