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

Displaying an Indoor Map

At a glance

Item Summary
Purpose Use the Indoor Mapping Data Format (IMDF) to show an indoor map with custom overlays and points of interest.
App architecture A Swift sample with the source-visible chain AppDelegateIndoorMapViewControllerMapKit APIs.
Main patterns View-controller organization, Protocol-oriented abstraction, Delegate or data-source callbacks
Project style 16 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
└── Dinoseum/
    ├── AppDelegate.swift
    ├── IMDFDecoder.swift
    ├── Views/
    │   ├── LevelPickerView.swift
    │   ├── LabelAnnotationView.swift
    │   └── PointAnnotationView.swift
    ├── IndoorMapViewController.swift
    ├── Styles.swift
    └── IMDFModel/
        ├── Amenity.swift
        ├── Anchor.swift
        ├── Level.swift
        ├── Occupant.swift
        └── Opening.swift

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 31 source declaration(s).

Overall architecture

Reference code

Dinoseum/AppDelegate.swift:10 — 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 MapKit.

Ownership and state

Ownership evidence

Dinoseum/AppDelegate.swift:13 — stored dependency or nearest verified ownership anchor

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?
    
}
Owner Object or state Relationship Mutation authority
AppDelegate UIWindow (window) stores or receives App/module collaborators
IMDFArchive URL (baseDirectory) owns value state Initialized by the owner; the binding is immutable
IMDFDecoder MKGeoJSONDecoder (geoJSONDecoder) creates and retains Initialized by the owner; the binding is immutable
LevelPickerView LevelPickerDelegate (delegate) holds a non-owning reference The referenced object’s lifecycle is owned elsewhere

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

Dinoseum/Views/LevelPickerView.swift:10 — representative type boundary

@objc protocol LevelPickerDelegate: AnyObject {
    func selectedLevelDidChange(selectedIndex: Int)
}
Type Responsibility Depends on or conforms to
AppDelegate Receives callback-driven events UIResponder, UIApplicationDelegate
LevelPickerDelegate Defines a capability or collaboration contract AnyObject
LevelPickerView User-interface presentation and input forwarding UIView
IndoorMapViewController View lifecycle, callbacks, and feature coordination UIViewController, MKMapViewDelegate, LevelPickerDelegate
LabelAnnotationView User-interface presentation and input forwarding MKAnnotationView
PointAnnotationView User-interface presentation and input forwarding MKAnnotationView
IMDFDecodableFeature Defines a capability or collaboration contract Concrete collaborators/imported frameworks
StylableFeature Defines a capability or collaboration contract Concrete collaborators/imported frameworks
IMDFError Represents feature failure conditions Error
IMDFArchive Represents a feature value or composable behavior Concrete collaborators/imported frameworks

The source explicitly defines local protocol relationships: IndoorMapViewControllerLevelPickerDelegate, LevelStylableFeature, UnitStylableFeature, OpeningStylableFeature, AmenityStylableFeature, OccupantStylableFeature.

Access control

Symbol Access Verified effect Likely rationale
geoJSONDecoder (Dinoseum/IMDFDecoder.swift:56) 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.
decodeOccupants (Dinoseum/IMDFDecoder.swift:120) 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.
decodeFeatures (Dinoseum/IMDFDecoder.swift:159) 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.
localizations (Dinoseum/IMDFModel/LocalizedName.swift:11) 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

Dinoseum/IMDFDecoder.swift:56 — representative boundary

    private let geoJSONDecoder = MKGeoJSONDecoder()

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
View lifecycle, callbacks, and feature coordination IndoorMapViewController The source’s Controller suffix makes this role explicit.
Receives callback-driven events AppDelegate, LevelPickerDelegate The source’s Delegate suffix makes this role explicit.
User-interface presentation and input forwarding LabelAnnotationView, LevelPickerView, PointAnnotationView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
View-controller organization Dinoseum/IndoorMapViewController.swift:12 A controller is the verified coordination boundary; this is MVC-style only where a separate model is present.
Protocol-oriented abstraction Dinoseum/IndoorMapViewController.swift:12 A local protocol and concrete conformance create an explicit capability boundary.
Delegate or data-source callbacks Dinoseum/AppDelegate.swift:11 Callback protocols invert event delivery back into the sample’s owner.

Naming conventions

  • Types: Controller: IndoorMapViewController; Delegate: AppDelegate, LevelPickerDelegate; View: LabelAnnotationView, LevelPickerView, PointAnnotationView.
  • Protocols: LevelPickerDelegate, IMDFDecodableFeature, StylableFeature.
  • Methods: fileURL, decode, decodeOccupants, decodeFeatures, selectedLevelDidChange, awakeFromNib, generateStackViewButtons, levelSelected.
  • Files: Dinoseum/AppDelegate.swift, Dinoseum/IMDFDecoder.swift, Dinoseum/Views/LevelPickerView.swift, Dinoseum/IndoorMapViewController.swift, Dinoseum/Views/LabelAnnotationView.swift, Dinoseum/Views/PointAnnotationView.swift.

Architecture takeaways

  • AppDelegate is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches MapKit, UIKit, 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.
  • Local protocol relationships provide an explicit substitution boundary.

Source map

Source file Relevant symbols
Dinoseum/AppDelegate.swift AppDelegate
Dinoseum/IMDFDecoder.swift IMDFDecodableFeature, IMDFError, IMDFArchive, File, IMDFDecoder
Dinoseum/Views/LevelPickerView.swift LevelPickerDelegate, LevelPickerView
Dinoseum/IndoorMapViewController.swift IndoorMapViewController
Dinoseum/Styles.swift StylableFeature, StylableCategory, StylableCategory, StylableCategory
Dinoseum/Views/LabelAnnotationView.swift LabelAnnotationView
Dinoseum/Views/PointAnnotationView.swift PointAnnotationView
Dinoseum/IMDFModel/Amenity.swift Amenity, Properties
Dinoseum/IMDFModel/Anchor.swift Anchor, Properties
Dinoseum/IMDFModel/Level.swift Level, Properties