# Checkbox

A small box that toggles an option on or off, with an indeterminate state.

Checkbox is an open-source mobile component from suiss/uim for React Native and Expo, with SwiftUI and Jetpack Compose versions built from the same design tokens. The @esuiss/uim CLI copies its source into your project, so you own the code.

Source: https://uim.suiss.app/docs/components/checkbox

![Preview](https://uim.suiss.app/previews/components-checkbox--default.light.webp)

```tsx
import * as React from "react"
import { Checkbox } from "@/components/ui/checkbox"

function CheckboxDemo({ initial = false }: { initial?: boolean }) {
  const [checked, setChecked] = React.useState(initial)
  return <Checkbox checked={checked} onCheckedChange={setChecked} />
}

export function CheckboxExample() {
  return (
    <CheckboxDemo />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CheckboxExample: View {
  var body: some View {
    CheckboxDemo(initial: false)
  }
}

struct CheckboxDemo: View {
  @State private var checked: Bool

  init(initial: Bool) {
    _checked = State(initialValue: initial)
  }

  var body: some View {
    Toggle(isOn: $checked) { EmptyView() }
      .toggleStyle(.checkbox)
  }
}
```

```kotlin
import androidx.compose.foundation.layout.Row
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import com.esuiss.ui.components.Checkbox

@Composable
fun CheckboxExample() {
    CheckboxDemo(initial = false)
}

@Composable
fun CheckboxDemo(initial: Boolean) {
    var checked by rememberSaveable { mutableStateOf(initial) }
    Row {
        Checkbox(checked, { checked = it })
    }
}
```

`Checkbox` is a `Pressable` with the `checkbox` role that shows a check icon when checked and a minus icon when `indeterminate`. It has an enlarged hit area around the box so it is easy to tap.

Use it for options that can be combined, such as terms acceptance or multi-select lists. For a single on/off setting that applies right away, use Switch.

## Installation

```bash title="Terminal"
npx @esuiss/uim@latest add checkbox
```

```bash title="Terminal"
npx @esuiss/uim@latest add checkbox --platform swift
```

```bash title="Terminal"
npx @esuiss/uim@latest add checkbox --platform kotlin
```

The CLI also adds what it builds on: [Icon](/docs/components/icon), [Text](/docs/components/text).

### Manual

**Uniwind**

1. Install the dependencies:

```bash title="Terminal"
npx expo install cn phosphor-react-native react-native-svg
```

2. Add the pieces it builds on: [Icon](/docs/components/icon), [Text](/docs/components/text), and the primitives `components/primitives/checkbox.tsx`, `components/primitives/use-render.tsx`.

3. Copy the source into `components/ui/checkbox.tsx`:

```tsx title="uniwind/components/ui/checkbox.tsx"
import { cn } from "cn"
import { CheckIcon, MinusIcon } from "phosphor-react-native"
import * as CheckboxPrimitive from "@/components/primitives/checkbox"
import { resolveClassName } from "@/components/primitives/use-render"
import { Icon } from "@/components/ui/icon"

const HIT_SLOP = { top: 8, bottom: 8, left: 12, right: 12 }

function checkboxClassName(
  state: CheckboxPrimitive.RootState,
  invalid: boolean | undefined
) {
  const checked = state.checked || state.indeterminate
  return cn(
    "size-4 shrink-0 items-center justify-center rounded-[4px] border",
    checked
      ? state.disabled
        ? "border-transparent bg-accent-disabled"
        : "border-accent bg-accent active:border-accent-pressed active:bg-accent-pressed"
      : state.disabled
        ? "border-label/10 bg-control-disabled dark:border-transparent"
        : cn(
            "border-label/25 bg-surface shadow-xs active:bg-control dark:border-transparent dark:bg-label-quaternary dark:shadow-none",
            invalid && "border-danger dark:border-danger"
          )
  )
}

function CheckboxIcon({ className }: { className?: string }) {
  const { state } = CheckboxPrimitive.useRootContext()
  return (
    <Icon
      as={state.indeterminate ? MinusIcon : CheckIcon}
      className={cn("size-3.5 text-on-accent", className)}
    />
  )
}

function Checkbox({
  className,
  iconClassName,
  invalid,
  ...props
}: React.ComponentProps<typeof CheckboxPrimitive.Root> & {
  iconClassName?: string
  invalid?: boolean
}) {
  return (
    <CheckboxPrimitive.Root
      className={(state) =>
        cn(
          checkboxClassName(state, invalid),
          resolveClassName(className, state)
        )
      }
      hitSlop={HIT_SLOP}
      {...props}
    >
      <CheckboxPrimitive.Indicator className="items-center justify-center">
        <CheckboxIcon className={iconClassName} />
      </CheckboxPrimitive.Indicator>
    </CheckboxPrimitive.Root>
  )
}

export { Checkbox }
```

4. Update the import paths to match your project.

**NativeWind**

1. Install the dependencies:

```bash title="Terminal"
npx expo install cn phosphor-react-native react-native-svg
```

2. Add the pieces it builds on: [Icon](/docs/components/icon), [Text](/docs/components/text), and the primitives `components/primitives/checkbox.tsx`, `components/primitives/use-render.tsx`.

3. Copy the source into `components/ui/checkbox.tsx`:

```tsx title="nativewind/components/ui/checkbox.tsx"
import { cn } from "cn"
import { CheckIcon, MinusIcon } from "phosphor-react-native"
import * as CheckboxPrimitive from "@/components/primitives/checkbox"
import { resolveClassName } from "@/components/primitives/use-render"
import { Icon } from "@/components/ui/icon"

const HIT_SLOP = { top: 8, bottom: 8, left: 12, right: 12 }

function checkboxClassName(
  state: CheckboxPrimitive.RootState,
  invalid: boolean | undefined
) {
  const checked = state.checked || state.indeterminate
  return cn(
    "size-4 shrink-0 items-center justify-center rounded-[4px] border",
    checked
      ? state.disabled
        ? "border-transparent bg-accent-disabled"
        : "border-accent bg-accent active:border-accent-pressed active:bg-accent-pressed"
      : state.disabled
        ? "border-label-10 bg-control-disabled dark:border-transparent"
        : cn(
            "border-label-25 bg-surface shadow-sm active:bg-control dark:border-transparent dark:bg-label-quaternary dark:shadow-none",
            invalid && "border-danger dark:border-danger"
          )
  )
}

function CheckboxIcon({ className }: { className?: string }) {
  const { state } = CheckboxPrimitive.useRootContext()
  return (
    <Icon
      as={state.indeterminate ? MinusIcon : CheckIcon}
      className={cn("size-3.5 text-on-accent", className)}
    />
  )
}

function Checkbox({
  className,
  iconClassName,
  invalid,
  ...props
}: React.ComponentProps<typeof CheckboxPrimitive.Root> & {
  iconClassName?: string
  invalid?: boolean
}) {
  return (
    <CheckboxPrimitive.Root
      className={(state) =>
        cn(
          checkboxClassName(state, invalid),
          resolveClassName(className, state)
        )
      }
      hitSlop={HIT_SLOP}
      {...props}
    >
      <CheckboxPrimitive.Indicator className="items-center justify-center">
        <CheckboxIcon className={iconClassName} />
      </CheckboxPrimitive.Indicator>
    </CheckboxPrimitive.Root>
  )
}

export { Checkbox }
```

4. Update the import paths to match your project.

**StyleSheet**

1. Install the dependencies:

```bash title="Terminal"
npx expo install phosphor-react-native react-native-svg
```

2. Add the pieces it builds on: [Icon](/docs/components/icon), [Text](/docs/components/text), and the primitives `components/primitives/checkbox.tsx`, `components/primitives/use-render.tsx`.

3. Copy the source into `components/ui/checkbox.tsx`:

```tsx title="stylesheet/components/ui/checkbox.tsx"
import { CheckIcon, MinusIcon } from "phosphor-react-native"
import {
  Pressable,
  type StyleProp,
  StyleSheet,
  type TextStyle,
  type ViewStyle,
} from "react-native"
import * as CheckboxPrimitive from "@/components/primitives/checkbox"
import { resolveStyle } from "@/components/primitives/use-render"
import { Icon } from "@/components/ui/icon"
import { TextStyleContext } from "@/components/ui/text"
import { shadow, type ThemeColors, useTheme } from "@/components/ui/theme"

const HIT_SLOP = { top: 8, bottom: 8, left: 12, right: 12 }

const styles = StyleSheet.create({
  root: {
    width: 16,
    height: 16,
    flexShrink: 0,
    alignItems: "center",
    justifyContent: "center",
    borderRadius: 4,
    borderWidth: 1,
  },
  indicator: { alignItems: "center", justifyContent: "center" },
})

type SelectionState = {
  checked: boolean
  disabled: boolean
}

function selectionControlStyle(
  colors: ThemeColors,
  isDark: boolean,
  state: SelectionState,
  pressed: boolean,
  invalid: boolean | undefined
): ViewStyle {
  if (state.checked) {
    if (state.disabled) {
      return {
        borderColor: "transparent",
        backgroundColor: colors.accentDisabled,
      }
    }
    const color = pressed ? colors.accentPressed : colors.accent
    return { borderColor: color, backgroundColor: color }
  }
  if (state.disabled) {
    return {
      borderColor: isDark ? "transparent" : `${colors.label}1a`,
      backgroundColor: colors.controlDisabled,
    }
  }
  return {
    borderColor: invalid
      ? colors.danger
      : isDark
        ? "transparent"
        : `${colors.label}40`,
    backgroundColor: isDark
      ? colors.labelQuaternary
      : pressed
        ? colors.control
        : colors.surface,
    ...(isDark ? null : shadow.xs),
  }
}

function CheckboxIcon({ iconStyle }: { iconStyle?: StyleProp<TextStyle> }) {
  const { colors } = useTheme()
  const { state } = CheckboxPrimitive.useRootContext()
  return (
    <TextStyleContext.Provider
      value={StyleSheet.flatten([{ color: colors.onAccent }, iconStyle])}
    >
      <Icon as={state.indeterminate ? MinusIcon : CheckIcon} size={14} />
    </TextStyleContext.Provider>
  )
}

function Checkbox({
  style,
  iconStyle,
  invalid,
  ...props
}: React.ComponentProps<typeof CheckboxPrimitive.Root> & {
  iconStyle?: StyleProp<TextStyle>
  invalid?: boolean
}) {
  const { colors, isDark } = useTheme()
  return (
    <CheckboxPrimitive.Root
      hitSlop={HIT_SLOP}
      {...props}
      render={(renderProps, state) => (
        <Pressable
          {...renderProps}
          style={({ pressed }) => [
            styles.root,
            selectionControlStyle(
              colors,
              isDark,
              {
                checked: state.checked || state.indeterminate,
                disabled: state.disabled,
              },
              pressed,
              invalid
            ),
            resolveStyle(style, state) as StyleProp<ViewStyle>,
          ]}
        />
      )}
    >
      <CheckboxPrimitive.Indicator style={styles.indicator}>
        <CheckboxIcon iconStyle={iconStyle} />
      </CheckboxPrimitive.Indicator>
    </CheckboxPrimitive.Root>
  )
}

export { Checkbox }
```

