# Stepper

A number input with minus and plus buttons that step the value, repeat while held and play a selection haptic.

Stepper is an open-source mobile interaction 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/interactions/stepper

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

```tsx
import { Stepper, StepperDecrement, StepperGroup, StepperIncrement, StepperInput, StepperSeparator } from "@/components/interactions/stepper"

export function StepperExample() {
  return (
    <Stepper defaultValue={1} min={0} max={10}>
      <StepperInput accessibilityLabel="Quantity" />
      <StepperGroup>
        <StepperDecrement />
        <StepperSeparator />
        <StepperIncrement />
      </StepperGroup>
    </Stepper>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct StepperParts: View {
  var body: some View {
    StepperInput()
    StepperGroup {
      StepperDecrement()
      StepperSeparator()
      StepperIncrement()
    }
  }
}

struct StepperQuantity: View {
  @State private var value = 1

  var body: some View {
    ValueStepper(value: $value, in: 0...10) {
      StepperParts()
    }
    .accessibilityLabel(Text("Quantity"))
  }
}
```

```kotlin
import androidx.compose.foundation.layout.Row
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableDoubleStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import com.esuiss.ui.interactions.Stepper
import com.esuiss.ui.interactions.StepperDecrement
import com.esuiss.ui.interactions.StepperGroup
import com.esuiss.ui.interactions.StepperIncrement
import com.esuiss.ui.interactions.StepperInput
import com.esuiss.ui.interactions.StepperSeparator

@Composable
fun StepperControls() {
    StepperGroup {
        StepperDecrement()
        StepperSeparator()
        StepperIncrement()
    }
}

@Composable
fun StepperDefault() {
    var value by rememberSaveable { mutableDoubleStateOf(1.0) }
    Row {
        Stepper(value = value, onValueChange = { value = it }, min = 0.0, max = 10.0) {
            StepperInput(contentDescription = "Quantity")
            StepperControls()
        }
    }
}
```

`Stepper` is a number field laid out as a right-aligned value followed by a field holding minus and plus buttons, inset from its edges. Each step snaps to `step` and stays within `min` and `max`, and a button that can go no further is shown as disabled.

Pressing and holding a button steps once, then repeats every 60 ms after 400 ms. The value can also be typed. Use it for quantities, copies or percentages in settings rows.

## Installation

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

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

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

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

### 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), and the primitives `components/primitives/number-field.tsx`, `components/primitives/use-render.tsx`.

3. Copy the source into `components/interactions/stepper.tsx`:

```tsx title="uniwind/components/interactions/stepper.tsx"
import { cn } from "cn"
import { MinusIcon, PlusIcon } from "phosphor-react-native"
import type * as React from "react"
import { View, type ViewProps } from "react-native"
import * as NumberFieldPrimitive from "@/components/primitives/number-field"
import { resolveClassName } from "@/components/primitives/use-render"
import { Icon } from "@/components/ui/icon"

function Stepper({
  value,
  defaultValue = 0,
  onValueChange,
  className,
  ...props
}: Omit<
  React.ComponentProps<typeof NumberFieldPrimitive.Root>,
  "value" | "defaultValue" | "onValueChange"
> & {
  value?: number
  defaultValue?: number
  onValueChange?: (
    value: number,
    eventDetails: NumberFieldPrimitive.ChangeEventDetails
  ) => void
}) {
  return (
    <NumberFieldPrimitive.Root
      value={value}
      defaultValue={defaultValue}
      onValueChange={(next, details) => {
        if (next === null) {
          details.cancel()
          return
        }
        onValueChange?.(next, details)
      }}
      className={(state) =>
        cn("flex-row items-center gap-3", resolveClassName(className, state))
      }
      {...props}
    />
  )
}

function StepperInput({
  className,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Input>) {
  return (
    <NumberFieldPrimitive.Input
      className={(state) =>
        cn(
          "h-8 w-16 min-w-0 rounded-md bg-transparent px-1 py-0 text-right text-base text-label tabular-nums",
          state.disabled && "text-label-quaternary",
          resolveClassName(className, state)
        )
      }
      cursorColorClassName="accent-accent"
      selectionColorClassName="accent-accent"
      {...props}
    />
  )
}

function StepperGroup({
  className,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Group>) {
  return (
    <NumberFieldPrimitive.Group
      className={(state) =>
        cn(
          "h-8 shrink-0 flex-row items-center gap-[3px] rounded-lg bg-control p-[3px]",
          resolveClassName(className, state)
        )
      }
      {...props}
    />
  )
}

function StepperDecrement({
  className,
  children,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Decrement>) {
  const { canDecrement } = NumberFieldPrimitive.useRootContext()
  return (
    <NumberFieldPrimitive.Decrement
      hitSlop={{ top: 9, bottom: 9 }}
      className={(state) =>
        cn(
          "relative h-full w-9 items-center justify-center rounded-md",
          state.disabled || !canDecrement
            ? "bg-control-disabled"
            : "bg-surface-raised shadow-sm active:bg-control-pressed active:shadow-none dark:bg-label-quaternary dark:shadow-none dark:active:bg-control-pressed",
          resolveClassName(className, state)
        )
      }
      {...props}
    >
      {children ?? (
        <Icon
          as={MinusIcon}
          weight="bold"
          className={cn(
            "size-4 text-label",
            !canDecrement && "text-label-quaternary"
          )}
        />
      )}
    </NumberFieldPrimitive.Decrement>
  )
}

function StepperIncrement({
  className,
  children,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Increment>) {
  const { canIncrement } = NumberFieldPrimitive.useRootContext()
  return (
    <NumberFieldPrimitive.Increment
      hitSlop={{ top: 9, bottom: 9 }}
      className={(state) =>
        cn(
          "relative h-full w-9 items-center justify-center rounded-md",
          state.disabled || !canIncrement
            ? "bg-control-disabled"
            : "bg-surface-raised shadow-sm active:bg-control-pressed active:shadow-none dark:bg-label-quaternary dark:shadow-none dark:active:bg-control-pressed",
          resolveClassName(className, state)
        )
      }
      {...props}
    >
      {children ?? (
        <Icon
          as={PlusIcon}
          weight="bold"
          className={cn(
            "size-4 text-label",
            !canIncrement && "text-label-quaternary"
          )}
        />
      )}
    </NumberFieldPrimitive.Increment>
  )
}

function StepperSeparator({ className, ...props }: ViewProps) {
  return (
    <View
      accessible={false}
      importantForAccessibility="no"
      className={cn("h-4.5 w-px shrink-0 bg-separator", className)}
      {...props}
    />
  )
}

export {
  Stepper,
  StepperDecrement,
  StepperGroup,
  StepperIncrement,
  StepperInput,
  StepperSeparator,
}
```

