Skip to content
niso

Apple platforms

Checked against c1b2fa4 on 2026-11-10. The files it covers are unchanged since.

The Apple host (hosts/apple) is one SwiftUI app that builds for iOS, iPadOS, macOS, visionOS, tvOS and watchOS. One page runs on all of them, and its widgets, Live Activity and CarPlay screens come from the same page. On macOS it’s native SwiftUI on AppKit, not Mac Catalyst, so its controls are Mac controls.

Build and run

Section titled “Build and run”
Terminal window
hosts/apple/build.sh                              # examples/counter on the iOS simulator
hosts/apple/build.sh --platform macos counter     # a Mac app, launched
hosts/apple/build.sh --platform macos --page DIR  # your own HTML page
hosts/apple/build.sh --platform ios --no-launch   # a device build (needs provisioning to install)

--platform is ios-sim (the default), ios, macos, tvos-sim, tvos, visionos-sim, visionos, watchos-sim or watchos. The script builds the core for that platform’s Rust target, compiles the host with swiftc (no Xcode project) and leaves an ad-hoc signed app in target/ios or target/apple/<platform>. The step-by-step setup is in Apple apps.

An app runs one of three things: a JS bundle (the examples), an HTML page and its files (--page), served at the app’s own origin https://<bundle id>.app.niso/, or a native app library in any language (--app LIB, see Native apps).

What each platform gets

Section titled “What each platform gets”

Every platform builds for its simulator and its device, and counter runs on each simulator. The details, including what’s missing per platform, are in the host’s own notes: The Apple host. In short:

  • iOS and iPadOS: taps; hover from a trackpad or mouse; Liquid Glass buttons, switches, sliders, pickers and text fields; one window (no second iPad window).
  • macOS: every mouse button, hover, wheel and trackpad scrolling, and keys with UI Events key and code values. The core doesn’t fire resize or contextmenu yet.
  • visionOS: look and pinch is a pointer; visionOS’s own buttons on glass. No ornaments: a page can’t declare one yet.
  • tvOS: the Siri Remote arrives as keys (arrows, Enter, Escape). Spatial navigation and the focus ring are planned (on the tv-input branch, not on main yet).
  • watchOS: taps, the Digital Crown scrolls, the system’s text input. Fixed colors on black and one text size.

Beyond the app

Section titled “Beyond the app”
  • Widgets and Live Activities come from surfaces the page declares (hosts/apple/Widgets, published by Sources/SurfacePublisher.swift). See Surfaces and Add a home screen widget.
  • Now Playing on the Lock Screen and Control Center comes from the page’s media session (Sources/Media.swift): Media session.
  • CarPlay shows a carplay.list surface as a list template and the media session as Now Playing (Sources/CarPlay.swift). It’s verified inside the app only (tests/carplay/check.sh): no CarPlay screen has shown these templates yet, because the Xcode 27 simulator’s CarPlay window was unavailable.

Appearance

Section titled “Appearance”

The host publishes the platform’s semantic colors, text styles and the user’s settings (dark mode, Bold Text, Increase Contrast, Dynamic Type, the accent color on a Mac) to the page as CSS variables and media queries, and updates them live (Platform style, System settings).