🎛 React Rotary Knob

Features

Precise mode: Doesn't jump on dragging (Increase drag distance for more precision)
Works in both controlled (recommended) and uncontrolled mode.
Support arrow keys.
Supports custom skins

Precision mode

When precision mode is active (default), a minimum dragging distance is required to unlock de control.

Usage (Controlled mode - recommended)

Similar to controlled mode for HTML input controls, you need to store the value and use the value and onChange props to update it. This is the recommended usage.

class App extends React.Component {

  state = {
    value: 50
  }

  changeValue(val) {
    this.setState({value:val})
  }

  render() {
    return <Knob onChange={this.changeValue.bind(this)} min={0} max={100} value={this.state.value}/>
     
  }
}

Usage (Uncontrolled mode)

In uncontrolled mode the component manages its own state. Instead of providing a value prop you should define a default value with the defaultValue prop. Use the onChange prop if you want to be notified when the value changes.

class App extends React.Component {

  changeValue(val) {
   console.log('The value changed to '+val)
  }

  render() {
    return <Knob defaultValue={0} min={0} max={100} onChange={this.changeValue.bind(this)}  />
  }
}

Non-endless behavior

For some applications it's not a good idea to jump from min to max values. If you need to limit the rotation take a look at this implementation of a limited knob

https://codesandbox.io/s/qvyyyvv346

Api

Props:

Prop	Description	Default Value
min	Minimum value	0
max	Maximum value	100
value	Control Value	0
defaultValue	start value for uncontrolled mode	0
onChange	Callback with the updated value
unlockDistance	Minimun drag distance required to unlock the knob	100
step	the step distance (when using the keyboard arrows)	1
skin	Skin object
onStart	Called when the dragging starts
onEnd	Called when the dragging ends
clampMin	degree value to move the starting point of the active area of the knob away from the center	0
clampMax	degree value to move the end point of the active area of the knob away from the center	360
rotateDegrees	degree value to rotate the knob component to have the starting / end points at a different position	0 (zero is at top

Custom skins

See defaultSkin.js for an example.

eran-sefirot/react-rotary-knob