# Message

A chat message row that lays out an avatar, a group of bubbles, and an optional header and footer.

Message 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/message

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

```tsx
import { Avatar, AvatarFallback } from "@/components/ui/avatar"
import { Bubble, BubbleContent } from "@/components/ui/bubble"
import { Message, MessageAvatar, MessageContent } from "@/components/ui/message"

export function MessageExample() {
  return (
    <Message align="start">
      <MessageAvatar>
        <Avatar>
          <AvatarFallback>MK</AvatarFallback>
        </Avatar>
      </MessageAvatar>
      <MessageContent>
        <Bubble variant="muted">
          <BubbleContent>Are we still on for lunch tomorrow?</BubbleContent>
        </Bubble>
      </MessageContent>
    </Message>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct MessageExample: View {
  var body: some View {
    Message {
      MessageAvatar {
        Avatar { AvatarFallback("MK") }
      }
      MessageContent {
        Bubble(variant: .muted) {
          BubbleContent("Are we still on for lunch tomorrow?")
        }
      }
    }
  }
}
```

```kotlin
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import com.esuiss.ui.components.Avatar
import com.esuiss.ui.components.AvatarFallback
import com.esuiss.ui.components.Bubble
import com.esuiss.ui.components.BubbleContent
import com.esuiss.ui.components.BubbleVariant
import com.esuiss.ui.components.Message
import com.esuiss.ui.components.MessageAvatar
import com.esuiss.ui.components.MessageContent

@Composable
fun MessageInitials(text: String) {
    MessageAvatar {
        Avatar(fallback = { AvatarFallback(text) })
    }
}

@Composable
fun MessageDefault() {
    Message(Modifier.fillMaxWidth()) {
        MessageInitials("MK")
        MessageContent {
            Bubble(variant = BubbleVariant.Muted) {
                BubbleContent("Are we still on for lunch tomorrow?")
            }
        }
    }
}
```

`Message` is a horizontal `View` that places an avatar next to a column of bubbles. Its `align` prop puts the row on the leading (`start`) or trailing (`end`) side and passes the alignment to any `Bubble` inside through context.

`MessageGroup` stacks several messages into a conversation. `MessageHeader` and `MessageFooter` hold small secondary text, such as a sender name or a timestamp.

## Installation

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

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

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

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

### Manual

**Uniwind**

1. Install the dependencies:

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

2. Add the pieces it builds on: [Bubble](/docs/components/bubble), [Icon](/docs/components/icon), [Text](/docs/components/text).

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

```tsx title="uniwind/components/ui/message.tsx"
import { cn } from "cn"
import * as React from "react"
import { View, type ViewProps } from "react-native"
import { BubbleAlignContext, BubbleGroup } from "@/components/ui/bubble"
import { IconClassContext } from "@/components/ui/icon"
import { Text, TextClassContext } from "@/components/ui/text"

type MessageAlign = "start" | "end"

const MessageContext = React.createContext<{
  align: MessageAlign
  footer: boolean
}>({ align: "start", footer: false })

function wrapText(children: React.ReactNode) {
  const output: React.ReactNode[] = []
  let run: (string | number)[] = []
  const flush = () => {
    if (run.length === 0) return
    output.push(<Text key={`text-${output.length}`}>{run.join("")}</Text>)
    run = []
  }
  for (const child of React.Children.toArray(children)) {
    if (typeof child === "string" || typeof child === "number") {
      run.push(child)
    } else {
      flush()
      output.push(child)
    }
  }
  flush()
  return output
}

function hasFooter(children: React.ReactNode) {
  let found = false
  React.Children.forEach(children, (child) => {
    if (
      !React.isValidElement<{ children?: React.ReactNode }>(child) ||
      child.type !== MessageContent
    ) {
      return
    }
    React.Children.forEach(child.props.children, (part) => {
      if (React.isValidElement(part) && part.type === MessageFooter) {
        found = true
      }
    })
  })
  return found
}

function MessageGroup({ className, ...props }: ViewProps) {
  return <View className={cn("min-w-0 flex-col gap-2", className)} {...props} />
}

function Message({
  className,
  align = "start",
  children,
  ...props
}: ViewProps & { align?: MessageAlign }) {
  const footer = hasFooter(children)
  const context = React.useMemo(() => ({ align, footer }), [align, footer])
  return (
    <MessageContext.Provider value={context}>
      <BubbleAlignContext.Provider value={align}>
        <View
          className={cn(
            "relative w-full min-w-0 gap-2",
            align === "end" ? "flex-row-reverse" : "flex-row",
            className
          )}
          {...props}
        >
          {children}
        </View>
      </BubbleAlignContext.Provider>
    </MessageContext.Provider>
  )
}

function MessageAvatar({ className, ...props }: ViewProps) {
  const { footer } = React.useContext(MessageContext)
  return (
    <View
      className={cn(
        "min-w-8 shrink-0 items-center justify-center self-end overflow-hidden rounded-full bg-surface-secondary",
        footer && "-translate-y-8",
        className
      )}
      {...props}
    />
  )
}

function MessageContent({
  className,
  ...props
}: React.ComponentProps<typeof BubbleGroup>) {
  const { align } = React.useContext(MessageContext)
  return (
    <BubbleGroup
      className={cn(
        "min-w-0 flex-1 gap-2.5",
        align === "end" ? "items-end" : "items-start",
        className
      )}
      {...props}
    />
  )
}

function MessageHeader({ className, children, ...props }: ViewProps) {
  return (
    <TextClassContext.Provider value="text-xs text-label-secondary">
      <IconClassContext.Provider value="size-3.5">
        <View
          className={cn(
            "min-w-0 max-w-full flex-row items-center px-3.5",
            className
          )}
          {...props}
        >
          {wrapText(children)}
        </View>
      </IconClassContext.Provider>
    </TextClassContext.Provider>
  )
}

function MessageFooter({ className, children, ...props }: ViewProps) {
  const { align } = React.useContext(MessageContext)
  return (
    <TextClassContext.Provider value="text-xs text-label-secondary">
      <IconClassContext.Provider value="size-3.5">
        <View
          className={cn(
            "min-w-0 max-w-full flex-row items-center px-3.5",
            align === "end" && "justify-end",
            className
          )}
          {...props}
        >
          {wrapText(children)}
        </View>
      </IconClassContext.Provider>
    </TextClassContext.Provider>
  )
}

export {
  Message,
  MessageAvatar,
  MessageContent,
  MessageFooter,
  MessageGroup,
  MessageHeader,
}
```

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: [Bubble](/docs/components/bubble), [Icon](/docs/components/icon), [Text](/docs/components/text).

