#Native MoonBit UI components

f4ah6o/yami_kumo_native is an independent MoonBit module. It imports the existing f4ah6o/yami_kumo enums and the portable layout, element, text-measurement, and scene APIs from gpui. The root Web module does not depend on this module, and its HTML/CSS APIs are unchanged.

Install the native module with:

moon add f4ah6o/yami_kumo_native

Building this module for MoonBit's native/LLVM targets requires Python 3 (python3) on PATH. GPUI 0.7.1 runs a Python prebuild during compilation to propagate macOS CoreText framework link settings. Python is needed only while building; the resulting application has no Python runtime dependency.

Windows native builds also require the Visual C++ compiler and SDK on PATH. Run the build from a Visual Studio Developer PowerShell, or initialize the environment with VsDevCmd.bat -arch=x64 -host_arch=x64 before running the Windows validation script. The script locates Git Bash from Git for Windows, checks for an importable Python 3.11 or newer interpreter, and ignores Windows Store execution aliases. Set YAMI_GIT_BASH to bash.exe if automatic Git discovery cannot find it. Set YAMI_PYTHON_PATH to the executable when it is not on PATH; the script temporarily provides a python3 forwarder so Moon's prebuild uses that interpreter without relocating it. Pass -TestsOnly to run the native package tests without opening the visible sample window. The runner checks argument boundaries, stdout, stderr, and exit status through the forwarder before running native tests.

The module source is MIT licensed; the package includes LICENSE.

The first native slice provides measured plain NativeText, square NativeButton surfaces and interaction state, a rectangular NativeCard, and a semantic NativeAppShell with header and main layout slots. The shared sample, Entity state, Flex layout, hit testing, pointer and keyboard activation are common to all three host entrypoints in examples/.

#Platform status

Host	Text measurement and display	Native UI proof
macOS	CoreText measurement and Metal scene presentation	The historical local pointer proof on Yami 086cfd1 (native 0.2.0 proof source) used GPUI's test hook to send a synthetic NSEvent through the sample's owned NSWindow. The current external CGEventPost(kCGHIDEventTap) helper route remains runtime-unqualified. The separate sample-only --ax-proof checks the Button's AXPress action and same-owner counter update through AXUIElement; neither proof covers general widget accessibility or text input.
Linux	Pango system-sans measurement and the GPUI Wayland host	Passed hosted E2E: XTest input is delivered through Xvfb and Weston's X11 backend, with completed-frame readback. The runner pins both generic sans aliases to the same DejaVu Sans file for matching measurement and rendering.
Windows	DirectWrite Segoe UI measurement and the GPUI Windows host	Passed hosted E2E: Win32 SendInput targets the uniquely titled visible HWND, with completed-frame readback. The sample also tests a copied Button projection with owner/layout freshness checks; no UI Automation provider or assistive-technology action transport is implemented.

The hosted macOS lane builds GPUI's test-hook library, runs the CoreText and shared native package tests, and compiles the Yami macOS sample. It does not launch a window or exercise runtime rendering or input, so it is build and portable-test evidence rather than a hosted native UI proof. Its external helper guard fixtures use fake posters only and send no native events.

The earlier local macOS pointer proof passed on Yami 086cfd1 with approved GPUI candidate ae45429; its tree is identical to merged GPUI revision 2c6e9a3df469922f79d7b2b8eb977a0524086486. Hosted Linux and Windows proofs passed in native UI CI run 37808645019 on those same source trees, qualifying native 0.2.0. The macOS pointer proof used GPUI's test hook to deliver a synthetic NSEvent through the sample's owned NSWindow. Native 0.2.3 used GPUI 0.7.0; its hosted proofs remain tied to the exact source revisions recorded by their CI run. Native 0.2.4 updates the module dependencies to GPUI 0.7.1 and the pure MoonBit module f4ah6o/yami_kumo 0.1.1. The native UI workflows now pin the reviewed GPUI source at gpui-revision.txt. Native 0.2.5 updates that dependency to GPUI 0.7.2 and includes stricter per-event target revalidation, bounded AX/helper lifetimes, owned input cleanup, and explicit zero-modifier events for the opt-in macOS sample runner. These guard fixtures use fake event posters only. The current external-input route remains unqualified at runtime, as detailed below.

These checks cover labeled Text and Button rendering, readback of a completed native frame, and a host-delivered click that changes the sample's App Entity and counter text. Headless tests and cross-compilation alone do not count as a native UI pass. The current macOS helper is designed to post synthetic mouse and Escape events via the global HID event tap only after an unlocked on-console and Accessibility preflight. It rechecks the complete target snapshot before every event, including the exact frontmost PID, focused AXWindow, unique visible WindowServer window and frame, and (for clicks) the current Button, topmost point owner, and AX hit ancestry. Each AX object receives a bounded messaging timeout, and the runner bounds the helper process and records sample cleanup on failure. The helper records pending input before its down post. If a release guard changes, cleanup is zero-modifier and PID-targeted to the original process; a click remains failed if its global release was refused. Escape may use that release only when the original window is gone or the target process has exited, and the driver still requires the sample completion marker. The inert --guard-fixtures mode tests the production guard/post seam with fake posters and never sends native input. Linux uses XTest and Windows uses Win32 SendInput. None of these checks claims physical-hardware input coverage. They do not qualify a native text editor, an Input component, or IME behavior. The browser Input API remains separate.

The current macOS external-input route has not yet been run end-to-end on this source tree: the local console was locked during qualification. The helper's read-only preflight confirmed the locked state and refused before launching the sample. The historical native 0.2.0 test-hook proof above does not qualify this external CGEventPost input route.