4. Update the import paths to match your project.

**NativeWind**

1. Install the dependencies:

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

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

3. Copy the source into `components/interactions/stepper.tsx`:

```tsx title="nativewind/components/interactions/stepper.tsx"
import { cn } from "cn"
import { cssInterop } from "nativewind"
import { MinusIcon, PlusIcon } from "phosphor-react-native"
import type * as React from "react"
import { TextInput, View, type ViewProps } from "react-native"
import * as NumberFieldPrimitive from "@/components/primitives/number-field"
import { resolveClassName } from "@/components/primitives/use-render"
import { Icon } from "@/components/ui/icon"

declare module "react-native" {
  interface TextInputProps {
    cursorColorClassName?: string
    selectionColorClassName?: string
  }
}

cssInterop(TextInput, {
  className: { target: "style", nativeStyleToProp: { textAlign: true } },
  placeholderClassName: {
    target: false,
    nativeStyleToProp: { color: "placeholderTextColor" },
  },
  cursorColorClassName: {
    target: false,
    nativeStyleToProp: { color: "cursorColor" },
  },
  selectionColorClassName: {
    target: false,
    nativeStyleToProp: { color: "selectionColor" },
  },
})

function Stepper({
  value,
  defaultValue = 0,
  onValueChange,
  className,
  ...props
}: Omit<
  React.ComponentProps<typeof NumberFieldPrimitive.Root>,
  "value" | "defaultValue" | "onValueChange"
> & {
  value?: number
  defaultValue?: number
  onValueChange?: (
    value: number,
    eventDetails: NumberFieldPrimitive.ChangeEventDetails
  ) => void
}) {
  return (
    <NumberFieldPrimitive.Root
      value={value}
      defaultValue={defaultValue}
      onValueChange={(next, details) => {
        if (next === null) {
          details.cancel()
          return
        }
        onValueChange?.(next, details)
      }}
      className={(state) =>
        cn("flex-row items-center gap-3", resolveClassName(className, state))
      }
      {...props}
    />
  )
}

function StepperInput({
  className,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Input>) {
  return (
    <NumberFieldPrimitive.Input
      className={(state) =>
        cn(
          "h-8 w-16 min-w-0 rounded-md bg-transparent px-1 py-0 text-right text-base text-label tabular-nums",
          state.disabled && "text-label-quaternary",
          resolveClassName(className, state)
        )
      }
      cursorColorClassName="text-accent"
      selectionColorClassName="text-accent"
      {...props}
    />
  )
}

function StepperGroup({
  className,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Group>) {
  return (
    <NumberFieldPrimitive.Group
      className={(state) =>
        cn(
          "h-8 shrink-0 flex-row items-center gap-[3px] rounded-lg bg-control p-[3px]",
          resolveClassName(className, state)
        )
      }
      {...props}
    />
  )
}

function StepperDecrement({
  className,
  children,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Decrement>) {
  const { canDecrement } = NumberFieldPrimitive.useRootContext()
  return (
    <NumberFieldPrimitive.Decrement
      hitSlop={{ top: 9, bottom: 9 }}
      className={(state) =>
        cn(
          "relative h-full w-9 items-center justify-center rounded-md",
          state.disabled || !canDecrement
            ? "bg-control-disabled"
            : "bg-surface-raised shadow active:bg-control-pressed active:shadow-none dark:bg-label-quaternary dark:shadow-none dark:active:bg-control-pressed",
          resolveClassName(className, state)
        )
      }
      {...props}
    >
      {children ?? (
        <Icon
          as={MinusIcon}
          weight="bold"
          className={cn(
            "size-4 text-label",
            !canDecrement && "text-label-quaternary"
          )}
        />
      )}
    </NumberFieldPrimitive.Decrement>
  )
}

function StepperIncrement({
  className,
  children,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Increment>) {
  const { canIncrement } = NumberFieldPrimitive.useRootContext()
  return (
    <NumberFieldPrimitive.Increment
      hitSlop={{ top: 9, bottom: 9 }}
      className={(state) =>
        cn(
          "relative h-full w-9 items-center justify-center rounded-md",
          state.disabled || !canIncrement
            ? "bg-control-disabled"
            : "bg-surface-raised shadow active:bg-control-pressed active:shadow-none dark:bg-label-quaternary dark:shadow-none dark:active:bg-control-pressed",
          resolveClassName(className, state)
        )
      }
      {...props}
    >
      {children ?? (
        <Icon
          as={PlusIcon}
          weight="bold"
          className={cn(
            "size-4 text-label",
            !canIncrement && "text-label-quaternary"
          )}
        />
      )}
    </NumberFieldPrimitive.Increment>
  )
}

function StepperSeparator({ className, ...props }: ViewProps) {
  return (
    <View
      accessible={false}
      importantForAccessibility="no"
      className={cn("h-[1.125rem] w-px shrink-0 bg-separator", className)}
      {...props}
    />
  )
}

export {
  Stepper,
  StepperDecrement,
  StepperGroup,
  StepperIncrement,
  StepperInput,
  StepperSeparator,
}
```

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), and the primitives `components/primitives/number-field.tsx`, `components/primitives/use-render.tsx`.