4. Update the import paths to match your project.

**SwiftUI**

1. Target iOS 17 or later.

2. Add the Swift package to your app:

```swift title="Package.swift"
.package(url: "https://github.com/phosphor-icons/swift", from: "2.1.0")
```

3. Copy the theme files every view uses:

```swift title="swift/Theme/Theme.swift"
import SwiftUI
import UIKit

struct RGBA: Sendable {
  let red: CGFloat
  let green: CGFloat
  let blue: CGFloat
  let alpha: CGFloat

  init(_ hex: UInt32, _ alpha: CGFloat = 1) {
    red = CGFloat((hex >> 16) & 0xFF) / 255
    green = CGFloat((hex >> 8) & 0xFF) / 255
    blue = CGFloat(hex & 0xFF) / 255
    self.alpha = alpha
  }

  var uiColor: UIColor {
    UIColor(red: red, green: green, blue: blue, alpha: alpha)
  }
}

extension Color {
  static func adaptive(light: RGBA, dark: RGBA) -> Color {
    let lightColor = light.uiColor
    let darkColor = dark.uiColor
    return Color(uiColor: UIColor { traits in
      traits.userInterfaceStyle == .dark ? darkColor : lightColor
    })
  }
}

public struct TextStyle: Sendable, Hashable {
  public let size: CGFloat
  public let lineHeight: CGFloat
  public let letterSpacing: CGFloat

  public init(size: CGFloat, lineHeight: CGFloat, letterSpacing: CGFloat) {
    self.size = size
    self.lineHeight = lineHeight
    self.letterSpacing = letterSpacing
  }

  public func font(weight: Font.Weight = .regular) -> Font {
    .system(size: size, weight: weight)
  }

  public var lineSpacing: CGFloat {
    max(0, lineHeight - UIFont.systemFont(ofSize: size).lineHeight)
  }
}

extension Hashable where Self == Font {
  public static func textStyle(_ style: TextStyle, weight: Font.Weight = .regular) -> Font {
    style.font(weight: weight)
  }
}

private struct TextStyleModifier: ViewModifier {
  let style: TextStyle
  let weight: Font.Weight

  func body(content: Content) -> some View {
    content
      .font(style.font(weight: weight))
      .tracking(style.letterSpacing)
      .lineSpacing(style.lineSpacing)
      .padding(.vertical, style.lineSpacing / 2)
  }
}

extension View {
  public func textStyle(_ style: TextStyle, weight: Font.Weight = .regular) -> some View {
    modifier(TextStyleModifier(style: style, weight: weight))
  }
}

public struct Shadow: Sendable, Hashable {
  public let color: Color
  public let radius: CGFloat
  public let x: CGFloat
  public let y: CGFloat

  public init(color: Color, radius: CGFloat, x: CGFloat = 0, y: CGFloat = 0) {
    self.color = color
    self.radius = radius
    self.x = x
    self.y = y
  }
}

extension View {
  public func shadow(_ shadow: Shadow) -> some View {
    self.shadow(color: shadow.color, radius: shadow.radius, x: shadow.x, y: shadow.y)
  }
}
```

```swift title="swift/Theme/Tokens.swift"
import SwiftUI

extension Color {
  public static let surface = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0x000000))
  public static let surfaceSecondary = Color.adaptive(light: .init(0xF5F5F7), dark: .init(0x161617))
  public static let surfaceTertiary = Color.adaptive(light: .init(0xE8E8ED), dark: .init(0x2C2C2E))
  public static let surfaceRaised = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0x1D1D1F))
  public static let label = Color.adaptive(light: .init(0x1D1D1F), dark: .init(0xF5F5F7))
  public static let labelSecondary = Color.adaptive(light: .init(0x6E6E73), dark: .init(0xA1A1A6))
  public static let labelTertiary = Color.adaptive(light: .init(0x86868B), dark: .init(0x86868B))
  public static let labelQuaternary = Color.adaptive(light: .init(0xD2D2D7), dark: .init(0x424245))
  public static let control = Color.adaptive(light: .init(0x000000, 0.04), dark: .init(0xFFFFFF, 0.1))
  public static let controlPressed = Color.adaptive(light: .init(0x000000, 0.12), dark: .init(0xFFFFFF, 0.22))
  public static let controlSelected = Color.adaptive(light: .init(0x1D1D1F), dark: .init(0xF5F5F7))
  public static let controlDisabled = Color.adaptive(light: .init(0x000000, 0.03), dark: .init(0xFFFFFF, 0.05))
  public static let onControlSelected = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0x000000))
  public static let itemPressed = Color.adaptive(light: .init(0x000000, 0.08), dark: .init(0xFFFFFF, 0.12))
  public static let itemSelected = Color.adaptive(light: .init(0x000000, 0.06), dark: .init(0xFFFFFF, 0.1))
  public static let separator = Color.adaptive(light: .init(0xD2D2D7), dark: .init(0x424245))
  public static let separatorStrong = Color.adaptive(light: .init(0x86868B), dark: .init(0x6E6E73))
  public static let accent = Color.adaptive(light: .init(0x0071E3), dark: .init(0x0071E3))
  public static let accentPressed = Color.adaptive(light: .init(0x005BB8), dark: .init(0x004D9E))
  public static let accentSelected = Color.adaptive(light: .init(0x0071E3), dark: .init(0x0071E3))
  public static let accentDisabled = Color.adaptive(light: .init(0x0071E3, 0.4), dark: .init(0x0071E3, 0.4))
  public static let onAccent = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0xFFFFFF))
  public static let accentSurface = Color.adaptive(light: .init(0x0071E3, 0.09), dark: .init(0x0071E3, 0.18))
  public static let accentSurfacePressed = Color.adaptive(light: .init(0x0071E3, 0.18), dark: .init(0x0071E3, 0.3))
  public static let link = Color.adaptive(light: .init(0x0066CC), dark: .init(0x2997FF))
  public static let focus = Color.adaptive(light: .init(0x0071E3), dark: .init(0x0071E3))
  public static let scrim = Color.adaptive(light: .init(0x000000, 0.48), dark: .init(0x000000, 0.48))
  public static let media = Color.adaptive(light: .init(0x000000), dark: .init(0x000000))
  public static let onMedia = Color.adaptive(light: .init(0xFFFFFF), dark: .init(0xFFFFFF))
  public static let danger = Color.adaptive(light: .init(0xD0000A), dark: .init(0xFF5447))
  public static let dangerSurface = Color.adaptive(light: .init(0xD70015, 0.08), dark: .init(0xFF453A, 0.2))
  public static let dangerSurfacePressed = Color.adaptive(light: .init(0xD70015, 0.16), dark: .init(0xFF453A, 0.36))
  public static let success = Color.adaptive(light: .init(0x008009), dark: .init(0x30D158))
  public static let successSurface = Color.adaptive(light: .init(0xEFFAF1), dark: .init(0x30D158, 0.16))
  public static let warning = Color.adaptive(light: .init(0xB64400), dark: .init(0xFF9F0A))
  public static let warningSurface = Color.adaptive(light: .init(0xFFF5EA), dark: .init(0xFF9F0A, 0.16))
}

public enum Radius {
  public static let xs: CGFloat = 3
  public static let sm: CGFloat = 5
  public static let md: CGFloat = 8
  public static let lg: CGFloat = 10
  public static let xl: CGFloat = 12
  public static let xl2: CGFloat = 18
  public static let xl3: CGFloat = 28
  public static let full: CGFloat = 9999
}

extension TextStyle {
  public static let xs3 = TextStyle(size: 11, lineHeight: 13, letterSpacing: 0.066)
  public static let xs2 = TextStyle(size: 12, lineHeight: 16, letterSpacing: 0)
  public static let xs = TextStyle(size: 13, lineHeight: 18, letterSpacing: -0.078)
  public static let sm = TextStyle(size: 15, lineHeight: 20, letterSpacing: -0.24)
  public static let md = TextStyle(size: 16, lineHeight: 21, letterSpacing: -0.32)
  public static let base = TextStyle(size: 17, lineHeight: 22, letterSpacing: -0.442)
  public static let lg = TextStyle(size: 20, lineHeight: 25, letterSpacing: -0.46)
  public static let xl = TextStyle(size: 22, lineHeight: 28, letterSpacing: -0.264)
  public static let xl2 = TextStyle(size: 28, lineHeight: 34, letterSpacing: 0.392)
  public static let xl3 = TextStyle(size: 34, lineHeight: 41, letterSpacing: 0.408)

  public static let allCases: [TextStyle] = [.xs3, .xs2, .xs, .sm, .md, .base, .lg, .xl, .xl2, .xl3]
}

extension Shadow {
  public static let md = Shadow(color: .black.opacity(0.08), radius: 6, x: 2, y: 4)
  public static let lg = Shadow(color: .black.opacity(0.12), radius: 12, y: 4)
}
```