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

```tsx title="nativewind/components/ui/message.tsx"
import { cn } from "cn"
import * as React from "react"
import { View, type ViewProps } from "react-native"
import { BubbleAlignContext, BubbleGroup } from "@/components/ui/bubble"
import { IconClassContext } from "@/components/ui/icon"
import { Text, TextClassContext } from "@/components/ui/text"

type MessageAlign = "start" | "end"

const MessageContext = React.createContext<{
  align: MessageAlign
  footer: boolean
}>({ align: "start", footer: false })

function wrapText(children: React.ReactNode) {
  const output: React.ReactNode[] = []
  let run: (string | number)[] = []
  const flush = () => {
    if (run.length === 0) return
    output.push(<Text key={`text-${output.length}`}>{run.join("")}</Text>)
    run = []
  }
  for (const child of React.Children.toArray(children)) {
    if (typeof child === "string" || typeof child === "number") {
      run.push(child)
    } else {
      flush()
      output.push(child)
    }
  }
  flush()
  return output
}

function hasFooter(children: React.ReactNode) {
  let found = false
  React.Children.forEach(children, (child) => {
    if (
      !React.isValidElement<{ children?: React.ReactNode }>(child) ||
      child.type !== MessageContent
    ) {
      return
    }
    React.Children.forEach(child.props.children, (part) => {
      if (React.isValidElement(part) && part.type === MessageFooter) {
        found = true
      }
    })
  })
  return found
}

function MessageGroup({ className, ...props }: ViewProps) {
  return <View className={cn("min-w-0 flex-col gap-2", className)} {...props} />
}

function Message({
  className,
  align = "start",
  children,
  ...props
}: ViewProps & { align?: MessageAlign }) {
  const footer = hasFooter(children)
  const context = React.useMemo(() => ({ align, footer }), [align, footer])
  return (
    <MessageContext.Provider value={context}>
      <BubbleAlignContext.Provider value={align}>
        <View
          className={cn(
            "relative w-full min-w-0 gap-2",
            align === "end" ? "flex-row-reverse" : "flex-row",
            className
          )}
          {...props}
        >
          {children}
        </View>
      </BubbleAlignContext.Provider>
    </MessageContext.Provider>
  )
}

function MessageAvatar({ className, ...props }: ViewProps) {
  const { footer } = React.useContext(MessageContext)
  return (
    <View
      className={cn(
        "min-w-8 shrink-0 items-center justify-center self-end overflow-hidden rounded-full bg-surface-secondary",
        footer && "-translate-y-8",
        className
      )}
      {...props}
    />
  )
}

function MessageContent({
  className,
  ...props
}: React.ComponentProps<typeof BubbleGroup>) {
  const { align } = React.useContext(MessageContext)
  return (
    <BubbleGroup
      className={cn(
        "min-w-0 flex-1 gap-2.5",
        align === "end" ? "items-end" : "items-start",
        className
      )}
      {...props}
    />
  )
}

function MessageHeader({ className, children, ...props }: ViewProps) {
  return (
    <TextClassContext.Provider value="text-xs text-label-secondary">
      <IconClassContext.Provider value="size-3.5">
        <View
          className={cn(
            "min-w-0 max-w-full flex-row items-center px-3.5",
            className
          )}
          {...props}
        >
          {wrapText(children)}
        </View>
      </IconClassContext.Provider>
    </TextClassContext.Provider>
  )
}

function MessageFooter({ className, children, ...props }: ViewProps) {
  const { align } = React.useContext(MessageContext)
  return (
    <TextClassContext.Provider value="text-xs text-label-secondary">
      <IconClassContext.Provider value="size-3.5">
        <View
          className={cn(
            "min-w-0 max-w-full flex-row items-center px-3.5",
            align === "end" && "justify-end",
            className
          )}
          {...props}
        >
          {wrapText(children)}
        </View>
      </IconClassContext.Provider>
    </TextClassContext.Provider>
  )
}

export {
  Message,
  MessageAvatar,
  MessageContent,
  MessageFooter,
  MessageGroup,
  MessageHeader,
}
```

4. Update the import paths to match your project.

**StyleSheet**

1. Add the pieces it builds on: [Bubble](/docs/components/bubble), [Icon](/docs/components/icon), [Text](/docs/components/text).

