# Wheel Picker

A scrolling wheel for picking one value per column, with items that curve away from the center.

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

Source: https://uim.suiss.app/docs/components/wheel-picker

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

```tsx
import { View } from "react-native"
import { WheelPicker, WheelPickerColumn, WheelPickerItem } from "@/components/ui/wheel-picker"

const fruits = [
  "Apple",
  "Banana",
  "Cherry",
  "Grape",
  "Lemon",
  "Mango",
  "Orange",
  "Peach",
  "Pear",
  "Plum",
]

export function WheelPickerExample() {
  return (
    <View className="w-80 rounded-2xl border border-label/5 bg-surface-raised p-4 shadow-md dark:border-label/10">
      <WheelPicker>
        <WheelPickerColumn accessibilityLabel="Fruit" defaultValue="Lemon">
          {fruits.map((fruit) => (
            <WheelPickerItem key={fruit} value={fruit}>
              {fruit}
            </WheelPickerItem>
          ))}
        </WheelPickerColumn>
      </WheelPicker>
    </View>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct WheelPickerExample: View {
  var body: some View {
    WheelPickerFrame {
      FruitDemo()
    }
  }
}

struct WheelPickerFrame<Content: View>: View {
  @ViewBuilder let content: () -> Content

  @Environment(\.colorScheme) private var colorScheme

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
    content()
      .padding(16)
      .frame(width: 320)
      .background(Color.surfaceRaised, in: shape)
      .overlay {
        shape.strokeBorder(Color.label.opacity(colorScheme == .dark ? 0.1 : 0.05))
      }
      .shadow(Shadow.md)
  }
}

let wheelFruits = ["Apple", "Banana", "Cherry", "Grape", "Lemon", "Mango", "Orange", "Peach", "Pear", "Plum"]

struct FruitDemo: View {
  @State private var fruit = "Lemon"

  var body: some View {
    WheelPicker {
      WheelPickerColumn(selection: $fruit) {
        ForEach(wheelFruits, id: \.self) { item in
          WheelPickerItem(verbatim: item, value: item)
        }
      }
      .accessibilityLabel(Text("Fruit"))
    }
  }
}
```

```kotlin
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.WheelPicker
import com.esuiss.ui.components.WheelPickerColumn
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Shadows
import com.esuiss.ui.theme.shadow

@Composable
fun WheelPickerExample() {
    WheelPickerFrame { WheelPickerFruits() }
}

val wheelPickerFruits = listOf(
    "Apple",
    "Banana",
    "Cherry",
    "Grape",
    "Lemon",
    "Mango",
    "Orange",
    "Peach",
    "Pear",
    "Plum",
)

@Composable
fun WheelPickerFrame(content: @Composable () -> Unit) {
    val colors = EsuissTheme.colors
    val shape = RoundedCornerShape(Radius.xl2)
    Box(
        Modifier
            .width(320.dp)
            .shadow(Shadows.md, shape)
            .background(colors.surfaceRaised, shape)
            .border(1.dp, colors.label.copy(alpha = if (colors.isDark) 0.1f else 0.05f), shape)
            .padding(16.dp),
    ) {
        content()
    }
}

@Composable
fun WheelPickerFruits() {
    var value by rememberSaveable { mutableStateOf("Lemon") }
    WheelPicker(Modifier.fillMaxWidth()) {
        WheelPickerColumn(value, { value = it }, label = "Fruit") {
            wheelPickerFruits.forEach { WheelPickerItem(it, it) }
        }
    }
}
```

`WheelPicker` lays out one or more `WheelPickerColumn` components side by side behind a shared highlight band. Each column is a snapping `ScrollView`; items above and below the center are scaled, moved and faded with React Native `Animated` interpolations to look like a rotating wheel.

Use it for times, dates and other values picked from a short, ordered list, often in a sheet or popover.

## Installation

```bash title="Terminal"
npx @esuiss/uim@latest add wheel-picker
```

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

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

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

### Manual

**Uniwind**

1. Install the dependencies:

```bash title="Terminal"
npx expo install cn
```

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

3. Copy the source into `components/ui/wheel-picker.tsx`:

```tsx title="uniwind/components/ui/wheel-picker.tsx"
import { cn } from "cn"
import type * as React from "react"
import { resolveClassName } from "@/components/primitives/use-render"
import * as WheelPickerPrimitive from "@/components/primitives/wheel-picker"
import { Text, TextClassContext } from "@/components/ui/text"

function WheelPicker({
  className,
  children,
  ...props
}: React.ComponentProps<typeof WheelPickerPrimitive.Root>) {
  return (
    <WheelPickerPrimitive.Root
      className={(state) =>
        cn(
          "relative flex-row items-stretch justify-center",
          resolveClassName(className, state)
        )
      }
      {...props}
    >
      <WheelPickerPrimitive.Indicator className="rounded-lg bg-control" />
      {children}
    </WheelPickerPrimitive.Root>
  )
}

function WheelPickerColumn({
  className,
  ...props
}: React.ComponentProps<typeof WheelPickerPrimitive.Column>) {
  return (
    <WheelPickerPrimitive.Column
      className={(state) =>
        cn("relative rounded-lg", resolveClassName(className, state))
      }
      {...props}
    />
  )
}

function WheelPickerItem({
  className,
  children,
  disabled = false,
  ...props
}: React.ComponentProps<typeof WheelPickerPrimitive.Item>) {
  return (
    <TextClassContext.Provider
      value={cn(
        "text-xl text-label tabular-nums",
        disabled && "text-label-tertiary"
      )}
    >
      <WheelPickerPrimitive.Item
        disabled={disabled}
        className={(state) =>
          cn(
            "flex-row items-center justify-center px-3",
            resolveClassName(className, state)
          )
        }
        {...props}
      >
        {typeof children === "string" || typeof children === "number" ? (
          <Text numberOfLines={1}>{children}</Text>
        ) : (
          children
        )}
      </WheelPickerPrimitive.Item>
    </TextClassContext.Provider>
  )
}

export { WheelPicker, WheelPickerColumn, WheelPickerItem }
```

4. Update the import paths to match your project.

**NativeWind**

1. Install the dependencies:

```bash title="Terminal"
npx expo install cn
```

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

3. Copy the source into `components/ui/wheel-picker.tsx`:

```tsx title="nativewind/components/ui/wheel-picker.tsx"
import { cn } from "cn"
import type * as React from "react"
import { resolveClassName } from "@/components/primitives/use-render"
import * as WheelPickerPrimitive from "@/components/primitives/wheel-picker"
import { Text, TextClassContext } from "@/components/ui/text"

function WheelPicker({
  className,
  children,
  ...props
}: React.ComponentProps<typeof WheelPickerPrimitive.Root>) {
  return (
    <WheelPickerPrimitive.Root
      className={(state) =>
        cn(
          "relative flex-row items-stretch justify-center",
          resolveClassName(className, state)
        )
      }
      {...props}
    >
      <WheelPickerPrimitive.Indicator className="rounded-lg bg-control" />
      {children}
    </WheelPickerPrimitive.Root>
  )
}

function WheelPickerColumn({
  className,
  ...props
}: React.ComponentProps<typeof WheelPickerPrimitive.Column>) {
  return (
    <WheelPickerPrimitive.Column
      className={(state) =>
        cn("relative rounded-lg", resolveClassName(className, state))
      }
      {...props}
    />
  )
}

function WheelPickerItem({
  className,
  children,
  disabled = false,
  ...props
}: React.ComponentProps<typeof WheelPickerPrimitive.Item>) {
  return (
    <TextClassContext.Provider
      value={cn(
        "text-xl text-label tabular-nums",
        disabled && "text-label-tertiary"
      )}
    >
      <WheelPickerPrimitive.Item
        disabled={disabled}
        className={(state) =>
          cn(
            "flex-row items-center justify-center px-3",
            resolveClassName(className, state)
          )
        }
        {...props}
      >
        {typeof children === "string" || typeof children === "number" ? (
          <Text numberOfLines={1}>{children}</Text>
        ) : (
          children
        )}
      </WheelPickerPrimitive.Item>
    </TextClassContext.Provider>
  )
}

export { WheelPicker, WheelPickerColumn, WheelPickerItem }
```

4. Update the import paths to match your project.

**StyleSheet**

1. Add the pieces it builds on: [Text](/docs/components/text), and the primitives `components/primitives/use-render.tsx`, `components/primitives/wheel-picker.tsx`.

2. Copy the source into `components/ui/wheel-picker.tsx`:

```tsx title="stylesheet/components/ui/wheel-picker.tsx"
import type * as React from "react"
import {
  type StyleProp,
  StyleSheet,
  type TextStyle,
  type ViewStyle,
} from "react-native"
import { resolveStyle } from "@/components/primitives/use-render"
import * as WheelPickerPrimitive from "@/components/primitives/wheel-picker"
import { Text, TextStyleContext } from "@/components/ui/text"
import { fontSize, radius, useTheme } from "@/components/ui/theme"

const styles = StyleSheet.create({
  root: {
    position: "relative",
    flexDirection: "row",
    alignItems: "stretch",
    justifyContent: "center",
  },
  indicator: { borderRadius: radius.lg },
  column: { position: "relative", borderRadius: radius.lg },
  item: {
    flexDirection: "row",
    alignItems: "center",
    justifyContent: "center",
    paddingHorizontal: 12,
  },
  text: { ...fontSize.xl, fontVariant: ["tabular-nums"] },
})

function WheelPicker({
  style,
  children,
  ...props
}: React.ComponentProps<typeof WheelPickerPrimitive.Root>) {
  const { colors } = useTheme()
  return (
    <WheelPickerPrimitive.Root
      style={(state) => [
        styles.root,
        resolveStyle(style, state) as StyleProp<ViewStyle>,
      ]}
      {...props}
    >
      <WheelPickerPrimitive.Indicator
        style={[styles.indicator, { backgroundColor: colors.control }]}
      />
      {children}
    </WheelPickerPrimitive.Root>
  )
}

function WheelPickerColumn({
  style,
  ...props
}: React.ComponentProps<typeof WheelPickerPrimitive.Column>) {
  return (
    <WheelPickerPrimitive.Column
      style={(state) => [
        styles.column,
        resolveStyle(style, state) as StyleProp<ViewStyle>,
      ]}
      {...props}
    />
  )
}

function WheelPickerItem({
  style,
  children,
  disabled = false,
  ...props
}: React.ComponentProps<typeof WheelPickerPrimitive.Item>) {
  const { colors } = useTheme()
  const textStyle: TextStyle = {
    ...styles.text,
    color: disabled ? colors.labelTertiary : colors.label,
  }
  return (
    <TextStyleContext.Provider value={textStyle}>
      <WheelPickerPrimitive.Item
        disabled={disabled}
        style={(state) => [
          styles.item,
          resolveStyle(style, state) as StyleProp<ViewStyle>,
        ]}
        {...props}
      >
        {typeof children === "string" || typeof children === "number" ? (
          <Text numberOfLines={1}>{children}</Text>
        ) : (
          children
        )}
      </WheelPickerPrimitive.Item>
    </TextStyleContext.Provider>
  )
}

export { WheelPicker, WheelPickerColumn, WheelPickerItem }
```