4. Copy the source and every file it uses:

```swift title="swift/Components/Checkbox.swift"
import PhosphorSwift
import SwiftUI

extension Shadow {
  static let control = Shadow(color: .black.opacity(0.08), radius: 0.5, y: 0.5)
  static let thumb = Shadow(color: .black.opacity(0.12), radius: 1.5, y: 1)
}

struct SelectionIndicator<Mark: View>: View {
  let checked: Bool
  let pressed: Bool
  let cornerRadius: CGFloat
  let mark: Mark

  @Environment(\.isEnabled) private var isEnabled
  @Environment(\.isInvalid) private var invalid
  @Environment(\.colorScheme) private var colorScheme

  init(checked: Bool, pressed: Bool, cornerRadius: CGFloat, @ViewBuilder mark: () -> Mark) {
    self.checked = checked
    self.pressed = pressed
    self.cornerRadius = cornerRadius
    self.mark = mark()
  }

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: cornerRadius, style: .continuous)
    ZStack {
      shape.fill(fill)
      shape.strokeBorder(border, lineWidth: 1)
      if checked {
        mark
      }
    }
    .frame(width: 16, height: 16)
    .shadow(raised ? .control : Shadow(color: .clear, radius: 0))
  }

  private var isDark: Bool { colorScheme == .dark }

  private var raised: Bool { !checked && isEnabled && !isDark }

  private var fill: Color {
    if checked {
      return !isEnabled ? .accentDisabled : pressed ? .accentPressed : .accent
    }
    if !isEnabled { return .controlDisabled }
    if isDark { return pressed ? .labelTertiary.opacity(0.6) : .labelQuaternary }
    return pressed ? .control : .surface
  }

  private var border: Color {
    if checked {
      return !isEnabled ? .clear : pressed ? .accentPressed : .accent
    }
    if !isEnabled { return isDark ? .clear : .label.opacity(0.1) }
    if invalid { return .danger }
    return isDark ? .clear : .label.opacity(0.25)
  }
}

struct PressReader<Content: View>: ButtonStyle {
  let content: (Bool) -> Content

  init(@ViewBuilder content: @escaping (Bool) -> Content) {
    self.content = content
  }

  func makeBody(configuration: Configuration) -> some View {
    content(configuration.isPressed)
  }
}

public struct CheckboxStyle: ToggleStyle {
  public init() {}

  public func makeBody(configuration: Configuration) -> some View {
    HapticButton(style: PressReader { pressed in
      HStack(spacing: 12) {
        SelectionIndicator(
          checked: configuration.isOn || configuration.isMixed,
          pressed: pressed,
          cornerRadius: 4
        ) {
          (configuration.isMixed ? Ph.minus.regular : Ph.check.regular)
            .frame(width: 14, height: 14)
            .foregroundStyle(Color.onAccent)
        }
        configuration.label
      }
      .contentShape(Rectangle().inset(by: -8))
    }) {
      configuration.isOn.toggle()
      return true
    }
    .accessibilityElement(children: .combine)
    .accessibilityRemoveTraits(.isButton)
    .accessibilityAddTraits(.isToggle)
    .accessibilityValue(
      configuration.isMixed
        ? Text("Mixed")
        : configuration.isOn ? Text("Checked") : Text("Unchecked")
    )
  }
}

extension ToggleStyle where Self == CheckboxStyle {
  public static var checkbox: CheckboxStyle { CheckboxStyle() }
}
```

```swift title="swift/Components/Field.swift"
import SwiftUI

extension EnvironmentValues {
  @Entry public var isInvalid = false
  @Entry var fieldInset = false
  @Entry var fieldGroupInset = false
  @Entry var fieldSetInset = false
}

extension View {
  public func invalid(_ isInvalid: Bool = true) -> some View {
    environment(\.isInvalid, isInvalid)
  }
}

public enum FieldOrientation: CaseIterable, Sendable {
  case vertical, horizontal
}

public struct Field<Content: View>: View {
  let orientation: FieldOrientation
  let invalid: Bool?
  let content: Content

  @Environment(\.fieldGroupInset) private var inset
  @Environment(\.isInvalid) private var inheritedInvalid

  public init(
    orientation: FieldOrientation = .vertical,
    invalid: Bool? = nil,
    @ViewBuilder content: () -> Content
  ) {
    self.orientation = orientation
    self.invalid = invalid
    self.content = content()
  }

  public var body: some View {
    Group {
      switch orientation {
      case .vertical:
        VStack(alignment: .leading, spacing: 12) { content }
      case .horizontal:
        HStack(alignment: .center, spacing: 12) { content }
      }
    }
    .frame(maxWidth: .infinity, alignment: .leading)
    .padding(.horizontal, inset ? 16 : 0)
    .padding(.vertical, inset ? 6 : 0)
    .frame(minHeight: inset ? 44 : nil)
    .overlay(alignment: .top) {
      if inset {
        Color.separator
          .frame(height: 1)
          .padding(.leading, 16)
          .offset(y: -1)
      }
    }
    .environment(\.fieldInset, inset)
    .environment(\.fieldGroupInset, false)
    .environment(\.isInvalid, invalid ?? inheritedInvalid)
  }
}

public struct FieldContent<Content: View>: View {
  let content: Content

  public init(@ViewBuilder content: () -> Content) {
    self.content = content()
  }

  public var body: some View {
    VStack(alignment: .leading, spacing: 4) {
      content
    }
    .frame(maxWidth: .infinity, alignment: .leading)
  }
}

public struct FieldTitle: View {
  let text: Text

  @Environment(\.isEnabled) private var isEnabled

  public init(_ title: LocalizedStringKey) {
    text = Text(title)
  }

  public init<S: StringProtocol>(_ title: S) {
    text = Text(title)
  }

  public var body: some View {
    text
      .scaledTextStyle(.base, weight: .semibold)
      .foregroundStyle(isEnabled ? Color.label : .labelQuaternary)
  }
}

public struct FieldDescription: View {
  let text: Text

  @Environment(\.fieldSetInset) private var inset

  public init(_ description: LocalizedStringKey) {
    text = Text(description)
  }

  public init<S: StringProtocol>(_ description: S) {
    text = Text(description)
  }

  public var body: some View {
    text
      .scaledTextStyle(inset ? .xs : .sm)
      .foregroundStyle(Color.labelSecondary)
      .multilineTextAlignment(.leading)
      .fixedSize(horizontal: false, vertical: true)
      .padding(.leading, inset ? 16 : 0)
  }
}

public struct FieldError: View {
  let messages: [String]
  let text: Text?

  public init(_ message: LocalizedStringKey) {
    messages = []
    text = Text(message)
  }

  public init(errors: [String?]) {
    var seen = Set<String>()
    messages = errors.compactMap { $0 }.filter { !$0.isEmpty && seen.insert($0).inserted }
    text = nil
  }

  public var body: some View {
    if let content {
      content
        .scaledTextStyle(.sm)
        .foregroundStyle(Color.danger)
        .multilineTextAlignment(.leading)
        .fixedSize(horizontal: false, vertical: true)
    }
  }

  private var content: Text? {
    if let text { return text }
    switch messages.count {
    case 0: return nil
    case 1: return Text(verbatim: messages[0])
    default: return Text(verbatim: messages.map { "\u{2022} \($0)" }.joined(separator: "\n"))
    }
  }
}

public enum FieldGroupVariant: CaseIterable, Sendable {
  case `default`, inset
}

public struct FieldGroup<Content: View>: View {
  let variant: FieldGroupVariant
  let content: Content

  public init(_ variant: FieldGroupVariant = .default, @ViewBuilder content: () -> Content) {
    self.variant = variant
    self.content = content()
  }

  public var body: some View {
    styled
      .environment(\.fieldGroupInset, variant == .inset)
      .environment(\.fieldSetInset, false)
      .transformPreference(FieldSetInsetKey.self) { $0 = variant == .inset }
  }

  @ViewBuilder private var styled: some View {
    let stack = VStack(alignment: .leading, spacing: variant == .inset ? 0 : 28) {
      content
    }
    .frame(maxWidth: .infinity, alignment: .leading)
    if variant == .inset {
      let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
      stack
        .background(Color.surfaceSecondary, in: shape)
        .clipShape(shape)
    } else {
      stack
    }
  }
}

struct FieldSetInsetKey: PreferenceKey {
  static let defaultValue = false

  static func reduce(value: inout Bool, nextValue: () -> Bool) {
    value = value || nextValue()
  }
}

public struct FieldSet<Content: View>: View {
  let content: Content

  @State private var inset = false

  public init(@ViewBuilder content: () -> Content) {
    self.content = content()
  }

  public var body: some View {
    VStack(alignment: .leading, spacing: inset ? 8 : 24) {
      content
    }
    .frame(maxWidth: .infinity, alignment: .leading)
    .environment(\.fieldSetInset, inset)
    .onPreferenceChange(FieldSetInsetKey.self) { inset = $0 }
    .transformPreference(FieldSetInsetKey.self) { $0 = false }
    .accessibilityElement(children: .contain)
  }
}

public struct FieldLegend: View {
  public enum Variant: CaseIterable, Sendable {
    case legend, label
  }

  let text: Text
  let variant: Variant

  @Environment(\.fieldSetInset) private var inset
  @Environment(\.isEnabled) private var isEnabled

  public init(_ title: LocalizedStringKey, variant: Variant = .legend) {
    text = Text(title)
    self.variant = variant
  }

  public init<S: StringProtocol>(_ title: S, variant: Variant = .legend) {
    text = Text(title)
    self.variant = variant
  }

  public var body: some View {
    Group {
      if inset {
        text
          .textCase(.uppercase)
          .scaledTextStyle(.xs)
          .foregroundStyle(isEnabled ? Color.labelSecondary : .labelQuaternary)
          .padding(.leading, 16)
      } else {
        text
          .scaledTextStyle(.base, weight: .semibold)
          .foregroundStyle(isEnabled ? Color.label : .labelQuaternary)
          .padding(.bottom, 12)
      }
    }
    .accessibilityAddTraits(variant == .legend ? .isHeader : [])
  }
}

public struct FieldSeparator<Content: View>: View {
  let content: Content

  public init(@ViewBuilder content: () -> Content) {
    self.content = content()
  }

  public var body: some View {
    ZStack {
      Separator()
      content
        .scaledTextStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .padding(.horizontal, 8)
        .background(Color.surface)
    }
    .frame(minHeight: 20)
    .padding(.vertical, -8)
  }
}

extension FieldSeparator where Content == EmptyView {
  public init() {
    self.init { EmptyView() }
  }
}

extension FieldSeparator where Content == Text {
  public init(_ title: LocalizedStringKey) {
    self.init { Text(title) }
  }
}
```

```swift title="swift/Components/Haptics.swift"
import SwiftUI

extension EnvironmentValues {
  @Entry public var hapticsEnabled = true
}

extension View {
  public func haptics(_ enabled: Bool) -> some View {
    environment(\.hapticsEnabled, enabled)
  }

  func hapticFeedback<Trigger: Equatable>(_ feedback: SensoryFeedback, trigger: Trigger) -> some View {
    modifier(HapticFeedbackModifier(feedback: feedback, trigger: trigger) { _, _ in true })
  }

  func hapticFeedback<Trigger: Equatable>(
    _ feedback: SensoryFeedback,
    trigger: Trigger,
    condition: @escaping (Trigger, Trigger) -> Bool
  ) -> some View {
    modifier(HapticFeedbackModifier(feedback: feedback, trigger: trigger, condition: condition))
  }
}

private struct HapticFeedbackModifier<Trigger: Equatable>: ViewModifier {
  let feedback: SensoryFeedback
  let trigger: Trigger
  let condition: (Trigger, Trigger) -> Bool

  @Environment(\.hapticsEnabled) private var enabled

  func body(content: Content) -> some View {
    let enabled = enabled
    let condition = condition
    content.sensoryFeedback(feedback, trigger: trigger) { old, new in
      enabled && condition(old, new)
    }
  }
}

enum HapticMoments {
  static func step(_ value: Double, bounds: ClosedRange<Double>, step: Double?) -> Int? {
    guard let step, step > 0 else { return nil }
    return Int(((value - bounds.lowerBound) / step).rounded())
  }

  static func lifted<Value: Equatable>(_ old: Value?, _ new: Value?) -> Bool {
    new != nil && old != new
  }

  static func crossed<Value: Equatable>(_ old: Value?, _ new: Value?) -> Bool {
    old == nil && new != nil
  }

  static func moved(_ old: Int?, _ new: Int?) -> Bool {
    guard let old, let new else { return false }
    return old != new
  }
}

struct HapticButton<Style: ButtonStyle>: View {
  let feedback: SensoryFeedback
  let action: () -> Bool
  let style: Style

  @State private var count = 0

  init(_ feedback: SensoryFeedback = .selection, style: Style, action: @escaping () -> Bool) {
    self.feedback = feedback
    self.style = style
    self.action = action
  }

  var body: some View {
    Button {
      if action() { count += 1 }
    } label: {
      EmptyView()
    }
    .buttonStyle(style)
    .hapticFeedback(feedback, trigger: count)
  }
}
```

```swift title="swift/Components/Separator.swift"
import SwiftUI

public struct Separator: View {
  let orientation: Axis

  public init(_ orientation: Axis = .horizontal) {
    self.orientation = orientation
  }

  public var body: some View {
    Rectangle()
      .fill(Color.separator)
      .frame(width: orientation == .vertical ? 1 : nil, height: orientation == .horizontal ? 1 : nil)
      .frame(maxWidth: orientation == .horizontal ? .infinity : nil, maxHeight: orientation == .vertical ? .infinity : nil)
      .accessibilityHidden(true)
  }
}
```

```swift title="swift/Components/TextVariant.swift"
import SwiftUI

public enum TextVariant: CaseIterable, Sendable {
  case `default`, h1, h2, h3, h4, p, blockquote, code, lead, large, small, muted

  var style: TextStyle {
    switch self {
    case .h1: .xl3
    case .h2: .xl2
    case .h3: .xl
    case .h4, .lead, .large: .lg
    case .code, .small, .muted: .sm
    default: .base
    }
  }

  var weight: Font.Weight {
    switch self {
    case .h1, .h2: .bold
    case .h3, .h4, .large, .code: .semibold
    case .small: .medium
    default: .regular
    }
  }

  var color: Color {
    switch self {
    case .lead, .muted: .labelSecondary
    default: .label
    }
  }

  var isHeading: Bool {
    switch self {
    case .h1, .h2, .h3, .h4: true
    default: false
    }
  }
}

private struct TextVariantModifier: ViewModifier {
  let variant: TextVariant

  func body(content: Content) -> some View {
    switch variant {
    case .blockquote:
      styled(content)
        .italic()
        .padding(.leading, 12)
        .overlay(alignment: .leading) {
          Rectangle().fill(Color.separator).frame(width: 2)
        }
        .padding(.top, 16)
    case .code:
      styled(content)
        .monospaced()
        .padding(.horizontal, 4)
        .padding(.vertical, 2)
        .background(Color.surfaceSecondary, in: RoundedRectangle(cornerRadius: Radius.sm, style: .continuous))
    case .p:
      styled(content).padding(.top, 12)
    default:
      styled(content)
    }
  }

  private func styled(_ content: Content) -> some View {
    content
      .scaledTextStyle(variant.style, weight: variant.weight)
      .foregroundStyle(variant.color)
      .accessibilityAddTraits(variant.isHeading ? .isHeader : [])
  }
}

extension View {
  public func textVariant(_ variant: TextVariant) -> some View {
    modifier(TextVariantModifier(variant: variant))
  }
}

private struct ScaledTextStyleModifier: ViewModifier {
  let style: TextStyle
  let weight: Font.Weight

  @ScaledMetric(relativeTo: .body) private var scale: CGFloat = 1

  func body(content: Content) -> some View {
    let size = style.size * scale
    let lineSpacing = max(0, style.lineHeight * scale - UIFont.systemFont(ofSize: size).lineHeight)
    content
      .font(.system(size: size, weight: weight))
      .tracking(style.letterSpacing)
      .lineSpacing(lineSpacing)
      .padding(.vertical, lineSpacing / 2)
  }
}

extension View {
  func scaledTextStyle(_ style: TextStyle, weight: Font.Weight = .regular) -> some View {
    modifier(ScaledTextStyleModifier(style: style, weight: weight))
  }

  func scaledFont(_ style: TextStyle, weight: Font.Weight = .regular) -> some View {
    modifier(ScaledFontModifier(style: style, weight: weight))
  }
}

private struct ScaledFontModifier: ViewModifier {
  let style: TextStyle
  let weight: Font.Weight

  @ScaledMetric(relativeTo: .body) private var scale: CGFloat = 1

  func body(content: Content) -> some View {
    content
      .font(.system(size: style.size * scale, weight: weight))
      .tracking(style.letterSpacing)
  }
}
```

