DreamKnob/packages/dreamknob/README.md
Dreamodus 54189ad07a Docs accuracy pass, guides, and a playable Web Audio synth demo
Docs/playground accuracy (from a full docs-vs-source audit):
- Playground: drag-feel select covers pickup/relative rotary modes, is
  disabled for faders, and generated code no longer emits props the
  target component does not accept
- API/README claims corrected: Shift-fine wheel scope, wheelStep and
  decimals defaults, trackInset row, data-part and ref-forwarding
  scope, VintageKnob readout exception, Meter peakHold tag, stale
  component lists, aria-valuetext wording, also-exported list

API consistency fixes surfaced by the audit and the tutorial:
- Keyboard gestures now fire onChangeStart (bracket parity with drag/
  wheel - fixes gesture-scoped undo patterns)
- name (hidden form input) added to Fader, LEDFader, ImageKnob
- PushButton gets a themed keyboard-only focus ring + data-focus-visible

New docs content:
- Getting Started: 7-step guide with live examples and a gotchas list
- Advanced guide: 8-step channel-strip tutorial ending in a live,
  themed, gesture-undoable strip with meter (plus headless demo)
- Synth section: playable Web Audio synth - osc/filter/env/LFO/master
  all dreamknob controls, momentary-pad keyboard, analyser-driven Meter
2026-07-12 18:27:06 -07:00