3. Update the import paths to match your project.

**SwiftUI**

1. Target iOS 17 or later.

2. Add the Swift package to your app:

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

3. Copy the theme files every view uses:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

4. Copy the source and every file it uses:

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

struct WheelPickerEntry: Equatable {
  let value: AnyHashable
  let disabled: Bool
  let text: Text?
}

struct WheelPickerEntriesKey: PreferenceKey {
  static var defaultValue: [WheelPickerEntry] { [] }

  static func reduce(value: inout [WheelPickerEntry], nextValue: () -> [WheelPickerEntry]) {
    value.append(contentsOf: nextValue())
  }
}

struct WheelPickerColumnContext {
  var alignment: Alignment
  var select: @MainActor (AnyHashable) -> Void
}

extension EnvironmentValues {
  @Entry var wheelPickerColumn: WheelPickerColumnContext?
  @Entry var wheelPickerItemInset: CGFloat = 12
}

enum WheelPickerMetrics {
  static let rowHeight: CGFloat = 32
  static let height: CGFloat = rowHeight * 6.75
  static let inset: CGFloat = (height - rowHeight) / 2
}

struct WheelPickerCurve: Equatable {
  static let rowAngle = Double.pi / 10.5
  static let maxAngle = Double.pi / 2
  static let perspective = 1200.0
  static let fadeAngle = 0.35

  let offset: Double
  let scaleX: Double
  let scaleY: Double
  let opacity: Double

  init(distance: Double, height: Double) {
    let radius = height / Self.rowAngle
    let angle = min(max(distance * Self.rowAngle, -Self.maxAngle), Self.maxAngle)
    let away = abs(distance)
    let tone = away < 1 ? 1 - away * 0.45 : 0.55 - (away - 1) * 0.06
    let fade = min(1, (Self.maxAngle - abs(angle)) / Self.fadeAngle)
    let depth = Self.perspective / (Self.perspective + radius - radius * cos(angle))
    offset = radius * sin(angle) - distance * height
    scaleX = depth
    scaleY = depth * cos(angle)
    opacity = max(0, tone * fade)
  }
}

enum WheelPickerNavigation {
  static func enabled(_ disabled: [Bool], from index: Int, step: Int) -> Int? {
    var current = index
    while current >= 0 && current < disabled.count {
      if !disabled[current] { return current }
      current += step
    }
    return nil
  }

  static func nearestEnabled(_ disabled: [Bool], from index: Int) -> Int? {
    for distance in 0..<max(disabled.count, 1) {
      let before = index - distance
      if before >= 0 && before < disabled.count && !disabled[before] { return before }
      let after = index + distance
      if after >= 0 && after < disabled.count && !disabled[after] { return after }
    }
    return nil
  }

  static func centered(offset: CGFloat, count: Int) -> Int {
    guard count > 0 else { return 0 }
    let index = Int((offset / WheelPickerMetrics.rowHeight).rounded())
    return min(max(index, 0), count - 1)
  }
}

struct WheelPickerSnap: ScrollTargetBehavior {
  let disabled: [Bool]

  func updateTarget(_ target: inout ScrollTarget, context: TargetContext) {
    let row = WheelPickerMetrics.rowHeight
    guard !disabled.isEmpty else {
      target.rect.origin.y = (target.rect.minY / row).rounded() * row
      return
    }
    let index = WheelPickerNavigation.centered(offset: target.rect.minY, count: disabled.count)
    let resolved = WheelPickerNavigation.nearestEnabled(disabled, from: index) ?? index
    target.rect.origin.y = CGFloat(resolved) * row
  }
}

public struct WheelPicker<Content: View>: View {
  let spacing: CGFloat
  let content: Content

  public init(spacing: CGFloat = 0, @ViewBuilder content: () -> Content) {
    self.spacing = spacing
    self.content = content()
  }

  public var body: some View {
    HStack(alignment: .center, spacing: spacing) {
      content
    }
    .frame(maxWidth: .infinity)
    .background {
      RoundedRectangle(cornerRadius: Radius.lg, style: .continuous)
        .fill(Color.control)
        .frame(height: WheelPickerMetrics.rowHeight)
    }
  }
}

public struct WheelPickerColumn<Value: Hashable & Sendable, Content: View>: View {
  let selection: Binding<Value>
  let alignment: HorizontalAlignment
  let content: Content

  @State private var entries: [WheelPickerEntry] = []
  @State private var offset: CGFloat = 0
  @State private var settling: Task<Void, Never>?
  @State private var ticks = 0
  @Environment(\.accessibilityReduceMotion) private var reduceMotion

  public init(
    selection: Binding<Value>,
    alignment: HorizontalAlignment = .center,
    @ViewBuilder content: () -> Content
  ) {
    self.selection = selection
    self.alignment = alignment
    self.content = content()
  }

  public var body: some View {
    ScrollViewReader { proxy in
      ScrollView(.vertical, showsIndicators: false) {
        VStack(spacing: 0) {
          content
        }
        .padding(.vertical, WheelPickerMetrics.inset)
        .onGeometryChange(for: CGFloat.self) { geometry in
          geometry.frame(in: .scrollView).minY
        } action: { value in
          offset = -value
          scheduleSettle(proxy)
        }
      }
      .scrollTargetBehavior(WheelPickerSnap(disabled: entries.map(\.disabled)))
      .frame(height: WheelPickerMetrics.height)
      .fixedSize(horizontal: true, vertical: false)
      .clipShape(RoundedRectangle(cornerRadius: Radius.lg, style: .continuous))
      .hapticFeedback(.selection, trigger: ticks)
      .environment(\.wheelPickerColumn, WheelPickerColumnContext(
        alignment: Alignment(horizontal: alignment, vertical: .center),
        select: { value in
          if let next = value.base as? Value { commit(next) }
        }
      ))
      .onPreferenceChange(WheelPickerEntriesKey.self) { value in
        entries = value
      }
      .onAppear {
        proxy.scrollTo(selection.wrappedValue, anchor: .center)
      }
      .onChange(of: selection.wrappedValue) { _, value in
        guard centeredValue != AnyHashable(value) else { return }
        scroll(proxy, to: value)
      }
      .accessibilityElement(children: .ignore)
      .accessibilityValue(entries.first { $0.value == AnyHashable(selection.wrappedValue) }?.text ?? Text(verbatim: String(describing: selection.wrappedValue)))
      .accessibilityAdjustableAction { direction in
        let disabled = entries.map(\.disabled)
        guard let current = entries.firstIndex(where: { $0.value == AnyHashable(selection.wrappedValue) }) else { return }
        let target: Int?
        switch direction {
        case .increment: target = WheelPickerNavigation.enabled(disabled, from: current + 1, step: 1)
        case .decrement: target = WheelPickerNavigation.enabled(disabled, from: current - 1, step: -1)
        @unknown default: target = nil
        }
        if let target, let next = entries[target].value.base as? Value { commit(next) }
      }
    }
  }

  private var centeredValue: AnyHashable? {
    guard !entries.isEmpty else { return nil }
    return entries[WheelPickerNavigation.centered(offset: offset, count: entries.count)].value
  }

  private func commit(_ value: Value) {
    if selection.wrappedValue != value {
      selection.wrappedValue = value
      ticks += 1
    }
  }

  private func scroll(_ proxy: ScrollViewProxy, to value: Value) {
    if reduceMotion {
      proxy.scrollTo(value, anchor: .center)
    } else {
      withAnimation(.timingCurve(0.32, 0.72, 0, 1, duration: 0.3)) {
        proxy.scrollTo(value, anchor: .center)
      }
    }
  }

  private func scheduleSettle(_ proxy: ScrollViewProxy) {
    settling?.cancel()
    settling = Task { @MainActor in
      try? await Task.sleep(for: .milliseconds(150))
      guard !Task.isCancelled else { return }
      settle(proxy)
    }
  }

  private func settle(_ proxy: ScrollViewProxy) {
    guard !entries.isEmpty else { return }
    let centered = WheelPickerNavigation.centered(offset: offset, count: entries.count)
    guard let index = WheelPickerNavigation.nearestEnabled(entries.map(\.disabled), from: centered),
      let next = entries[index].value.base as? Value
    else { return }
    if index != centered { scroll(proxy, to: next) }
    commit(next)
  }
}

public struct WheelPickerItem<Value: Hashable & Sendable, Label: View>: View {
  let value: Value
  let text: Text?
  let label: Label

  @Environment(\.wheelPickerColumn) private var column
  @Environment(\.wheelPickerItemInset) private var inset
  @Environment(\.isEnabled) private var isEnabled

  public init(value: Value, @ViewBuilder label: () -> Label) {
    self.value = value
    text = nil
    self.label = label()
  }

  init(value: Value, text: Text, label: Label) {
    self.value = value
    self.text = text
    self.label = label
  }

  public var body: some View {
    label
      .font(TextStyle.xl.font())
      .tracking(TextStyle.xl.letterSpacing)
      .monospacedDigit()
      .lineLimit(1)
      .fixedSize()
      .foregroundStyle(isEnabled ? Color.label : .labelTertiary)
      .visualEffect { content, geometry in
        let row = Double(WheelPickerMetrics.rowHeight)
        let center = Double(WheelPickerMetrics.height) / 2
        let distance = (Double(geometry.frame(in: .scrollView).midY) - center) / row
        let curve = WheelPickerCurve(distance: distance, height: row)
        return content
          .scaleEffect(x: curve.scaleX, y: curve.scaleY)
          .offset(y: curve.offset)
          .opacity(curve.opacity)
      }
      .padding(.horizontal, inset)
      .frame(maxWidth: .infinity, alignment: column?.alignment ?? .center)
      .frame(height: WheelPickerMetrics.rowHeight)
      .contentShape(Rectangle())
      .onTapGesture {
        if isEnabled { column?.select(AnyHashable(value)) }
      }
      .id(value)
      .preference(key: WheelPickerEntriesKey.self, value: [WheelPickerEntry(value: AnyHashable(value), disabled: !isEnabled, text: text)])
  }
}

extension WheelPickerItem where Label == Text {
  public init(_ title: LocalizedStringKey, value: Value) {
    self.init(value: value, text: Text(title), label: Text(title))
  }