The hosted macOS build lane compiles the external Objective-C helper but does not launch it or the sample window; that lane does not count as runtime UI qualification.

The macOS AX proof is an additional sample-only lane: the current Button snapshot is published with its enabled state and activation count, and an AXPress request increments the same sample-owned App Entity. Snapshot owner and layout generations reject requests from another sample or an invalidated layout. This is not a general accessibility API for NativeButton, and it does not qualify VoiceOver interaction quality or text/IME support.

The Windows sample copies its current Button semantics through GPUI's transport-free AccessibilityProjection; its fixture checks immutable node data, supported Invoke actions, owner freshness and layout-generation revalidation before the same sample-owned App Entity can change. The Windows adapter has no UI Automation provider and returns no host requests, so this is contract coverage rather than an assistive-technology proof.

#Kumo visual subset

Colors are derived from the pinned styles/kumo-standalone.css generated from Kumo 2.14.0. OKLCH tokens are converted through OKLab to linear sRGB, gamma encoded, clamped, and rounded to the nearest 8-bit channel. Alpha is rounded separately; the light control-line token's 10% opacity becomes alpha 26.

Role / source token	Light RGBA	Dark RGBA
Base canvas: white / kumo-neutral-925 at 17%	(255,255,255,255)	(15,15,15,255)
Elevated surface: kumo-neutral-75 at 98% / kumo-neutral-975 at 12%	(248,248,248,255)	(6,6,6,255)
Default text: neutral-900 at 20.5% / neutral-100 at 97%	(23,23,23,255)	(245,245,245,255)
Subtle text: neutral-500 / neutral-400	(115,115,115,255)	(161,161,161,255)
Link and generated TextVariant::Success mapping: blue-800 / blue-400	(25,60,184,255)	(81,162,255,255)
Error and SecondaryDestructive text: red-700 / red-400	(193,0,7,255)	(255,100,103,255)
Destructive control fill: red-500 / red-600	(251,44,54,255)	(231,0,11,255)
Brand fill: kumo-brand	(5,109,255,255)	(0,90,235,255)
Hairline: kumo-neutral-150 / neutral-800	(233,233,233,255)	(38,38,38,255)
Control line: black at 10% / kumo-neutral-750	(10,10,10,26)	(51,51,51,255)

The native renderer uses plain system sans text and solid quads. It intentionally does not claim Kumo gradients, rounded corners, shadows, font-weight variants, or the browser's color-mix compositing. The fixed system-sans text pipeline rejects Mono and MonoSecondary instead of measuring with one font and rendering with another. Measured text items keep the complete copied TextMeasurement and use the union of logical and ink bounds, including negative glyph overhangs.

Component IDs are caller-owned. A Text uses its ID. A Card reserves id..id+4 for its fill and border; a Button reserves id..id+5 for its background, label, and border. Keep those ranges disjoint from every other scene item in a snapshot.

#Input and IME follow-up

Button activation is implemented in MoonBit: a matching primary down/up pair activates once; Enter/Space use matching key-down/key-up while the Button owns focus. Disabled controls, an outside primary release, focus loss, and layout invalidation cancel pending gestures. This does not establish text editing or IME behavior.

The GPUI host capabilities differ by platform. The macOS host guide covers bounded single-line measurement and drawing; a native editor and IME are not implemented. The Ubuntu text-field guide documents an experimental single-line LTR field with caret, selection, undo, and a private direct-keyboard route. Public TextInput and IME transport are not supported; the Wayland IME transport is private opt-in work and is not qualified. The Windows host guide describes a focused single-line field and a private, default-off IMM32 session; real Japanese IME and candidate-window behavior are not qualified.

Before exposing NativeInput, Yami needs shared focus and edit ownership plus per-platform committed-text, composition, and caret integration with separate tests. The native Button click/frame proof above does not qualify text input or IME support.

#Maintainer checks

These checks use scripts in the Yami source repository and are for maintainers; they are not required when consuming the published module. The cross-platform native UI scripts create a temporary Moon workspace that links the Yami and gpui checkouts without adding a local workspace manifest to either repository. From the Yami-kumo repository root, set GPUI_SOURCE when the GPUI checkout is not the sibling ../gpui.mbt:

YAMI_SOURCE=$PWD
GPUI_SOURCE=/path/to/gpui.mbt sh "$YAMI_SOURCE/scripts/native_ui_workspace.sh" \
  sh "$YAMI_SOURCE/scripts/native_ui_tests.sh"
GPUI_SOURCE=/path/to/gpui.mbt sh "$YAMI_SOURCE/scripts/native_ui_macos.sh"
GPUI_SOURCE=/path/to/gpui.mbt sh "$YAMI_SOURCE/scripts/native_ui_macos.sh" --ax-proof
GPUI_SOURCE=/path/to/gpui.mbt sh "$YAMI_SOURCE/scripts/native_ui_linux.sh"

The hosted macOS build and portable checks can be run locally without opening the sample window:

GPUI_SOURCE=/path/to/gpui.mbt sh "$YAMI_SOURCE/scripts/native_ui_macos.sh" --build-and-test

On Windows, run scripts/native_ui_windows.ps1 from PowerShell with the native MoonBit toolchain and Visual C++ build tools installed. The host-specific E2E scripts build and run examples/{macos,ubuntu,windows}; they save native PPM captures and logs in _build/native-ui/<platform> by default. The Linux run requires Xvfb, Weston, XTest/xdotool, and the GPUI Wayland dependencies; macOS requires Xcode command-line tools.

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