react-curse

A curses-like blazingly fast react renderer

• It is fast, intuitive and easy to use
• It draws only changed characters
• It uses a small amount of SSH traffic

See it in action:

Still here? Let's go deeper:

• It has fancy components that are ready to use or can be tree-shaked from your final bundle
• It supports keyboard and mouse
• It works in fullscreen and inline modes
• It has cool hooks like animation with trail
• It is solely dependent on react
• It can generate an all-in-one bundle around 100 kb

You can easily build full-scale terminal UI applications like:

Apps that use it

• mngr - Database manager supports mongodb, mysql/mariadb, postgresql, sqlite and json-server
• nfi - Simple nerd fonts icons cheat sheet that allows you to quickly find and copy glyph to clipboard

Installation

Just run npm init react-curse answer a few questions and you are ready to go

Examples

Hello world

import React from 'react'
import ReactCurse, { Text } from 'react-curse'

const App = ({ text }) => {
  return <Text color="Red">{text}</Text>
}

ReactCurse.render(<App text="hello world" />)

How to handle input

import React, { useState } from 'react'
import ReactCurse, { Text, useInput, exit } from 'react-curse'

const App = () => {
  const [counter, setCounter] = useState(0)

  useInput(
    input => {
      if (input === 'k') setCounter(counter + 1)
      if (input === 'j') setCounter(counter - 1)
      if (input === 'q') exit()
    },
    [counter]
  )

  return (
    <Text>
      counter: <Text bold>{counter}</Text>
    </Text>
  )
}

ReactCurse.render(<App />)

How to animate

import React from 'react'
import ReactCurse, { useAnimation } from 'react-curse'

const App = () => {
  const { interpolate, interpolateColor } = useAnimation(1000)

  return <Text width={interpolate(0, 80)} background={interpolateColor('#282828', '#d79921')} />
}

ReactCurse.render(<App />)

Contents

• Components
  • <Text>
  • <Input>
  • <Banner>
  • <Bar>
  • <Block>
  • <Canvas>, <Point>, <Line>
  • <Frame>
  • <List>
  • <ListTable>
  • <Scrollbar>
  • <Separator>
  • <Spinner>
  • <View>
• Hooks
  • useAnimation, useTrail, <Trail>
  • useChildrenSize
  • useClipboard
  • useInput
  • useMouse
  • useSize
  • useWordWrap
• API
  • render
  • inline
  • bell
  • exit

Components

<Text>

Base component
The only component required to do anything
Every other component uses this one to draw

y?, x?: number | string

Position from top left corner relative to parent
Content will be cropped by parent
See absolute to avoid this behavior
Example: 32, '100%', '100%-8'

height?, width?: number | string

Size of block, will be cropped by parent
See absolute to avoid this behavior

absolute?: boolean

Makes position and size ignoring parent container

background?, color?: number | string

Background and foreground color
Example: 31, 'Red', '#f04020', '#f42'

clear?: boolean

Clears block before drawing content
height and width

block?: boolean

Moves cursor to a new line after its content relative to parent

bold?, dim?, italic?, underline?, blinking?, inverse?, strikethrough?: boolean

Text modifiers

Examples

<Text color="Red" block>hello world</Text>
<Text color="Green" bold block>hello world</Text>
<Text color="BrightBlue" underline block>hello world</Text>
<Text y={0} x="50%">
  <Text color={128} italic block>hello world</Text>
  <Text x="100%-11" color="#1ff" strikethrough block>hello world</Text>
  <Text x="50%-5" color="#e94691" inverse>hello world</Text>
</Text>

<Input>

Text input component with cursor movement and text scroll support
If its height is more than 1, then it switches to multiline, like textarea
Most terminal shortcuts are supported

focus?: boolean = true

Makes it active

type?: 'text' | 'password' | 'hidden' = ‘text'

initialValue?: string

cursorBackground?: number | string

onCancel?: () => void

onChange?: (string) => void

onSubmit?: (string) => void

Examples

<Input background="#404040" height={1} width={8} />

<Banner>

Displays big text

y?, x?: number | string

background?, color?: number | string

children: string

Examples

<Banner>{new Date().toTimeString().substring(0, 8)}</Banner>

<Bar>

Displays vertical or horizontal bar with 1/8 character resolution

type: 'vertical' | 'horizontal'

y & height, x & width: number

Examples

<>
  {[...Array(24)].map((_, index) => (
    <Bar key={index} type="vertical" x={index * 2} height={(index + 1) / 8} />
  ))}
</>

Compare to <Text>

<Block>

Aligns content

width?: number

align?: 'left' | 'center' | 'right' = 'left'

Examples

<Block>left</Block>
<Block align="center">center</Block>
<Block align="right">right</Block>

<Canvas>

Create a canvas for drawing with one these modes

mode: { h: 1, w: 1 } | { h: 2, w: 1 } | { h: 2, w: 2 } | { h: 4, w: 2 }

Pixels per character

height, width: number

Size in pixels

children: (Point | Line)[]

<Point>

Draws a point at the coordinates

y, x: number

color?: number | string

<Line>

Draws a line using coordinates

y, x, dy, dx: number

color?: number | string

Examples

<Canvas width={80} height={6}>
  <Point x={1} y={1} color="Yellow" />
  <Line x={0} y={5} dx={79} dy={0} />
</Canvas>

Braille's font demo ({ h: 4, w: 2 })

