tldraw/components/status-bar.tsx

import { useStateDesigner } from '@state-designer/react'
import state from 'state'
import styled from 'styles'
import { useRef } from 'react'

export default function StatusBar() {
  const local = useStateDesigner(state)
  const { count, time } = useRenderCount()

  const active = local.active.slice(1).map((s) => {
    const states = s.split('.')
    return states[states.length - 1]
  })
  const log = local.log[0]

  return (
    <StatusBarContainer
      size={{
        '@sm': 'small',
      }}
    >
      <Section>
        {active.join(' | ')} | {log}
      </Section>
      {/* <Section
        title="Renders | Time"
      >
        {count} | {time.toString().padStart(3, '0')}
      </Section> */}
    </StatusBarContainer>
  )
}

const StatusBarContainer = styled('div', {
  position: 'absolute',
  bottom: 0,
  left: 0,
  width: '100%',
  zIndex: 300,
  height: 40,
  userSelect: 'none',
  borderTop: '1px solid black',
  gridArea: 'status',
  display: 'grid',
  gridTemplateColumns: 'auto 1fr auto',
  alignItems: 'center',
  backgroundColor: 'white',
  gap: 8,
  fontSize: '$0',
  padding: '0 16px',

  variants: {
    size: {
      small: {
        fontSize: '$1',
      },
    },
  },
})

const Section = styled('div', {
  whiteSpace: 'nowrap',
  overflow: 'hidden',
})

function useRenderCount() {
  const rTime = useRef(Date.now())
  const rCounter = useRef(0)

  rCounter.current++
  const now = Date.now()
  let time = now - rTime.current
  if (time > 100) {
    time = 0
  }
  rTime.current = now

  return { count: rCounter.current, time }
}