2. Copy the source into `components/ui/message.tsx`:

```tsx title="stylesheet/components/ui/message.tsx"
import * as React from "react"
import { StyleSheet, View, type ViewProps } from "react-native"
import { BubbleAlignContext, BubbleGroup } from "@/components/ui/bubble"
import { IconSizeContext } from "@/components/ui/icon"
import { Text, TextStyleContext } from "@/components/ui/text"
import { fontSize, radius, useTheme } from "@/components/ui/theme"

type MessageAlign = "start" | "end"

const MessageContext = React.createContext<{
  align: MessageAlign
  footer: boolean
}>({ align: "start", footer: false })

const styles = StyleSheet.create({
  group: { minWidth: 0, flexDirection: "column", gap: 8 },
  message: { position: "relative", width: "100%", minWidth: 0, gap: 8 },
  avatar: {
    minWidth: 32,
    flexShrink: 0,
    alignItems: "center",
    justifyContent: "center",
    alignSelf: "flex-end",
    overflow: "hidden",
    borderRadius: radius.full,
  },
  content: { minWidth: 0, flex: 1, gap: 10 },
  meta: {
    minWidth: 0,
    maxWidth: "100%",
    flexDirection: "row",
    alignItems: "center",
    paddingHorizontal: 14,
  },
})

function wrapText(children: React.ReactNode) {
  const output: React.ReactNode[] = []
  let run: (string | number)[] = []
  const flush = () => {
    if (run.length === 0) return
    output.push(<Text key={`text-${output.length}`}>{run.join("")}</Text>)
    run = []
  }
  for (const child of React.Children.toArray(children)) {
    if (typeof child === "string" || typeof child === "number") {
      run.push(child)
    } else {
      flush()
      output.push(child)
    }
  }
  flush()
  return output
}

function hasFooter(children: React.ReactNode) {
  let found = false
  React.Children.forEach(children, (child) => {
    if (
      !React.isValidElement<{ children?: React.ReactNode }>(child) ||
      child.type !== MessageContent
    ) {
      return
    }
    React.Children.forEach(child.props.children, (part) => {
      if (React.isValidElement(part) && part.type === MessageFooter) {
        found = true
      }
    })
  })
  return found
}

function MessageGroup({ style, ...props }: ViewProps) {
  return <View style={[styles.group, style]} {...props} />
}

function Message({
  style,
  align = "start",
  children,
  ...props
}: ViewProps & { align?: MessageAlign }) {
  const footer = hasFooter(children)
  const context = React.useMemo(() => ({ align, footer }), [align, footer])
  return (
    <MessageContext.Provider value={context}>
      <BubbleAlignContext.Provider value={align}>
        <View
          style={[
            styles.message,
            { flexDirection: align === "end" ? "row-reverse" : "row" },
            style,
          ]}
          {...props}
        >
          {children}
        </View>
      </BubbleAlignContext.Provider>
    </MessageContext.Provider>
  )
}

function MessageAvatar({ style, ...props }: ViewProps) {
  const { colors } = useTheme()
  const { footer } = React.useContext(MessageContext)
  return (
    <View
      style={[
        styles.avatar,
        { backgroundColor: colors.surfaceSecondary },
        footer && { transform: [{ translateY: -32 }] },
        style,
      ]}
      {...props}
    />
  )
}

function MessageContent({
  style,
  ...props
}: React.ComponentProps<typeof BubbleGroup>) {
  const { align } = React.useContext(MessageContext)
  return (
    <BubbleGroup
      style={[
        styles.content,
        { alignItems: align === "end" ? "flex-end" : "flex-start" },
        style,
      ]}
      {...props}
    />
  )
}

function MessageMeta({
  style,
  children,
  end,
  ...props
}: ViewProps & { end?: boolean }) {
  const { colors } = useTheme()
  return (
    <TextStyleContext.Provider
      value={{ ...fontSize.xs, color: colors.labelSecondary }}
    >
      <IconSizeContext.Provider value={14}>
        <View
          style={[styles.meta, end && { justifyContent: "flex-end" }, style]}
          {...props}
        >
          {wrapText(children)}
        </View>
      </IconSizeContext.Provider>
    </TextStyleContext.Provider>
  )
}

function MessageHeader(props: ViewProps) {
  return <MessageMeta {...props} />
}

function MessageFooter(props: ViewProps) {
  const { align } = React.useContext(MessageContext)
  return <MessageMeta end={align === "end"} {...props} />
}

export {
  Message,
  MessageAvatar,
  MessageContent,
  MessageFooter,
  MessageGroup,
  MessageHeader,
}
```

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/Message.swift"
import SwiftUI

public typealias MessageAlign = BubbleAlign

struct MessageGhostKey: PreferenceKey {
  static let defaultValue = false

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

struct MessageFooterKey: PreferenceKey {
  static let defaultValue: CGFloat = 0

  static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
    value = max(value, nextValue())
  }
}

struct MessageAvatarKey: LayoutValueKey {
  static let defaultValue = false
}

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

  public init(spacing: CGFloat = 8, @ViewBuilder content: () -> Content) {
    self.spacing = spacing
    self.content = content()
  }

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

public struct Message<Content: View>: View {
  public typealias Align = MessageAlign

  let align: Align
  let content: Content

  @State private var footer: CGFloat = 0
  @State private var ghost = false

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

  public var body: some View {
    MessageLayout(align: align, lift: footer > 0 ? footer + 10 : 0) {
      content
    }
    .environment(\.messageAlign, align)
    .environment(\.messageGhost, ghost)
    .onPreferenceChange(MessageFooterKey.self) { footer = $0 }
    .onPreferenceChange(MessageGhostKey.self) { ghost = $0 }
    .transformPreference(MessageFooterKey.self) { $0 = 0 }
    .transformPreference(MessageGhostKey.self) { $0 = false }
    .frame(maxWidth: .infinity)
    .accessibilityElement(children: .contain)
  }
}

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

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

  public var body: some View {
    content
      .frame(minWidth: 32, minHeight: 32)
      .background(Color.surfaceSecondary, in: Circle())
      .clipShape(Circle())
      .fixedSize()
      .layoutValue(key: MessageAvatarKey.self, value: true)
  }
}

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

  @Environment(\.messageAlign) private var align

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

  public var body: some View {
    let end = align == .end
    VStack(alignment: end ? .trailing : .leading, spacing: 10) {
      content
    }
    .frame(maxWidth: .infinity, alignment: end ? .trailing : .leading)
    .modifier(BubbleRunScope())
  }
}

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

  @Environment(\.messageAlign) private var align
  @Environment(\.messageGhost) private var ghost

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

  public var body: some View {
    HStack(spacing: 4) {
      content
    }
    .scaledFont(.xs)
    .lineLimit(1)
    .foregroundStyle(Color.labelSecondary)
    .padding(.horizontal, ghost ? 0 : 14)
    .accessibilityElement(children: .combine)
  }
}

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

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

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

  @Environment(\.messageAlign) private var align
  @Environment(\.messageGhost) private var ghost

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

  public var body: some View {
    HStack(spacing: 4) {
      content
    }
    .scaledFont(.xs)
    .lineLimit(1)
    .foregroundStyle(Color.labelSecondary)
    .padding(.horizontal, ghost ? 0 : 14)
    .background {
      GeometryReader { proxy in
        Color.clear.preference(key: MessageFooterKey.self, value: proxy.size.height)
      }
    }
    .accessibilityElement(children: .combine)
  }
}

