react/components/checkbox/checkbox-group.tsx

import React, { useEffect, useMemo, useState } from 'react'
import withDefaults from '../utils/with-defaults'
import { CheckboxContext } from './checkbox-context'
import useWarning from '../utils/use-warning'
import { NormalSizes } from '../utils/prop-types'

interface Props {
  value: string[]
  disabled?: boolean
  size?: NormalSizes
  onChange?: (values: string[]) => void
  className?: string
}

const defaultProps = {
  disabled: false,
  size: 'small' as NormalSizes,
  className: '',
}

type NativeAttrs = Omit<React.HTMLAttributes<any>, keyof Props>
export type CheckboxGroupProps = Props & typeof defaultProps & NativeAttrs

export const getCheckboxSize = (size: NormalSizes): string => {
  const sizes: { [key in NormalSizes]: string } = {
    mini: '.75rem',
    small: '.875rem',
    medium: '1rem',
    large: '1.125rem',
  }
  return sizes[size]
}

const CheckboxGroup: React.FC<React.PropsWithChildren<CheckboxGroupProps>> = ({
  disabled,
  onChange,
  value,
  size,
  children,
  className,
  ...props
}) => {
  const [selfVal, setSelfVal] = useState<string[]>([])
  if (!value) {
    value = []
    useWarning('Props "value" is required.', 'Checkbox Group')
  }

  const updateState = (val: string, checked: boolean) => {
    const removed = selfVal.filter(v => v !== val)
    const next = checked ? [...removed, val] : removed
    setSelfVal(next)
    onChange && onChange(next)
  }

  const providerValue = useMemo(() => {
    return {
      updateState,
      disabledAll: disabled,
      inGroup: true,
      values: selfVal,
    }
  }, [disabled, selfVal])
  const fontSize = useMemo(() => getCheckboxSize(size), [size])

  useEffect(() => {
    setSelfVal(value)
  }, [value.join(',')])

  return (
    <CheckboxContext.Provider value={providerValue}>
      <div className={`group ${className}`} {...props}>
        {children}
        <style jsx>{`
          .group :global(label) {
            margin-right: calc(${fontSize} * 2);
            --checkbox-size: ${fontSize};
          }
        `}</style>
      </div>
    </CheckboxContext.Provider>
  )
}

export default withDefaults(CheckboxGroup, defaultProps)