3. Copy the source into `components/interactions/stepper.tsx`:

```tsx title="stylesheet/components/interactions/stepper.tsx"
import { MinusIcon, PlusIcon } from "phosphor-react-native"
import type * as React from "react"
import {
  Pressable,
  type StyleProp,
  StyleSheet,
  type TextStyle,
  View,
  type ViewProps,
  type ViewStyle,
} from "react-native"
import * as NumberFieldPrimitive from "@/components/primitives/number-field"
import { resolveStyle } from "@/components/primitives/use-render"
import { Icon } from "@/components/ui/icon"
import {
  fontSize,
  radius,
  shadow,
  type ThemeColors,
  useTheme,
} from "@/components/ui/theme"

const styles = StyleSheet.create({
  root: { flexDirection: "row", alignItems: "center", gap: 12 },
  input: {
    ...fontSize.base,
    height: 32,
    width: 64,
    minWidth: 0,
    borderRadius: radius.md,
    backgroundColor: "transparent",
    paddingHorizontal: 4,
    paddingVertical: 0,
    textAlign: "right",
    fontVariant: ["tabular-nums"],
  },
  group: {
    height: 32,
    flexShrink: 0,
    flexDirection: "row",
    alignItems: "center",
    gap: 3,
    borderRadius: radius.lg,
    padding: 3,
  },
  button: {
    position: "relative",
    height: "100%",
    width: 36,
    alignItems: "center",
    justifyContent: "center",
    borderRadius: radius.md,
  },
  separator: { height: 18, width: 1, flexShrink: 0 },
})

function buttonStyle(
  colors: ThemeColors,
  isDark: boolean,
  disabled: boolean,
  pressed: boolean
): StyleProp<ViewStyle> {
  if (disabled) return { backgroundColor: colors.controlDisabled }
  if (pressed) return { backgroundColor: colors.controlPressed }
  if (isDark) return { backgroundColor: colors.labelQuaternary }
  return [{ backgroundColor: colors.surfaceRaised }, shadow.sm]
}

function Stepper({
  value,
  defaultValue = 0,
  onValueChange,
  style,
  ...props
}: Omit<
  React.ComponentProps<typeof NumberFieldPrimitive.Root>,
  "value" | "defaultValue" | "onValueChange"
> & {
  value?: number
  defaultValue?: number
  onValueChange?: (
    value: number,
    eventDetails: NumberFieldPrimitive.ChangeEventDetails
  ) => void
}) {
  return (
    <NumberFieldPrimitive.Root
      value={value}
      defaultValue={defaultValue}
      onValueChange={(next, details) => {
        if (next === null) {
          details.cancel()
          return
        }
        onValueChange?.(next, details)
      }}
      style={(state) => [
        styles.root,
        resolveStyle(style, state) as StyleProp<ViewStyle>,
      ]}
      {...props}
    />
  )
}

function StepperInput({
  style,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Input>) {
  const { colors } = useTheme()
  return (
    <NumberFieldPrimitive.Input
      style={(state) => [
        styles.input,
        { color: state.disabled ? colors.labelQuaternary : colors.label },
        resolveStyle(style, state) as StyleProp<TextStyle>,
      ]}
      cursorColor={colors.accent}
      selectionColor={colors.accent}
      {...props}
    />
  )
}

function StepperGroup({
  style,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Group>) {
  const { colors } = useTheme()
  return (
    <NumberFieldPrimitive.Group
      style={(state) => [
        styles.group,
        { backgroundColor: colors.control },
        resolveStyle(style, state) as StyleProp<ViewStyle>,
      ]}
      {...props}
    />
  )
}

function StepperDecrement({
  style,
  children,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Decrement>) {
  const { colors, isDark } = useTheme()
  const { canDecrement } = NumberFieldPrimitive.useRootContext()
  return (
    <NumberFieldPrimitive.Decrement
      hitSlop={{ top: 9, bottom: 9 }}
      render={(renderProps, state) => (
        <Pressable
          {...renderProps}
          style={({ pressed }) => [
            styles.button,
            buttonStyle(
              colors,
              isDark,
              state.disabled || !canDecrement,
              pressed
            ),
            resolveStyle(style, state) as StyleProp<ViewStyle>,
          ]}
        />
      )}
      {...props}
    >
      {children ?? (
        <Icon
          as={MinusIcon}
          weight="bold"
          size={16}
          color={canDecrement ? colors.label : colors.labelQuaternary}
        />
      )}
    </NumberFieldPrimitive.Decrement>
  )
}

function StepperIncrement({
  style,
  children,
  ...props
}: React.ComponentProps<typeof NumberFieldPrimitive.Increment>) {
  const { colors, isDark } = useTheme()
  const { canIncrement } = NumberFieldPrimitive.useRootContext()
  return (
    <NumberFieldPrimitive.Increment
      hitSlop={{ top: 9, bottom: 9 }}
      render={(renderProps, state) => (
        <Pressable
          {...renderProps}
          style={({ pressed }) => [
            styles.button,
            buttonStyle(
              colors,
              isDark,
              state.disabled || !canIncrement,
              pressed
            ),
            resolveStyle(style, state) as StyleProp<ViewStyle>,
          ]}
        />
      )}
      {...props}
    >
      {children ?? (
        <Icon
          as={PlusIcon}
          weight="bold"
          size={16}
          color={canIncrement ? colors.label : colors.labelQuaternary}
        />
      )}
    </NumberFieldPrimitive.Increment>
  )
}

function StepperSeparator({ style, ...props }: ViewProps) {
  const { colors } = useTheme()
  return (
    <View
      accessible={false}
      importantForAccessibility="no"
      style={[styles.separator, { backgroundColor: colors.separator }, style]}
      {...props}
    />
  )
}

export {
  Stepper,
  StepperDecrement,
  StepperGroup,
  StepperIncrement,
  StepperInput,
  StepperSeparator,
}
```