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

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

struct MessageLayout: Layout {
  let align: MessageAlign
  let lift: CGFloat

  private let spacing: CGFloat = 8

  private func avatarWidth(_ subviews: Subviews) -> CGFloat {
    subviews.filter { $0[MessageAvatarKey.self] }.map { $0.sizeThatFits(.unspecified).width }.max() ?? 0
  }

  private func remaining(_ proposal: ProposedViewSize, subviews: Subviews) -> CGFloat? {
    let avatar = avatarWidth(subviews)
    return proposal.width.map { max(0, $0 - (avatar > 0 ? avatar + spacing : 0)) }
  }

  func sizeThatFits(proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) -> CGSize {
    let width = remaining(proposal, subviews: subviews)
    var height: CGFloat = 0
    var contentWidth: CGFloat = 0
    for subview in subviews {
      if subview[MessageAvatarKey.self] {
        height = max(height, subview.sizeThatFits(.unspecified).height)
      } else {
        let size = subview.sizeThatFits(ProposedViewSize(width: width, height: nil))
        height = max(height, size.height)
        contentWidth = max(contentWidth, size.width)
      }
    }
    let avatar = avatarWidth(subviews)
    return CGSize(width: proposal.width ?? contentWidth + (avatar > 0 ? avatar + spacing : 0), height: height)
  }

  func placeSubviews(in bounds: CGRect, proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) {
    let avatar = avatarWidth(subviews)
    let offset = avatar > 0 ? avatar + spacing : 0
    let width = max(0, bounds.width - offset)
    for subview in subviews {
      if subview[MessageAvatarKey.self] {
        let size = subview.sizeThatFits(.unspecified)
        let x = align == .end ? bounds.maxX - size.width : bounds.minX
        let y = max(bounds.minY, bounds.maxY - size.height - lift)
        subview.place(at: CGPoint(x: x, y: y), proposal: ProposedViewSize(size))
      } else {
        let x = align == .end ? bounds.minX : bounds.minX + offset
        subview.place(at: CGPoint(x: x, y: bounds.minY), proposal: ProposedViewSize(width: width, height: nil))
      }
    }
  }
}