  public init(verbatim title: String, value: Value) {
    self.init(value: value, text: Text(verbatim: title), label: Text(verbatim: title))
  }
}
```

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

public struct VariantButtonStyle: ButtonStyle {
  public enum Variant: CaseIterable, Sendable {
    case `default`, outline, secondary, tinted, ghost, plain, destructive, link
  }

  public enum Size: CaseIterable, Sendable {
    case `default`, xs, sm, lg, xl, icon, iconXs, iconSm, iconLg, iconXl

    var height: CGFloat {
      switch self {
      case .xs, .iconXs: 24
      case .sm, .iconSm: 32
      case .default, .icon: 36
      case .lg, .iconLg: 44
      case .xl, .iconXl: 56
      }
    }

    var horizontalPadding: CGFloat {
      switch self {
      case .xs: 11
      case .sm: 12
      case .default: 16
      case .lg: 22
      case .xl: 31
      case .icon, .iconXs, .iconSm, .iconLg, .iconXl: 0
      }
    }

    var spacing: CGFloat {
      switch self {
      case .xs, .sm, .iconXs, .iconSm: 4
      case .xl, .iconXl: 8
      default: 6
      }
    }

    var textStyle: TextStyle {
      switch self {
      case .xs, .iconXs: .xs2
      case .lg, .xl: .base
      default: .sm
      }
    }

    public var iconSize: CGFloat {
      switch self {
      case .xs, .iconXs: 12
      default: 16
      }
    }

    var blockRadius: CGFloat {
      switch self {
      case .xs, .iconXs: Radius.sm
      case .lg, .iconLg: Radius.lg
      case .xl, .iconXl: Radius.xl
      default: Radius.md
      }
    }

    var isIcon: Bool {
      switch self {
      case .icon, .iconXs, .iconSm, .iconLg, .iconXl: true
      default: false
      }
    }
  }

  let variant: Variant
  let size: Size
  let block: Bool
  var metrics: ButtonMetrics?

  public init(_ variant: Variant = .default, size: Size = .default, block: Bool = false) {
    self.variant = variant
    self.size = size
    self.block = block
  }

  init(_ variant: Variant, size: Size, metrics: ButtonMetrics) {
    self.variant = variant
    self.size = size
    self.block = false
    self.metrics = metrics
  }

  public func makeBody(configuration: Configuration) -> some View {
    StyledButton(configuration: configuration, variant: variant, size: size, block: block, metrics: metrics)
  }
}

struct ButtonMetrics: Sendable {
  var horizontalPadding: CGFloat
  var spacing: CGFloat
  var iconSize: CGFloat
  var textStyle: TextStyle
}

private struct StyledButton: View {
  let configuration: ButtonStyleConfiguration
  let variant: VariantButtonStyle.Variant
  let size: VariantButtonStyle.Size
  let block: Bool
  let metrics: ButtonMetrics?

  @Environment(\.colorScheme) private var colorScheme
  @Environment(\.isEnabled) private var isEnabled
  @Environment(\.buttonGroup) private var group

  var body: some View {
    let joined = group != nil && variant != .ghost && variant != .plain
    let rounded = RoundedRectangle(
      cornerRadius: block ? size.blockRadius : Radius.full,
      style: .continuous
    )
    let shape = joined ? AnyShape(Rectangle()) : AnyShape(rounded)
    configuration.label
      .labelStyle(ButtonLabelStyle(spacing: metrics?.spacing ?? size.spacing, iconSize: metrics?.iconSize ?? size.iconSize))
    .font((metrics?.textStyle ?? size.textStyle).font())
    .tracking((metrics?.textStyle ?? size.textStyle).letterSpacing)
    .underline(variant == .link && pressed && isEnabled)
    .lineLimit(1)
    .foregroundStyle(foreground)
    .padding(.horizontal, metrics?.horizontalPadding ?? size.horizontalPadding)
    .frame(width: size.isIcon && !block ? size.height : nil, height: size.height)
    .frame(maxWidth: block || group == .vertical ? .infinity : nil)
    .background(background, in: shape)
    .overlay {
      if variant == .outline && !joined {
        rounded.strokeBorder(Color.separator)
      }
    }
    .contentShape(shape)
    .anchorPreference(key: ButtonGroupFramesKey.self, value: .bounds) { anchor in
      joined ? [ButtonGroupFrame(bounds: anchor, outlined: variant == .outline)] : []
    }
  }

  private var isDark: Bool { colorScheme == .dark }
  private var pressed: Bool { configuration.isPressed }

  private var foreground: Color {
    switch variant {
    case .default:
      .onAccent
    case .outline, .secondary, .ghost:
      isEnabled ? .label : .labelQuaternary
    case .tinted, .plain:
      isEnabled ? .link : .link.opacity(0.4)
    case .destructive:
      isEnabled ? .danger : .danger.opacity(0.4)
    case .link:
      isEnabled ? .link : .labelQuaternary
    }
  }

  private var background: Color {
    switch variant {
    case .default:
      !isEnabled ? .accentDisabled : pressed ? .accentPressed : .accent
    case .outline:
      isEnabled && pressed ? .itemPressed : isDark ? .clear : .surface
    case .secondary:
      !isEnabled ? .controlDisabled : pressed ? .controlPressed : .control
    case .tinted:
      isEnabled && pressed ? .accentSurfacePressed : .accentSurface
    case .ghost:
      isEnabled && pressed ? .itemPressed : .clear
    case .plain:
      isEnabled && pressed ? .itemPressed : .clear
    case .destructive:
      isEnabled && pressed ? .dangerSurfacePressed : .dangerSurface
    case .link:
      .clear
    }
  }
}

struct ButtonLabelStyle: LabelStyle {
  let spacing: CGFloat
  let iconSize: CGFloat

  func makeBody(configuration: Configuration) -> some View {
    HStack(spacing: spacing) {
      configuration.icon
        .frame(width: iconSize, height: iconSize)
      configuration.title
    }
  }
}

extension ButtonStyle where Self == VariantButtonStyle {
  public static func variant(
    _ variant: VariantButtonStyle.Variant = .default,
    size: VariantButtonStyle.Size = .default,
    block: Bool = false
  ) -> VariantButtonStyle {
    VariantButtonStyle(variant, size: size, block: block)
  }
}
```

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

extension EnvironmentValues {
  @Entry var buttonGroup: Axis? = nil
  @Entry var buttonGroupSize: CGSize = .zero
}

enum ButtonGroupSpace: Hashable {
  case group
}

struct ButtonGroupFrame {
  let bounds: Anchor<CGRect>
  let outlined: Bool
}

struct ButtonGroupFramesKey: PreferenceKey {
  static var defaultValue: [ButtonGroupFrame] { [] }

  static func reduce(value: inout [ButtonGroupFrame], nextValue: () -> [ButtonGroupFrame]) {
    value.append(contentsOf: nextValue())
  }
}

struct ButtonGroupNestedKey: PreferenceKey {
  static var defaultValue: Bool { false }

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

public struct ButtonGroup<Content: View>: View {
  let orientation: Axis
  let content: Content

  @State private var nested = false
  @State private var size: CGSize = .zero

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

  public var body: some View {
    let shape = orientation == .horizontal
      ? AnyShape(Capsule())
      : AnyShape(RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous))
    stack
      .coordinateSpace(.named(ButtonGroupSpace.group))
      .onGeometryChange(for: CGSize.self) { $0.size } action: { size = $0 }
      .environment(\.buttonGroup, nested ? nil : orientation)
      .environment(\.buttonGroupSize, size)
      .onPreferenceChange(ButtonGroupNestedKey.self) { nested = $0 }
      .modifier(ButtonGroupClip(shape: nested ? nil : shape))
      .overlayPreferenceValue(ButtonGroupFramesKey.self) { frames in
        if !nested {
          GeometryReader { proxy in
            outline(frames.map { (proxy[$0.bounds], $0.outlined) }, shape: shape)
          }
        }
      }
      .transformPreference(ButtonGroupFramesKey.self) { $0 = [] }
      .transformPreference(ButtonGroupNestedKey.self) { $0 = true }
      .fixedSize(horizontal: orientation == .vertical, vertical: orientation == .horizontal)
      .accessibilityElement(children: .contain)
  }

  @ViewBuilder private var stack: some View {
    switch orientation {
    case .horizontal:
      HStack(spacing: nested ? 8 : 0) { content }
    case .vertical:
      VStack(spacing: nested ? 8 : 0) { content }
    }
  }

  @ViewBuilder private func outline(_ frames: [(CGRect, Bool)], shape: AnyShape) -> some View {
    if frames.contains(where: \.1) {
      ZStack(alignment: .topLeading) {
        shape
          .stroke(Color.separator, lineWidth: 1)
          .padding(0.5)
          .mask {
            Path { path in
              for (rect, outlined) in frames where outlined {
                path.addRect(rect)
              }
            }
          }
        ForEach(Array(frames.dropLast().enumerated()), id: \.offset) { _, frame in
          if frame.1 {
            divider(frame.0)
          }
        }
      }
      .clipShape(shape)
      .allowsHitTesting(false)
    }
  }

  private func divider(_ rect: CGRect) -> some View {
    let horizontal = orientation == .horizontal
    return Rectangle()
      .fill(Color.separator)
      .frame(width: horizontal ? 1 : rect.width, height: horizontal ? rect.height : 1)
      .position(
        x: horizontal ? rect.maxX - 0.5 : rect.midX,
        y: horizontal ? rect.midY : rect.maxY - 0.5
      )
  }
}

struct ButtonGroupItem<Content: View>: View {
  let radius: CGFloat
  let content: (UnevenRoundedRectangle) -> Content

  @State private var frame: CGRect = .zero
  @Environment(\.buttonGroup) private var group
  @Environment(\.buttonGroupSize) private var groupSize

  init(radius: CGFloat, @ViewBuilder content: @escaping (UnevenRoundedRectangle) -> Content) {
    self.radius = radius
    self.content = content
  }

  var body: some View {
    if let group {
      content(shape(group))
        .onGeometryChange(for: CGRect.self) { $0.frame(in: .named(ButtonGroupSpace.group)) } action: { frame = $0 }
    } else {
      content(UnevenRoundedRectangle(cornerRadii: RectangleCornerRadii(
        topLeading: radius,
        bottomLeading: radius,
        bottomTrailing: radius,
        topTrailing: radius
      ), style: .continuous))
    }
  }

  private func shape(_ group: Axis) -> UnevenRoundedRectangle {
    let horizontal = group == .horizontal
    let first = horizontal ? frame.minX <= 0.5 : frame.minY <= 0.5
    let last = horizontal
      ? frame.maxX >= groupSize.width - 0.5
      : frame.maxY >= groupSize.height - 0.5
    let round = horizontal ? frame.height / 2 : Radius.xl2
    let start: CGFloat = first ? round : 0
    let end: CGFloat = last ? round : 0
    let radii = horizontal
      ? RectangleCornerRadii(topLeading: start, bottomLeading: start, bottomTrailing: end, topTrailing: end)
      : RectangleCornerRadii(topLeading: start, bottomLeading: end, bottomTrailing: end, topTrailing: start)
    return UnevenRoundedRectangle(cornerRadii: radii, style: .continuous)
  }
}

private struct ButtonGroupClip: ViewModifier {
  let shape: AnyShape?

  func body(content: Content) -> some View {
    if let shape {
      content.clipShape(shape)
    } else {
      content
    }
  }
}

