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GBGBridge ships two stub camera views — StubDocumentCameraView and StubSelfieCameraView — that let you prove the bridge works end-to-end without installing the SmartCapture SDKs.
Development and testing only. On a real device the stub views use UIImagePickerController to take a plain photo. On the Simulator they display programmatically drawn placeholder images with a shutter button. They do not perform document detection, auto-cropping, liveness checks, or biometric encryption. Do not ship them in production.

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When to Use Stubs

  • Early integration — You want to verify the bridge protocol, capability negotiation, and data flow before the SmartCapture SDKs are available or configured.
  • CI / automated testing — Stubs work on Simulator (displaying placeholder images) without requiring camera hardware.
  • Prototyping — You’re building the host app shell and want a capture flow that “just works” while you focus on other parts of the integration.

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StubDocumentCameraView

Presents the rear camera on a real device, or a programmatically drawn placeholder document image on Simulator. Returns a DocumentCaptureResult containing the PNG-encoded image. 
import GBGBridge

.fullScreenCover(isPresented: $showDocumentCamera, onDismiss: {
    if host.documentCapture.activeRequest != nil {
        host.documentCapture.complete(.cancelled(reason: "Dismissed"))
    }
}) {
    StubDocumentCameraView(
        onCaptured: { result in
            host.documentCapture.complete(.document(result))
        },
        onCancelled: {
            host.documentCapture.complete(.cancelled(reason: "User dismissed"))
        }
    )
}

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What you get

FieldValue
imageDataPNG-encoded photo from the rear camera (device) or placeholder image (Simulator)
width / heightPixel dimensions of the captured image
mimeType"image/png"

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What you don’t get

  • Document edge detection and auto-crop
  • Blur / glare / quality scoring
  • Guided capture overlay with real-time feedback
  • Auto-capture on frame quality threshold

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StubSelfieCameraView

Presents the front camera on a real device, or a programmatically drawn face silhouette on Simulator. Returns a SelfieCaptureResult with the JPEG image and placeholder biometric blobs. 
import GBGBridge

.fullScreenCover(isPresented: $showSelfieCamera, onDismiss: {
    if host.selfieCapture.activeRequest != nil {
        host.selfieCapture.complete(.cancelled(reason: "Dismissed"))
    }
}) {
    StubSelfieCameraView(
        onCaptured: { result in
            host.selfieCapture.complete(.selfie(result))
        },
        onCancelled: {
            host.selfieCapture.complete(.cancelled(reason: "User dismissed"))
        }
    )
}

​
What you get

FieldValue
previewImageDataJPEG-encoded selfie from the front camera (device) or placeholder image (Simulator)
width / heightPixel dimensions of the captured image
mimeType"image/jpeg"
encryptedBlobRaw JPEG data (placeholder)
unencryptedBlobRaw JPEG data (placeholder)

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What you don’t get

  • Liveness detection (active or passive)
  • Face mesh / landmark analysis
  • Encrypted biometric blobs that pass server-side validation
  • Guided selfie overlay with positioning feedback
The encryptedBlob and unencryptedBlob fields contain the raw JPEG image data as a stand-in. They are structurally valid (non-empty Data) so the bridge protocol works, but they will not pass liveness verification on the server. This is by design — the stubs exist to prove the integration, not to produce real biometric data.

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Simulator Support

On Simulator, there is no camera hardware. Both stub views automatically display programmatically drawn placeholder images — a passport-style document card for StubDocumentCameraView and a face silhouette for StubSelfieCameraView — with a shutter-style capture button. Tapping the shutter generates a synthetic image and returns it through the normal callback, so you can exercise the full capture flow in CI or on your Mac without a physical device.

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Swapping Stubs for Real SDKs

The stub views are a drop-in replacement for the real SmartCapture views. The handler setup and bridge wiring stay the same — only the view inside fullScreenCover changes.
For a complete step-by-step walkthrough of the swap, see Tutorial Part 2: Integrate Smart Capture SDKs. It covers obtaining the frameworks, setting up the compiler flag, and building the wrapper views.

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Before (stub)

.fullScreenCover(isPresented: $showDocumentCamera) {
    StubDocumentCameraView(
        onCaptured: { result in
            host.documentCapture.complete(.document(result))
        },
        onCancelled: {
            host.documentCapture.complete(.cancelled(reason: "User dismissed"))
        }
    )
}

​
After (real SDK)

.fullScreenCover(isPresented: $showDocumentCamera) {
    SmartCaptureDocumentView(
        documentSide: .front,
        onCaptured: { imageData, width, height in
            host.documentCapture.complete(.document(
                DocumentCaptureResult(imageData: imageData, width: width, height: height)
            ))
        },
        onFailed: { message in
            host.documentCapture.complete(.failed(
                code: "CAPTURE_FAILED", message: message, recoverable: true
            ))
        }
    )
}
The key differences when swapping:
  1. View type — Replace StubDocumentCameraView / StubSelfieCameraView with your SDK-backed view.
  2. Callback shape — The real SDK views may have different callback signatures (e.g., separate onCaptured and onFailed callbacks instead of a single DocumentCaptureResult). Construct the DocumentCaptureResult or SelfieCaptureResult in the callback.
  3. Nothing else changes — The handler on the typed slot, the awaitCompletion() / complete() pattern, the bridge protocol, and the fullScreenCover presentation logic all stay the same.

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Complete Example

A minimal SwiftUI view using both stub views: 
import GBGBridge
import SwiftUI

struct StubJourneyView: View {
    @StateObject private var host = BridgeHost(hostVersion: "1.0.0")
    @State private var showDocumentCamera = false
    @State private var showSelfieCamera = false
    let journeyURL: URL

    var body: some View {
        BridgeWebView(url: journeyURL, host: host)
            .onAppear { setupHandlers() }
            .onChange(of: host.documentCapture.activeRequest?.correlationId) { _ in
                showDocumentCamera = host.documentCapture.activeRequest != nil
            }
            .onChange(of: host.selfieCapture.activeRequest?.correlationId) { _ in
                showSelfieCamera = host.selfieCapture.activeRequest != nil
            }
            .fullScreenCover(isPresented: $showDocumentCamera, onDismiss: {
                if host.documentCapture.activeRequest != nil {
                    host.documentCapture.complete(.cancelled(reason: "Dismissed"))
                }
            }) {
                StubDocumentCameraView(
                    onCaptured: { result in
                        host.documentCapture.complete(.document(result))
                    },
                    onCancelled: {
                        host.documentCapture.complete(.cancelled(reason: "User dismissed"))
                    }
                )
            }
            .fullScreenCover(isPresented: $showSelfieCamera, onDismiss: {
                if host.selfieCapture.activeRequest != nil {
                    host.selfieCapture.complete(.cancelled(reason: "Dismissed"))
                }
            }) {
                StubSelfieCameraView(
                    onCaptured: { result in
                        host.selfieCapture.complete(.selfie(result))
                    },
                    onCancelled: {
                        host.selfieCapture.complete(.cancelled(reason: "User dismissed"))
                    }
                )
            }
    }

    private func setupHandlers() {
        let camera = CameraDetector.check()
        host.documentCapture.permissionState = camera.permissionState
        host.selfieCapture.permissionState = camera.permissionState

        host.documentCapture.handler = { [weak host] request in
            guard let host else { return .cancelled(reason: "Host deallocated") }
            return await host.documentCapture.awaitCompletion()
        }

        host.selfieCapture.handler = { [weak host] request in
            guard let host else { return .cancelled(reason: "Host deallocated") }
            return await host.selfieCapture.awaitCompletion()
        }
    }
}

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Next Steps