5. Add the files to your app target.

**Jetpack Compose**

1. Set `minSdk` to 24 or higher and add the dependencies:

```kotlin title="build.gradle.kts"
implementation(platform("androidx.compose:compose-bom:2026.09.00"))
implementation("androidx.compose.foundation:foundation")
implementation("androidx.compose.ui:ui")
implementation("com.adamglin:phosphor-icon-android:1.0.0")
```

2. Copy the theme files every view uses:

```kt title="kotlin/theme/Theme.kt"
package com.esuiss.ui.theme

import androidx.compose.foundation.isSystemInDarkTheme
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.dropShadow
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.Shape
import androidx.compose.ui.graphics.shadow.Shadow as DropShadow
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.style.LineHeightStyle
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.DpOffset
import androidx.compose.ui.unit.em
import androidx.compose.ui.unit.sp

internal fun textStyle(size: Double, lineHeight: Double, letterSpacing: Double) = TextStyle(
    fontSize = size.sp,
    lineHeight = lineHeight.sp,
    letterSpacing = letterSpacing.em,
    lineHeightStyle = LineHeightStyle(
        alignment = LineHeightStyle.Alignment.Center,
        trim = LineHeightStyle.Trim.None,
    ),
)

@Immutable
data class Shadow(
    val offsetX: Dp,
    val offsetY: Dp,
    val blur: Dp,
    val color: Color,
)

fun Modifier.shadow(shadow: Shadow, shape: Shape): Modifier = dropShadow(
    shape,
    DropShadow(
        radius = shadow.blur,
        color = shadow.color,
        offset = DpOffset(shadow.offsetX, shadow.offsetY),
    ),
)

val LocalColors = staticCompositionLocalOf { LightColors }

object EsuissTheme {
    val colors: Colors
        @Composable get() = LocalColors.current

    val typography: Typography
        get() = Typography

    val radius: Radius
        get() = Radius

    val shadows: Shadows
        get() = Shadows
}

@Composable
fun EsuissTheme(
    darkTheme: Boolean = isSystemInDarkTheme(),
    content: @Composable () -> Unit,
) {
    CompositionLocalProvider(
        LocalColors provides if (darkTheme) DarkColors else LightColors,
        content = content,
    )
}
```

```kt title="kotlin/theme/Tokens.kt"
package com.esuiss.ui.theme

import androidx.compose.runtime.Immutable
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp

@Immutable
data class Colors(
    val surface: Color,
    val surfaceSecondary: Color,
    val surfaceTertiary: Color,
    val surfaceRaised: Color,
    val label: Color,
    val labelSecondary: Color,
    val labelTertiary: Color,
    val labelQuaternary: Color,
    val control: Color,
    val controlPressed: Color,
    val controlSelected: Color,
    val controlDisabled: Color,
    val onControlSelected: Color,
    val itemPressed: Color,
    val itemSelected: Color,
    val separator: Color,
    val separatorStrong: Color,
    val accent: Color,
    val accentPressed: Color,
    val accentSelected: Color,
    val accentDisabled: Color,
    val onAccent: Color,
    val accentSurface: Color,
    val accentSurfacePressed: Color,
    val link: Color,
    val focus: Color,
    val scrim: Color,
    val media: Color,
    val onMedia: Color,
    val danger: Color,
    val dangerSurface: Color,
    val dangerSurfacePressed: Color,
    val success: Color,
    val successSurface: Color,
    val warning: Color,
    val warningSurface: Color,
    val blue: Color,
    val green: Color,
    val orange: Color,
    val red: Color,
    val yellow: Color,
    val purple: Color,
    val pink: Color,
    val indigo: Color,
    val teal: Color,
    val mint: Color,
    val cyan: Color,
    val brown: Color,
    val gray: Color,
    val isDark: Boolean,
)

val LightColors = Colors(
    surface = Color(0xFFFFFFFF),
    surfaceSecondary = Color(0xFFF5F5F7),
    surfaceTertiary = Color(0xFFE8E8ED),
    surfaceRaised = Color(0xFFFFFFFF),
    label = Color(0xFF1D1D1F),
    labelSecondary = Color(0xFF6E6E73),
    labelTertiary = Color(0xFF86868B),
    labelQuaternary = Color(0xFFD2D2D7),
    control = Color(0xFF000000).copy(alpha = 0.04f),
    controlPressed = Color(0xFF000000).copy(alpha = 0.12f),
    controlSelected = Color(0xFF1D1D1F),
    controlDisabled = Color(0xFF000000).copy(alpha = 0.03f),
    onControlSelected = Color(0xFFFFFFFF),
    itemPressed = Color(0xFF000000).copy(alpha = 0.08f),
    itemSelected = Color(0xFF000000).copy(alpha = 0.06f),
    separator = Color(0xFFD2D2D7),
    separatorStrong = Color(0xFF86868B),
    accent = Color(0xFF0071E3),
    accentPressed = Color(0xFF005BB8),
    accentSelected = Color(0xFF0071E3),
    accentDisabled = Color(0xFF0071E3).copy(alpha = 0.4f),
    onAccent = Color(0xFFFFFFFF),
    accentSurface = Color(0xFF0071E3).copy(alpha = 0.09f),
    accentSurfacePressed = Color(0xFF0071E3).copy(alpha = 0.18f),
    link = Color(0xFF0066CC),
    focus = Color(0xFF0071E3),
    scrim = Color(0xFF000000).copy(alpha = 0.48f),
    media = Color(0xFF000000),
    onMedia = Color(0xFFFFFFFF),
    danger = Color(0xFFD0000A),
    dangerSurface = Color(0xFFD70015).copy(alpha = 0.08f),
    dangerSurfacePressed = Color(0xFFD70015).copy(alpha = 0.16f),
    success = Color(0xFF008009),
    successSurface = Color(0xFFEFFAF1),
    warning = Color(0xFFB64400),
    warningSurface = Color(0xFFFFF5EA),
    blue = Color(0xFF007AFF),
    green = Color(0xFF34C759),
    orange = Color(0xFFFF9500),
    red = Color(0xFFFF3B30),
    yellow = Color(0xFFFFCC00),
    purple = Color(0xFFAF52DE),
    pink = Color(0xFFFF2D55),
    indigo = Color(0xFF5856D6),
    teal = Color(0xFF30B0C7),
    mint = Color(0xFF00C7BE),
    cyan = Color(0xFF32ADE6),
    brown = Color(0xFFA2845E),
    gray = Color(0xFF8E8E93),
    isDark = false,
)

val DarkColors = Colors(
    surface = Color(0xFF000000),
    surfaceSecondary = Color(0xFF161617),
    surfaceTertiary = Color(0xFF2C2C2E),
    surfaceRaised = Color(0xFF1D1D1F),
    label = Color(0xFFF5F5F7),
    labelSecondary = Color(0xFFA1A1A6),
    labelTertiary = Color(0xFF86868B),
    labelQuaternary = Color(0xFF424245),
    control = Color(0xFFFFFFFF).copy(alpha = 0.1f),
    controlPressed = Color(0xFFFFFFFF).copy(alpha = 0.22f),
    controlSelected = Color(0xFFF5F5F7),
    controlDisabled = Color(0xFFFFFFFF).copy(alpha = 0.05f),
    onControlSelected = Color(0xFF000000),
    itemPressed = Color(0xFFFFFFFF).copy(alpha = 0.12f),
    itemSelected = Color(0xFFFFFFFF).copy(alpha = 0.1f),
    separator = Color(0xFF424245),
    separatorStrong = Color(0xFF6E6E73),
    accent = Color(0xFF0071E3),
    accentPressed = Color(0xFF004D9E),
    accentSelected = Color(0xFF0071E3),
    accentDisabled = Color(0xFF0071E3).copy(alpha = 0.4f),
    onAccent = Color(0xFFFFFFFF),
    accentSurface = Color(0xFF0071E3).copy(alpha = 0.18f),
    accentSurfacePressed = Color(0xFF0071E3).copy(alpha = 0.3f),
    link = Color(0xFF2997FF),
    focus = Color(0xFF0071E3),
    scrim = Color(0xFF000000).copy(alpha = 0.48f),
    media = Color(0xFF000000),
    onMedia = Color(0xFFFFFFFF),
    danger = Color(0xFFFF5447),
    dangerSurface = Color(0xFFFF453A).copy(alpha = 0.2f),
    dangerSurfacePressed = Color(0xFFFF453A).copy(alpha = 0.36f),
    success = Color(0xFF30D158),
    successSurface = Color(0xFF30D158).copy(alpha = 0.16f),
    warning = Color(0xFFFF9F0A),
    warningSurface = Color(0xFFFF9F0A).copy(alpha = 0.16f),
    blue = Color(0xFF0A84FF),
    green = Color(0xFF30D158),
    orange = Color(0xFFFF9F0A),
    red = Color(0xFFFF453A),
    yellow = Color(0xFFFFD60A),
    purple = Color(0xFFBF5AF2),
    pink = Color(0xFFFF375F),
    indigo = Color(0xFF5E5CE6),
    teal = Color(0xFF40C8E0),
    mint = Color(0xFF66D4CF),
    cyan = Color(0xFF64D2FF),
    brown = Color(0xFFAC8E68),
    gray = Color(0xFF8E8E93),
    isDark = true,
)

object Radius {
    val xs = 3.dp
    val sm = 5.dp
    val md = 8.dp
    val lg = 10.dp
    val xl = 12.dp
    val xl2 = 18.dp
    val xl3 = 28.dp
    val full = 9999.dp
}

object Typography {
    val xs3 = textStyle(11.0, 13.0, 0.006)
    val xs2 = textStyle(12.0, 16.0, 0.0)
    val xs = textStyle(13.0, 18.0, -0.006)
    val sm = textStyle(15.0, 20.0, -0.016)
    val md = textStyle(16.0, 21.0, -0.02)
    val base = textStyle(17.0, 22.0, -0.026)
    val lg = textStyle(20.0, 25.0, -0.023)
    val xl = textStyle(22.0, 28.0, -0.012)
    val xl2 = textStyle(28.0, 34.0, 0.014)
    val xl3 = textStyle(34.0, 41.0, 0.012)

    val all = listOf(xs3, xs2, xs, sm, md, base, lg, xl, xl2, xl3)
}

object Shadows {
    val md = Shadow(2.dp, 4.dp, 12.dp, Color.Black.copy(alpha = 0.08f))
    val lg = Shadow(0.dp, 4.dp, 24.dp, Color.Black.copy(alpha = 0.12f))
}
```