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/Interactions/Stepper.swift"
import PhosphorSwift
import SwiftUI

enum StepperMath {
  static func canChange(_ value: Double, direction: Int, bounds: ClosedRange<Double>) -> Bool {
    direction > 0 ? value < bounds.upperBound : value > bounds.lowerBound
  }

  static func next(_ value: Double, direction: Int, step: Double, bounds: ClosedRange<Double>) -> Double? {
    guard canChange(value, direction: direction, bounds: bounds) else { return nil }
    let precision = max(0, -Int(log10(step).rounded(.down)))
    let factor = pow(10, Double(precision))
    let raw = ((value + Double(direction) * step) * factor).rounded() / factor
    return min(max(raw, bounds.lowerBound), bounds.upperBound)
  }

  static func delay(after count: Int) -> Duration {
    if count == 0 { return .milliseconds(400) }
    return .milliseconds(Int(max(35, 180 * pow(0.86, Double(count)))))
  }
}

struct StepperFormat {
  var format: (Double) -> String
  var parse: (String) -> Double?
}

struct StepperContext {
  var value: Double
  var enabled: Bool
  var format: (Double) -> String
  var parse: (String) -> Double?
  var canChange: @MainActor (Int) -> Bool
  var change: @MainActor (Int) -> Bool
  var set: @MainActor (Double) -> Void
}

extension EnvironmentValues {
  @Entry var stepper: StepperContext?
}

public struct ValueStepper<Content: View>: View {
  let value: Binding<Double>
  let bounds: ClosedRange<Double>
  let step: Double
  let style: (Locale) -> StepperFormat
  let content: Content

  @Environment(\.isEnabled) private var isEnabled
  @Environment(\.locale) private var locale
  @State private var ticks = 0

  public init<F: ParseableFormatStyle>(
    value: Binding<Double>,
    in bounds: ClosedRange<Double> = -Double.infinity...Double.infinity,
    step: Double = 1,
    format: F,
    @ViewBuilder content: () -> Content
  ) where F.FormatInput == Double, F.FormatOutput == String {
    self.value = value
    self.bounds = bounds
    self.step = step
    style = { _ in StepperFormat(format: { format.format($0) }, parse: { try? format.parseStrategy.parse($0) }) }
    self.content = content()
  }

  public init(
    value: Binding<Double>,
    in bounds: ClosedRange<Double> = -Double.infinity...Double.infinity,
    step: Double = 1,
    @ViewBuilder content: () -> Content
  ) {
    self.value = value
    self.bounds = bounds
    self.step = step
    style = { locale in
      let format = FloatingPointFormatStyle<Double>.number.locale(locale)
      return StepperFormat(format: { format.format($0) }, parse: { try? format.parseStrategy.parse($0) })
    }
    self.content = content()
  }

  public init(
    value: Binding<Int>,
    in bounds: ClosedRange<Int>? = nil,
    step: Int = 1,
    @ViewBuilder content: () -> Content
  ) {
    let double = Binding<Double>(
      get: { Double(value.wrappedValue) },
      set: { value.wrappedValue = Int($0.rounded()) }
    )
    let range = bounds.map { Double($0.lowerBound)...Double($0.upperBound) } ?? -Double.infinity...Double.infinity
    self.value = double
    self.bounds = range
    self.step = Double(step)
    style = { locale in
      let format = IntegerFormatStyle<Int>.number.locale(locale)
      return StepperFormat(format: { format.format(Int($0.rounded())) }, parse: { (try? format.parseStrategy.parse($0)).map(Double.init) })
    }
    self.content = content()
  }

  public var body: some View {
    let binding = value
    let bounds = bounds
    let step = step
    let enabled = isEnabled
    let resolved = style(locale)
    let ticks = $ticks
    HStack(spacing: 12) {
      content
    }
    .environment(\.stepper, StepperContext(
      value: binding.wrappedValue,
      enabled: enabled,
      format: resolved.format,
      parse: resolved.parse,
      canChange: { direction in
        enabled && StepperMath.canChange(binding.wrappedValue, direction: direction, bounds: bounds)
      },
      change: { direction in
        guard enabled, let next = StepperMath.next(binding.wrappedValue, direction: direction, step: step, bounds: bounds) else { return false }
        binding.wrappedValue = next
        ticks.wrappedValue += 1
        return true
      },
      set: { next in
        binding.wrappedValue = min(max(next, bounds.lowerBound), bounds.upperBound)
      }
    ))
    .hapticFeedback(.selection, trigger: ticks.wrappedValue)
    .accessibilityElement(children: .contain)
  }
}

public struct StepperInput: View {
  @Environment(\.stepper) private var stepper
  @State private var text = ""
  @FocusState private var focused: Bool