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

  @Environment(\.buttonGroup) private var group

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

  public var body: some View {
    let shape = group == nil ? AnyShape(Capsule()) : AnyShape(Rectangle())
    HStack(spacing: 8) {
      content
    }
    .labelStyle(ButtonLabelStyle(spacing: 8, iconSize: 16))
    .scaledFont(.sm)
    .lineLimit(1)
    .foregroundStyle(Color.label)
    .padding(.horizontal, 10)
    .frame(minHeight: 36)
    .frame(maxWidth: group == .vertical ? .infinity : nil, maxHeight: group == .horizontal ? .infinity : nil)
    .background(Color.control, in: shape)
    .anchorPreference(key: ButtonGroupFramesKey.self, value: .bounds) { anchor in
      group == nil ? [] : [ButtonGroupFrame(bounds: anchor, outlined: false)]
    }
  }
}

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

  public init(verbatim title: String) {
    self.init { Text(verbatim: title) }
  }
}

public struct ButtonGroupSeparator: View {
  let orientation: Axis

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

  public var body: some View {
    let vertical = orientation == .vertical
    Rectangle()
      .fill(Color.label.opacity(0.2))
      .frame(width: vertical ? 1 : nil, height: vertical ? nil : 1)
      .padding(vertical ? .vertical : .horizontal, 9)
      .frame(maxWidth: vertical ? nil : .infinity, maxHeight: vertical ? .infinity : nil)
      .padding(vertical ? .trailing : .bottom, -1)
      .zIndex(1)
      .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/DropdownMenu.swift"
import PhosphorSwift
import SwiftUI

enum MenuPresentation: Sendable {
  case system, popup
}

extension EnvironmentValues {
  @Entry var menuPresentation: MenuPresentation = .system
  @Entry var menuRadio = MenuRadioContext()
}

struct MenuRadioContext: @unchecked Sendable {
  var selected: AnyHashable?
  var select: @MainActor @Sendable (AnyHashable) -> Void = { _ in }
}

public struct DropdownMenu<Label: View, Content: View>: View {
  let side: Edge
  let align: PopupAlignment
  let sideOffset: CGFloat
  let alignOffset: CGFloat
  let external: Binding<Bool>?
  let content: () -> Content
  let label: Label

  @State private var local = false

  public init(
    isPresented: Binding<Bool>? = nil,
    side: Edge = .bottom,
    align: PopupAlignment = .start,
    sideOffset: CGFloat = 4,
    alignOffset: CGFloat = 0,
    @ViewBuilder content: @escaping () -> Content,
    @ViewBuilder label: () -> Label
  ) {
    self.external = isPresented
    self.side = side
    self.align = align
    self.sideOffset = sideOffset
    self.alignOffset = alignOffset
    self.content = content
    self.label = label()
  }

  public var body: some View {
    let binding = external ?? $local
    Button {
      binding.wrappedValue = true
    } label: {
      label
    }
    .accessibilityHint(Text("Opens a menu"))
    .anchoredPopup(
      isPresented: binding,
      side: side,
      align: align,
      sideOffset: sideOffset,
      alignOffset: alignOffset,
      minWidth: 192
    ) {
      MenuPanel(content: content)
    }
  }
}

extension DropdownMenu where Label == Text {
  public init(
    _ title: LocalizedStringKey,
    isPresented: Binding<Bool>? = nil,
    side: Edge = .bottom,
    align: PopupAlignment = .start,
    @ViewBuilder content: @escaping () -> Content
  ) {
    self.init(isPresented: isPresented, side: side, align: align, content: content) { Text(title) }
  }
}

struct MenuPanel<Content: View>: View {
  @ViewBuilder let content: () -> Content

  var body: some View {
    let stack = VStack(alignment: .leading, spacing: 0) {
      content()
    }
    .padding(6)
    ViewThatFits(in: .vertical) {
      stack
      ScrollView { stack }
    }
    .font(TextStyle.base.font())
    .tracking(TextStyle.base.letterSpacing)
    .foregroundStyle(Color.label)
    .environment(\.menuPresentation, .popup)
    .popupSurface(radius: Radius.xl)
    .accessibilityElement(children: .contain)
  }
}

struct MenuRowStyle: ButtonStyle {
  var destructive = false
  var inset = false
  var trailing: CGFloat = 12
  var selected = false

  @Environment(\.isEnabled) private var isEnabled

  func makeBody(configuration: Configuration) -> some View {
    configuration.label
      .labelStyle(ButtonLabelStyle(spacing: 10, iconSize: 16))
      .lineLimit(1)
      .foregroundStyle(!isEnabled ? Color.labelQuaternary : destructive ? .danger : .label)
      .padding(.leading, inset ? 38 : 12)
      .padding(.trailing, trailing)
      .padding(.vertical, 8)
      .frame(maxWidth: .infinity, alignment: .leading)
      .background(background(pressed: configuration.isPressed), in: RoundedRectangle(cornerRadius: Radius.md, style: .continuous))
      .contentShape(Rectangle())
  }

  private func background(pressed: Bool) -> Color {
    if pressed && isEnabled {
      return destructive ? .dangerSurfacePressed : .itemPressed
    }
    return selected ? .itemSelected : .clear
  }
}

private struct MenuCheckmark: View {
  let visible: Bool

  var body: some View {
    Ph.check.regular
      .frame(width: 16, height: 16)
      .opacity(visible ? 1 : 0)
      .padding(.trailing, 8)
      .accessibilityHidden(true)
  }
}

public struct DropdownMenuItem<Label: View>: View {
  public enum Variant: CaseIterable, Sendable {
    case `default`, destructive
  }

  let variant: Variant
  let inset: Bool
  let action: () -> Void
  let label: Label

  @Environment(\.menuPresentation) private var presentation
  @Environment(\.overlayDismiss) private var dismiss

  public init(
    variant: Variant = .default,
    inset: Bool = false,
    action: @escaping () -> Void,
    @ViewBuilder label: () -> Label
  ) {
    self.variant = variant
    self.inset = inset
    self.action = action
    self.label = label()
  }

  public var body: some View {
    if presentation == .system {
      Button(role: variant == .destructive ? .destructive : nil, action: action) {
        label
      }
    } else {
      Button {
        action()
        dismiss?()
      } label: {
        HStack(spacing: 10) {
          label
        }
      }
      .buttonStyle(MenuRowStyle(destructive: variant == .destructive, inset: inset))
    }
  }
}

extension DropdownMenuItem where Label == Text {
  public init(
    _ title: LocalizedStringKey,
    variant: Variant = .default,
    inset: Bool = false,
    action: @escaping () -> Void
  ) {
    self.init(variant: variant, inset: inset, action: action) { Text(title) }
  }
}

extension DropdownMenuItem where Label == SwiftUI.Label<Text, Image> {
  public init(
    _ title: LocalizedStringKey,
    icon: Image,
    variant: Variant = .default,
    action: @escaping () -> Void
  ) {
    self.init(variant: variant, action: action) {
      SwiftUI.Label { Text(title) } icon: { icon }
    }
  }
}

public struct DropdownMenuCheckboxItem<Label: View>: View {
  let isOn: Binding<Bool>
  let inset: Bool
  let label: Label

  @Environment(\.menuPresentation) private var presentation

  public init(isOn: Binding<Bool>, inset: Bool = false, @ViewBuilder label: () -> Label) {
    self.isOn = isOn
    self.inset = inset
    self.label = label()
  }

  public var body: some View {
    if presentation == .system {
      Toggle(isOn: isOn) { label }
    } else {
      Button {
        isOn.wrappedValue.toggle()
      } label: {
        label
      }
      .buttonStyle(MenuRowStyle(inset: inset, trailing: 32))
      .overlay(alignment: .trailing) { MenuCheckmark(visible: isOn.wrappedValue) }
      .accessibilityAddTraits(isOn.wrappedValue ? [.isToggle, .isSelected] : .isToggle)
    }
  }
}

extension DropdownMenuCheckboxItem where Label == Text {
  public init(_ title: LocalizedStringKey, isOn: Binding<Bool>, inset: Bool = false) {
    self.init(isOn: isOn, inset: inset) { Text(title) }
  }
}

public struct DropdownMenuRadioGroup<Content: View>: View {
  let selection: Binding<AnyHashable>
  let content: Content

  public init<Value: Hashable & Sendable>(selection: Binding<Value>, @ViewBuilder content: () -> Content) {
    self.selection = Binding(
      get: { AnyHashable(selection.wrappedValue) },
      set: { value in
        if let value = value.base as? Value { selection.wrappedValue = value }
      }
    )
    self.content = content()
  }

  public var body: some View {
    let binding = selection
    content
      .environment(
        \.menuRadio,
        MenuRadioContext(selected: binding.wrappedValue, select: { binding.wrappedValue = $0 })
      )
  }
}

public struct DropdownMenuRadioItem<Label: View>: View {
  let value: AnyHashable
  let inset: Bool
  let label: Label

  @Environment(\.menuPresentation) private var presentation
  @Environment(\.menuRadio) private var radio

  public init<Value: Hashable & Sendable>(value: Value, inset: Bool = false, @ViewBuilder label: () -> Label) {
    self.value = AnyHashable(value)
    self.inset = inset
    self.label = label()
  }

  public var body: some View {
    let selected = radio.selected == value
    if presentation == .system {
      let radio = radio
      let value = value
      Toggle(isOn: Binding(get: { selected }, set: { if $0 { radio.select(value) } })) { label }
    } else {
      Button {
        radio.select(value)
      } label: {
        label
      }
      .buttonStyle(MenuRowStyle(inset: inset, trailing: 32))
      .overlay(alignment: .trailing) { MenuCheckmark(visible: selected) }
      .accessibilityAddTraits(selected ? .isSelected : [])
    }
  }
}

extension DropdownMenuRadioItem where Label == Text {
  public init<Value: Hashable & Sendable>(_ title: LocalizedStringKey, value: Value, inset: Bool = false) {
    self.init(value: value, inset: inset) { Text(title) }
  }
}

public struct DropdownMenuLabel: View {
  let title: LocalizedStringKey
  let inset: Bool

  @Environment(\.menuPresentation) private var presentation

  public init(_ title: LocalizedStringKey, inset: Bool = false) {
    self.title = title
    self.inset = inset
  }

  public var body: some View {
    if presentation == .system {
      Text(title)
    } else {
      Text(title)
        .font(TextStyle.xs.font(weight: .semibold))
        .tracking(TextStyle.xs.letterSpacing)
        .foregroundStyle(Color.labelSecondary)
        .padding(.leading, inset ? 38 : 12)
        .padding(.trailing, 12)
        .padding(.vertical, 10)
        .frame(maxWidth: .infinity, alignment: .leading)
        .accessibilityAddTraits(.isHeader)
    }
  }
}

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

  @Environment(\.menuPresentation) private var presentation

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

  public var body: some View {
    if presentation == .system {
      Section { content }
    } else {
      VStack(alignment: .leading, spacing: 0) { content }
    }
  }
}

public struct DropdownMenuSeparator: View {
  @Environment(\.menuPresentation) private var presentation

  public init() {}

  public var body: some View {
    if presentation == .system {
      Divider()
    } else {
      Rectangle()
        .fill(Color.separator.opacity(0.5))
        .frame(height: 1)
        .padding(.vertical, 6)
        .padding(.horizontal, -6)
        .accessibilityHidden(true)
    }
  }
}

public struct DropdownMenuSub<Label: View, Content: View>: View {
  let inset: Bool
  let content: Content
  let label: Label

