edui (module)

The editor UI framework, built on the CSS-parity ui.* surface. edui is editor-only — gameplay and normal UI author raw ui.* widget trees ({ type, style, props, children }) and need no framework. edui provides the one thing a framework earns its keep for: editor chrome — a reactive app, a dock shell, and chrome primitives (panels, trees, toolbars, inspector rows, context menus, drag-and-drop). It replaces the deprecated zui for the editor.

The reactive core (edui.app)

ui.* dispatches interaction through string callback ids — a widget carries props.onClick = "<id>", and the screen's registered env receives onCallback(id, data). Closures can't cross the FFI boundary, so raw ui.* makes you manage those ids by hand.

An edui app hides that. During a build it allocates an id per closure and records id→closure; its single onCallback looks the id up, calls the closure, and rebuilds:

local edui = require("@builtin::modules.edui")

local count = 0
local app = edui.createApp("counter", { layer = editorMask })
app:mount(function(a)
    return {
        type = "vertical",
        children = {
            { type = "label",  props = { text = "count: " .. count } },
            { type = "button", props = { text = "+1",
                onClick = a:cb(function() count += 1 end, "inc") } },
        },
    }
end)

• app:cb(closure, key?) — allocate a callback id for closure. Pass a stable key so the id survives rebuilds (required for focus / drag / ui.widgetState).
• app:dispatch(id, data) — what the broadcast calls; routes id→closure and rebuilds. Returns whether this app owned the id.
• app:markDirty() — request a rebuild (coalesced during an in-progress build).
• app:rebuild() / app:mount(fn) / app:unmount() — lifecycle.
• edui.current() — the app whose builder is running (the primitives use it so you don't thread the app through every call).

Builder and handler errors are logged, never thrown — one bad build never wedges the editor.