extension EnvironmentValues {
  @Entry var messageAlign: MessageAlign? = nil
  @Entry var messageGhost = false
}
```

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

public enum BubbleVariant: CaseIterable, Sendable {
  case `default`, secondary, muted, tinted, outline, ghost, destructive

  var hasTail: Bool {
    self != .ghost && self != .outline
  }
}

public enum BubbleAlign: CaseIterable, Sendable {
  case start, end
}

public enum BubbleReactionsSide: CaseIterable, Sendable {
  case top, bottom
}

struct BubbleRunEntry: Equatable {
  let id: UUID
  let align: BubbleAlign
  let tail: Bool
}

enum BubbleRun {
  static func tails(_ entries: [BubbleRunEntry]) -> Set<UUID> {
    var result = Set<UUID>()
    for (index, entry) in entries.enumerated() where entry.tail {
      let next = index + 1 < entries.count ? entries[index + 1] : nil
      if next?.align != entry.align {
        result.insert(entry.id)
      }
    }
    return result
  }
}

struct BubbleRunKey: PreferenceKey {
  static var defaultValue: [BubbleRunEntry] { [] }

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

struct BubbleRunScope: ViewModifier {
  @State private var tails: Set<UUID>?

  func body(content: Content) -> some View {
    content
      .environment(\.bubbleTails, tails)
      .onPreferenceChange(BubbleRunKey.self) { entries in
        tails = BubbleRun.tails(entries)
      }
      .transformPreference(BubbleRunKey.self) { $0 = [] }
  }
}

struct BubbleStyle: Sendable {
  var variant: BubbleVariant = .default
  var align: BubbleAlign = .start
  var tail = false
}

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

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

  public var body: some View {
    VStack(alignment: .leading, spacing: 8) {
      content
    }
    .frame(maxWidth: .infinity, alignment: .leading)
    .modifier(BubbleRunScope())
  }
}

public struct Bubble<Content: View>: View {
  public typealias Variant = BubbleVariant
  public typealias Align = BubbleAlign

  let variant: Variant
  let align: Align
  let onLongPress: (() -> Void)?
  let content: Content

  @State private var id = UUID()
  @Environment(\.messageAlign) private var messageAlign
  @Environment(\.bubbleTails) private var tails

  public init(
    variant: Variant = .default,
    align: Align = .start,
    onLongPress: (() -> Void)? = nil,
    @ViewBuilder content: () -> Content
  ) {
    self.variant = variant
    self.align = align
    self.onLongPress = onLongPress
    self.content = content()
  }

  public var body: some View {
    let resolved: Align = messageAlign == .end ? .end : align
    let tail = variant.hasTail && (tails.map { $0.contains(id) } ?? true)
    BubbleLayout(align: resolved, fraction: variant == .ghost ? 1 : 0.8) {
      content
    }
    .environment(\.bubbleStyle, BubbleStyle(variant: variant, align: resolved, tail: tail))
    .modifier(BubbleLongPress(action: onLongPress))
    .frame(maxWidth: .infinity, alignment: resolved == .end ? .trailing : .leading)
    .preference(key: BubbleRunKey.self, value: [BubbleRunEntry(id: id, align: resolved, tail: variant.hasTail)])
    .preference(key: MessageGhostKey.self, value: variant == .ghost)
  }
}

private struct BubbleLongPress: ViewModifier {
  let action: (() -> Void)?

  func body(content: Content) -> some View {
    if let action {
      content
        .contentShape(Rectangle())
        .onLongPressGesture(minimumDuration: 0.5, maximumDistance: 10, perform: action)
        .accessibilityAction(named: Text("Show actions"), action)
    } else {
      content
    }
  }
}

public struct BubbleContent<Content: View>: View {
  let action: (() -> Void)?
  let content: Content

  @Environment(\.bubbleStyle) private var style

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

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

  public var body: some View {
    if let action {
      Button(action: action) {
        content
      }
      .buttonStyle(BubbleContentButtonStyle(style: style))
    } else {
      BubbleContentBody(style: style, pressed: false) {
        content
      }
    }
  }
}

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

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

private struct BubbleContentButtonStyle: ButtonStyle {
  let style: BubbleStyle

  func makeBody(configuration: Configuration) -> some View {
    BubbleContentBody(style: style, pressed: configuration.isPressed) {
      configuration.label
    }
  }
}

private struct BubbleContentBody<Content: View>: View {
  let style: BubbleStyle
  let pressed: Bool
  let content: Content

  @Environment(\.screenBackground) private var surface

  init(style: BubbleStyle, pressed: Bool, @ViewBuilder content: () -> Content) {
    self.style = style
    self.pressed = pressed
    self.content = content()
  }

  var body: some View {
    let ghost = style.variant == .ghost
    let shape = BubbleShape(tail: style.tail, mirrored: style.align == .end)
    content
      .scaledTextStyle(.base)
      .foregroundStyle(foreground)
      .multilineTextAlignment(.leading)
      .fixedSize(horizontal: false, vertical: true)
      .padding(.horizontal, ghost ? 0 : 15)
      .padding(.vertical, ghost ? 0 : 7)
      .background {
        if ghost {
          Rectangle().fill(pressed ? Color.itemPressed : .clear)
        } else {
          shape.fill(background)
        }
      }
      .overlay {
        if style.variant == .outline {
          RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
            .strokeBorder(Color.separator, lineWidth: 1)
        }
      }
      .contentShape(shape)
  }

  private var foreground: Color {
    switch style.variant {
    case .default: .onAccent
    case .destructive: .danger
    case .secondary, .muted, .tinted, .outline, .ghost: .label
    }
  }

  private var background: Color {
    switch style.variant {
    case .default: pressed ? .accentPressed : .accent
    case .secondary: pressed ? .controlPressed : .control
    case .muted: pressed ? .surfaceTertiary : .surfaceSecondary
    case .tinted: pressed ? .accentSurfacePressed : .accentSurface
    case .outline: pressed ? .control : surface
    case .ghost: pressed ? .itemPressed : .clear
    case .destructive: pressed ? .dangerSurfacePressed : .dangerSurface
    }
  }
}

struct BubbleShape: Shape {
  let tail: Bool
  let mirrored: Bool

  func path(in rect: CGRect) -> Path {
    let body = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous).path(in: rect)
    guard tail else { return body }
    let originX = mirrored ? rect.maxX + 6.9 - 20 : rect.minX - 6.9
    let originY = rect.maxY - 20
    let points = BubbleShape.tailPoints.map { point in
      CGPoint(x: originX + (mirrored ? 20 - point.x : point.x), y: originY + point.y)
    }
    var tailPath = Path()
    tailPath.addLines(points)
    tailPath.closeSubpath()
    return body.union(tailPath)
  }

  static let tailPoints: [CGPoint] = {
    var points = [CGPoint(x: 7, y: 0), CGPoint(x: 20, y: 0), CGPoint(x: 20, y: 4)]
    for step in 1...12 {
      let angle = Double(step) / 12 * .pi / 2
      points.append(CGPoint(x: 4 + 16 * cos(angle), y: 4 + 16 * sin(angle)))
    }
    points.append(CGPoint(x: 0, y: 20))
    points.append(CGPoint(x: 0, y: 19.54))
    let start = atan2(9.54, 3.0)
    for step in 1...12 {
      let angle = start * (1 - Double(step) / 12)
      points.append(CGPoint(x: -3 + 10 * cos(angle), y: 10 + 10 * sin(angle)))
    }
    return points
  }()
}

struct BubbleReactionsPlacement: Equatable, Sendable {
  let side: BubbleReactionsSide
  let align: BubbleAlign
}

struct BubbleReactionsKey: LayoutValueKey {
  static let defaultValue: BubbleReactionsPlacement? = nil
}

public struct BubbleReactions<Content: View>: View {
  let side: BubbleReactionsSide
  let align: BubbleAlign
  let content: Content

  @Environment(\.screenBackground) private var surface

  public init(
    side: BubbleReactionsSide = .bottom,
    align: BubbleAlign = .end,
    @ViewBuilder content: () -> Content
  ) {
    self.side = side
    self.align = align
    self.content = content()
  }

  public var body: some View {
    HStack(spacing: 4) {
      content
    }
    .scaledFont(.sm)
    .lineLimit(1)
    .fixedSize()
    .foregroundStyle(Color.label)
    .padding(.horizontal, 6)
    .padding(.vertical, 2)
    .background(Color.surfaceSecondary, in: Capsule())
    .background {
      Capsule().fill(surface).padding(-3)
    }
    .accessibilityElement(children: .combine)
    .layoutValue(key: BubbleReactionsKey.self, value: BubbleReactionsPlacement(side: side, align: align))
  }
}

extension BubbleReactions where Content == Text {
  public init(_ text: LocalizedStringKey, side: BubbleReactionsSide = .bottom, align: BubbleAlign = .end) {
    self.init(side: side, align: align) { Text(text) }
  }

  public init(verbatim text: String, side: BubbleReactionsSide = .bottom, align: BubbleAlign = .end) {
    self.init(side: side, align: align) { Text(verbatim: text) }
  }
}

struct BubbleLayout: Layout {
  let align: BubbleAlign
  let fraction: CGFloat

  private let spacing: CGFloat = 4
  private let reactionMargin: CGFloat = 20

  private func measure(_ proposal: ProposedViewSize, subviews: Subviews) -> (sizes: [CGSize], width: CGFloat, height: CGFloat) {
    let limit = proposal.width.map { $0 * fraction }
    var sizes: [CGSize] = []
    var width: CGFloat = 0
    var height: CGFloat = 0
    var count = 0
    for subview in subviews {
      if subview[BubbleReactionsKey.self] != nil {
        sizes.append(subview.sizeThatFits(.unspecified))
        continue
      }
      let size = subview.sizeThatFits(ProposedViewSize(width: limit, height: nil))
      sizes.append(size)
      width = max(width, size.width)
      height += size.height + (count > 0 ? spacing : 0)
      count += 1
    }
    return (sizes, width, height)
  }

  private func margins(_ subviews: Subviews) -> (top: CGFloat, bottom: CGFloat) {
    let sides = subviews.compactMap { $0[BubbleReactionsKey.self]?.side }
    return (sides.contains(.top) ? reactionMargin : 0, sides.contains(.bottom) ? reactionMargin : 0)
  }

  func sizeThatFits(proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) -> CGSize {
    let measured = measure(proposal, subviews: subviews)
    let margins = margins(subviews)
    return CGSize(width: measured.width, height: measured.height + margins.top + margins.bottom)
  }

  func placeSubviews(in bounds: CGRect, proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) {
    let measured = measure(proposal, subviews: subviews)
    let margins = margins(subviews)
    let box = CGRect(
      x: bounds.minX,
      y: bounds.minY + margins.top,
      width: bounds.width,
      height: measured.height
    )
    var y = box.minY
    for (index, subview) in subviews.enumerated() {
      let size = measured.sizes[index]
      if let placement = subview[BubbleReactionsKey.self] {
        let x = placement.align == .end ? box.maxX - 12 - size.width : box.minX + 12
        let top = placement.side == .bottom ? box.maxY - size.height * 0.25 : box.minY - size.height * 0.75
        subview.place(at: CGPoint(x: x, y: top), proposal: ProposedViewSize(size))
        continue
      }
      let x = align == .end ? box.maxX - size.width : box.minX
      subview.place(at: CGPoint(x: x, y: y), proposal: ProposedViewSize(width: size.width, height: size.height))
      y += size.height + spacing
    }
  }
}

extension EnvironmentValues {
  @Entry var bubbleStyle = BubbleStyle()
  @Entry var bubbleTails: Set<UUID>? = nil
}
```