  public init() {}

  public var body: some View {
    let enabled = stepper?.enabled ?? true
    TextField("", text: $text)
      .focused($focused)
      .keyboardType(.decimalPad)
      .multilineTextAlignment(.trailing)
      .font(TextStyle.base.font())
      .tracking(TextStyle.base.letterSpacing)
      .monospacedDigit()
      .foregroundStyle(enabled ? Color.label : .labelQuaternary)
      .tint(Color.accent)
      .padding(.horizontal, 4)
      .frame(width: 64, height: 32)
      .contentShape(RoundedRectangle(cornerRadius: Radius.md, style: .continuous))
      .onAppear { sync() }
      .onChange(of: stepper?.value) { _, _ in
        if !focused { sync() }
      }
      .onChange(of: focused) { _, isFocused in
        if !isFocused { commit() }
      }
      .onSubmit { commit() }
      .accessibilityValue(Text(verbatim: stepper.map { $0.format($0.value) } ?? ""))
      .accessibilityAdjustableAction { direction in
        _ = stepper?.change(direction == .increment ? 1 : -1)
      }
  }

  private func sync() {
    guard let stepper else { return }
    text = stepper.format(stepper.value)
  }

  private func commit() {
    guard let stepper else { return }
    if let parsed = stepper.parse(text) ?? Double(text) {
      stepper.set(parsed)
    }
    text = stepper.format(stepper.value)
  }
}

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

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

  public var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.lg, style: .continuous)
    HStack(spacing: 3) {
      content
    }
    .padding(3)
    .frame(height: 32)
    .background(Color.control, in: shape)
    .fixedSize()
    .accessibilityElement(children: .contain)
  }
}

@MainActor
final class StepperPress {
  var handled = false
  var repeating: Task<Void, Never>?
}

struct StepperButton<Label: View>: View {
  let direction: Int
  let label: Label

  @Environment(\.stepper) private var stepper
  @State private var press = StepperPress()

  var body: some View {
    let enabled = stepper?.canChange(direction) ?? false
    Button {
      if press.handled {
        press.handled = false
      } else {
        _ = stepper?.change(direction)
      }
    } label: {
      label
    }
    .buttonStyle(StepperButtonStyle(direction: direction, press: press))
    .disabled(!enabled)
    .accessibilityAction {
      _ = stepper?.change(direction)
    }
  }
}

private struct StepperButtonStyle: ButtonStyle {
  let direction: Int
  let press: StepperPress

  func makeBody(configuration: Configuration) -> some View {
    StepperButtonBody(direction: direction, pressed: configuration.isPressed, press: press, label: configuration.label)
  }
}

private struct StepperButtonBody<Label: View>: View {
  let direction: Int
  let pressed: Bool
  let press: StepperPress
  let label: Label

  @Environment(\.stepper) private var stepper
  @Environment(\.isEnabled) private var isEnabled
  @Environment(\.colorScheme) private var colorScheme

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.md, style: .continuous)
    label
      .frame(width: 16, height: 16)
      .foregroundStyle(isEnabled ? Color.label : .labelQuaternary)
      .frame(width: 36)
      .frame(maxHeight: .infinity)
      .background {
        if !isEnabled {
          shape.fill(Color.controlDisabled)
        } else if pressed && isEnabled {
          shape.fill(Color.controlPressed)
        } else if colorScheme == .dark {
          shape.fill(Color.labelQuaternary)
        } else {
          shape.fill(Color.surfaceRaised).shadow(.thumb)
        }
      }
      .padding(.vertical, 9)
      .contentShape(Rectangle())
      .padding(.vertical, -9)
      .onChange(of: pressed) { _, isPressed in
        press.repeating?.cancel()
        press.repeating = nil
        guard isPressed else {
          let current = press
          Task { @MainActor in
            try? await Task.sleep(for: .milliseconds(350))
            current.handled = false
          }
          return
        }
        guard let stepper, stepper.change(direction) else { return }
        press.handled = true
        press.repeating = Task { @MainActor in
          var count = 0
          while !Task.isCancelled {
            try? await Task.sleep(for: StepperMath.delay(after: count))
            guard !Task.isCancelled, stepper.change(direction) else { return }
            count += 1
          }
        }
      }
      .onDisappear {
        press.repeating?.cancel()
      }
  }
}

public struct StepperDecrement<Label: View>: View {
  let label: Label

  public init(@ViewBuilder label: () -> Label) {
    self.label = label()
  }

  public var body: some View {
    StepperButton(direction: -1, label: label)
      .accessibilityLabel(Text("Decrease"))
  }
}

extension StepperDecrement where Label == Image {
  public init() {
    self.init { Ph.minus.bold }
  }
}

public struct StepperIncrement<Label: View>: View {
  let label: Label

  public init(@ViewBuilder label: () -> Label) {
    self.label = label()
  }

  public var body: some View {
    StepperButton(direction: 1, label: label)
      .accessibilityLabel(Text("Increase"))
  }
}

extension StepperIncrement where Label == Image {
  public init() {
    self.init { Ph.plus.bold }
  }
}

public struct StepperSeparator: View {
  public init() {}

  public var body: some View {
    Color.separator
      .frame(width: 1, height: 18)
      .accessibilityHidden(true)
  }
}
```