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# dreamknob
Studio-grade React knobs & faders. Rotary, linear, 2D, 3D, digital and analog — with a
headless core, any number range, any decimal precision, and colors you fully control.
Zero runtime dependencies.
```
npm install dreamknob
```
## Quick start
```tsx
import { FlatKnob } from 'dreamknob'
function Volume() {
const [value, setValue] = useState(64)
return (
<FlatKnob
size={90}
value={value}
onChange={setValue}
min={0}
max={100}
step={0.5}
label="Volume"
unit="%"
aria-label="Volume"
/>
)
}
```
Uncontrolled works too: pass `defaultValue` instead of `value`/`onChange`
(it also becomes the double-click reset target).
## Interaction model
Every component shares one core:
| Gesture | Behaviour |
| --- | --- |
| Drag | `rotary` (grab & turn, follows the pointer angle), `vertical`, `horizontal`, `both`, or absolute `track-*` (faders) |
| Scroll wheel | one `step` per notch (else 1% of range); `Shift` = fine on continuous values — snapped controls always move whole steps |
| `↑ → / ↓ ←` | ± one step (`Shift` = 10×) |
| `PageUp/PageDown` | ± 10 % of range |
| `Home/End` | min / max |
| Double-click | reset to `defaultValue` — or open the type-in editor with `editable` |
| `Escape` | cancel an in-flight drag, restoring the start value |
| Touch / pen | pointer capture, `touch-action: none` |
All knobs render `role="slider"` with `aria-valuemin/max/now` (and `aria-valuetext`
when you provide `getAriaValueText`).
## Value handling
- `min` / `max` — any numbers (negative, fractional, huge).
- `step` — decimal snap increments (`0.5`, `0.001`, `1e-7`…) with float-drift-safe
rounding; display precision inferred automatically, overridable via `decimals`.
- `values={[0.25, 0.5, 1, 2, 4]}` — discrete allowed values.
- `steps={5}` — evenly spaced detents (selector knobs).
- `taper``linearTaper` (default), `logTaper` (frequencies), `powTaper(n)` (gain),
or your own `{ toNormalized, fromNormalized }`.
- `origin={0}` — bipolar anchor: arcs/fader fills draw from this value (pan, gain trim).
- `detents={[0]}` + `detentSize` — magnetic snap points while dragging.
- `editable` — double-click (knobs) or click the readout (faders) to type an exact
value; `parseValue` customizes parsing (`"1.2k"` → 1200 out of the box).
- `rotaryMode``'absolute'` (rc-knob feel), `'relative'` (no grab jump), or
`'pickup'` (MIDI-style: engages when the pointer sweeps past the value).
- `dragAcceleration` — velocity gain for relative drags; `hideCursorOnDrag` hides
the cursor mid-gesture.
- `wheelStep` / `wheelRequiresFocus` — tune wheel notches, or keep hover-scroll free.
- `onChange` / `onChangeStart` / `onChangeEnd` — gesture-aware callbacks with
`meta.source` (`'drag' | 'wheel' | 'keyboard' | 'reset' | 'api'`).
- `wrap` — endless encoder mode: values roll around min↔max (pair with
`angleOffset={0} angleRange={360}`).
- `animateChanges` — tween the pointer on programmatic changes (preset loads);
gestures never animate and `prefers-reduced-motion` is honored.
- `valueBubble` — floating readout above the control while dragging.
- `name` — hidden form input for plain `<form>` posts on every knob, fader and
`PushButton` (`XYPad` uses `nameX`/`nameY`). Interactive components forward a ref
to their root element, and primitive-drawn SVG parts carry `data-part` attributes
for CSS styling.
## Prebuilt skins
```tsx
import {
FlatKnob, // clean 2D arc knob (arcFrom="center" for pan knobs)
MetalKnob, // 3D brushed aluminum, knurled rim (tone="silver" | "dark")
RubberKnob, // 3D soft-touch synth knob with glow halo
VintageKnob, // chicken-head bakelite over a printed scale
LEDKnob, // segmented LED ring + true seven-segment readout
NeonKnob, // glowing arc for dark UIs
SteppedKnob, // detented selector (positions={['LP','BP','HP']})
Fader, // linear channel fader, vertical or horizontal
LEDFader, // segmented LED meter-fader with color zones
ImageKnob, // film-strip sprite knob (KnobMan-style PNG strips)
Meter, // read-only LED level meter with peak hold
XYPad, // two-parameter pad (cutoff/resonance, vector mixing)
PushButton, // panel button with LED strip (toggle or momentary)
SegmentDisplay, // standalone seven-segment numeric display
AlphaDisplay, // fourteen-segment alphanumeric display
} from 'dreamknob'
```
## Theming
```tsx
import { DreamknobProvider } from 'dreamknob'
<DreamknobProvider base="dark" theme={{ accent: '#ff4d6b' }}>
{/* every control below inherits the tokens; instance props still win */}
</DreamknobProvider>
```
`base="light"` swaps in light-background defaults. Tokens: `accent`, `track`, `face`,
`text`, `label`, `ticks`, `focusRing`, `fontMono`, `fontUI`.
Every knob skin and fader takes the core props plus `size`, `label`, `showValue`,
`unit`, `format`, and per-part color props (`color`, `trackColor`, `faceColor`,
`bodyColor`, …). `VintageKnob` has no readout, so it omits `showValue`/`unit`/`format`;
the display components (`Meter`, `SegmentDisplay`, `AlphaDisplay`) have their own
smaller prop sets.
Also exported for custom builds: primitives (`Arc`, `Pointer`, `Ticks`, `TickLabels`,
`Face`, `KnobValue`, `KnobLabel`, `GlowFilter`), theming (`useKnobTheme`, `darkTheme`,
`lightTheme`), editing (`ValueInput`, `defaultParseValue`), colors (`mixColors`,
`sampleGradient`), and the math kit (`clamp`, `roundTo`, `snapToStep`,
`decimalsFromStep`, `findClosest`, `applyDetents`, tapers, angle/arc helpers).
## Compose your own
```tsx
import { Knob, Arc, Pointer, Ticks, KnobValue } from 'dreamknob'
<Knob size={96} min={-24} max={24} step={0.5} defaultValue={0} aria-label="Trim">
<Ticks count={25} activeColor="#ffd23e" />
<Arc radius={36} thickness={3} color="#ffd23e" from="center" />
<Pointer type="triangle" radius={33} length={9} width={8} color="#ffd23e" />
<KnobValue unit=" dB" />
</Knob>
```
`<Knob>` also accepts a render function: `{(ctx) => <YourSVG angle={ctx.angle} />}`.
## Fully headless
```tsx
import { useKnob } from 'dreamknob'
const { value, normalized, angle, isDragging, bind, setValue } = useKnob({
min: 0, max: 11, step: 0.1, defaultValue: 11, 'aria-label': 'Volume',
})
return <div {...bind}>your own rendering</div>
```
MIT