Skip to content

apple-development.md

Latest commit

 

History

History
63 lines (49 loc) · 2.76 KB

apple-development.md

File metadata and controls

63 lines (49 loc) · 2.76 KB
Raw

Apple development

Experimental CPU path for iOS 15+. Default Flutter capture remains RepaintBoundary. Native capture is opt-in (TugboatScreenshotCaptureBackend.nativeCpuExperimental).

Layout

Path Role
Package.swift Root SwiftPM entry
TugboatCaptureRuntime.podspec Root CocoaPod (version 0.1.0)
platforms/apple/Sources/TugboatCaptureRuntime Public Swift API
platforms/apple/Sources/TugboatImageCoreBridge Objective-C++ bridge to the C ABI
platforms/apple/Tests XCTest (MaskMapper, runtime constants)
platforms/apple/Sample Usage notes, not a full Xcode app
sdks/flutter/packages/tugboat/ios Pigeon plugin; depends on CocoaPods TugboatCaptureRuntime

Do not copy core/image-processing into the published pub package. The Flutter plugin depends on CocoaPods TugboatCaptureRuntime 0.1.0 and requires iOS 15. The example app path-overrides the pod to this repository. Native capture still reports unsupported below iOS 15 on devices that somehow run a lower OS; hosts must set iOS 15 as the floor.

Capture

The default runtime renders the live Flutter view with view.layer.render(in:) into a BGRA bitmap whose size is the Dart request (pixelWidth × pixelHeight). FlutterView implements CALayerDelegate, which is intended to rerender the last Flutter layer tree into CPU-readable memory. Core Graphics does not copy CAMetalLayer contents by itself, so physical Metal coverage is still an open lab gate; simulator output is not that gate. Coverage is reported as engineSurface. Embedded UIKit platform views are not guaranteed.

Native Apple integrations can initialize CaptureRuntime with coverage: .viewHierarchy. That compatibility mode uses drawHierarchy(in:afterScreenUpdates: false), reports viewHierarchy, and sets incomplete when the draw returns false. The Flutter plugin uses the default engine-surface coverage.

Masks and dHash go through the C++ core. JPEG is ImageIO quality 80. SHA-256 is CryptoKit over the JPEG. Raw pixels never enter Dart.

View capture runs on the main thread. Mask fill, dHash, JPEG, and SHA-256 run on the serial tugboat-capture queue. Timeout is 2000 ms covering readback plus processing. Status × fallback matches native-capture-contracts.md.

Public Swift surface golden: platforms/apple/api.txt (bash tool/ci/verify-swift-api.sh).

Build

Requires Xcode. This Linux CI host cannot compile for simulator or device.

swift test --package-path .  # needs Xcode / iOS SDK

publish-apple.yml pushes TugboatCaptureRuntime 0.1.0 to CocoaPods trunk when COCOAPODS_TRUNK_TOKEN is set. The live-layer path uses Flutter's existing Metal readback. It does not call private Flutter selectors directly.