```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/interactions/Stepper.kt"
package com.esuiss.ui.interactions

import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.awaitEachGesture
import androidx.compose.foundation.gestures.awaitFirstDown
import androidx.compose.foundation.gestures.waitForUpOrCancellation
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.foundation.interaction.collectIsFocusedAsState
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.fillMaxHeight
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.BasicTextField
import androidx.compose.foundation.text.KeyboardActions
import androidx.compose.foundation.text.KeyboardOptions
import androidx.compose.foundation.text.selection.LocalTextSelectionColors
import androidx.compose.foundation.text.selection.TextSelectionColors
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.runtime.rememberUpdatedState
import androidx.compose.runtime.setValue
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.focus.FocusManager
import androidx.compose.ui.graphics.SolidColor
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.input.pointer.pointerInput
import androidx.compose.ui.platform.LocalFocusManager
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.semantics.contentDescription
import androidx.compose.ui.semantics.disabled
import androidx.compose.ui.semantics.onClick
import androidx.compose.ui.semantics.role
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.input.ImeAction
import androidx.compose.ui.text.input.KeyboardType
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Bold
import com.adamglin.phosphoricons.bold.Minus
import com.adamglin.phosphoricons.bold.Plus
import com.esuiss.ui.components.FormShadowSm
import com.esuiss.ui.components.Icon
import com.esuiss.ui.components.LocalContentColor
import com.esuiss.ui.components.LocalIconSize
import com.esuiss.ui.components.rememberHaptics
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography
import com.esuiss.ui.theme.shadow
import java.text.NumberFormat
import java.text.ParsePosition
import kotlin.math.floor
import kotlin.math.log10
import kotlin.math.max
import kotlin.math.pow
import kotlinx.coroutines.Job
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch

private const val StartDelay = 400L

private const val FirstTick = 180.0

private const val MinTick = 35.0

private const val Acceleration = 0.86

@Immutable
private class StepperContext(
    val value: Double,
    val enabled: Boolean,
    val format: NumberFormat,
    val canChange: (Int) -> Boolean,
    val change: (Int) -> Boolean,
    val commit: (Double) -> Unit,
)

private val LocalStepper = staticCompositionLocalOf<StepperContext?> { null }

private fun stepperContext(): Nothing = error("Stepper parts must be used within a Stepper")

@Composable
fun Stepper(
    value: Double,
    onValueChange: (Double) -> Unit,
    modifier: Modifier = Modifier,
    min: Double = Double.NEGATIVE_INFINITY,
    max: Double = Double.POSITIVE_INFINITY,
    step: Double = 1.0,
    enabled: Boolean = true,
    format: NumberFormat = remember { NumberFormat.getNumberInstance() },
    content: @Composable RowScope.() -> Unit,
) {
    val currentValue by rememberUpdatedState(value)
    val currentOnValueChange by rememberUpdatedState(onValueChange)
    val currentHaptics by rememberUpdatedState(rememberHaptics())
    val canChange: (Int) -> Boolean = { direction ->
        enabled && if (direction > 0) currentValue < max else currentValue > min
    }
    val context = StepperContext(
        value = value,
        enabled = enabled,
        format = format,
        canChange = canChange,
        change = { direction ->
            if (!canChange(direction)) {
                false
            } else {
                val precision = max(0, -floor(log10(step)).toInt())
                val factor = 10.0.pow(precision)
                val next = Math.round((currentValue + direction * step) * factor) / factor
                currentHaptics.selection()
                currentOnValueChange(next.coerceIn(min, max))
                true
            }
        },
        commit = { next -> currentOnValueChange(next.coerceIn(min, max)) },
    )
    CompositionLocalProvider(LocalStepper provides context) {
        Row(
            modifier = modifier,
            horizontalArrangement = Arrangement.spacedBy(12.dp),
            verticalAlignment = Alignment.CenterVertically,
            content = content,
        )
    }
}

@Composable
fun StepperInput(
    modifier: Modifier = Modifier,
    contentDescription: String? = null,
) {
    val stepper = LocalStepper.current ?: stepperContext()
    val colors = EsuissTheme.colors
    val interaction = remember { MutableInteractionSource() }
    val focused by interaction.collectIsFocusedAsState()
    val formatted = stepper.format.format(stepper.value)
    var text by remember { mutableStateOf(formatted) }
    LaunchedEffect(formatted, focused) {
        if (!focused) text = formatted
    }
    val focusManager = LocalFocusManager.current
    val commit = {
        val position = ParsePosition(0)
        val parsed = stepper.format.parse(text.trim(), position)
        if (parsed != null && position.index > 0) stepper.commit(parsed.toDouble())
        text = stepper.format.format(stepper.value)
    }
    LaunchedEffect(focused) {
        if (!focused && text != formatted) commit()
    }
    CompositionLocalProvider(
        LocalTextSelectionColors provides TextSelectionColors(colors.accent, colors.accent.copy(alpha = 0.3f)),
    ) {
        BasicTextField(
            value = text,
            onValueChange = { text = it },
            modifier = modifier
                .height(32.dp)
                .width(64.dp)
                .padding(horizontal = 4.dp)
                .then(
                    if (contentDescription != null) {
                        Modifier.semantics { this.contentDescription = contentDescription }
                    } else {
                        Modifier
                    },
                ),
            enabled = stepper.enabled,
            singleLine = true,
            textStyle = Typography.base.copy(
                color = if (stepper.enabled) colors.label else colors.labelQuaternary,
                textAlign = TextAlign.End,
                fontFeatureSettings = "tnum",
            ),
            keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal, imeAction = ImeAction.Done),
            keyboardActions = KeyboardActions(onDone = { focusManager.clearFocusAndCommit(commit) }),
            interactionSource = interaction,
            cursorBrush = SolidColor(colors.accent),
            decorationBox = { inner ->
                Box(contentAlignment = Alignment.CenterEnd) { inner() }
            },
        )
    }
}

private fun FocusManager.clearFocusAndCommit(commit: () -> Unit) {
    commit()
    clearFocus()
}

@Composable
fun StepperGroup(
    modifier: Modifier = Modifier,
    content: @Composable RowScope.() -> Unit,
) {
    Row(
        modifier = modifier
            .height(32.dp)
            .background(EsuissTheme.colors.control, RoundedCornerShape(Radius.lg))
            .padding(3.dp),
        horizontalArrangement = Arrangement.spacedBy(3.dp),
        verticalAlignment = Alignment.CenterVertically,
        content = content,
    )
}

