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

Landmarks: Refining the system provided Liquid Glass effect in toolbars

At a glance

Item Summary
Purpose Organize toolbars into related groupings to improve their appearance and utility.
App architecture A Swift sample with the source-visible chain LandmarksAppLandmarksSplitViewSwiftUI APIs.
Main patterns Delegate or data-source callbacks, Actor-isolated state
Project style 37 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries.

Project structure

Source bundle/
└── Landmarks/
    └── Landmarks/
        ├── LandmarksApp.swift
        └── Views/
            ├── Landmarks/
            │   ├── Landmark Detail/
            │   │   ├── LandmarkDetailInspectorView.swift
            │   │   ├── LandmarkDetailView.swift
            │   │   └── LandmarkDetailMapView.swift
            │   └── Landmarks View/
            │       └── LandmarksView.swift
            ├── Badges/
            │   └── BadgesView.swift
            ├── Collections/
            │   ├── Collections/
            │   │   ├── CollectionsView.swift
            │   │   └── CollectionListItemView.swift
            │   └── Collection Detail/
            │       ├── CollectionDetailDisplayView.swift
            │       ├── CollectionDetailEditingView.swift
            │       └── CollectionDetailView.swift
            └── Landmarks Split View/
                └── LandmarksSplitView.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 4 project/configuration file(s) and 50 source declaration(s).

Overall architecture

Reference code

Landmarks/Landmarks/LandmarksApp.swift:11 — architecture anchor

@main
struct LandmarksApp: App {
    // ...
}

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 SwiftUI.

Ownership and state

Ownership evidence

Landmarks/Landmarks/LandmarksApp.swift:14 — stored dependency or nearest verified ownership anchor

@main
struct LandmarksApp: App {
    // ...
    @State private var modelData = ModelData()
    // ...
}
Owner Object or state Relationship Mutation authority
LandmarksApp ModelData (modelData) owns wrapper-managed state Owning lexical scope
Constants CGFloat (cornerRadius) owns value state Initialized by the owner; the binding is immutable
Constants CGFloat (leadingContentInset) owns value state Initialized by the owner; the binding is immutable
Constants CGFloat (standardPadding) owns value state Initialized by the owner; the binding is immutable

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

Landmarks/Landmarks/LandmarksApp.swift:12 — representative type boundary

struct LandmarksApp: App {
    // ...
}
Type Responsibility Depends on or conforms to
LandmarksApp Application entry and top-level composition App
LandmarkDetailInspectorView User-interface presentation and input forwarding View
LandmarkInspectorFormView User-interface presentation and input forwarding View
LandmarkInspectorBadgeView User-interface presentation and input forwarding View
EarnedBadgeView User-interface presentation and input forwarding View
BadgeProgressView User-interface presentation and input forwarding View
BadgesView User-interface presentation and input forwarding View
CollectionsView User-interface presentation and input forwarding View
CollectionTitleView User-interface presentation and input forwarding View
LandmarkDetailView User-interface presentation and input forwarding View

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
modelData (Landmarks/Landmarks/LandmarksApp.swift:14) 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.
progress (Landmarks/Landmarks/Model/BadgeProgress.swift:14) 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.
currentLocationManager (Landmarks/Landmarks/Model/LocationFinder.swift:15) 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.
landmarksByContinent (Landmarks/Landmarks/Model/ModelData.swift:195) 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.

Reference code

Landmarks/Landmarks/LandmarksApp.swift:14 — representative boundary

@main
struct LandmarksApp: App {
    // ...
    @State private var modelData = ModelData()
    // ...
}

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 LandmarksApp The source’s App suffix makes this role explicit.
User-interface presentation and input forwarding BadgeProgressView, BadgesView, CollectionDetailDisplayView, CollectionDetailEditingView The source’s View suffix makes this role explicit.

Design patterns

Pattern Source evidence Purpose or tradeoff
Delegate or data-source callbacks Landmarks/Landmarks/Model/LocationFinder.swift:13 Callback protocols invert event delivery back into the sample’s owner.
Actor-isolated state Landmarks/Landmarks/Model/BadgeProgress.swift:11 Actor annotations make the concurrency ownership boundary explicit.

Naming conventions

  • Types: App: LandmarksApp; View: BadgeProgressView, BadgesView, CollectionDetailDisplayView, CollectionDetailEditingView, CollectionDetailView.
  • Protocols: no local protocol declaration in the scanned source.
  • Methods: body, showsBadges.
  • Files: Landmarks/Landmarks/LandmarksApp.swift, Landmarks/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailInspectorView.swift, Landmarks/Landmarks/Views/Badges/BadgesView.swift, Landmarks/Landmarks/Views/Collections/Collections/CollectionsView.swift, Landmarks/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailView.swift, Landmarks/Landmarks/Views/Landmarks/Landmarks View/LandmarksView.swift.

Architecture takeaways

  • LandmarksApp is the main source-visible entry or composition anchor for this sample.
  • Framework work reaches SwiftUI, MapKit, CoreLocation, CoreTransferable 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
Landmarks/Landmarks/LandmarksApp.swift LandmarksApp
Landmarks/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailInspectorView.swift LandmarkDetailInspectorView, Segment, LandmarkInspectorFormView, LandmarkInspectorBadgeView, EarnedBadgeView, BadgeProgressView
Landmarks/Landmarks/Views/Badges/BadgesView.swift BadgesView, BadgeLabel, ToggleBadgesLabel, ShowsBadgesViewModifier
Landmarks/Landmarks/Views/Collections/Collections/CollectionsView.swift CollectionsView, CollectionTitleView
Landmarks/Landmarks/Views/Landmarks/Landmark Detail/LandmarkDetailView.swift LandmarkDetailView, FavoriteButtonLabel
Landmarks/Landmarks/Views/Landmarks/Landmarks View/LandmarksView.swift LandmarksView, ContinentTitleView
Landmarks/Landmarks/Views/Collections/Collection Detail/CollectionDetailDisplayView.swift CollectionDetailDisplayView
Landmarks/Landmarks/Views/Collections/Collection Detail/CollectionDetailEditingView.swift CollectionDetailEditingView
Landmarks/Landmarks/Views/Collections/Collection Detail/CollectionDetailView.swift CollectionDetailView
Landmarks/Landmarks/Views/Collections/Collections/CollectionListItemView.swift CollectionListItemView