  @State private var open = false
  @Environment(\.menuPresentation) private var presentation
  @Environment(\.accessibilityReduceMotion) private var reduceMotion

  public init(inset: Bool = false, @ViewBuilder content: () -> Content, @ViewBuilder label: () -> Label) {
    self.inset = inset
    self.content = content()
    self.label = label()
  }

  public var body: some View {
    if presentation == .system {
      Menu { content } label: { label }
    } else {
      VStack(alignment: .leading, spacing: 0) {
        Button {
          withAnimation(reduceMotion ? nil : .easeInOut(duration: 0.2)) { open.toggle() }
        } label: {
          HStack(spacing: 8) {
            label
            Spacer(minLength: 16)
            Ph.caretRight.regular
              .frame(width: 16, height: 16)
              .rotationEffect(.degrees(open ? 90 : 0))
          }
        }
        .buttonStyle(MenuRowStyle(inset: inset, selected: open))
        .accessibilityValue(Text(open ? "Expanded" : "Collapsed"))
        if open {
          VStack(alignment: .leading, spacing: 0) { content }
            .padding(.leading, 12)
            .transition(.opacity)
        }
      }
    }
  }
}

extension DropdownMenuSub where Label == Text {
  public init(_ title: LocalizedStringKey, inset: Bool = false, @ViewBuilder content: () -> Content) {
    self.init(inset: inset, content: content) { Text(title) }
  }
}

extension DropdownMenuSub where Label == SwiftUI.Label<Text, Image> {
  public init(_ title: LocalizedStringKey, icon: Image, @ViewBuilder content: () -> Content) {
    self.init(content: content) {
      SwiftUI.Label { Text(title) } icon: { icon }
    }
  }
}
```

```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/Overlay.swift"
import PhosphorSwift
import Observation
import SwiftUI

public enum PopupAlignment: Sendable, CaseIterable {
  case start, center, end
}

struct OverlayDismiss: Sendable {
  let action: @MainActor @Sendable () -> Void

  @MainActor func callAsFunction() {
    action()
  }
}

extension EnvironmentValues {
  @Entry var overlayDismiss: OverlayDismiss? = nil
}

private var instantTransaction: Transaction {
  var transaction = Transaction()
  transaction.disablesAnimations = true
  return transaction
}

struct CoverPresenter<Cover: View>: ViewModifier {
  @Binding var isPresented: Bool
  var enter: Animation = .easeOut(duration: 0.15)
  var exit: Animation = .easeIn(duration: 0.1)
  @ViewBuilder let cover: (Bool) -> Cover

  @State private var presented = false
  @State private var visible = false

  func body(content: Content) -> some View {
    let binding = $isPresented
    content
      .fullScreenCover(isPresented: coverBinding) {
        cover(visible)
          .environment(\.overlayDismiss, OverlayDismiss { binding.wrappedValue = false })
          .presentationBackground(.clear)
          .onAppear {
            withAnimation(enter) { visible = true }
          }
      }
      .onChange(of: isPresented, initial: true) { _, value in
        if value {
          withTransaction(instantTransaction) { presented = true }
        } else if presented {
          withAnimation(exit) {
            visible = false
          } completion: {
            withTransaction(instantTransaction) { presented = false }
          }
        }
      }
  }

  private var coverBinding: Binding<Bool> {
    Binding(
      get: { presented },
      set: { value in
        presented = value
        if !value {
          visible = false
          isPresented = false
        }
      }
    )
  }
}

struct PopupLayout: Layout {
  var anchor: CGRect
  var side: Edge
  var align: PopupAlignment
  var sideOffset: CGFloat
  var alignOffset: CGFloat
  var matchWidth: Bool
  var minWidth: CGFloat
  var maxHeight: CGFloat
  var margin: CGFloat = 8

  func sizeThatFits(proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) -> CGSize {
    proposal.replacingUnspecifiedDimensions()
  }

  func placeSubviews(in bounds: CGRect, proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) {
    guard let view = subviews.first else { return }
    let anchor = anchor.offsetBy(dx: bounds.minX, dy: bounds.minY)
    let maxWidth = max(0, bounds.width - margin * 2)
    var width: CGFloat
    if matchWidth {
      width = max(anchor.width, minWidth)
    } else {
      width = max(view.sizeThatFits(ProposedViewSize(width: nil, height: nil)).width, minWidth)
    }
    width = min(width, maxWidth)
    let natural = view.sizeThatFits(ProposedViewSize(width: width, height: nil))
    let vertical = side == .top || side == .bottom
    let before = vertical
      ? anchor.minY - sideOffset - bounds.minY - margin
      : anchor.minX - sideOffset - bounds.minX - margin
    let after = vertical
      ? bounds.maxY - margin - anchor.maxY - sideOffset
      : bounds.maxX - margin - anchor.maxX - sideOffset
    let extent = vertical ? natural.height : natural.width
    var resolved = side
    switch side {
    case .bottom where extent > after && before > after: resolved = .top
    case .top where extent > before && after > before: resolved = .bottom
    case .trailing where extent > after && before > after: resolved = .leading
    case .leading where extent > before && after > before: resolved = .trailing
    default: break
    }
    var height = natural.height
    let space: CGFloat
    switch resolved {
    case .top, .leading: space = before
    case .bottom, .trailing: space = after
    }
    if vertical {
      height = min(height, maxHeight, max(space, 0))
    } else {
      height = min(height, maxHeight, bounds.height - margin * 2)
      width = min(width, max(space, 0))
    }
    var x: CGFloat
    var y: CGFloat
    if vertical {
      switch align {
      case .start: x = anchor.minX + alignOffset
      case .center: x = anchor.midX - width / 2 + alignOffset
      case .end: x = anchor.maxX - width - alignOffset
      }
      y = resolved == .bottom ? anchor.maxY + sideOffset : anchor.minY - sideOffset - height
    } else {
      switch align {
      case .start: y = anchor.minY + alignOffset
      case .center: y = anchor.midY - height / 2 + alignOffset
      case .end: y = anchor.maxY - height - alignOffset
      }
      x = resolved == .trailing ? anchor.maxX + sideOffset : anchor.minX - sideOffset - width
    }
    x = min(max(x, bounds.minX + margin), bounds.maxX - margin - width)
    y = min(max(y, bounds.minY + margin), bounds.maxY - margin - height)
    view.place(
      at: CGPoint(x: x, y: y),
      anchor: .topLeading,
      proposal: ProposedViewSize(width: width, height: height)
    )
  }
}

struct PopupPresenter<Popup: View>: ViewModifier {
  @Binding var isPresented: Bool
  var side: Edge = .bottom
  var align: PopupAlignment = .start
  var sideOffset: CGFloat = 4
  var alignOffset: CGFloat = 0
  var matchWidth = false
  var minWidth: CGFloat = 0
  var maxHeight: CGFloat = .infinity
  @ViewBuilder let popup: () -> Popup

  @State private var anchor = PopupAnchor()

  func body(content: Content) -> some View {
    content
      .onGeometryChange(for: CGRect.self) { proxy in
        proxy.frame(in: .global)
      } action: { frame in
        anchor.frame = frame
      }
      .modifier(
        CoverPresenter(isPresented: $isPresented) { visible in
          PopupCanvas(
            anchor: anchor,
            side: side,
            align: align,
            sideOffset: sideOffset,
            alignOffset: alignOffset,
            matchWidth: matchWidth,
            minWidth: minWidth,
            maxHeight: maxHeight,
            visible: visible,
            popup: popup
          )
        }
      )
  }
}

@Observable
final class PopupAnchor {
  var frame: CGRect = .zero
}

struct PopupCanvas<Popup: View>: View {
  let anchor: PopupAnchor
  let side: Edge
  let align: PopupAlignment
  let sideOffset: CGFloat
  let alignOffset: CGFloat
  let matchWidth: Bool
  let minWidth: CGFloat
  let maxHeight: CGFloat
  let visible: Bool
  @ViewBuilder let popup: () -> Popup

  @Environment(\.overlayDismiss) private var dismiss
  @Environment(\.accessibilityReduceMotion) private var reduceMotion

  var body: some View {
    GeometryReader { proxy in
      let origin = proxy.frame(in: .global).origin
      PopupLayout(
        anchor: anchor.frame.offsetBy(dx: -origin.x, dy: -origin.y),
        side: side,
        align: align,
        sideOffset: sideOffset,
        alignOffset: alignOffset,
        matchWidth: matchWidth,
        minWidth: minWidth,
        maxHeight: maxHeight
      ) {
        popup()
          .accessibilityAddTraits(.isModal)
          .scaleEffect(visible || reduceMotion ? 1 : 0.96, anchor: scaleAnchor)
          .opacity(visible ? 1 : 0)
      }
    }
    .background {
      Color.clear
        .contentShape(Rectangle())
        .ignoresSafeArea()
        .onTapGesture { dismiss?() }
        .accessibilityHidden(true)
    }
    .accessibilityAction(.escape) { dismiss?() }
  }

  private var scaleAnchor: UnitPoint {
    switch side {
    case .top: .bottom
    case .bottom: .top
    case .leading: .trailing
    case .trailing: .leading
    }
  }
}

extension View {
  func anchoredPopup<Popup: View>(
    isPresented: Binding<Bool>,
    side: Edge = .bottom,
    align: PopupAlignment = .start,
    sideOffset: CGFloat = 4,
    alignOffset: CGFloat = 0,
    matchWidth: Bool = false,
    minWidth: CGFloat = 0,
    maxHeight: CGFloat = .infinity,
    @ViewBuilder popup: @escaping () -> Popup
  ) -> some View {
    modifier(
      PopupPresenter(
        isPresented: isPresented,
        side: side,
        align: align,
        sideOffset: sideOffset,
        alignOffset: alignOffset,
        matchWidth: matchWidth,
        minWidth: minWidth,
        maxHeight: maxHeight,
        popup: popup
      )
    )
  }

  func popupSurface(radius: CGFloat = Radius.xl, shadow: Shadow = .lg) -> some View {
    modifier(PopupSurface(radius: radius, shadow: shadow))
  }
}

struct PopupSurface: ViewModifier {
  let radius: CGFloat
  let shadow: Shadow

  @Environment(\.colorScheme) private var colorScheme

  func body(content: Content) -> some View {
    let shape = RoundedRectangle(cornerRadius: radius, style: .continuous)
    content
      .clipShape(shape)
      .background {
        shape
          .fill(Color.surfaceRaised)
          .shadow(shadow)
      }
      .overlay {
        shape.strokeBorder(Color.label.opacity(colorScheme == .dark ? 0.1 : 0.05))
      }
  }
}

struct OverlayCloseButton: View {
  let label: LocalizedStringKey?