3. Copy the source and every file it uses:

```kt title="kotlin/components/Checkbox.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.foundation.interaction.collectIsPressedAsState
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.selection.triStateToggleable
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.semantics.error
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.state.ToggleableState
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.Check
import com.adamglin.phosphoricons.regular.Minus
import com.esuiss.ui.theme.Colors
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.shadow

@Composable
fun Checkbox(
    checked: Boolean,
    onCheckedChange: ((Boolean) -> Unit)?,
    modifier: Modifier = Modifier,
    enabled: Boolean = LocalFieldState.current.enabled,
    invalid: Boolean = LocalFieldState.current.invalid,
    interactionSource: MutableInteractionSource? = null,
) {
    TriStateCheckbox(
        state = ToggleableState(checked),
        onClick = onCheckedChange?.let { { it(!checked) } },
        modifier = modifier,
        enabled = enabled,
        invalid = invalid,
        interactionSource = interactionSource,
    )
}

@Composable
fun TriStateCheckbox(
    state: ToggleableState,
    onClick: (() -> Unit)?,
    modifier: Modifier = Modifier,
    enabled: Boolean = LocalFieldState.current.enabled,
    invalid: Boolean = LocalFieldState.current.invalid,
    interactionSource: MutableInteractionSource? = null,
) {
    val colors = EsuissTheme.colors
    val haptics = rememberHaptics()
    val source = interactionSource ?: remember { MutableInteractionSource() }
    val pressed by source.collectIsPressedAsState()
    val on = state != ToggleableState.Off
    val shape = RoundedCornerShape(4.dp)
    val look = selectionControlLook(colors, on, enabled, invalid, pressed)
    val toggle = if (onClick != null) {
        Modifier
            .triStateToggleable(
                state = state,
                interactionSource = source,
                indication = null,
                enabled = enabled,
                role = Role.Checkbox,
                onClick = {
                    haptics.toggle(state != ToggleableState.On)
                    onClick()
                },
            )
            .formTouchTarget()
    } else {
        Modifier
    }
    Box(
        modifier = modifier
            .then(toggle)
            .then(if (invalid) Modifier.semantics { error("Invalid") } else Modifier)
            .size(16.dp)
            .then(if (look.shadow) Modifier.shadow(FormShadowXs, shape) else Modifier)
            .background(look.background, shape)
            .border(1.dp, look.border, shape),
        contentAlignment = Alignment.Center,
    ) {
        if (on) {
            Icon(
                if (state == ToggleableState.Indeterminate) PhosphorIcons.Regular.Minus else PhosphorIcons.Regular.Check,
                contentDescription = null,
                size = 14.dp,
                tint = colors.onAccent,
            )
        }
    }
}

internal class SelectionControlLook(val background: Color, val border: Color, val shadow: Boolean)

internal fun selectionControlLook(
    colors: Colors,
    on: Boolean,
    enabled: Boolean,
    invalid: Boolean,
    pressed: Boolean,
): SelectionControlLook = when {
    on && !enabled -> SelectionControlLook(colors.accentDisabled, Color.Transparent, false)
    on -> {
        val color = if (pressed) colors.accentPressed else colors.accent
        SelectionControlLook(color, color, false)
    }
    !enabled -> SelectionControlLook(
        colors.controlDisabled,
        if (colors.isDark) Color.Transparent else colors.label.copy(alpha = 0.1f),
        false,
    )
    colors.isDark -> SelectionControlLook(
        colors.labelQuaternary,
        if (invalid) colors.danger else Color.Transparent,
        false,
    )
    else -> SelectionControlLook(
        if (pressed) colors.control else colors.surface,
        if (invalid) colors.danger else colors.label.copy(alpha = 0.25f),
        true,
    )
}
```

```kt title="kotlin/components/Content.kt"
package com.esuiss.ui.components

import androidx.compose.runtime.compositionLocalOf
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.dp

val LocalContentStyle = compositionLocalOf { TextStyle.Default }

val LocalContentColor = compositionLocalOf { Color.Unspecified }

val LocalIconSize = compositionLocalOf { 20.dp }
```

```kt title="kotlin/components/Field.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.ColumnScope
import androidx.compose.foundation.layout.LayoutScopeMarker
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.heightIn
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.remember
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.layout.layout
import androidx.compose.ui.platform.LocalConfiguration
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.heading
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

enum class FieldOrientation { Vertical, Horizontal, Responsive }

enum class FieldGroupVariant { Default, Inset }

enum class FieldLegendVariant { Legend, Label }

@Immutable
internal class FieldState(val enabled: Boolean, val invalid: Boolean)

internal val LocalFieldState = staticCompositionLocalOf { FieldState(enabled = true, invalid = false) }

private val LocalFieldSetInset = staticCompositionLocalOf { false }

private val LocalFieldGroupVariant = staticCompositionLocalOf<FieldGroupVariant?> { null }

private val LocalFieldInset = staticCompositionLocalOf { false }

@LayoutScopeMarker
@Immutable
interface FieldScope {
    fun Modifier.weight(weight: Float): Modifier
}

private class RowFieldScope(private val scope: RowScope) : FieldScope {
    override fun Modifier.weight(weight: Float): Modifier = with(scope) { this@weight.weight(weight, true) }
}

private object ColumnFieldScope : FieldScope {
    override fun Modifier.weight(weight: Float): Modifier = this
}

@Composable
fun FieldSet(
    modifier: Modifier = Modifier,
    variant: FieldGroupVariant = FieldGroupVariant.Default,
    enabled: Boolean = true,
    content: @Composable ColumnScope.() -> Unit,
) {
    val inset = variant == FieldGroupVariant.Inset
    CompositionLocalProvider(
        LocalFieldSetInset provides inset,
        LocalFieldState provides FieldState(enabled, LocalFieldState.current.invalid),
    ) {
        Column(
            modifier = modifier.fillMaxWidth(),
            verticalArrangement = Arrangement.spacedBy(if (inset) 8.dp else 24.dp),
            content = content,
        )
    }
}

@Composable
fun FieldLegend(
    text: String,
    modifier: Modifier = Modifier,
    variant: FieldLegendVariant = FieldLegendVariant.Legend,
) {
    val colors = EsuissTheme.colors
    val inset = LocalFieldSetInset.current
    val enabled = LocalFieldState.current.enabled
    val style = if (inset) {
        Typography.xs.copy(color = if (enabled) colors.labelSecondary else colors.labelQuaternary)
    } else {
        Typography.base.copy(color = if (enabled) colors.label else colors.labelQuaternary, fontWeight = FontWeight.SemiBold)
    }
    BasicText(
        text = if (inset) text.uppercase() else text,
        modifier = modifier
            .then(if (variant == FieldLegendVariant.Legend) Modifier.semantics { heading() } else Modifier)
            .padding(start = if (inset) 16.dp else 0.dp, bottom = if (inset) 0.dp else 12.dp),
        style = style,
    )
}

@Composable
fun FieldGroup(
    modifier: Modifier = Modifier,
    variant: FieldGroupVariant = FieldGroupVariant.Default,
    content: @Composable () -> Unit,
) {
    val colors = EsuissTheme.colors
    CompositionLocalProvider(
        LocalFieldSetInset provides false,
        LocalFieldGroupVariant provides variant,
    ) {
        if (variant == FieldGroupVariant.Inset) {
            FormDividedStack(
                orientation = Orientation.Vertical,
                dividerColor = colors.separator,
                modifier = modifier
                    .fillMaxWidth()
                    .clip(RoundedCornerShape(Radius.xl2))
                    .background(colors.surfaceSecondary),
                dividerInsetStart = 16.dp,
                content = content,
            )
        } else {
            Column(
                modifier = modifier.fillMaxWidth(),
                verticalArrangement = Arrangement.spacedBy(28.dp),
            ) {
                content()
            }
        }
    }
}

@Composable
fun Field(
    modifier: Modifier = Modifier,
    orientation: FieldOrientation = FieldOrientation.Vertical,
    enabled: Boolean = LocalFieldState.current.enabled,
    invalid: Boolean = false,
    content: @Composable FieldScope.() -> Unit,
) {
    val inset = LocalFieldGroupVariant.current == FieldGroupVariant.Inset
    val horizontal = when (orientation) {
        FieldOrientation.Vertical -> false
        FieldOrientation.Horizontal -> true
        FieldOrientation.Responsive -> LocalConfiguration.current.screenWidthDp >= 768
    }
    val sizing = modifier
        .fillMaxWidth()
        .then(if (inset) Modifier.heightIn(min = 44.dp).padding(horizontal = 16.dp, vertical = 6.dp) else Modifier)
    CompositionLocalProvider(
        LocalFieldGroupVariant provides null,
        LocalFieldInset provides inset,
        LocalFieldState provides FieldState(enabled, invalid),
    ) {
        if (horizontal) {
            Row(
                modifier = sizing,
                horizontalArrangement = Arrangement.spacedBy(12.dp),
                verticalAlignment = Alignment.CenterVertically,
            ) {
                val scope = remember(this) { RowFieldScope(this) }
                scope.content()
            }
        } else {
            Column(
                modifier = sizing,
                verticalArrangement = Arrangement.spacedBy(12.dp, Alignment.CenterVertically),
            ) {
                ColumnFieldScope.content()
            }
        }
    }
}

@Composable
fun FieldScope.FieldContent(
    modifier: Modifier = Modifier,
    content: @Composable ColumnScope.() -> Unit,
) {
    Column(
        modifier = modifier.weight(1f),
        verticalArrangement = Arrangement.spacedBy(4.dp),
        content = content,
    )
}

@Composable
fun FieldLabel(text: String, modifier: Modifier = Modifier) {
    val colors = EsuissTheme.colors
    val enabled = LocalFieldState.current.enabled
    BasicText(
        text = text,
        modifier = modifier,
        style = Typography.base.copy(
            color = if (enabled) colors.label else colors.labelQuaternary,
            fontWeight = if (LocalFieldInset.current) FontWeight.Normal else FontWeight.SemiBold,
        ),
    )
}

@Composable
fun FieldTitle(text: String, modifier: Modifier = Modifier) {
    val colors = EsuissTheme.colors
    val enabled = LocalFieldState.current.enabled
    BasicText(
        text = text,
        modifier = modifier,
        style = Typography.base.copy(
            color = if (enabled) colors.label else colors.labelQuaternary,