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

public struct FieldTitle: View {
  let text: Text

  @Environment(\.isEnabled) private var isEnabled

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

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

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

public struct FieldDescription: View {
  let text: Text

  @Environment(\.fieldSetInset) private var inset

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

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

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

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

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

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

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

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

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

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

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

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

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

struct FieldSetInsetKey: PreferenceKey {
  static let defaultValue = false

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

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

  @State private var inset = false

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

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

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

  let text: Text
  let variant: Variant

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

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

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

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

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

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

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

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

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

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

extension EnvironmentValues {
  @Entry public var hapticsEnabled = true
}

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

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

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

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

  @Environment(\.hapticsEnabled) private var enabled

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

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

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

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

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

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

  @State private var count = 0

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

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

```swift title="swift/Components/KeyboardScrollView.swift"
import SwiftUI
import UIKit

public struct KeyboardScrollView<Content: View>: View {
  let showsIndicators: Bool
  let content: Content

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

  public var body: some View {
    ScrollView(.vertical, showsIndicators: showsIndicators) {
      content
        .frame(maxWidth: .infinity, alignment: .topLeading)
        .background {
          Color.clear
            .contentShape(Rectangle())
            .onTapGesture { KeyboardScrollView.dismissKeyboard() }
        }
    }
    .scrollDismissesKeyboard(.interactively)
  }

  @MainActor
  static func dismissKeyboard() {
    UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
  }
}
```

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

extension EnvironmentValues {
  @Entry var screenBackground: Color = .surface
}

public struct Screen<Content: View>: View {
  public enum Background: CaseIterable, Sendable {
    case surface, surfaceSecondary

    var color: Color {
      switch self {
      case .surface: .surface
      case .surfaceSecondary: .surfaceSecondary
      }
    }
  }

  let edges: Edge.Set
  let background: Background
  let content: Content

  public init(
    edges: Edge.Set = .all,
    background: Background = .surface,
    @ViewBuilder content: () -> Content
  ) {
    self.edges = edges
    self.background = background
    self.content = content()
  }

  public var body: some View {
    VStack(spacing: 0) {
      content
    }
    .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .top)
    .ignoresSafeArea(.container, edges: Edge.Set.all.subtracting(edges))
    .foregroundStyle(Color.label)
    .background(background.color.ignoresSafeArea())
    .environment(\.screenBackground, background.color)
  }
}

public struct ScreenContent<Content: View>: View {
  let scroll: Bool
  let padded: Bool
  let content: Content

  public init(scroll: Bool = true, padded: Bool = true, @ViewBuilder content: () -> Content) {
    self.scroll = scroll
    self.padded = padded
    self.content = content()
  }

  public var body: some View {
    if scroll {
      KeyboardScrollView {
        stack
      }
    } else {
      stack
        .frame(maxHeight: .infinity, alignment: .top)
    }
  }

  private var stack: some View {
    VStack(alignment: .leading, spacing: 16) {
      content
    }
    .padding(padded ? 16 : 0)
    .frame(maxWidth: .infinity, alignment: .leading)
  }
}
```

```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/Message.kt"
package com.esuiss.ui.components

import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.BoxScope
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.ColumnScope
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.widthIn
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.DisposableEffect
import androidx.compose.runtime.Stable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.layout.Layout
import androidx.compose.ui.layout.layoutId
import androidx.compose.ui.layout.onSizeChanged
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.Constraints
import androidx.compose.ui.unit.constrainHeight
import androidx.compose.ui.unit.constrainWidth
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

enum class MessageAlign { Start, End }

@Stable
internal class MessageState(val align: MessageAlign) {
    var ghosts by mutableIntStateOf(0)
    var footers by mutableIntStateOf(0)
    var footerHeight by mutableIntStateOf(0)
}

private enum class MessageSlot { Avatar, Content }

internal val LocalMessage = staticCompositionLocalOf<MessageState?> { null }

@Composable
fun MessageGroup(
    modifier: Modifier = Modifier,
    content: @Composable ColumnScope.() -> Unit,
) {
    Column(
        modifier = modifier.fillMaxWidth(),
        verticalArrangement = Arrangement.spacedBy(8.dp),
        content = content,
    )
}