  @Environment(\.overlayDismiss) private var dismiss

  var body: some View {
    if let label {
      Button {
        dismiss?()
      } label: {
        Text(label).font(TextStyle.base.font())
      }
      .buttonStyle(.variant(.plain, size: .sm))
    } else {
      Button {
        dismiss?()
      } label: {
        Ph.x.regular
          .frame(width: 16, height: 16)
          .foregroundStyle(Color.label)
      }
      .buttonStyle(CloseIconButtonStyle())
      .accessibilityLabel(Text("Close"))
    }
  }
}

private struct CloseIconButtonStyle: ButtonStyle {
  func makeBody(configuration: Configuration) -> some View {
    configuration.label
      .frame(width: 32, height: 32)
      .background(configuration.isPressed ? Color.separator : .surfaceTertiary, in: Circle())
      .contentShape(Circle().inset(by: -8))
  }
}

struct ReversedVStack: Layout {
  var spacing: CGFloat

  func sizeThatFits(proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) -> CGSize {
    let width = proposal.width
    var height: CGFloat = 0
    var widest: CGFloat = 0
    for view in subviews {
      let size = view.sizeThatFits(ProposedViewSize(width: width, height: nil))
      height += size.height
      widest = max(widest, size.width)
    }
    height += spacing * CGFloat(max(subviews.count - 1, 0))
    return CGSize(width: width ?? widest, height: height)
  }

  func placeSubviews(in bounds: CGRect, proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) {
    var y = bounds.minY
    for view in subviews.reversed() {
      let size = view.sizeThatFits(ProposedViewSize(width: bounds.width, height: nil))
      view.place(
        at: CGPoint(x: bounds.minX, y: y),
        anchor: .topLeading,
        proposal: ProposedViewSize(width: bounds.width, height: size.height)
      )
      y += size.height + spacing
    }
  }
}

struct ScrimLayer: View {
  let visible: Bool
  var dismissible = true

  @Environment(\.overlayDismiss) private var dismiss

  var body: some View {
    Color.scrim
      .ignoresSafeArea()
      .opacity(visible ? 1 : 0)
      .contentShape(Rectangle())
      .onTapGesture {
        if dismissible { dismiss?() }
      }
      .accessibilityHidden(true)
  }
}
```

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

struct SelectContext: @unchecked Sendable {
  var selected: AnyHashable?
  var registering = false
  var select: @MainActor @Sendable (AnyHashable) -> Void = { _ in }
}

extension EnvironmentValues {
  @Entry var select = SelectContext()
}

struct SelectLabelsKey: PreferenceKey {
  static var defaultValue: [AnyHashable: Text] { [:] }

  static func reduce(value: inout [AnyHashable: Text], nextValue: () -> [AnyHashable: Text]) {
    value.merge(nextValue()) { current, _ in current }
  }
}

public enum SelectSize: CaseIterable, Sendable {
  case `default`, sm
}

public struct SelectField<Value: Hashable & Sendable, Content: View>: View {
  public typealias Size = SelectSize

  let selection: Binding<Value?>
  let placeholder: LocalizedStringKey
  let size: Size
  let content: () -> Content

  @State private var open = false
  @State private var labels: [AnyHashable: Text] = [:]
  @Environment(\.isEnabled) private var isEnabled
  @Environment(\.isInvalid) private var invalid
  @Environment(\.colorScheme) private var colorScheme

  public init(
    selection: Binding<Value?>,
    placeholder: LocalizedStringKey = "Select",
    size: Size = .default,
    @ViewBuilder content: @escaping () -> Content
  ) {
    self.selection = selection
    self.placeholder = placeholder
    self.size = size
    self.content = content
  }

  public var body: some View {
    let binding = selection
    let current = binding.wrappedValue.map { AnyHashable($0) }
    let valueText = current.flatMap { labels[$0] }
    let context = SelectContext(
      selected: current,
      select: { value in
        if let value = value.base as? Value { binding.wrappedValue = value }
      }
    )
    ButtonGroupItem(radius: size == .sm ? Radius.md : Radius.lg) { shape in
      Button {
        open = true
      } label: {
        HStack(spacing: 6) {
          (valueText ?? Text(placeholder))
            .font(TextStyle.base.font())
            .tracking(TextStyle.base.letterSpacing)
            .lineLimit(1)
            .foregroundStyle(!isEnabled ? Color.labelQuaternary : valueText == nil ? .labelSecondary : .label)
            .frame(maxWidth: .infinity, alignment: .leading)
          Ph.caretUpDown.regular
            .frame(width: 16, height: 16)
            .foregroundStyle(Color.labelSecondary)
            .accessibilityHidden(true)
        }
        .padding(.horizontal, 12)
        .frame(height: size == .sm ? 36 : 44)
        .background(background, in: shape)
        .overlay {
          if invalid {
            shape.strokeBorder(Color.danger)
          }
        }
        .contentShape(shape)
      }
      .buttonStyle(SelectTriggerStyle())
    }
    .accessibilityHint(Text("Shows options"))
    .background {
      VStack(spacing: 0) { content() }
        .environment(\.select, SelectContext(registering: true))
        .hidden()
        .frame(width: 0, height: 0)
        .clipped()
        .accessibilityHidden(true)
        .allowsHitTesting(false)
    }
    .onPreferenceChange(SelectLabelsKey.self) { value in
      labels = value
    }
    .anchoredPopup(
      isPresented: $open,
      side: .bottom,
      align: .center,
      matchWidth: true,
      minWidth: 144
    ) {
      SelectPanel(content: content)
        .environment(\.select, context)
    }
  }

  private var background: Color {
    if !isEnabled { return .controlDisabled }
    if invalid { return .danger.opacity(colorScheme == .dark ? 0.1 : 0.05) }
    return .control
  }
}

private struct SelectTriggerStyle: ButtonStyle {
  func makeBody(configuration: Configuration) -> some View {
    configuration.label.opacity(configuration.isPressed ? 0.8 : 1)
  }
}

struct SelectPanel<Content: View>: View {
  @ViewBuilder let content: () -> Content

  var body: some View {
    let stack = VStack(alignment: .leading, spacing: 0) {
      content()
    }
    .padding(6)
    ViewThatFits(in: .vertical) {
      stack
      ScrollView { stack }
    }
    .font(TextStyle.base.font())
    .tracking(TextStyle.base.letterSpacing)
    .foregroundStyle(Color.label)
    .popupSurface(radius: Radius.xl)
    .accessibilityElement(children: .contain)
  }
}

public struct SelectItem: View {
  let value: AnyHashable
  let title: Text

  @Environment(\.select) private var select
  @Environment(\.overlayDismiss) private var dismiss

  public init<Value: Hashable & Sendable>(_ title: LocalizedStringKey, value: Value) {
    self.value = AnyHashable(value)
    self.title = Text(title)
  }

  public init<Value: Hashable & Sendable>(verbatim title: String, value: Value) {
    self.value = AnyHashable(value)
    self.title = Text(verbatim: title)
  }

  public var body: some View {
    if select.registering {
      Color.clear
        .frame(width: 0, height: 0)
        .preference(key: SelectLabelsKey.self, value: [value: title])
    } else {
      let selected = select.selected == value
      Button {
        select.select(value)
        dismiss?()
      } label: {
        title
      }
      .buttonStyle(MenuRowStyle(trailing: 32))
      .overlay(alignment: .trailing) {
        if selected {
          Ph.check.regular
            .frame(width: 16, height: 16)
            .foregroundStyle(Color.link)
            .padding(.trailing, 8)
            .accessibilityHidden(true)
        }
      }
      .accessibilityAddTraits(selected ? .isSelected : [])
    }
  }
}

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

  @Environment(\.select) private var select

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

  public var body: some View {
    VStack(alignment: .leading, spacing: 0) { content }
  }
}

public struct SelectLabel: View {
  let title: LocalizedStringKey

  @Environment(\.select) private var select

  public init(_ title: LocalizedStringKey) {
    self.title = title
  }

  public var body: some View {
    if !select.registering {
      Text(title)
        .font(TextStyle.xs.font(weight: .semibold))
        .tracking(TextStyle.xs.letterSpacing)
        .foregroundStyle(Color.labelSecondary)
        .padding(.horizontal, 12)
        .padding(.vertical, 10)
        .frame(maxWidth: .infinity, alignment: .leading)
        .accessibilityAddTraits(.isHeader)
    }
  }
}

public struct SelectSeparator: View {
  @Environment(\.select) private var select

  public init() {}

  public var body: some View {
    if !select.registering {
      Rectangle()
        .fill(Color.separator)
        .frame(height: 1)
        .padding(.vertical, 6)
        .padding(.horizontal, -6)
        .accessibilityHidden(true)
    }
  }
}
```

```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")
```

2. Copy the theme files every view uses:

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

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

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

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

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

val LocalColors = staticCompositionLocalOf { LightColors }

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

    val typography: Typography
        get() = Typography

    val radius: Radius
        get() = Radius

    val shadows: Shadows
        get() = Shadows
}

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

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

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

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

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

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

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

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

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

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

3. Copy the source and every file it uses:

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

import androidx.compose.foundation.background
import androidx.compose.foundation.clickable
import androidx.compose.foundation.gestures.snapping.SnapPosition
import androidx.compose.foundation.gestures.snapping.rememberSnapFlingBehavior
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.PaddingValues
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.wrapContentWidth
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.LazyListState
import androidx.compose.foundation.lazy.itemsIndexed
import androidx.compose.foundation.lazy.rememberLazyListState
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberUpdatedState
import androidx.compose.runtime.snapshotFlow
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.graphicsLayer
import androidx.compose.ui.layout.Layout
import androidx.compose.ui.semantics.ProgressBarRangeInfo
import androidx.compose.ui.semantics.clearAndSetSemantics
import androidx.compose.ui.semantics.contentDescription
import androidx.compose.ui.semantics.progressBarRangeInfo
import androidx.compose.ui.semantics.setProgress
import androidx.compose.ui.semantics.stateDescription
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography
import kotlin.math.PI
import kotlin.math.abs
import kotlin.math.cos
import kotlin.math.max
import kotlin.math.min
import kotlin.math.roundToInt
import kotlin.math.sin
import kotlinx.coroutines.flow.drop
import kotlinx.coroutines.flow.filter

private val WheelItemHeight = 32.dp

private const val RowAngle = (PI / 10.5).toFloat()

private const val MaxAngle = (PI / 2).toFloat()

private const val Perspective = 1200f

private const val FadeAngle = 0.35f

@Immutable
private class WheelEntry(
    val value: String,
    val text: String?,
    val enabled: Boolean,
    val content: @Composable () -> Unit,
)

interface WheelPickerColumnScope {
    fun WheelPickerItem(value: String, enabled: Boolean = true, content: @Composable () -> Unit)

    fun WheelPickerItem(value: String, text: String, enabled: Boolean = true)
}

private class WheelPickerColumnScopeImpl : WheelPickerColumnScope {
    val entries = mutableListOf<WheelEntry>()

    override fun WheelPickerItem(value: String, enabled: Boolean, content: @Composable () -> Unit) {
        entries += WheelEntry(value, null, enabled, content)
    }

    override fun WheelPickerItem(value: String, text: String, enabled: Boolean) {
        entries += WheelEntry(value, text, enabled) {
            BasicText(text, style = LocalContentStyle.current, maxLines = 1, softWrap = false)
        }
    }
}