            fontWeight = FontWeight.SemiBold,
        ),
    )
}

@Composable
fun FieldDescription(text: String, modifier: Modifier = Modifier) {
    val colors = EsuissTheme.colors
    val inset = LocalFieldSetInset.current
    BasicText(
        text = text,
        modifier = modifier.padding(start = if (inset) 16.dp else 0.dp),
        style = (if (inset) Typography.xs else Typography.sm).copy(color = colors.labelSecondary),
    )
}

@Composable
fun FieldSeparator(
    modifier: Modifier = Modifier,
    text: String? = null,
) {
    val colors = EsuissTheme.colors
    Box(
        modifier = modifier
            .fillMaxWidth()
            .layout { measurable, constraints ->
                val placeable = measurable.measure(constraints)
                val overlap = 8.dp.roundToPx()
                val height = (placeable.height - overlap * 2).coerceAtLeast(0)
                layout(placeable.width, height) { placeable.place(0, -overlap) }
            }
            .heightIn(min = 20.dp),
        contentAlignment = Alignment.Center,
    ) {
        Separator()
        if (text != null) {
            BasicText(
                text = text,
                modifier = Modifier.background(colors.surface).padding(horizontal = 8.dp),
                style = Typography.sm.copy(color = colors.labelSecondary),
            )
        }
    }
}

@Composable
fun FieldError(text: String?, modifier: Modifier = Modifier) {
    if (text.isNullOrEmpty()) return
    BasicText(
        text = text,
        modifier = modifier.semantics { liveRegion = LiveRegionMode.Polite },
        style = Typography.sm.copy(color = EsuissTheme.colors.danger),
    )
}

@Composable
fun FieldError(errors: List<String?>, modifier: Modifier = Modifier) {
    val messages = errors.filterNotNull().filter { it.isNotEmpty() }.distinct()
    val text = when (messages.size) {
        0 -> null
        1 -> messages[0]
        else -> messages.joinToString("\n") { "• $it" }
    }
    FieldError(text, modifier)
}
```

```kt title="kotlin/components/FormSupport.kt"
package com.esuiss.ui.components

import android.provider.Settings
import androidx.compose.animation.core.CubicBezierEasing
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.text.selection.TextSelectionColors
import androidx.compose.runtime.Composable
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.draw.drawWithContent
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.Shape
import androidx.compose.ui.layout.Layout
import androidx.compose.ui.layout.layout
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.unit.Constraints
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.LayoutDirection
import androidx.compose.ui.unit.constrainHeight
import androidx.compose.ui.unit.constrainWidth
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.Colors
import com.esuiss.ui.theme.Shadow

internal val FormShadowXs = Shadow(0.dp, 1.dp, 2.dp, Color.Black.copy(alpha = 0.05f))

internal val FormShadowSm = Shadow(0.dp, 1.dp, 3.dp, Color.Black.copy(alpha = 0.1f))

internal val FormEasing = CubicBezierEasing(0.32f, 0.72f, 0f, 1f)

internal fun Modifier.formTouchTarget(): Modifier = layout { measurable, constraints ->
    val minimum = 48.dp.roundToPx()
    val placeable = measurable.measure(constraints)
    val width = constraints.constrainWidth(maxOf(placeable.width, minimum))
    val height = constraints.constrainHeight(maxOf(placeable.height, minimum))
    layout(width, height) {
        placeable.place((width - placeable.width) / 2, (height - placeable.height) / 2)
    }
}

@Composable
internal fun formReducedMotion(): Boolean {
    val context = LocalContext.current
    return remember(context) {
        Settings.Global.getFloat(context.contentResolver, Settings.Global.ANIMATOR_DURATION_SCALE, 1f) == 0f
    }
}

internal fun formSelectionColors(colors: Colors) = TextSelectionColors(
    handleColor = colors.accent,
    backgroundColor = colors.accent.copy(alpha = 0.3f),
)

internal fun Modifier.formInputSurface(
    colors: Colors,
    shape: Shape,
    focused: Boolean,
    invalid: Boolean,
    enabled: Boolean,
): Modifier {
    val background = when {
        !enabled -> colors.controlDisabled
        invalid -> colors.danger.copy(alpha = if (colors.isDark) 0.1f else 0.05f)
        else -> colors.control
    }
    val border = when {
        invalid -> colors.danger
        focused -> colors.focus
        else -> Color.Transparent
    }
    return clip(shape).background(background, shape).border(1.dp, border, shape)
}

@Composable
internal fun FormDividedStack(
    orientation: Orientation,
    dividerColor: Color,
    modifier: Modifier = Modifier,
    dividerInsetStart: Dp = 0.dp,
    content: @Composable () -> Unit,
) {
    val boundaries = remember { mutableStateOf(IntArray(0)) }
    val vertical = orientation == Orientation.Vertical
    Layout(
        content = content,
        modifier = modifier.drawWithContent {
            drawContent()
            val stroke = 1.dp.toPx()
            val inset = dividerInsetStart.toPx()
            boundaries.value.forEach { position ->
                if (vertical) {
                    val start = if (layoutDirection == LayoutDirection.Rtl) 0f else inset
                    drawRect(dividerColor, Offset(start, position.toFloat()), Size(size.width - inset, stroke))
                } else {
                    val x = if (layoutDirection == LayoutDirection.Rtl) size.width - position - stroke else position.toFloat()
                    drawRect(dividerColor, Offset(x, 0f), Size(stroke, size.height))
                }
            }
        },
    ) { measurables, constraints ->
        if (vertical) {
            val width = if (constraints.hasFixedWidth) {
                constraints.maxWidth
            } else {
                constraints.constrainWidth(measurables.maxOfOrNull { it.maxIntrinsicWidth(Constraints.Infinity) } ?: 0)
            }
            val placeables = measurables.map {
                it.measure(Constraints(minWidth = width, maxWidth = width))
            }
            val offsets = IntArray(placeables.size)
            var y = 0
            placeables.forEachIndexed { index, placeable ->
                offsets[index] = y
                y += placeable.height
            }
            val next = offsets.drop(1).toIntArray()
            if (!next.contentEquals(boundaries.value)) boundaries.value = next
            layout(width, constraints.constrainHeight(y)) {
                placeables.forEachIndexed { index, placeable -> placeable.placeRelative(0, offsets[index]) }
            }
        } else {
            val height = if (constraints.hasFixedHeight) {
                constraints.maxHeight
            } else {
                constraints.constrainHeight(measurables.maxOfOrNull { it.maxIntrinsicHeight(Constraints.Infinity) } ?: 0)
            }
            val placeables = measurables.map {
                it.measure(Constraints(minHeight = height, maxHeight = height))
            }
            val offsets = IntArray(placeables.size)
            var x = 0
            placeables.forEachIndexed { index, placeable ->
                offsets[index] = x
                x += placeable.width
            }
            val next = offsets.drop(1).toIntArray()
            if (!next.contentEquals(boundaries.value)) boundaries.value = next
            layout(constraints.constrainWidth(x), height) {
                placeables.forEachIndexed { index, placeable -> placeable.placeRelative(offsets[index], 0) }
            }
        }
    }
}
```

```kt title="kotlin/components/Haptics.kt"
package com.esuiss.ui.components

import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.remember
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.hapticfeedback.HapticFeedback
import androidx.compose.ui.hapticfeedback.HapticFeedbackType
import androidx.compose.ui.platform.LocalHapticFeedback

val LocalHapticsEnabled = staticCompositionLocalOf { true }

@Composable
fun ProvideHaptics(enabled: Boolean, content: @Composable () -> Unit) {
    CompositionLocalProvider(LocalHapticsEnabled provides enabled, content = content)
}

internal class Haptics(private val feedback: HapticFeedback, private val enabled: Boolean) {
    fun perform(type: HapticFeedbackType) {
        if (enabled) feedback.performHapticFeedback(type)
    }

    fun toggle(on: Boolean) = perform(if (on) HapticFeedbackType.ToggleOn else HapticFeedbackType.ToggleOff)

    fun selection() = perform(HapticFeedbackType.SegmentTick)
}

@Composable
internal fun rememberHaptics(): Haptics {
    val feedback = LocalHapticFeedback.current
    val enabled = LocalHapticsEnabled.current
    return remember(feedback, enabled) { Haptics(feedback, enabled) }
}
```

```kt title="kotlin/components/Icon.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.Image
import androidx.compose.foundation.layout.size
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.ColorFilter
import androidx.compose.ui.graphics.takeOrElse
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.unit.Dp
import com.esuiss.ui.theme.EsuissTheme

@Composable
fun Icon(
    imageVector: ImageVector,
    contentDescription: String?,
    modifier: Modifier = Modifier,
    size: Dp = LocalIconSize.current,
    tint: Color = LocalContentColor.current.takeOrElse { EsuissTheme.colors.label },
) {
    Image(
        imageVector = imageVector,
        contentDescription = contentDescription,
        modifier = modifier.size(size),
        colorFilter = ColorFilter.tint(tint),
    )
}
```

```kt title="kotlin/components/Label.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

@Composable
fun Label(
    modifier: Modifier = Modifier,
    enabled: Boolean = true,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val color = if (enabled) colors.label else colors.labelQuaternary
    Row(
        modifier = modifier,
        horizontalArrangement = Arrangement.spacedBy(8.dp),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        CompositionLocalProvider(
            LocalContentStyle provides Typography.base.copy(color = color, fontWeight = FontWeight.SemiBold),
            LocalContentColor provides color,
        ) {
            content()
        }
    }
}

@Composable
fun Label(
    text: String,
    modifier: Modifier = Modifier,
    enabled: Boolean = true,
) {
    Label(modifier, enabled) {
        BasicText(text, style = LocalContentStyle.current)
    }
}
```

```kt title="kotlin/components/Separator.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxHeight
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.width
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme

@Composable
fun Separator(
    modifier: Modifier = Modifier,
    orientation: Orientation = Orientation.Horizontal,
) {
    val sizing = if (orientation == Orientation.Horizontal) {
        Modifier.fillMaxWidth().height(1.dp)
    } else {
        Modifier.fillMaxHeight().width(1.dp)
    }
    Box(modifier.then(sizing).background(EsuissTheme.colors.separator))
}
```

