# Now Playing (Notchset): prompt.md (v1.0.0)

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

A compact player bar with a pulsing dot-matrix cover, sliding titles and an equaliser that unrolls into chapters, a chapter seek ruler, speed and the queue.

## 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/notchset/now-playing.tsx`; shared code: `lib/beautiful-ui/notchset/instrument.tsx`, `lib/beautiful-ui/notchset/root.ts`, `lib/beautiful-ui/notchset/calendar.tsx`.
- Registry dependencies, installed with it automatically: shadcn `utils` (cn), `segmented-control`, `notchset-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: `NowPlaying`, and every exported type.
- CSS: the install adds the notchset foundation (tokens, keyframes, motion levels) to your global stylesheet 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 `--notchset-*` custom properties (`--notchset-check`, `--notchset-control-edge`, `--notchset-draw-from`, `--notchset-ease-bloom`, `--notchset-ease-travel`, `--notchset-fade`, `--notchset-focus-color`, `--notchset-focus-inset`, `--notchset-life-from`, `--notchset-life-ms`, `--notchset-node-blink`, `--notchset-node-bloom`, `--notchset-node-delay`, `--notchset-plate-color`, `--notchset-rise-from`, `--notchset-rule`, `--notchset-scroll`, `--notchset-signal`, `--notchset-sweep-to`). Never add Tailwind colour classes inside the component.

```tsx
import { NowPlaying } from "@/components/ui/notchset/now-playing";
```

## Parts

| Part | data-slot | What it is for |
|---|---|---|
| `NowPlaying` | `now-playing` | Bar and panel. |

Style a part with `[data-slot="<slot>"]` selectors or its `className`; keep the attributes when editing.

## 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 `SoundProvider` once (install: `npx shadcn@latest add https://beautiful-ui.dev/r/notchset-sound.json`, import from `@/components/ui/notchset/sound-provider`); `useSound()` gives `muted` and `setMuted` for a mute control. Without a provider the audio engine never loads.

## Match the original
- Read `components/ui/notchset/now-playing.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
- now playing, audio player, podcast, read-out, playlist, chapters, Notchset
- Playing agent read-outs or short audio

### Not when
- Video: use a video player

## Mistakes
- Without src playback is simulated

## Usage

```tsx
import { NowPlaying } from "@/components/ui/notchset/now-playing";

<NowPlaying tracks={[{ title: "Weekly brief", source: "PLANNER", duration: 134, src: "/brief.mp3" }]} />
```

## Props

| Prop | Type | Default | What it does |
|---|---|---|---|
| `tracks` | `{ title, source, duration, chapters?, src?, cover? }[]` |  | Chapters as [label, seconds]. |
| `defaultIndex / onTrackChange` | `number / (i) => void` |  | Start track and changes. |

Full docs: https://beautiful-ui.dev/components/now-playing

## Customising
- Colours: the component reads your shadcn tokens (`--background`, `--foreground`, `--border` …), refined by the `--notchset-*` tokens. The signal colour is `--notchset-signal` (it falls back to `--destructive`). Set tokens on `:root`, or on any container to retheme one area.
- 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 |
|---|---|
| ← → | Seek 5s on the ruler |
| Enter | Open the panel from the title |

## Performance

- One 250ms interval while playing.

## Responsive

- The title flexes between cover and controls.

## Motion inventory

| Interaction | What moves |
|---|---|
| Track change | Titles slide (420ms settle) |
| Panel | Unrolls 380ms; closes 260ms |

## Accessibility contract (preserve when editing)
- The title is a disclosure button; the seek ruler is a slider naming the chapter

## Install

```bash
npx shadcn@latest add @beautiful-ui-pro/now-playing
```

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 notchset 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/notchset-foundation.json.