@Composable
fun WheelPicker(
    modifier: Modifier = Modifier,
    horizontalArrangement: Arrangement.Horizontal = Arrangement.Center,
    content: @Composable RowScope.() -> Unit,
) {
    Box(modifier = modifier, contentAlignment = Alignment.Center) {
        Box(
            modifier = Modifier
                .fillMaxWidth()
                .height(WheelItemHeight)
                .background(EsuissTheme.colors.control, RoundedCornerShape(Radius.lg)),
        )
        Row(
            horizontalArrangement = horizontalArrangement,
            verticalAlignment = Alignment.CenterVertically,
            content = content,
        )
    }
}

@Composable
fun WheelPickerColumn(
    value: String?,
    onValueChange: (String) -> Unit,
    modifier: Modifier = Modifier,
    label: String? = null,
    horizontalAlignment: Alignment.Horizontal = Alignment.CenterHorizontally,
    itemPadding: Dp = 12.dp,
    content: WheelPickerColumnScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val entries = WheelPickerColumnScopeImpl().apply(content).entries.toList()
    val selectedIndex = entries.indexOfFirst { it.value == value }
    val state = rememberLazyListState(initialFirstVisibleItemIndex = selectedIndex.coerceAtLeast(0))
    val fling = rememberSnapFlingBehavior(state, SnapPosition.Center)
    val reducedMotion = formReducedMotion()
    val currentValue by rememberUpdatedState(value)
    val currentEntries by rememberUpdatedState(entries)
    val haptics = rememberHaptics()
    val select: (String) -> Unit = {
        if (it != value) haptics.selection()
        onValueChange(it)
    }
    val currentOnValueChange by rememberUpdatedState(select)

    LaunchedEffect(state) {
        snapshotFlow { state.isScrollInProgress }
            .drop(1)
            .filter { !it }
            .collect {
                val list = currentEntries
                if (list.isEmpty()) return@collect
                val centered = state.wheelPosition().roundToInt().coerceIn(0, list.lastIndex)
                val index = nearestEnabledIndex(list, centered)
                if (index < 0) return@collect
                if (index != centered) {
                    if (reducedMotion) state.scrollToItem(index) else state.animateScrollToItem(index)
                }
                if (list[index].value != currentValue) currentOnValueChange(list[index].value)
            }
    }

    LaunchedEffect(value, entries.size) {
        if (selectedIndex < 0 || state.isScrollInProgress) return@LaunchedEffect
        if (state.layoutInfo.visibleItemsInfo.isEmpty()) {
            state.scrollToItem(selectedIndex)
            return@LaunchedEffect
        }
        if (selectedIndex == state.wheelPosition().roundToInt()) return@LaunchedEffect
        if (reducedMotion) state.scrollToItem(selectedIndex) else state.animateScrollToItem(selectedIndex)
    }

    val itemStyle = Typography.xl.copy(fontFeatureSettings = "tnum")
    Box(modifier = modifier.height(WheelItemHeight * 6.75f)) {
        Layout(
            content = {
                entries.forEach { entry ->
                    Box(Modifier.padding(horizontal = itemPadding)) {
                        CompositionLocalProvider(LocalContentStyle provides itemStyle) { entry.content() }
                    }
                }
            },
        ) { measurables, constraints ->
            val width = measurables.maxOfOrNull { it.maxIntrinsicWidth(WheelItemHeight.roundToPx()) } ?: 0
            layout(width.coerceIn(constraints.minWidth, constraints.maxWidth), 0) {}
        }
        LazyColumn(
            state = state,
            flingBehavior = fling,
            contentPadding = PaddingValues(vertical = WheelItemHeight * 2.875f),
            horizontalAlignment = horizontalAlignment,
            modifier = Modifier
                .matchParentSize()
                .clip(RoundedCornerShape(Radius.lg))
                .clearAndSetSemantics {
                    if (label != null) contentDescription = label
                    if (selectedIndex >= 0) {
                        stateDescription = entries[selectedIndex].text ?: entries[selectedIndex].value
                    }
                    if (entries.isNotEmpty()) {
                        val last = entries.lastIndex
                        progressBarRangeInfo = ProgressBarRangeInfo(
                            selectedIndex.coerceAtLeast(0).toFloat(),
                            0f..last.toFloat().coerceAtLeast(1f),
                            max(0, last - 1),
                        )
                        setProgress { target ->
                            val current = selectedIndex.coerceAtLeast(0)
                            val wanted = target.roundToInt().coerceIn(0, last)
                            val index = when {
                                wanted > current -> enabledIndex(entries, wanted, 1)
                                wanted < current -> enabledIndex(entries, wanted, -1)
                                else -> -1
                            }
                            if (index >= 0) select(entries[index].value)
                            index >= 0
                        }
                    }
                },
        ) {
            itemsIndexed(entries, key = { _, entry -> entry.value }) { index, entry ->
                Box(
                    modifier = Modifier
                        .height(WheelItemHeight)
                        .fillMaxWidth()
                        .clickable(interactionSource = null, indication = null, enabled = entry.enabled) {
                            select(entry.value)
                        }
                        .padding(horizontal = itemPadding),
                    contentAlignment = Alignment.CenterStart,
                ) {
                    Box(
                        modifier = Modifier
                            .align(Alignment.Center)
                            .fillMaxWidth()
                            .wrapContentWidth(horizontalAlignment, unbounded = true)
                            .graphicsLayer {
                                val distance = index - state.wheelPosition()
                                val height = WheelItemHeight.value
                                val radius = height / RowAngle
                                val angle = (distance * RowAngle).coerceIn(-MaxAngle, MaxAngle)
                                val offset = abs(distance)
                                val tone = if (offset < 1f) 1f - offset * 0.45f else 0.55f - (offset - 1f) * 0.06f
                                val fade = min(1f, (MaxAngle - abs(angle)) / FadeAngle)
                                val depth = Perspective / (Perspective + radius - radius * cos(angle))
                                translationY = (radius * sin(angle) - distance * height) * density
                                scaleX = depth
                                scaleY = depth * cos(angle)
                                alpha = max(0f, tone * fade)
                            },
                    ) {
                        CompositionLocalProvider(
                            LocalContentStyle provides itemStyle.copy(
                                color = if (entry.enabled) colors.label else colors.labelTertiary,
                            ),
                            LocalContentColor provides if (entry.enabled) colors.label else colors.labelTertiary,
                        ) {
                            entry.content()
                        }
                    }
                }
            }
        }
    }
}

private fun LazyListState.wheelPosition(): Float {
    val info = layoutInfo
    val first = info.visibleItemsInfo.firstOrNull() ?: return firstVisibleItemIndex.toFloat()
    if (first.size == 0) return first.index.toFloat()
    val center = (info.viewportStartOffset + info.viewportEndOffset) / 2f
    return first.index - (first.offset - center) / first.size - 0.5f
}

private fun enabledIndex(entries: List<WheelEntry>, from: Int, step: Int): Int {
    var index = from
    while (index >= 0 && index < entries.size) {
        if (entries[index].enabled) return index
        index += step
    }
    return -1
}

private fun nearestEnabledIndex(entries: List<WheelEntry>, from: Int): Int {
    for (distance in entries.indices) {
        if (entries.getOrNull(from - distance)?.enabled == true) return from - distance
        if (entries.getOrNull(from + distance)?.enabled == true) return from + distance
    }
    return -1
}
```

```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) }
}
```

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

## Usage

```tsx
import { WheelPicker, WheelPickerColumn, WheelPickerItem } from "@/components/ui/wheel-picker"
```

```tsx
<View className="w-80 rounded-2xl border border-label/5 bg-surface-raised p-4 shadow-md dark:border-label/10">
  <WheelPicker>
    <WheelPickerColumn accessibilityLabel="Fruit" defaultValue="Lemon">
      {fruits.map((fruit) => (
        <WheelPickerItem key={fruit} value={fruit}>
          {fruit}
        </WheelPickerItem>
      ))}
    </WheelPickerColumn>
  </WheelPicker>
</View>
```

Give each column a `defaultValue`, or `value` with `onValueChange`, and fill it with `WheelPickerItem` components that each have a unique `value`. Plain string or number children are wrapped in single-line `Text`.

The value is set when scrolling settles or when an item is pressed. Disabled items are skipped: if the wheel stops on one, it moves to the nearest enabled item.

Combine several columns for compound values such as day, hour and minute, and use `className` on columns and items to control width and alignment. Set `itemHeight` on `WheelPicker` to change the row height.

## Examples

### Disabled items

A time list where booked slots are disabled and skipped.

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

```tsx
import { View } from "react-native"
import { WheelPicker, WheelPickerColumn, WheelPickerItem } from "@/components/ui/wheel-picker"

const slots = Array.from({ length: 11 }, (_, index) => {
  const minutes = 18 * 60 + index * 30
  return `${Math.floor(minutes / 60)}:${String(minutes % 60).padStart(2, "0")}`
})

const booked = new Set(["19:30", "20:00", "20:30"])

const minutes = Array.from({ length: 12 }, (_, step) =>
  String(step * 5).padStart(2, "0")
)

export function WheelPickerDisabledItemsExample() {
  return (
    <View className="w-80 rounded-2xl border border-label/5 bg-surface-raised p-4 shadow-md dark:border-label/10">
      <WheelPicker>
        <WheelPickerColumn
          accessibilityLabel="Reservation time"
          defaultValue="19:00"
        >
          {slots.map((slot) => (
            <WheelPickerItem key={slot} value={slot} disabled={booked.has(slot)}>
              {slot}
            </WheelPickerItem>
          ))}
        </WheelPickerColumn>
      </WheelPicker>
    </View>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct WheelPickerDisabledItemsExample: View {
  var body: some View {
    WheelPickerFrame {
      SlotsDemo()
    }
  }
}

struct WheelPickerFrame<Content: View>: View {
  @ViewBuilder let content: () -> Content

  @Environment(\.colorScheme) private var colorScheme

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
    content()
      .padding(16)
      .frame(width: 320)
      .background(Color.surfaceRaised, in: shape)
      .overlay {
        shape.strokeBorder(Color.label.opacity(colorScheme == .dark ? 0.1 : 0.05))
      }
      .shadow(Shadow.md)
  }
}

let wheelSlots: [String] = (0..<11).map { index in
  let minutes = 18 * 60 + index * 30
  return String(format: "%d:%02d", minutes / 60, minutes % 60)
}

let wheelBooked: Set<String> = ["19:30", "20:00", "20:30"]

struct SlotsDemo: View {
  @State private var slot = "19:00"

  var body: some View {
    WheelPicker {
      WheelPickerColumn(selection: $slot) {
        ForEach(wheelSlots, id: \.self) { item in
          WheelPickerItem(verbatim: item, value: item)
            .disabled(wheelBooked.contains(item))
        }
      }
      .accessibilityLabel(Text("Reservation time"))
    }
  }
}
```

