Sample CodeiOS 27.0 beta, iPadOS 27.0 beta, Mac Catalyst 27.0 beta, macOS 27.0 beta, Xcode 27.0 betaReviewed 2026-07-21View on Apple Developer

Build a responsive camera app that launches quickly

Source availability limitation

The verified archive is documentation-only. It contains README.md, configuration, license, and .gitignore, but no Swift source, Xcode project, or FastCameraLaunch folder. The architecture below is limited to the README’s embedded examples and statements. It does not claim to verify the complete sample implementation, class ownership, folder structure, or access-control choices.

At a glance

Item	Summary
Purpose	Explain how to show camera preview quickly by postponing noncritical UI and deferring expensive capture outputs.
App architecture	README-described two-phase launch built on AVCam; full implementation is absent from the archive.
Main patterns	Critical-path prioritization, deferred initialization, UI gated by running state.
Project style	Extracted bundle is documentation-only; application folders and targets cannot be inspected.

Project structure

.gitignore
Configuration/SampleCode.xcconfig
LICENSE.txt
README.md                       # Narrative and two embedded Swift examples

Structure observations

There are no compilable source files in this archive.
README.md:7 says FastCameraLaunch builds on AVCam, but that relationship cannot be checked against an extracted project here.
No class/file inventory should be inferred from the embedded snippets.

Overall architecture

This diagram represents only the launch phases explicitly described by README.md:21-31 and the embedded conditional UI at lines 35-57.

flowchart LR
    Launch["App launch"] --> Critical["Critical phase"]
    Critical --> Preview["Camera preview"]
    Critical --> Shutter["Shutter button"]
    Preview --> Running["camera.status == running"]
    Running --> DeferredUI["Image well / thumbnail"]
    Running --> ModeUI["Mode or camera switch UI"]
    Session["AVCaptureSession"] --> DeferredOutput["Deferred photo output initialization"]

Reference code

README.md:35 — documentation-embedded Swift example, not an extracted source file

@State var camera: CameraModel
var body: some View {
    HStack {
        if camera.status == .running {
            ThumbnailButton(camera: camera)
        }
        CaptureButton(camera: camera)
        if camera.status == .running {
            SwitchCameraButton(camera: camera)
        }
    }
}

Interpretation

The documented design divides launch work by whether it is necessary to render preview. The shutter remains in the initial UI, while thumbnail and switch controls appear only after the camera reaches .running. The README separately defers photo-output initialization. Whether the actual sample uses the exact ownership model or file layout of AVCam is not verifiable from this archive.

Ownership and state

No source-backed ownership diagram is possible. The embedded snippet demonstrates that a SwiftUI view stores a CameraModel in @State and reads its status; it does not show where the model is constructed, what it owns, or who is authorized to mutate the status.

Documented symbol	Verifiable relationship	Unknown from archive
`camera: CameraModel`	Stored with `@State` in the README snippet	Construction site, lifetime beyond the snippet, dependencies
`camera.status`	Read to gate noncritical UI	Setter access, state machine, mutation owner
`captureSession`	Configured for automatic deferred start in a second snippet	Declaring type and ownership
`photoCapture.output`	Marked as deferred	Declaring type and ownership

Class and protocol design

The README names CameraModel, ThumbnailButton, CaptureButton, SwitchCameraButton, captureSession, and photoCapture, but contains no declarations or protocol conformances. A class diagram would invent relationships, so it is intentionally omitted.

Access control

Symbol	Access visible in extracted material	Verified effect	Limitation
README’s `camera` example	No explicit access modifier	Swift’s snippet-level default would be module-scoped in a real declaration	The containing type/source file is absent, so actual access may differ.
All named model/session/output members	Not shown	None can be verified	`private`, `fileprivate`, `private(set)`, `public`, and ownership cannot be audited.

Reference code

README.md:74 — documentation-embedded setup excerpt

captureSession.automaticallyRunsDeferredStart = true
photoCapture.output.isDeferredStartEnabled = true
captureSession.setDeferredStartDelegate(
    deferredStartDelegate,
    deferredStartDelegateCallbackQueue: sessionQueue
)

This excerpt demonstrates API use, not the declarations or access levels of its surrounding type.

Logic ownership and placement

Logic	Documented placement	What remains unknown
Gate noncritical controls on running state	SwiftUI `body` example in `README.md:35`	Actual view filename/type and model state implementation
Enable automatic deferred start	Capture-session setup excerpt in `README.md:74`	Actual service type and setup method
Manual deferred-start alternative	Described at `README.md:83-87`	Actual sample code path, if any

Design patterns

Pattern	Source evidence	Purpose or tradeoff
Two-phase initialization	`README.md:23-31`	Prioritizes preview and shutter; accepts later appearance of secondary controls.
Conditional UI composition	`README.md:35-57`	Uses camera running state as the release point for noncritical UI.
Deferred initialization	`README.md:59-87`	Avoids constructing expensive outputs on the preview-critical path.

These are documentation-supported techniques, not a complete source-derived app architecture.

Naming conventions

The examples use role names consistent with AVCam: CameraModel, CaptureButton, ThumbnailButton, and SwitchCameraButton.
Boolean/API names follow AVFoundation conventions: automaticallyRunsDeferredStart and isDeferredStartEnabled.
No file, protocol, extension, or full project naming convention can be verified.

Architecture takeaways

Treat preview as the launch-critical product outcome and delay secondary controls until the camera reports running.
Defer outputs that are not required to render preview.
Keep automatic and manual deferred-start modes explicit in session setup.
Do not use this archive as evidence for FastCameraLaunch ownership, class design, access control, or folder layout; those sources are missing.

Source map

Source file	Relevant symbols
`README.md`	Launch phases, conditional SwiftUI example, deferred-start setup example

Official Apple documentation