Box

Box lays out child renderables and can draw a background, border, and title. Use ScrollBox when the children must scroll.

Availability

Field	Availability
Package	`@opentui/core`
Core renderable	`BoxRenderable`
React	`<box>` (automatic)
Solid	`<box>` (automatic)
Status	Built in

Basic usage

Renderable API

OpenTUI preview

Run this example to open an interactive terminal.

Source code · typescript

import { BoxRenderable, TextRenderable, createCliRenderer } from "@opentui/core"

const renderer = await createCliRenderer()

const panel = new BoxRenderable(renderer, {
  id: "panel",
  width: 30,
  height: 10,
  backgroundColor: "#333366",
  borderStyle: "double",
  borderColor: "#FFFFFF",
})

renderer.root.add(panel)

Border styles

// No border
{
  border: false
}

// Simple border (default style)
{
  border: true
}

// Specific border styles
{
  borderStyle: "single"
} // Single line: ┌─┐│└─┘
{
  borderStyle: "double"
} // Double line: ╔═╗║╚═╝
{
  borderStyle: "rounded"
} // Rounded corners: ╭─╮│╰─╯
{
  borderStyle: "heavy"
} // Heavy lines: ┏━┓┃┗━┛

┌─────single─────┐  ╔═════double═════╗
│ single line    │  ║ double lines   ║
└────────────────┘  ╚════════════════╝

╭────rounded─────╮  ┏━━━━━heavy━━━━━━┓
│ round corners  │  ┃ heavy strokes  ┃
╰────────────────╯  ┗━━━━━━━━━━━━━━━━┛

Titles

Add a title and bottom title to the box border:

const panel = new BoxRenderable(renderer, {
  id: "settings",
  width: 40,
  height: 15,
  borderStyle: "rounded",
  title: "Settings",
  titleColor: "yellow",
  titleAlignment: "center",
  bottomTitle: "Footer",
  bottomTitleAlignment: "center",
})

Title alignment (both top and bottom titles)

{
  titleAlignment: "left"
} // ┌─ Title ────────┐
{
  titleAlignment: "center"
} // ┌──── Title ─────┐
{
  titleAlignment: "right"
} // ┌────────── Title ┐

{
  bottomTitleAlignment: "left"
} // └─ Title ────────┘
{
  bottomTitleAlignment: "center"
} // └──── Title ─────┘
{
  bottomTitleAlignment: "right"
} // └────────── Title ┘

┌───────────settings───────────┐
│ Top and bottom titles        │
└────────────────────────close─┘

Layout container

Box works as a flex container for child elements:

const container = new BoxRenderable(renderer, {
  flexDirection: "column",
  justifyContent: "space-between",
  alignItems: "stretch",
  width: 50,
  height: 20,
  padding: 1,
  gap: 1,
})
const content = new BoxRenderable(renderer, { flexGrow: 1, backgroundColor: "#222" })

content.add(new TextRenderable(renderer, { content: "Content area" }))
container.add(new TextRenderable(renderer, { content: "Header" }))
container.add(content)
container.add(new TextRenderable(renderer, { content: "Footer" }))

Mouse events

Handle mouse interactions on the box:

const button = new BoxRenderable(renderer, {
  id: "button",
  width: 12,
  height: 3,
  border: true,
  backgroundColor: "#444",
  onMouseDown: () => {
    console.log("Button clicked!")
  },
  onMouseOver: () => {
    button.backgroundColor = "#666"
  },
  onMouseOut: () => {
    button.backgroundColor = "#444"
  },
})

Properties

Property	Type	Default	Description
`width`	`number \| string`	-	Width in terminal columns or percentage
`height`	`number \| string`	-	Height in rows or percentage
`backgroundColor`	`string \| RGBA`	`transparent`	Background fill color
`border`	`boolean`	`false`	Show border
`borderStyle`	`string`	`"single"`	Border style
`borderColor`	`string \| RGBA`	`#FFFFFF`	Border color
`title`	`string`	-	Title text in border
`titleColor`	`string \| RGBA`	`borderColor`	Color of the title text
`titleAlignment`	`string`	`"left"`	Title position
`bottomTitle`	`string`	-	Bottom title text in border
`bottomTitleAlignment`	`string`	`"left"`	Bottom title position
`padding`	`number`	`0`	Internal padding
`gap`	`number \| string`	-	Gap between children
`flexDirection`	`string`	`"column"`	Child layout direction
`justifyContent`	`string`	`"flex-start"`	Main axis alignment
`alignItems`	`string`	`"stretch"`	Cross axis alignment

Example: card component

import { BoxRenderable, TextRenderable, t, bold, fg } from "@opentui/core"

function Card(props: { title: string; description: string }) {
  const card = new BoxRenderable(renderer, {
    width: 40,
    borderStyle: "rounded",
    borderColor: "#666",
    padding: 1,
    margin: 1,
  })
  card.add(
    new TextRenderable(renderer, {
      content: t`${bold(fg("#00FFFF")(props.title))}`,
    }),
  )
  card.add(
    new TextRenderable(renderer, {
      content: props.description,
      fg: "#AAAAAA",
    }),
  )
  return card
}

const cards = new BoxRenderable(renderer, { flexDirection: "row", flexWrap: "wrap" })
cards.add(Card({ title: "Feature 1", description: "Description of feature 1" }))
cards.add(Card({ title: "Feature 2", description: "Description of feature 2" }))
cards.add(Card({ title: "Feature 3", description: "Description of feature 3" }))
renderer.root.add(cards)

Read Layout for sizing and flex behavior. See Colors for color formats and Interaction, focus, and selection for mouse event propagation. Use Text for labels and other text content.

Box