@Composable
fun StepperDecrement(
    modifier: Modifier = Modifier,
    contentDescription: String = "Decrease",
    content: (@Composable () -> Unit)? = null,
) {
    StepperButton(-1, PhosphorIcons.Bold.Minus, contentDescription, modifier, content)
}

@Composable
fun StepperIncrement(
    modifier: Modifier = Modifier,
    contentDescription: String = "Increase",
    content: (@Composable () -> Unit)? = null,
) {
    StepperButton(1, PhosphorIcons.Bold.Plus, contentDescription, modifier, content)
}

@Composable
fun StepperSeparator(modifier: Modifier = Modifier) {
    Box(
        modifier = modifier
            .width(1.dp)
            .height(18.dp)
            .background(EsuissTheme.colors.separator),
    )
}

@Composable
private fun StepperButton(
    direction: Int,
    icon: ImageVector,
    contentDescription: String,
    modifier: Modifier,
    content: (@Composable () -> Unit)?,
) {
    val stepper = LocalStepper.current ?: stepperContext()
    val colors = EsuissTheme.colors
    val enabled = stepper.canChange(direction)
    val currentStepper by rememberUpdatedState(stepper)
    val scope = rememberCoroutineScope()
    var pressed by remember { mutableStateOf(false) }
    val shape = RoundedCornerShape(Radius.md)
    val surface = when {
        !enabled -> Modifier.background(colors.controlDisabled, shape)
        pressed && enabled -> Modifier.background(colors.controlPressed, shape)
        colors.isDark -> Modifier.background(colors.labelQuaternary, shape)
        else -> Modifier.shadow(FormShadowSm, shape).background(colors.surfaceRaised, shape)
    }
    Box(
        modifier = modifier
            .fillMaxHeight()
            .width(36.dp)
            .then(surface)
            .semantics {
                this.contentDescription = contentDescription
                role = Role.Button
                if (enabled) {
                    onClick {
                        currentStepper.change(direction)
                    }
                } else {
                    disabled()
                }
            }
            .pointerInput(enabled) {
                if (!enabled) return@pointerInput
                awaitEachGesture {
                    awaitFirstDown()
                    pressed = true
                    var repeat: Job? = null
                    if (currentStepper.change(direction)) {
                        repeat = scope.launch {
                            delay(StartDelay)
                            var count = 1
                            while (currentStepper.change(direction)) {
                                delay(max(MinTick, FirstTick * Acceleration.pow(count)).toLong())
                                count++
                            }
                        }
                    }
                    waitForUpOrCancellation()
                    repeat?.cancel()
                    pressed = false
                }
            },
        contentAlignment = Alignment.Center,
    ) {
        val tint = if (enabled) colors.label else colors.labelQuaternary
        CompositionLocalProvider(LocalContentColor provides tint, LocalIconSize provides 16.dp) {
            if (content != null) content() else Icon(icon, contentDescription = null, size = 16.dp, tint = tint)
        }
    }
}
```

```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/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),
    )
}
```

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

## Usage

```tsx
import { Stepper, StepperInput, StepperGroup, StepperDecrement, StepperIncrement, StepperSeparator } from "@/components/interactions/stepper"
```

```tsx
<Stepper defaultValue={1} min={0} max={10}>
  <StepperInput accessibilityLabel="Quantity" />
  <StepperGroup>
    <StepperDecrement />
    <StepperSeparator />
    <StepperIncrement />
  </StepperGroup>
</Stepper>
```

Compose `StepperInput` and a `StepperGroup` containing `StepperDecrement`, `StepperSeparator` and `StepperIncrement` inside `Stepper`.

Use it uncontrolled with `defaultValue` (`0` by default) or controlled with `value` and `onValueChange`. Clearing the field never reports `null`; the change is cancelled instead. `min`, `max`, `step`, `format` (`Intl.NumberFormatOptions`), `locale` and `disabled` are passed to the number field.

## Examples

### Print

A print settings list with copies, a percentage scale stepping by 5, and a disabled row.

![Preview](https://uim.suiss.app/previews/interactions-stepper--print.light.webp)

```tsx
import * as React from "react"
import { View } from "react-native"
import { Stepper, StepperDecrement, StepperGroup, StepperIncrement, StepperInput, StepperSeparator } from "@/components/interactions/stepper"
import { Text } from "@/components/ui/text"

function StepperRow({
  label,
  ...props
}: React.ComponentProps<typeof Stepper> & { label: string }) {
  const labelId = React.useId()

  return (
    <View className="min-h-11 flex-row items-center justify-between gap-4 px-4 py-1.5">
      <Text nativeID={labelId} className="text-base">
        {label}
      </Text>
      <Stepper {...props}>
        <StepperInput accessibilityLabelledBy={labelId} />
        <StepperGroup>
          <StepperDecrement />
          <StepperSeparator />
          <StepperIncrement />
        </StepperGroup>
      </Stepper>
    </View>
  )
}

function PrintExample() {
  const [copies, setCopies] = React.useState(1)
  const [scale, setScale] = React.useState(100)

  return (
    <View className="w-full gap-3">
      <View className="overflow-hidden rounded-2xl border border-separator">
        <StepperRow
          label="Copies"
          value={copies}
          onValueChange={setCopies}
          min={1}
          max={999}
        />
        <View className="h-px bg-separator" />
        <StepperRow
          label="Scale"
          value={scale}
          onValueChange={setScale}
          min={25}
          max={400}
          step={5}
          format={{ style: "unit", unit: "percent" }}
        />
        <View className="h-px bg-separator" />
        <StepperRow label="Pages per sheet" defaultValue={1} disabled />
      </View>
      <Text
        accessibilityLiveRegion="polite"
        className="text-sm text-label-secondary"
      >
        {copies} {copies === 1 ? "copy" : "copies"} at {scale}%
      </Text>
    </View>
  )
}