4. Update the `com.esuiss.ui` package names to match your project.

## Usage

```tsx
import { Checkbox } from "@/components/ui/checkbox"
```

```tsx
<CheckboxDemo />
```

Use `checked` with `onCheckedChange` for controlled state, or `defaultChecked` for uncontrolled. Set `indeterminate` for a parent checkbox whose children are partly selected.

Pair the checkbox with a `Label`: give the label a `nativeID` and the checkbox a matching `accessibilityLabelledBy`, and toggle the value from the label's `onPress`. Set `invalid` to show a danger border.

## Examples

### Checked

Starts checked.

![Preview](https://uim.suiss.app/previews/components-checkbox--checked.light.webp)

```tsx
import * as React from "react"
import { Checkbox } from "@/components/ui/checkbox"

function CheckboxDemo({ initial = false }: { initial?: boolean }) {
  const [checked, setChecked] = React.useState(initial)
  return <Checkbox checked={checked} onCheckedChange={setChecked} />
}

export function CheckboxCheckedExample() {
  return (
    <CheckboxDemo initial />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CheckboxCheckedExample: View {
  var body: some View {
    CheckboxDemo(initial: true)
  }
}

struct CheckboxDemo: View {
  @State private var checked: Bool

  init(initial: Bool) {
    _checked = State(initialValue: initial)
  }

  var body: some View {
    Toggle(isOn: $checked) { EmptyView() }
      .toggleStyle(.checkbox)
  }
}
```

```kotlin
import androidx.compose.foundation.layout.Row
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import com.esuiss.ui.components.Checkbox

@Composable
fun CheckboxCheckedExample() {
    CheckboxDemo(initial = true)
}

@Composable
fun CheckboxDemo(initial: Boolean) {
    var checked by rememberSaveable { mutableStateOf(initial) }
    Row {
        Checkbox(checked, { checked = it })
    }
}
```

### With label

Linked to a `Label` that also toggles it.

