Locating and displaying recognized text
At a glance
| Item | Summary |
|---|---|
| Purpose | Perform text recognition on a photo using the Vision framework’s text-recognition request. |
| App architecture | A Swift sample with the source-visible chain SampleTextScannerApp → InitialView → Vision APIs. |
| Main patterns | Delegate or data-source callbacks, Binding-based state propagation |
| Project style | 8 scanned source file(s) across Swift, organized around ranked entry, type, and file boundaries. |
Project structure
Source bundle/
├── SampleTextScanner/
│ ├── SampleTextScannerApp.swift
│ ├── ImageView.swift
│ ├── InitialView.swift
│ ├── TranscriptView.swift
│ ├── Camera/
│ │ ├── CameraUI.swift
│ │ ├── CameraPreview.swift
│ │ └── Camera.swift
│ └── TextRecognition.swift
├── Configuration/
│ └── SampleCode.xcconfig
└── SampleTextScanner.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 12 source declaration(s).
Overall architecture
flowchart LR
N1["SampleTextScannerApp"]
N2["InitialView"]
N3["Vision APIs"]
N1 --> N2
N2 --> N3
Reference code
SampleTextScanner/SampleTextScannerApp.swift:10 — architecture anchor
@main
struct SampleTextScannerApp: App {
var body: some Scene {
WindowGroup {
InitialView()
}
}
}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 Vision.
Ownership and state
classDiagram
ImageView o-- Bool : showCamera
ImageView o-- Data : imageData
ImageView *-- OCR : imageOCR
ImageView *-- Locale : selectedLanguage
Ownership evidence
SampleTextScanner/ImageView.swift:11 — stored dependency or nearest verified ownership anchor
@Binding var showCamera: Bool
@Binding var imageData: Data?
@State private var imageOCR = OCR()
@State private var languageCorrection = false
@State private var selectedRecognitionLevel = "Accurate"
@State private var selectedLanguage = Locale.Language(identifier: "en-US")| Owner | Object or state | Relationship | Mutation authority |
|---|---|---|---|
ImageView |
Bool (showCamera) |
borrows mutable state | The upstream binding owner is authoritative |
ImageView |
Data (imageData) |
borrows mutable state | The upstream binding owner is authoritative |
ImageView |
OCR (imageOCR) |
owns wrapper-managed state | Owning lexical scope |
ImageView |
Locale (selectedLanguage) |
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
SampleTextScanner/SampleTextScannerApp.swift:11 — representative type boundary
struct SampleTextScannerApp: App {
var body: some Scene {
WindowGroup {
InitialView()
}
}
}| Type | Responsibility | Depends on or conforms to |
|---|---|---|
SampleTextScannerApp |
Application entry and top-level composition | App |
ImageView |
User-interface presentation and input forwarding | View |
InitialView |
User-interface presentation and input forwarding | View |
TranscriptView |
User-interface presentation and input forwarding | View |
PreviewView |
User-interface presentation and input forwarding | UIView |
CameraUI |
Represents a feature value or composable behavior | View |
DoneButtonStyle |
Represents a feature value or composable behavior | ButtonStyle |
CaptureButtonStyle |
Represents a feature value or composable behavior | ButtonStyle |
CameraPreview |
Represents a feature value or composable behavior | UIViewRepresentable |
OCR |
Owns feature behavior and collaborator lifecycle | 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 |
|---|---|---|---|
imageOCR (SampleTextScanner/ImageView.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. |
languageCorrection (SampleTextScanner/ImageView.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. |
selectedRecognitionLevel (SampleTextScanner/ImageView.swift:16) |
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. |
selectedLanguage (SampleTextScanner/ImageView.swift:17) |
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
SampleTextScanner/ImageView.swift:14 — representative boundary
@State private var imageOCR = OCR()
@State private var languageCorrection = false
@State private var selectedRecognitionLevel = "Accurate"
@State private var selectedLanguage = Locale.Language(identifier: "en-US")
var recognitionLevels = ["Accurate", "Fast"]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 | SampleTextScannerApp |
The source’s App suffix makes this role explicit. |
| User-interface presentation and input forwarding | ImageView, InitialView, PreviewView, TranscriptView |
The source’s View suffix makes this role explicit. |
Design patterns
| Pattern | Source evidence | Purpose or tradeoff |
|---|---|---|
| Delegate or data-source callbacks | SampleTextScanner/Camera/Camera.swift:12 |
Callback protocols invert event delivery back into the sample’s owner. |
| Binding-based state propagation | SampleTextScanner/Camera/CameraPreview.swift:12 |
A binding exposes controlled read/write access while the upstream owner remains authoritative. |
Naming conventions
- Types: App: SampleTextScannerApp; View: ImageView, InitialView, PreviewView, TranscriptView.
- Protocols: no local protocol declaration in the scanned source.
- Methods:
updateRequestSettings,properly,makeBody,makeUIView,updateUIView,performOCR,path,checkCameraAuthorization. - Files:
SampleTextScanner/SampleTextScannerApp.swift,SampleTextScanner/ImageView.swift,SampleTextScanner/InitialView.swift,SampleTextScanner/TranscriptView.swift,SampleTextScanner/Camera/CameraUI.swift,SampleTextScanner/Camera/CameraPreview.swift.
Architecture takeaways
SampleTextScannerAppis the main source-visible entry or composition anchor for this sample.- Framework work reaches SwiftUI, AVFoundation, Vision 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 |
|---|---|
SampleTextScanner/SampleTextScannerApp.swift |
SampleTextScannerApp |
SampleTextScanner/ImageView.swift |
ImageView |
SampleTextScanner/InitialView.swift |
InitialView |
SampleTextScanner/TranscriptView.swift |
TranscriptView |
SampleTextScanner/Camera/CameraUI.swift |
CameraUI, DoneButtonStyle, CaptureButtonStyle |
SampleTextScanner/Camera/CameraPreview.swift |
CameraPreview, PreviewView |
SampleTextScanner/TextRecognition.swift |
OCR, Box |
SampleTextScanner/Camera/Camera.swift |
Camera |