export function StepperPrintExample() {
  return (
    <PrintExample />
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct StepperParts: View {
  var body: some View {
    StepperInput()
    StepperGroup {
      StepperDecrement()
      StepperSeparator()
      StepperIncrement()
    }
  }
}

struct StepperRow<Content: View>: View {
  let label: LocalizedStringKey
  @ViewBuilder let content: () -> Content

  var body: some View {
    HStack(spacing: 16) {
      Text(label)
        .textStyle(.base)
        .foregroundStyle(Color.label)
        .frame(maxWidth: .infinity, alignment: .leading)
      content()
        .accessibilityLabel(Text(label))
    }
    .padding(.horizontal, 16)
    .padding(.vertical, 6)
    .frame(minHeight: 44)
  }
}

struct StepperPrint: View {
  @State private var copies = 1
  @State private var scale = 100.0
  @State private var pages = 1

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
    VStack(alignment: .leading, spacing: 12) {
      VStack(spacing: 0) {
        StepperRow(label: "Copies") {
          ValueStepper(value: $copies, in: 1...999) { StepperParts() }
        }
        Color.separator.frame(height: 1)
        StepperRow(label: "Scale") {
          ValueStepper(
            value: $scale,
            in: 25...400,
            step: 5,
            format: FloatingPointFormatStyle<Double>.Percent().scale(1)
          ) { StepperParts() }
        }
        Color.separator.frame(height: 1)
        StepperRow(label: "Pages per sheet") {
          ValueStepper(value: $pages) { StepperParts() }
            .disabled(true)
        }
      }
      .clipShape(shape)
      .overlay { shape.strokeBorder(Color.separator) }
      Text(verbatim: "\(copies) \(copies == 1 ? "copy" : "copies") at \(Int(scale))%")
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .accessibilityAddTraits(.updatesFrequently)
    }
  }
}
```

```kotlin
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.heightIn
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableDoubleStateOf
import androidx.compose.runtime.remember
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.draw.clip
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.Stepper
import com.esuiss.ui.interactions.StepperDecrement
import com.esuiss.ui.interactions.StepperGroup
import com.esuiss.ui.interactions.StepperIncrement
import com.esuiss.ui.interactions.StepperInput
import com.esuiss.ui.interactions.StepperSeparator
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography
import java.text.DecimalFormat
import java.text.NumberFormat

@Composable
fun StepperControls() {
    StepperGroup {
        StepperDecrement()
        StepperSeparator()
        StepperIncrement()
    }
}

@Composable
fun StepperRow(
    label: String,
    value: Double,
    onValueChange: (Double) -> Unit,
    min: Double = Double.NEGATIVE_INFINITY,
    max: Double = Double.POSITIVE_INFINITY,
    step: Double = 1.0,
    enabled: Boolean = true,
    format: NumberFormat = remember { NumberFormat.getNumberInstance() },
) {
    Row(
        modifier = Modifier
            .fillMaxWidth()
            .heightIn(min = 44.dp)
            .padding(horizontal = 16.dp, vertical = 6.dp),
        horizontalArrangement = Arrangement.spacedBy(16.dp),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        Text(label, modifier = Modifier.weight(1f), style = Typography.base)
        Stepper(value = value, onValueChange = onValueChange, min = min, max = max, step = step, enabled = enabled, format = format) {
            StepperInput(contentDescription = label)
            StepperControls()
        }
    }
}

@Composable
fun StepperPrint() {
    val colors = EsuissTheme.colors
    var copies by rememberSaveable { mutableDoubleStateOf(1.0) }
    var scale by rememberSaveable { mutableDoubleStateOf(100.0) }
    var pages by rememberSaveable { mutableDoubleStateOf(1.0) }
    val percent = remember { DecimalFormat("0'%'") }
    val shape = RoundedCornerShape(Radius.xl2)
    Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Column(
            Modifier
                .fillMaxWidth()
                .clip(shape)
                .border(1.dp, colors.separator, shape),
        ) {
            StepperRow("Copies", copies, { copies = it }, min = 1.0, max = 999.0)
            Box(Modifier.fillMaxWidth().height(1.dp).background(colors.separator))
            StepperRow("Scale", scale, { scale = it }, min = 25.0, max = 400.0, step = 5.0, format = percent)
            Box(Modifier.fillMaxWidth().height(1.dp).background(colors.separator))
            StepperRow("Pages per sheet", pages, { pages = it }, enabled = false)
        }
        Text(
            "${copies.toInt()} ${if (copies == 1.0) "copy" else "copies"} at ${scale.toInt()}%",
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = colors.labelSecondary),
        )
    }
}
```

## API Reference

### Stepper

The root that holds the value and limits.

### StepperInput

The editable, right-aligned value.

### StepperGroup

The rounded field that holds the buttons.

### StepperDecrement

The minus button.

### StepperIncrement

The plus button.

### StepperSeparator

A thin divider between the buttons.

## Accessibility

- The minus and plus buttons have the `button` role.
- Label the value with `accessibilityLabel` or `accessibilityLabelledBy` on `StepperInput`.
- The separator is hidden from screen readers.

## Notes

- A selection haptic plays on each step, if the app provides an adapter through `HapticsProvider`.
- The group uses `bg-control`. Buttons use `bg-surface-raised` with a small shadow (`bg-label-quaternary` in dark mode) and `bg-control-pressed` when pressed; a disabled button or one at its limit uses `bg-control-disabled` with a `text-label-quaternary` icon.
- Disabled text uses `text-label-quaternary`.