![Preview](https://uim.suiss.app/previews/components-checkbox--with-label.light.webp)

```tsx
import * as React from "react"
import { View } from "react-native"
import { Checkbox } from "@/components/ui/checkbox"
import { Label } from "@/components/ui/label"

function WithLabelDemo() {
  const [checked, setChecked] = React.useState(false)
  return (
    <View className="flex-row items-center gap-3">
      <Checkbox
        accessibilityLabelledBy="terms"
        checked={checked}
        onCheckedChange={setChecked}
      />
      <Label nativeID="terms" onPress={() => setChecked((value) => !value)}>
        Accept terms and conditions
      </Label>
    </View>
  )
}

export function CheckboxWithLabelExample() {
  return (
    <WithLabelDemo />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CheckboxWithLabelDemo: View {
  @State private var checked = false

  var body: some View {
    Toggle(isOn: $checked) {
      FieldLabel("Accept terms and conditions")
    }
    .toggleStyle(.checkbox)
  }
}
```

```kotlin
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Row
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.semantics.contentDescription
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Checkbox
import com.esuiss.ui.components.Label

fun Modifier.checkboxLabelToggle(onToggle: () -> Unit): Modifier =
    clickable(interactionSource = null, indication = null, onClick = onToggle)

@Composable
fun CheckboxWithLabel() {
    var checked by rememberSaveable { mutableStateOf(false) }
    Row(horizontalArrangement = Arrangement.spacedBy(12.dp), verticalAlignment = Alignment.CenterVertically) {
        Checkbox(checked, { checked = it }, Modifier.semantics { contentDescription = "Accept terms and conditions" })
        Label("Accept terms and conditions", Modifier.checkboxLabelToggle { checked = !checked })
    }
}
```

### With description

A label with a supporting description.

![Preview](https://uim.suiss.app/previews/components-checkbox--with-description.light.webp)

```tsx
import * as React from "react"
import { View } from "react-native"
import { Checkbox } from "@/components/ui/checkbox"
import { Label } from "@/components/ui/label"
import { Text } from "@/components/ui/text"

function WithDescriptionDemo() {
  const [checked, setChecked] = React.useState(true)
  return (
    <View className="flex-row items-start gap-3">
      <Checkbox
        accessibilityLabelledBy="notifications"
        checked={checked}
        onCheckedChange={setChecked}
      />
      <View className="flex-1 gap-1.5">
        <Label
          nativeID="notifications"
          onPress={() => setChecked((value) => !value)}
        >
          Enable notifications
        </Label>
        <Text className="text-sm text-label-secondary">
          You can enable or disable notifications at any time.
        </Text>
      </View>
    </View>
  )
}

export function CheckboxWithDescriptionExample() {
  return (
    <WithDescriptionDemo />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CheckboxWithDescriptionDemo: View {
  @State private var checked = true

  var body: some View {
    HStack(alignment: .top, spacing: 12) {
      Toggle(isOn: $checked) { EmptyView() }
        .toggleStyle(.checkbox)
        .accessibilityLabel(Text("Enable notifications"))
        .padding(.top, 2)
      VStack(alignment: .leading, spacing: 6) {
        FieldLabel("Enable notifications")
          .onTapGesture { checked.toggle() }
        Text("You can enable or disable notifications at any time.")
          .textStyle(.sm)
          .foregroundStyle(Color.labelSecondary)
      }
      .frame(maxWidth: .infinity, alignment: .leading)
    }
  }
}
```

```kotlin
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.semantics.contentDescription
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Checkbox
import com.esuiss.ui.components.Label
import com.esuiss.ui.components.Text
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

fun Modifier.checkboxLabelToggle(onToggle: () -> Unit): Modifier =
    clickable(interactionSource = null, indication = null, onClick = onToggle)

@Composable
fun CheckboxWithDescription() {
    var checked by rememberSaveable { mutableStateOf(true) }
    Row(horizontalArrangement = Arrangement.spacedBy(12.dp), verticalAlignment = Alignment.Top) {
        Checkbox(checked, { checked = it }, Modifier.semantics { contentDescription = "Enable notifications" })
        Column(Modifier.weight(1f), verticalArrangement = Arrangement.spacedBy(6.dp)) {
            Label("Enable notifications", Modifier.checkboxLabelToggle { checked = !checked })
            Text(
                "You can enable or disable notifications at any time.",
                style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
            )
        }
    }
}
```

### Disabled

Disabled checkboxes in both states.

![Preview](https://uim.suiss.app/previews/components-checkbox--disabled.light.webp)

```tsx
import { View } from "react-native"
import { Checkbox } from "@/components/ui/checkbox"
import { Label } from "@/components/ui/label"

export function CheckboxDisabledExample() {
  return (
    <View className="gap-4">
      <View className="flex-row items-center gap-3">
        <Checkbox disabled checked={false} onCheckedChange={() => {}} />
        <Label disabled>Unchecked</Label>
      </View>
      <View className="flex-row items-center gap-3">
        <Checkbox disabled checked onCheckedChange={() => {}} />
        <Label disabled>Checked</Label>
      </View>
    </View>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CheckboxDisabledExample: View {
  var body: some View {
    VStack(alignment: .leading, spacing: 16) {
      Toggle(isOn: .constant(false)) { FieldLabel("Unchecked") }
      Toggle(isOn: .constant(true)) { FieldLabel("Checked") }
    }
    .toggleStyle(.checkbox)
    .disabled(true)
  }
}
```

```kotlin
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Checkbox
import com.esuiss.ui.components.Label

@Composable
fun CheckboxDisabled() {
    Column(verticalArrangement = Arrangement.spacedBy(16.dp)) {
        Row(horizontalArrangement = Arrangement.spacedBy(12.dp), verticalAlignment = Alignment.CenterVertically) {
            Checkbox(false, {}, enabled = false)
            Label("Unchecked", enabled = false)
        }
        Row(horizontalArrangement = Arrangement.spacedBy(12.dp), verticalAlignment = Alignment.CenterVertically) {
            Checkbox(true, {}, enabled = false)
            Label("Checked", enabled = false)
        }
    }
}
```

### Indeterminate

A select-all checkbox in the indeterminate state.

![Preview](https://uim.suiss.app/previews/components-checkbox--indeterminate.light.webp)

```tsx
import { View } from "react-native"
import { Checkbox } from "@/components/ui/checkbox"
import { Label } from "@/components/ui/label"

export function CheckboxIndeterminateExample() {
  return (
    <View className="flex-row items-center gap-3">
      <Checkbox
        indeterminate
        checked={false}
        onCheckedChange={() => {}}
        accessibilityLabelledBy="select-all"
      />
      <Label nativeID="select-all">Select all</Label>
    </View>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CheckboxIndeterminateExample: View {
  var body: some View {
    Toggle(sources: [Binding.constant(true), .constant(false)], isOn: \.self) {
      FieldLabel("Select all")
    }
    .toggleStyle(.checkbox)
  }
}
```

```kotlin
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Row
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.semantics.contentDescription
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.state.ToggleableState
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Label
import com.esuiss.ui.components.TriStateCheckbox

fun Modifier.checkboxLabelToggle(onToggle: () -> Unit): Modifier =
    clickable(interactionSource = null, indication = null, onClick = onToggle)

@Composable
fun CheckboxIndeterminate() {
    Row(horizontalArrangement = Arrangement.spacedBy(12.dp), verticalAlignment = Alignment.CenterVertically) {
        TriStateCheckbox(ToggleableState.Indeterminate, {}, Modifier.semantics { contentDescription = "Select all" })
        Label("Select all")
    }
}
```

### Invalid

A required checkbox with the `invalid` border.

![Preview](https://uim.suiss.app/previews/components-checkbox--invalid.light.webp)

```tsx
import * as React from "react"
import { View } from "react-native"
import { Checkbox } from "@/components/ui/checkbox"
import { Label } from "@/components/ui/label"

function InvalidDemo() {
  const [checked, setChecked] = React.useState(false)
  return (
    <View className="flex-row items-center gap-3">
      <Checkbox
        invalid={!checked}
        accessibilityLabelledBy="terms-invalid"
        checked={checked}
        onCheckedChange={setChecked}
      />
      <Label
        nativeID="terms-invalid"
        onPress={() => setChecked((value) => !value)}
      >
        Accept terms and conditions
      </Label>
    </View>
  )
}

export function CheckboxInvalidExample() {
  return (
    <InvalidDemo />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct CheckboxInvalidDemo: View {
  @State private var checked = false

  var body: some View {
    Toggle(isOn: $checked) {
      FieldLabel("Accept terms and conditions")
    }
    .toggleStyle(.checkbox)
    .invalid(!checked)
  }
}
```

```kotlin
import androidx.compose.foundation.clickable
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Row
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.semantics.contentDescription
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Checkbox
import com.esuiss.ui.components.Label

fun Modifier.checkboxLabelToggle(onToggle: () -> Unit): Modifier =
    clickable(interactionSource = null, indication = null, onClick = onToggle)

@Composable
fun CheckboxInvalid() {
    var checked by rememberSaveable { mutableStateOf(false) }
    Row(horizontalArrangement = Arrangement.spacedBy(12.dp), verticalAlignment = Alignment.CenterVertically) {
        Checkbox(
            checked,
            { checked = it },
            Modifier.semantics { contentDescription = "Accept terms and conditions" },
            invalid = !checked,
        )
        Label("Accept terms and conditions", Modifier.checkboxLabelToggle { checked = !checked })
    }
}
```

## API Reference

### Checkbox

## Accessibility

- Has the `checkbox` role with `checked` (or `mixed` when indeterminate) and `disabled` state.
- Link it to a visible label with `accessibilityLabelledBy`, or give it an `accessibilityLabel`.

## Notes

- Uses `bg-accent` when checked and `bg-surface` with a translucent border when unchecked; in dark mode the unchecked box is filled instead of outlined.
- Light and dark follow the system appearance.