# Tree View (Lumen Halo): prompt.md (v1.0.0)

- id: `lumen-tree-view` · version 1.0.0 · component · pro (Pro)
- category: Navigation
- build: Base UI (one set of files; its dependencies follow the build)
- install (this build): `npx shadcn@latest add @beautiful-ui-pro/lumen-tree-view`
- npm dependencies: none
- registry dependencies: utils, https://beautiful-ui.dev/r/lumen-foundation.json
- docs: https://beautiful-ui.dev/components/lumen-tree-view
- The install command carries everything this item needs (files, CSS, tokens, npm and registry dependencies). Prefer it to copying source by hand.

Nested folders and files the WAI-ARIA tree way: one tab stop, arrows that move and open, typing to jump to a name, single or multiple selection, hairline guides down each open folder.

## Build it
- Stack: React 19 (`ref` is a plain prop), TypeScript, Tailwind CSS v4 utilities, a shadcn-initialised project with the `@/*` alias.
- Packages: none beyond React.
- Files: `components/ui/lumen/controls/tree-view.tsx`.
- Registry dependencies, installed with it automatically: shadcn `utils` (cn), `lumen-foundation`.
- Builds: one set of files for both, but its dependencies come in Base UI and Radix builds. Install the one that matches the project (see Install): a free item's bare URL installs the Base UI build of it and its dependencies.
- Exports to keep: `TreeView`, `(item)`, and every exported type.
- CSS: the install merges this item's rules (the registry `css` field) into your global stylesheet, in `@layer components`, and adds the lumen foundation (tokens, keyframes, motion levels) once. Nothing to import by hand.
- Re-running `add` (or `--overwrite`) re-applies those rules: put overrides in your own CSS, never in the installed rules.
- Tokens: retheme with the `--lumen-*` custom properties (`--lumen-accent`, `--lumen-accent-foreground`, `--lumen-accent-text`, `--lumen-bad`, `--lumen-bad-text`, `--lumen-chart-accent`, `--lumen-chart-accent-foreground`, `--lumen-chart-accent-text`, `--lumen-focus`, `--lumen-good`, `--lumen-good-text`, `--lumen-hairline`, `--lumen-ink`, `--lumen-muted-ink`, `--lumen-series-1`, `--lumen-series-2`, `--lumen-series-3`, `--lumen-series-4`, `--lumen-series-5`, `--lumen-series-6`, `--lumen-warn`, `--lumen-warn-text`); this item's CSS also reads `--lumen-font-mono`, `--lumen-font-sans`, `--lumen-radius-k`. Never add Tailwind colour classes inside the component.

```tsx
import { TreeView, type TreeNode } from "@/components/ui/lumen/controls/tree-view";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `TreeView` | — | The tree. |
| `(item)` | — | A treeitem: its row (tree-row) and, when open, its group (tree-group). |

## Sound
- Keep every `data-slot` and `data-sound` attribute: the sound layer reads them.
- Installing this item adds no audio. Nothing plays until the app mounts `GlassSoundProvider` once (install: `npx shadcn@latest add https://beautiful-ui.dev/r/glass-sound.json`, import from `@/components/beautiful-ui/glass-sound`); `GlassSoundToggle` is its mute control. Without a provider the audio engine never loads.

## Match the original
- Read `components/ui/lumen/controls/tree-view.tsx` as the reference implementation before changing or recreating anything, and match it: sizes, colours per theme, motion timings, copy and behaviour.
- If you deviate (a prop you can't honour, a style you changed, a dependency you swapped), say so in your reply, part by part.
- Keep the accessibility contract, the keyboard map and the motion levels listed below.

## Use it when
- tree view, file tree, folder tree, nested list, file explorer, hierarchy, outline, sidebar tree, directory
- Files and folders, a document outline, nested categories, an org chart as a list
- Any hierarchy deeper than two levels that people browse

### Not when
- One level of links: use Sidebar or a list
- Hierarchies you pick one value from in a form: use Combobox

## Mistakes
- Ids must be unique across the whole tree, not only among siblings
- Give the tree an aria-label

## Usage

```tsx
"use client";

import { TreeView, type TreeNode } from "@/components/ui/lumen/controls/tree-view";

const files: TreeNode[] = [
  {
    id: "src",
    label: "src",
    children: [
      { id: "src/app", label: "app", children: [{ id: "src/app/page.tsx", label: "page.tsx", meta: "2 KB" }] },
      { id: "src/lib/utils.ts", label: "utils.ts", meta: "1 KB" },
    ],
  },
  { id: "package.json", label: "package.json", meta: "3 KB" },
];

export function FileTree({ onOpen }: { onOpen: (path: string) => void }) {
  return <TreeView aria-label="Files" items={files} defaultExpanded={["src"]} onActivate={(node) => onOpen(node.id)} />;
}
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `items` | `{ id, label, icon?, meta?, children?, disabled? }[]` |  | The tree. A node with children is a folder. |
| `aria-label` | `string` |  | Names the tree, e.g. "Files". |
| `expanded / defaultExpanded / onExpandedChange` | `string[] / string[] / (ids: string[]) => void` |  | Open folder ids. |
| `selected / defaultSelected / onSelectedChange` | `string[] / string[] / (ids: string[]) => void` |  | Selected ids. |
| `selectionMode` | `"single" \| "multiple" \| "none"` | `"single"` | none makes a navigable outline. |
| `onActivate` | `(node) => void` |  | Enter, or a double click on a file. |

Full docs: https://beautiful-ui.dev/components/lumen-tree-view

## Customising
- Colours: set the `--lumen-*` tokens on `:root`, or on a container with the `lumen-scope` class to retheme one area. Add the `lumen-inherit` class to follow your shadcn palette instead (`--chart-N`, `--destructive`).
- Dark mode follows the `.dark` class on an ancestor (the shadcn and next-themes convention).
- Update later by re-running the install with `--overwrite` (review the diff if you edited it). Changelog: https://beautiful-ui.dev/r/changelog.json

## Keyboard

| Keys | Action |
|---|---|
| Up / Down | Previous / next visible row (Shift extends in multiple mode) |
| Right | Open a folder, or go to its first child |
| Left | Close a folder, or go to its parent |
| Home / End | First / last row |
| Enter | Select and activate (opens or closes a folder when there's no onActivate) |
| Space | Select (toggle in multiple mode) |
| * | Open every folder at this level |
| Letters | Jump to the next name that starts with what you typed |
| Ctrl or Cmd + A | Select all visible rows (multiple mode) |

## Motion inventory

| Interaction | What moves |
|---|---|
| Open a folder | Its chevron turns and the children rise 3px into place; reduced motion skips both |

## Accessibility contract (preserve when editing)
- role=tree with treeitems that carry level, position, expanded and selected; groups for children
- One tab stop (roving focus); aria-multiselectable in multiple mode
- Disabled rows are announced and skipped by the arrows

## Install

```bash
npx shadcn@latest add @beautiful-ui-pro/lumen-tree-view
```

Pro item: needs the `@beautiful-ui-pro` registry in `components.json` and `BEAUTIFUL_UI_TOKEN` in `.env.local` (https://beautiful-ui.dev/account). Setup: https://beautiful-ui.dev/docs/pro. Your components.json `style` picks the build: radix-*, new-york and default get Radix, base-* gets Base UI.

## Credits
- Built on shadcn/ui (https://ui.shadcn.com)

The lumen foundation (the tokens listed above, keyframes and motion levels) installs once with the first component; its CSS is public at https://beautiful-ui.dev/r/lumen-foundation.json.