dmg_background

A browser-local editor for creating macOS DMG background assets and a versioned Finder layout manifest. It exports design inputs for a separate macOS packager; it does not create, sign, or notarize a .dmg.

简体中文

Pre-release maturity: v0.1.0 is the first versioned public release. No non-maintainer workflow has been recorded yet, so this is not a stable claim.

Open the browser editor

Download v0.1.0 and verification assets

Why This Exists

macOS application maintainers repeatedly need to align a Finder window, background artwork, an application icon, and the Applications alias. The visual work is easier in a browser, while final image creation still requires macOS tools and release credentials. dmg_background keeps those concerns separate.

Output

The editor downloads one ZIP with exactly five members:

.background/background.png
.background/background@2x.png
preview.png
dmg_layout.json
README.txt

The two files under .background/ contain artwork, text, and the direction arrow, but never simulated Finder icons. preview.png includes simulated icons for review. dmg_layout.json records logical Finder content coordinates for a separate packager.

See Contract for compatibility rules and Product scope for explicit non-goals.

Capability

• Human-usable: the browser editor can create and download the asset ZIP.
• Machine-readable: the ZIP contains a versioned JSON layout document.
• Not Agent-callable: there is no MCP server, transport, hosted API, authentication layer, or Agent registration.
• Not a DMG packager: there is no hdiutil, Finder automation, signing, or notarization integration.

A machine-readable file contract does not by itself make a product Agent-callable.

Requirements

• Rust 1.85 or newer
• wasm32-unknown-unknown target
• wasm-pack 0.15.0
• Node.js 24 or newer for the Chromium suite

Develop

Run native and WASM checks from the repository root:

cargo fmt --all -- --check
cargo test --workspace --locked
cargo clippy --workspace --all-targets --locked -- -D warnings
cargo check -p dmg_background_web --target wasm32-unknown-unknown --locked

Build and serve the editor locally:

wasm-pack build --target web crates/dmg_background_web \
  --out-dir static/pkg --out-name dmg_background_web -- --locked
python3 -m http.server 4173 --directory crates/dmg_background_web/static

Open http://127.0.0.1:4173/.

Run the real WASM browser suite:

cd crates/dmg_background_web
npm ci
npx --no-install playwright install chromium
npm run test:wasm-smoke:local

Generated pkg/, node_modules/, Rust target/, and browser artifacts are ignored and must not be committed.

Privacy

Selected PNG or JPEG files and generated ZIP bytes stay in browser memory until the user downloads them. The application has no upload path, analytics, cookies, remote API, persistence, or external font dependency. Installing dependencies can contact the configured Cargo and npm registries.

See Security for input and resource boundaries.

Contributing

Read Contributing before opening a pull request. Public commit subjects and bodies use English Conventional Commits.

License

MIT. See LICENSE.