Users can now launch Kapture at login, keep multiple screenshot windows open
at once, and copy a screenshot to the clipboard. Builds sign with a Developer
ID identity when present, falling back to the ad-hoc self-signed key, so
Screen Recording permission survives rebuilds.
💘 Generated with Crush
Assisted-by: Crush:deepseek-v4-flash-0731
113 lines
6.5 KiB
Markdown
113 lines
6.5 KiB
Markdown
# AGENTS.md
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Kapture is a native macOS menu-bar screenshot + OCR app written in Swift/SwiftUI.
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Single executable SwiftPM package, no external dependencies (all Apple frameworks).
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## Architecture
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Control flow for the main path: menu bar → hotkey → overlay → capture → result window → OCR.
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- `Sources/Kapture/App.swift` — `@main` entry. `MenuBarExtra` menu, `AppDelegate`
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(wires hotkey → `CaptureController.begin()`; handles `--test-ocr`), `PermissionManager`
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(wraps `CGPreflightScreenCaptureAccess` / `CGRequestScreenCaptureAccess`).
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- `Sources/Kapture/HotkeyManager.swift` — Carbon `RegisterEventHotKey`, hardcoded
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⌘⇧S (`kVK_ANSI_S`, `cmdKey | shiftKey`), signature `0x4B505452`.
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- `Sources/Kapture/CaptureController.swift` — selection flow. Creates one borderless
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`NSPanel` overlay per screen, then captures via `ScreenCapture` and hands the image
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to `ResultWindow`. Coordination happens in `begin()`/`finishSelection()`/`cancelSelection()`.
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- `Sources/Kapture/ScreenCapture` (same file) — macOS 14+: ScreenCaptureKit
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`SCScreenshotManager` + manual pixel-space crop (`display.width / display.frame.width`
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scale); macOS 13: `CGWindowListCreateImage` fallback.
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- `Sources/Kapture/OverlayView.swift` — `NSPanel` + `NSView` drawing overlay; mouse-driven
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rect selection (min 2×2 pt), Escape (keyCode 53) cancels; selection committed via
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`window.convertToScreen` (screen coordinates).
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- `Sources/Kapture/OCRService.swift` — Vision `VNRecognizeTextRequest`, `.accurate`
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level, languages `["en-US", "zh-Hans", "zh-Hant", "ja-JP", "ko-KR"]`. Custom
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line-order sort: observations sorted top→bottom by `boundingBox.midY` (tolerance
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`0.02`), then left→right. Runs on a private serial `DispatchQueue`
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(`dev.tzgyn.kapture.ocr`), completes on that queue — callers must hop back to main.
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- `Sources/Kapture/ResultWindow.swift` — `ResultWindow.show(image:)` (single shared
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floating window, closes previous), `CaptureModel` (ObservableObject, `@Published`
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`mode` = screenshot/text), `ResultView` (SwiftUI, Screenshot/Text tabs, Get Text /
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Save PNG / Copy Text).
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Singletons everywhere: `HotkeyManager.shared`, `CaptureController.shared`,
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`ScreenCapture.shared`, `OCRService.shared`, `ResultWindow.shared`.
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Note: packaging references `dev.tzgyn.kapture` as the bundle identifier — match this
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in any new code (queue labels, TCC/plist references).
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## Commands
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```bash
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swift build # debug build (also: swift run Kapture)
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swift build -c release # release build (what build-app.sh uses)
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swift run Kapture # dev run from terminal (app appears in Dock)
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swift run Kapture --test-ocr # OCR smoke test: renders text, OCRs it, prints PASS/FAIL, exit 0/1
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./build-app.sh # release build + Kapture.app bundle + icon + ad-hoc codesign
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./release.sh <version> # e.g. ./release.sh 1.0.1: builds app, zips to dist/Kapture.zip, prints sha256
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scripts/make-icon.sh # regenerates Kapture.app/Contents/Resources/Icon.icns from scripts/gen-icon.swift
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```
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There is no test target and no linter/formatter configured. Verification = build +
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`--test-ocr`.
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## Bundle build & signing
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`build-app.sh` does: release build → handwritten `Info.plist` (NOT generated from
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`Package.swift`) → `make-icon.sh` → `codesign` with self-signed identity `kapture-dev`
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stored in a dedicated keychain at `~/.config/kapture/signing.keychain-db` (not the
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login keychain). Honest bugs to keep in mind:
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- Uses `security create-keychain`/`unlock-keychain` with a hardcoded password
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(`kapture-dev`) — if the cert creation fails midway, the keychain may be left in an
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undefined state; the script is mostly idempotent but re-run it before assuming failure.
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- The self-signed cert is created with Homebrew OpenSSL (`/opt/homebrew/bin/openssl`,
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falls back to `/usr/local/bin/openssl`, then system `openssl`) and imported as a
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pkcs12 (`-export -legacy`). The legacy flag is important — modern OpenSSL defaults
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to formats the macOS `security` tool rejects.
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- `LSUIElement` = true → no Dock icon. Info.plist also hardcodes
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`CFBundleShortVersionString` 1.0 / `CFBundleVersion` 1 — bump here for releases,
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and match it in `release.sh` args.
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macOS may require re-granting Screen Recording permission when the binary identity
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changes (TCC tracks the binary, not the source).
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## Release process
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1. `./release.sh <version>` — builds, zips `Kapture.app` to `dist/Kapture.zip`,
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prints its sha256 (that's all it does, it does not tag or upload).
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2. Tag `git tag v<version> && git push origin v<version>` and attach the zip to a
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GitHub release manually (the old `.github/workflows/release.yml` was removed;
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`release.sh` output still says the workflow will upload the zip, which is stale).
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3. The Homebrew cask lives in `TZGyn/homebrew-tap` — bump `version` and `sha256`
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there for each release.
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Icon note: the cask references the `Icon.icns` built into the app bundle, so no
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separate icon release step needed.
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## Gotchas
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- Coordinate spaces differ: overlay selections are in global screen points
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(via `convertToScreen`), ScreenCaptureKit images are in pixels and the crop must
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scale by `display.width / display.frame.width`. Don't mix them.
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- Starting on macOS 13 vs 14 changes the capture path: 13 uses the `CGWindowListCreateImage`
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fallback, which only handles the primary screen (`frame.origin == .zero`) and
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needs explicit Y-flip (`primary.frame.height - rect.maxY`). Get selection rect
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handling wrong on one path and you break only one OS version — test on both.
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- When selection overlays are active for more than one screen macOS may also be
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capturing the overlay panels themselves while the selection is running; the overlay
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windows' `windowNumber` IDs are collected in `begin()` and excluded via
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`SCContentFilter(excludingWindows:)` when capturing. If you add any new window that
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shows during overlay/selection, add it to the exclusion set.
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- The OCR completion runs on a background queue — never touch `CaptureModel`/UI from
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it; `runOCR` hops to `@MainActor` via `Task { @MainActor in ... }`.
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- `--test-ocr` is processed in `AppDelegate.applicationDidFinishLaunching` and must
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`exit()` with 0/1 inside the completion; the `RunLoop.main.run()` after is what keeps
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the process alive until the async OCR finishes. If OCR returns empty text it
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doesn't crash — just prints FAIL.
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- No `@MainActor` annotations on AppDelegate / HotkeyManager; keep new code on main
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thread for AppKit calls.
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- `.gitignore` covers `.build/`, `Kapture.app/`, `dist/` — build artifacts should
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never be committed.
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