```kotlin
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.WheelPicker
import com.esuiss.ui.components.WheelPickerColumn
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Shadows
import com.esuiss.ui.theme.shadow

@Composable
fun WheelPickerDisabledItemsExample() {
    WheelPickerFrame { WheelPickerDisabledItems() }
}

val wheelPickerSlots = List(11) { index ->
    val minutes = 18 * 60 + index * 30
    "${minutes / 60}:${(minutes % 60).toString().padStart(2, '0')}"
}

val wheelPickerBooked = setOf("19:30", "20:00", "20:30")

@Composable
fun WheelPickerFrame(content: @Composable () -> Unit) {
    val colors = EsuissTheme.colors
    val shape = RoundedCornerShape(Radius.xl2)
    Box(
        Modifier
            .width(320.dp)
            .shadow(Shadows.md, shape)
            .background(colors.surfaceRaised, shape)
            .border(1.dp, colors.label.copy(alpha = if (colors.isDark) 0.1f else 0.05f), shape)
            .padding(16.dp),
    ) {
        content()
    }
}

@Composable
fun WheelPickerDisabledItems() {
    var value by rememberSaveable { mutableStateOf("19:00") }
    WheelPicker(Modifier.fillMaxWidth()) {
        WheelPickerColumn(value, { value = it }, label = "Reservation time") {
            wheelPickerSlots.forEach { WheelPickerItem(it, it, enabled = it !in wheelPickerBooked) }
        }
    }
}
```

### Date time

Controlled day, hour and minute columns combined into one value.

![Preview](https://uim.suiss.app/previews/components-wheel-picker--date-time.light.webp)

```tsx
import * as React from "react"
import { View } from "react-native"
import { Text } from "@/components/ui/text"
import { WheelPicker, WheelPickerColumn, WheelPickerItem } from "@/components/ui/wheel-picker"

function toDayValue(date: Date) {
  return [
    date.getFullYear(),
    String(date.getMonth() + 1).padStart(2, "0"),
    String(date.getDate()).padStart(2, "0"),
  ].join("-")
}

const today = new Date(2026, 9, 4)

const days = Array.from({ length: 15 }, (_, index) => {
  const date = new Date(
    today.getFullYear(),
    today.getMonth(),
    today.getDate() + index - 7
  )
  const label =
    index === 7
      ? "Today"
      : date.toLocaleDateString("en-US", {
          weekday: "short",
          month: "short",
          day: "numeric",
        })
  return { value: toDayValue(date), label }
})

const hours = Array.from({ length: 24 }, (_, hour) =>
  String(hour).padStart(2, "0")
)

const minutes = Array.from({ length: 12 }, (_, step) =>
  String(step * 5).padStart(2, "0")
)

function DateTimeExample() {
  const [day, setDay] = React.useState(toDayValue(today))
  const [hour, setHour] = React.useState("19")
  const [minute, setMinute] = React.useState("30")

  return (
    <View className="gap-3">
      <WheelPicker>
        <WheelPickerColumn
          accessibilityLabel="Day"
          value={day}
          onValueChange={setDay}
          className="grow-[1.6]"
        >
          {days.map(({ value, label }) => (
            <WheelPickerItem key={value} value={value} className="justify-end">
              {label}
            </WheelPickerItem>
          ))}
        </WheelPickerColumn>
        <WheelPickerColumn
          accessibilityLabel="Hour"
          value={hour}
          onValueChange={setHour}
        >
          {hours.map((value) => (
            <WheelPickerItem key={value} value={value}>
              {value}
            </WheelPickerItem>
          ))}
        </WheelPickerColumn>
        <WheelPickerColumn
          accessibilityLabel="Minute"
          value={minute}
          onValueChange={setMinute}
          className="grow"
        >
          {minutes.map((value) => (
            <WheelPickerItem
              key={value}
              value={value}
              className="justify-start"
            >
              {value}
            </WheelPickerItem>
          ))}
        </WheelPickerColumn>
      </WheelPicker>
      <Text className="text-center text-sm text-label-secondary tabular-nums">
        {day} {hour}:{minute}
      </Text>
    </View>
  )
}

export function WheelPickerDateTimeExample() {
  return (
    <View className="w-80 rounded-2xl border border-label/5 bg-surface-raised p-4 shadow-md dark:border-label/10">
      <DateTimeExample />
    </View>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct WheelPickerDateTimeExample: View {
  var body: some View {
    WheelPickerFrame {
      DateTimeDemo()
    }
  }
}

struct WheelPickerFrame<Content: View>: View {
  @ViewBuilder let content: () -> Content

  @Environment(\.colorScheme) private var colorScheme

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
    content()
      .padding(16)
      .frame(width: 320)
      .background(Color.surfaceRaised, in: shape)
      .overlay {
        shape.strokeBorder(Color.label.opacity(colorScheme == .dark ? 0.1 : 0.05))
      }
      .shadow(Shadow.md)
  }
}

struct WheelDay {
  let value: String
  let label: String
}

let wheelDays: [WheelDay] = {
  var calendar = Calendar(identifier: .gregorian)
  calendar.timeZone = TimeZone(identifier: "UTC") ?? .current
  let today = calendar.date(from: DateComponents(year: 2026, month: 10, day: 4)) ?? .now
  let label = Date.FormatStyle(timeZone: calendar.timeZone)
    .weekday(.abbreviated)
    .month(.abbreviated)
    .day()
    .locale(Locale(identifier: "en_US"))
  return (0..<15).map { index in
    let date = calendar.date(byAdding: .day, value: index - 7, to: today) ?? today
    let parts = calendar.dateComponents([.year, .month, .day], from: date)
    let value = String(format: "%04d-%02d-%02d", parts.year ?? 0, parts.month ?? 0, parts.day ?? 0)
    return WheelDay(value: value, label: index == 7 ? "Today" : date.formatted(label))
  }
}()

let wheelHours = (0..<24).map { String(format: "%02d", $0) }

let wheelMinutes = (0..<12).map { String(format: "%02d", $0 * 5) }

struct DateTimeDemo: View {
  @State private var day = "2026-10-04"
  @State private var hour = "19"
  @State private var minute = "30"

  var body: some View {
    VStack(spacing: 12) {
      WheelPicker {
        WheelPickerColumn(selection: $day, alignment: .trailing) {
          ForEach(wheelDays, id: \.value) { item in
            WheelPickerItem(verbatim: item.label, value: item.value)
          }
        }
        .frame(minWidth: 150, maxWidth: .infinity, alignment: .trailing)
        .accessibilityLabel(Text("Day"))
        WheelPickerColumn(selection: $hour) {
          ForEach(wheelHours, id: \.self) { item in
            WheelPickerItem(verbatim: item, value: item)
          }
        }
        .accessibilityLabel(Text("Hour"))
        WheelPickerColumn(selection: $minute, alignment: .leading) {
          ForEach(wheelMinutes, id: \.self) { item in
            WheelPickerItem(verbatim: item, value: item)
          }
        }
        .frame(maxWidth: .infinity, alignment: .leading)
        .accessibilityLabel(Text("Minute"))
      }
      Text(verbatim: "\(day) \(hour):\(minute)")
        .textStyle(.sm)
        .monospacedDigit()
        .foregroundStyle(Color.labelSecondary)
        .multilineTextAlignment(.center)
        .frame(maxWidth: .infinity)
    }
  }
}
```

```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.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.text.style.TextAlign
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Text
import com.esuiss.ui.components.WheelPicker
import com.esuiss.ui.components.WheelPickerColumn
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Shadows
import com.esuiss.ui.theme.Typography
import com.esuiss.ui.theme.shadow
import java.text.SimpleDateFormat
import java.util.Calendar
import java.util.Locale

@Composable
fun WheelPickerDateTimeExample() {
    WheelPickerFrame { WheelPickerDateTime() }
}

class WheelPickerDay(val value: String, val label: String)

val wheelPickerDays: List<WheelPickerDay> = run {
    val format = SimpleDateFormat("EEE, MMM d", Locale.US)
    val key = SimpleDateFormat("yyyy-MM-dd", Locale.US)
    List(15) { index ->
        val calendar = Calendar.getInstance(Locale.US)
        calendar.clear()
        calendar.set(2026, Calendar.OCTOBER, 4 + index - 7)
        WheelPickerDay(key.format(calendar.time), if (index == 7) "Today" else format.format(calendar.time))
    }
}

val wheelPickerHours = List(24) { it.toString().padStart(2, '0') }

val wheelPickerMinutes = List(12) { (it * 5).toString().padStart(2, '0') }

@Composable
fun WheelPickerFrame(content: @Composable () -> Unit) {
    val colors = EsuissTheme.colors
    val shape = RoundedCornerShape(Radius.xl2)
    Box(
        Modifier
            .width(320.dp)
            .shadow(Shadows.md, shape)
            .background(colors.surfaceRaised, shape)
            .border(1.dp, colors.label.copy(alpha = if (colors.isDark) 0.1f else 0.05f), shape)
            .padding(16.dp),
    ) {
        content()
    }
}

@Composable
fun WheelPickerDateTime() {
    var day by rememberSaveable { mutableStateOf(wheelPickerDays[7].value) }
    var hour by rememberSaveable { mutableStateOf("19") }
    var minute by rememberSaveable { mutableStateOf("30") }
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        WheelPicker(Modifier.fillMaxWidth()) {
            WheelPickerColumn(
                day,
                { day = it },
                Modifier.weight(1.6f),
                label = "Day",
                horizontalAlignment = Alignment.End,
            ) {
                wheelPickerDays.forEach { WheelPickerItem(it.value, it.label) }
            }
            WheelPickerColumn(hour, { hour = it }, label = "Hour") {
                wheelPickerHours.forEach { WheelPickerItem(it, it) }
            }
            WheelPickerColumn(
                minute,
                { minute = it },
                Modifier.weight(1f),
                label = "Minute",
                horizontalAlignment = Alignment.Start,
            ) {
                wheelPickerMinutes.forEach { WheelPickerItem(it, it) }
            }
        }
        Text(
            "$day $hour:$minute",
            modifier = Modifier.fillMaxWidth(),
            style = Typography.sm.copy(fontFeatureSettings = "tnum"),
            color = EsuissTheme.colors.labelSecondary,
            textAlign = TextAlign.Center,
        )
    }
}
```

## API Reference

### WheelPicker

Root row of columns with the selection highlight.

### WheelPickerColumn

Snapping scroll column that holds one value.

### WheelPickerItem

Single row in a column.

## Accessibility

- Each column has the `adjustable` role and announces the selected item's label as its value.
- VoiceOver and TalkBack users swipe up or down to move to the next or previous enabled item.
- Give each column an `accessibilityLabel`, such as `Hour` or `Minute`.
- The highlight band is hidden from screen readers.

## Notes

- A selection haptic plays when the value changes, if a haptics adapter is provided through the haptics context.
- The highlight uses `bg-control`; items use `text-xl text-label` with tabular numbers and `text-label-tertiary` when disabled.
- Light and dark colors follow the system appearance.