@Composable
fun Message(
    modifier: Modifier = Modifier,
    align: MessageAlign = MessageAlign.Start,
    content: @Composable () -> Unit,
) {
    val state = remember(align) { MessageState(align) }
    val end = align == MessageAlign.End
    CompositionLocalProvider(
        LocalMessage provides state,
        LocalBubbleAlign provides if (end) BubbleAlign.End else BubbleAlign.Start,
    ) {
        Layout(content = content, modifier = modifier.fillMaxWidth()) { measurables, constraints ->
            val gap = 8.dp.roundToPx()
            val width = if (constraints.hasBoundedWidth) constraints.maxWidth else Constraints.Infinity
            val fixed = measurables.filter { it.layoutId != MessageSlot.Content }
                .associateWith { it.measure(Constraints(maxWidth = width, maxHeight = constraints.maxHeight)) }
            val flexible = measurables.filter { it.layoutId == MessageSlot.Content }
            val used = fixed.values.sumOf { it.width } + gap * (measurables.size - 1).coerceAtLeast(0)
            val remaining = if (width == Constraints.Infinity) Constraints.Infinity else (width - used).coerceAtLeast(0)
            val share = if (flexible.isEmpty() || remaining == Constraints.Infinity) remaining else remaining / flexible.size
            val measured = flexible.associateWith {
                it.measure(
                    if (share == Constraints.Infinity) {
                        Constraints(maxHeight = constraints.maxHeight)
                    } else {
                        Constraints(minWidth = share, maxWidth = share, maxHeight = constraints.maxHeight)
                    },
                )
            }
            val placeables = measurables.map { fixed[it] ?: measured.getValue(it) }
            val totalWidth = placeables.sumOf { it.width } + gap * (placeables.size - 1).coerceAtLeast(0)
            val layoutWidth = constraints.constrainWidth(totalWidth)
            val height = constraints.constrainHeight(placeables.maxOfOrNull { it.height } ?: 0)
            val lift = if (state.footers > 0) state.footerHeight + 10.dp.roundToPx() else 0
            layout(layoutWidth, height) {
                var x = if (end) layoutWidth else 0
                measurables.forEachIndexed { index, measurable ->
                    val placeable = placeables[index]
                    val y = if (measurable.layoutId == MessageSlot.Avatar) {
                        (height - placeable.height - lift).coerceAtLeast(0)
                    } else {
                        0
                    }
                    if (end) {
                        x -= placeable.width
                        placeable.placeRelative(x, y)
                        x -= gap
                    } else {
                        placeable.placeRelative(x, y)
                        x += placeable.width + gap
                    }
                }
            }
        }
    }
}

@Composable
fun MessageAvatar(
    modifier: Modifier = Modifier,
    content: @Composable BoxScope.() -> Unit,
) {
    Box(
        modifier = modifier
            .layoutId(MessageSlot.Avatar)
            .widthIn(min = 32.dp)
            .clip(CircleShape)
            .background(EsuissTheme.colors.surfaceSecondary, CircleShape),
        contentAlignment = Alignment.Center,
        content = content,
    )
}

@Composable
fun MessageContent(
    modifier: Modifier = Modifier,
    content: @Composable () -> Unit,
) {
    val message = LocalMessage.current
    BubbleStack(
        modifier = modifier.layoutId(MessageSlot.Content),
        spacing = 10.dp,
        alignEnd = message?.align == MessageAlign.End,
        content = content,
    )
}

@Composable
private fun MessageLine(
    modifier: Modifier,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val message = LocalMessage.current
    Row(
        modifier = modifier.padding(horizontal = if ((message?.ghosts ?: 0) > 0) 0.dp else 14.dp),
        horizontalArrangement = Arrangement.spacedBy(4.dp),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        CompositionLocalProvider(
            LocalContentStyle provides Typography.xs.copy(color = colors.labelSecondary),
            LocalContentColor provides colors.labelSecondary,
            LocalIconSize provides 14.dp,
        ) {
            content()
        }
    }
}

@Composable
fun MessageHeader(
    modifier: Modifier = Modifier,
    content: @Composable RowScope.() -> Unit,
) {
    MessageLine(modifier, content)
}

@Composable
fun MessageHeader(text: String, modifier: Modifier = Modifier) {
    MessageHeader(modifier) {
        BasicText(text, style = LocalContentStyle.current, maxLines = 1, overflow = TextOverflow.Ellipsis)
    }
}

@Composable
fun MessageFooter(
    modifier: Modifier = Modifier,
    content: @Composable RowScope.() -> Unit,
) {
    val message = LocalMessage.current
    if (message != null) {
        DisposableEffect(message) {
            message.footers += 1
            onDispose {
                message.footers -= 1
                if (message.footers == 0) message.footerHeight = 0
            }
        }
    }
    MessageLine(
        modifier.onSizeChanged { message?.footerHeight = it.height },
        content,
    )
}