<Frame>

Draws frame around its content

children: string

type?: 'single' | 'double' | 'rounded' = 'single'

height?, width?: number

Examples

<Frame type="single" color="Red">single border type</Frame>
<Frame type="double" color="Green" y={0}>double border type</Frame>
<Frame type="rounded" color="Blue" y={0}>rounded border type</Frame>

<List>

Creates a list with navigation support
Vim shortcuts are supported

focus?: boolean

initialPos?: { y: number }

data?: any[]

renderItem?: (object) => JSX.Element

height?, width?: number

scrollbar?: boolean

scrollbarBackground?: boolean

scrollbarColor?: boolean

vi?: boolean = true

pass?: any

onChange?: (object) => void

onSubmit?: (object) => void

Examples

const items = [...Array(8)].map((_, index) => ({ id: index + 1, title: `Task ${index + 1}` }))
return (
  <List
    data={items}
    renderItem={({ item, selected }) => <Text color={selected ? 'Green' : undefined}>{item.title}</Text>}
  />
)

<ListTable>: <List>

Creates a table with navigation support
Vim shortcuts are supported

mode?: 'cell' | 'row' = 'cell'

head?: any[]

renderHead?: (object) => JSX.Element

data?: any[][]

Examples

const head = ['id', 'title']
const items = [...Array(8)].map((_, index) => [index + 1, `Task ${index + 1}`])
return (
  <ListTable
    head={head}
    renderHead={({ item }) =>
      item.map((i, key) => (
        <Text key={key} width={8}>
          {i}
        </Text>
      ))
    }
    data={items}
    renderItem={({ item, x, y, index }) =>
      item.map((text, key) => (
        <Text key={key} color={y === index && x === key ? 'Green' : undefined} width={8}>
          {text}
        </Text>
      ))
    }
  />
)

<Scrollbar>

Draws a scrollbar with 1/8 character resolution

type?: 'vertical' | 'horizontal' = 'vertical'

offset: number

limit: number

length: number

background?, color?: number | string

Examples

<Scrollbar type="horizontal" offset={10} limit={80} length={160} />

<Separator>

Draws a vertical or horizontal line

type: 'vertical' | 'horizontal'

height, width: number

Examples

<Separator type="vertical" height={3} />
<Separator type="horizontal" y={1} x={1} width={79} />

<Spinner>

Draws an animated spinner

children?: string

Examples

<Spinner block />
<Spinner color="BrightGreen">-\|/</Spinner>

<View>

Creates a scrollable viewport
Vim shortcuts are supported

focus?: boolean

height?: number

scrollbar?: boolean

vi?: boolean = true

children: any

Examples

<View>{JSON.stringify(json, null, 2)}</View>

hooks

useAnimation

(time: number, fps?: 'number' = 60) => object

Creates a timer for a specified duration
That gives you time and interpolation functions each frame of animation

return

ms: number

interpolate: (from: number, to: number, delay?: number)

interpolateColor: (from: string, to: string: delay?: number)

Examples

const { ms } = useAnimation(1000, 4)
return ms // 0, 250, 500, 750, 1000

const { interpolate } = useAnimation(1000, 4)
return interpolate(0, 80) // 0, 20, 40, 60, 80

const { interpolateColor } = useAnimation(1000, 4)
return interpolateColor('#000', '#0f8') // #000, #042, #084, #0c6, #0f8

<Trail>

Mutate array of items to show one by one with latency

delay: number

children: JSX.Element[]

Examples

const items = [...Array(8)].map((_, index) => ({ id: index + 1, title: `Task ${index + 1}` }))
return (
  <Trail delay={100}>
    {items.map(({ id, title }) => (
      <Text key={id} block>
        {title}
      </Text>
    ))}
  </Trail>
)

useTrail

(delay: number, items: JSX.Element[], key?: string = 'key') => JSX.Element[]

Same as <Trail> but hook
You can pass it to data property of <List> component for example

Examples

<List data={useTrail(items)} />

useChildrenSize

(value: string) => object

Gives you content size

return

height, width: number

Examples

useChildrenSize('1\n22\n333') // { height: 3, width: 3 }

useClipboard

() => array

Allows you to work with the system clipboard

return

getClipboard: () => string

setClipboard: (value: string) => void

Examples

const { getClipboard, setClipboard } = useClipboard()
const string = getClipboard()
setClipboard(string.toUpperCase()) // copied

useInput

(callback: (string) => void, dependencies: any[]) => void

Allows you to handle keyboard input

Examples

set[(counter, setCounter)] = useState(0)

useInput(
  input => {
    if (input === 'k') setCounter(counter + 1)
    if (input === 'j') setCounter(counter - 1)
  },
  [counter]
)

useMouse

(callback: (object) => void, dependencies: any[])

Allows you to handle mouse input

Examples

set[(counter, setCounter)] = useState(0)

useMouse(
  event => {
    if (event.type === 'wheelup') setCounter(counter + 1)
    if (event.type === 'wheeldown') setCounter(counter - 1)
  },
  [counter]
)

useSize

() => object

Gives you terminal size
Updates when size is changing

return

height, width: number

Examples

useSize() // { height: 24, width: 80 }

useWordWrap

(text: string, width?: number) => object

Gives your text a word wrap

return

height, width: number

Examples

useWordWrap('hello world', 5) // hello\nworld

API

render (children: JSX.Element) => void

Renders your fullscreen application to stdout

inline (children: JSX.Element) => void

Renders your inline application to stdout

bell

() => void

Makes a terminal bell

bell() // ding

exit

(code: number = 0) => void

Allows you to exit from an application that waits for user input or has timers

Examples

useInput(input => {
  if (input === 'q') exit()
})