dify/web/app/components/base/auto-height-textarea/index.tsx

import { useEffect, useRef } from 'react'
import cn from '@/utils/classnames'
import { sleep } from '@/utils'

type IProps = {
  placeholder?: string
  value: string
  onChange: (e: React.ChangeEvent<HTMLTextAreaElement>) => void
  className?: string
  wrapperClassName?: string
  minHeight?: number
  maxHeight?: number
  autoFocus?: boolean
  controlFocus?: number
  onKeyDown?: (e: React.KeyboardEvent<HTMLTextAreaElement>) => void
  onKeyUp?: (e: React.KeyboardEvent<HTMLTextAreaElement>) => void
}

const AutoHeightTextarea = (
  {
    ref: outerRef,
    value,
    onChange,
    placeholder,
    className,
    wrapperClassName,
    minHeight = 36,
    maxHeight = 96,
    autoFocus,
    controlFocus,
    onKeyDown,
    onKeyUp,
  }: IProps & {
    ref: React.RefObject<unknown>;
  },
) => {
  // eslint-disable-next-line react-hooks/rules-of-hooks
  const ref = outerRef || useRef<HTMLTextAreaElement>(null)

  const doFocus = () => {
    if (ref.current) {
      ref.current.setSelectionRange(value.length, value.length)
      ref.current.focus()
      return true
    }
    return false
  }

  const focus = async () => {
    if (!doFocus()) {
      let hasFocus = false
      await sleep(100)
      hasFocus = doFocus()
      if (!hasFocus)
        focus()
    }
  }

  useEffect(() => {
    if (autoFocus)
      focus()
  }, [])
  useEffect(() => {
    if (controlFocus)
      focus()
  }, [controlFocus])

  return (
    (<div className={`relative ${wrapperClassName}`}>
      <div className={cn(className, 'invisible overflow-y-auto whitespace-pre-wrap  break-all')} style={{
        minHeight,
        maxHeight,
        paddingRight: (value && value.trim().length > 10000) ? 140 : 130,
      }}>
        {!value ? placeholder : value.replace(/\n$/, '\n ')}
      </div>
      <textarea
        ref={ref}
        autoFocus={autoFocus}
        className={cn(className, 'absolute inset-0 resize-none overflow-auto')}
        style={{
          paddingRight: (value && value.trim().length > 10000) ? 140 : 130,
        }}
        placeholder={placeholder}
        onChange={onChange}
        onKeyDown={onKeyDown}
        onKeyUp={onKeyUp}
        value={value}
      />
    </div>)
  )
}

AutoHeightTextarea.displayName = 'AutoHeightTextarea'

export default AutoHeightTextarea