UI.Orbit
luastra/uiUI.Orbit(input: Input): Node
Creates the bounded root for Constellation Orbit navigation and delegates geometry, semantic zoom, focus movement, inactive-depth isolation, themes, and reduced-motion behavior to the host.
Mental model
This is a declarative node: app.render describes it again from current state, while the host matches its stable id to the existing view.
Before you use it
Add luastra/ui to this module's dependencies in luastra.json, then import it with require("luastra/ui"). The project must declare the ui.render capability. app.render must return one UI.Screen root; place this node inside that tree rather than invoking it for a hidden side effect.
How it fits
The constructor validates its fields immediately and returns a UI.Node. After app.render returns, the host reconciles that node by stable id with the current semantic DOM-based interface. Current desktop and mobile hosts package the same web artifact; native adapters are used at capability boundaries.
When to use it
Use UI.Orbit when an application benefits from spatial discovery while still requiring a complete list fallback, stable navigation state, keyboard access, and identical meaning across host presentations.
Shared parameter groups
Parameters
| Parameter | Type / values | Description |
|---|---|---|
| id | lowercase path, required | Unique Orbit ID. |
| presentation | auto | spatial | list? | Preferred presentation; unsafe spatial geometry still falls back to list. |
| orbitTheme | built-in theme ID? | One of the curated Orbit themes. |
| orbitMotion | system | off? | Orbit-owned motion preference. |
| maxVisible | integer 4…32? | Density bound before list fallback. |
| children | OrbitPath | OrbitSearch | Constellation | FocusSurface[] | Orbit experience content with at least one constellation. |
| gap | none | xs | sm | md | lg | xl | Space between children. Group: Layout and surfaces. |
| padding | none | xs | sm | md | lg | xl | responsive | All-side inner spacing; responsive is supported only by padding. Group: Layout and surfaces. |
| margin | none | xs | sm | md | lg | xl | All-side outer spacing. Group: Layout and surfaces. |
| paddingX / paddingY | none | xs | sm | md | lg | xl | Axis-specific inner spacing. Group: Layout and surfaces. |
| paddingTop / paddingBottom / paddingStart / paddingEnd | none | xs | sm | md | lg | xl | Logical side-specific inner spacing. Group: Layout and surfaces. |
| marginX / marginY | none | xs | sm | md | lg | xl | Axis-specific outer spacing. Group: Layout and surfaces. |
| marginTop / marginBottom / marginStart / marginEnd | none | xs | sm | md | lg | xl | Logical side-specific outer spacing. Group: Layout and surfaces. |
| surface | plain | card | elevated | accent | Background, border, and elevation. Group: Layout and surfaces. |
| width | full | content | wide | Available width, 720 px maximum, or 1180 px maximum. Group: Layout and surfaces. |
| align | start | center | end | stretch | between | Cross-axis alignment. Group: Layout and surfaces. |
| justify | start | center | end | between | Main-axis alignment. Group: Layout and surfaces. |
| flow | wrap | nowrap | Flex wrapping. Group: Layout and surfaces. |
| responsive | boolean | Narrow-screen adaptation. Group: Layout and surfaces. |
| className | safe string ≤ 256 bytes | Additional admitted class tokens. Group: Layout and surfaces. |
| tone | muted | error | success | Semantic text tone. Group: State and semantics. |
| appearance | primary | secondary | danger | ghost | Action appearance. Group: State and semantics. |
| variant | body | subheading | heading | title | Body text or h3, h2, and h1 heading semantics. Group: State and semantics. |
| role | alert | group | status | Supported ARIA role. Group: State and semantics. |
| label | string | Accessible name. Group: State and semantics. |
| hidden | boolean | Visibility state. Group: State and semantics. |
| disabled | boolean | Disabled state. Group: State and semantics. |
| busy | boolean | aria-busy state. Group: State and semantics. |
| required | boolean | Required input state. Group: State and semantics. |
| errorId | component id | Associates a visible role=alert. Group: State and semantics. |
| textColor | token | #RRGGBB | Local or inherited foreground. Group: Text and local colors. |
| backgroundColor | token | #RRGGBB | Component-box background. Group: Text and local colors. |
| Color tokens | accent | danger | muted | surface | success | text | transparent | warning | Current Screen theme colors. Group: Text and local colors. |
Children and layout
Orbit experience content with at least one constellation.
Accessibility and keyboard
The host preserves one semantic model across spatial and list presentations and isolates every inactive constellation from interaction.
Common mistakes
- Adding application-owned absolute coordinates.
- Assuming spatial mode is guaranteed when bounds require the list fallback.
Returns
Node — a validated declarative UI node that becomes part of the next host-neutral render tree.
What happens next
A validated declarative node appears after it is returned as part of the current render tree.
Failures and fixes
Invalid fields, duplicate IDs, unsupported child combinations, or a missing ui.render capability fail during check, render-tree validation, or host startup.
Availability
Experimental Constellation Orbit API in 0.5.0-alpha. Verify it against the selected SDK before depending on its shape.
Focused example
UI.Orbit {
id = "map",
label = "Application map",
UI.Constellation {
id = "map/root",
UI.OrbitCenter { id = "map/root/center", title = "My app" },
UI.OrbitNode { id = "map/start", title = "Start", onTap = "start" },
},
}Continue with a complete recipe
This checked recipe uses UI.Orbit inside complete authored files with the required manifest, test, and run steps.
Open build a small Constellation Orbit recipe