@Composable
fun MessageFooter(text: String, modifier: Modifier = Modifier) {
    MessageFooter(modifier) {
        BasicText(text, style = LocalContentStyle.current, maxLines = 1, overflow = TextOverflow.Ellipsis)
    }
}
```

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

import androidx.compose.foundation.Image
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.offset
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.staticCompositionLocalOf
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.painter.Painter
import androidx.compose.ui.layout.ContentScale
import androidx.compose.ui.layout.Layout
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.constrainHeight
import androidx.compose.ui.unit.constrainWidth
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

enum class AvatarSize(
    val size: Dp,
    internal val iconSize: Dp,
    internal val badgeSize: Dp,
    internal val badgeIconSize: Dp,
    internal val countIconSize: Dp,
) {
    Sm(24.dp, 14.dp, 12.dp, 0.dp, 12.dp),
    Default(32.dp, 20.dp, 16.dp, 8.dp, 16.dp),
    Lg(40.dp, 24.dp, 18.dp, 10.dp, 20.dp),
    Xl(64.dp, 40.dp, 22.dp, 12.dp, 28.dp),
    ;

    internal val textStyle: TextStyle
        get() = when (this) {
            Sm -> Typography.xs3
            Default -> Typography.xs
            Lg -> Typography.md
            Xl -> Typography.xl2
        }
}

private val LocalAvatarSize = staticCompositionLocalOf { AvatarSize.Default }

private val LocalAvatarGrouped = staticCompositionLocalOf { false }

@Composable
fun Avatar(
    modifier: Modifier = Modifier,
    size: AvatarSize = AvatarSize.Default,
    image: Painter? = null,
    contentDescription: String? = null,
    badge: (@Composable () -> Unit)? = null,
    fallback: (@Composable () -> Unit)? = null,
) {
    val colors = EsuissTheme.colors
    val grouped = LocalAvatarGrouped.current
    CompositionLocalProvider(LocalAvatarSize provides size, LocalAvatarGrouped provides false) {
        Box(modifier.size(size.size)) {
            Box(
                Modifier
                    .fillMaxSize()
                    .then(
                        if (grouped) {
                            Modifier.background(colors.surface, CircleShape).padding(2.dp)
                        } else {
                            Modifier
                        },
                    )
                    .clip(CircleShape),
                contentAlignment = Alignment.Center,
            ) {
                fallback?.invoke()
                if (image != null) {
                    Image(
                        painter = image,
                        contentDescription = contentDescription,
                        modifier = Modifier.fillMaxSize(),
                        contentScale = ContentScale.Crop,
                    )
                }
            }
            if (badge != null) {
                Box(Modifier.align(Alignment.BottomEnd).offset(2.dp, 2.dp)) {
                    badge()
                }
            }
        }
    }
}

@Composable
fun AvatarFallback(
    modifier: Modifier = Modifier,
    content: @Composable () -> Unit,
) {
    val colors = EsuissTheme.colors
    val size = LocalAvatarSize.current
    val background = if (colors.isDark) {
        colors.labelSecondary.copy(alpha = colors.labelSecondary.alpha * 0.6f)
    } else {
        colors.labelSecondary
    }
    Box(
        modifier = modifier.fillMaxSize().background(background, CircleShape),
        contentAlignment = Alignment.Center,
    ) {
        CompositionLocalProvider(
            LocalContentStyle provides size.textStyle.copy(color = colors.onAccent, fontWeight = FontWeight.SemiBold),
            LocalContentColor provides colors.onAccent,
            LocalIconSize provides size.iconSize,
        ) {
            content()
        }
    }
}

@Composable
fun AvatarFallback(
    text: String,
    modifier: Modifier = Modifier,
) {
    AvatarFallback(modifier) {
        BasicText(text.uppercase(), style = LocalContentStyle.current, maxLines = 1)
    }
}

@Composable
fun AvatarBadge(
    modifier: Modifier = Modifier,
    content: @Composable () -> Unit = {},
) {
    val colors = EsuissTheme.colors
    val size = LocalAvatarSize.current
    Box(
        modifier = modifier
            .size(size.badgeSize)
            .background(colors.surface, CircleShape)
            .padding(2.dp)
            .background(colors.accent, CircleShape),
        contentAlignment = Alignment.Center,
    ) {
        if (size != AvatarSize.Sm) {
            CompositionLocalProvider(
                LocalContentStyle provides Typography.xs3.copy(color = colors.onAccent),
                LocalContentColor provides colors.onAccent,
                LocalIconSize provides size.badgeIconSize,
            ) {
                content()
            }
        }
    }
}

@Composable
fun AvatarGroup(
    modifier: Modifier = Modifier,
    content: @Composable () -> Unit,
) {
    Layout(
        content = { CompositionLocalProvider(LocalAvatarGrouped provides true, content = content) },
        modifier = modifier,
    ) { measurables, constraints ->
        val loose = constraints.copy(minWidth = 0, minHeight = 0)
        val placeables = measurables.map { it.measure(loose) }
        val large = AvatarSize.Xl.size.roundToPx()
        val offsets = IntArray(placeables.size)
        var x = 0
        placeables.forEachIndexed { index, placeable ->
            if (index > 0) x -= if (placeable.height >= large) 16.dp.roundToPx() else 8.dp.roundToPx()
            offsets[index] = x
            x += placeable.width
        }
        val height = placeables.maxOfOrNull { it.height } ?: 0
        layout(constraints.constrainWidth(x.coerceAtLeast(0)), constraints.constrainHeight(height)) {
            placeables.forEachIndexed { index, placeable ->
                placeable.placeRelative(offsets[index], (height - placeable.height) / 2)
            }
        }
    }
}

@Composable
fun AvatarGroupCount(
    modifier: Modifier = Modifier,
    size: AvatarSize = AvatarSize.Default,
    content: @Composable () -> Unit,
) {
    val colors = EsuissTheme.colors
    Box(
        modifier = modifier
            .size(size.size)
            .background(colors.surface, CircleShape)
            .padding(2.dp)
            .background(colors.surfaceSecondary, CircleShape),
        contentAlignment = Alignment.Center,
    ) {
        CompositionLocalProvider(
            LocalContentStyle provides size.textStyle.copy(color = colors.label, fontWeight = FontWeight.SemiBold),
            LocalContentColor provides colors.label,
            LocalIconSize provides size.countIconSize,
        ) {
            content()
        }
    }
}

@Composable
fun AvatarGroupCount(
    text: String,
    modifier: Modifier = Modifier,
    size: AvatarSize = AvatarSize.Default,
) {
    AvatarGroupCount(modifier, size) {
        BasicText(text, style = LocalContentStyle.current, maxLines = 1)
    }
}
```

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

import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.combinedClickable
import androidx.compose.foundation.gestures.detectTapGestures
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.foundation.interaction.collectIsPressedAsState
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.CircleShape
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.DisposableEffect
import androidx.compose.runtime.SideEffect
import androidx.compose.runtime.compositionLocalOf
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.CornerRadius
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.draw.drawBehind
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.RectangleShape
import androidx.compose.ui.graphics.compositeOver
import androidx.compose.ui.graphics.drawscope.withTransform
import androidx.compose.ui.graphics.lerp
import androidx.compose.ui.graphics.vector.PathParser
import androidx.compose.ui.hapticfeedback.HapticFeedbackType
import androidx.compose.ui.input.pointer.pointerInput
import androidx.compose.ui.layout.Layout
import androidx.compose.ui.layout.layoutId
import androidx.compose.ui.semantics.onLongClick
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.Constraints
import androidx.compose.ui.unit.constrainHeight
import androidx.compose.ui.unit.constrainWidth
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.LayoutDirection
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.Colors
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography
import kotlin.math.roundToInt

enum class BubbleVariant { Default, Secondary, Muted, Tinted, Outline, Ghost, Destructive }

enum class BubbleAlign { Start, End }

enum class BubbleReactionsSide { Top, Bottom }

internal class BubbleSlot {
    var align by mutableStateOf(BubbleAlign.Start)
    var tailed by mutableStateOf(true)
}

private class BubbleInfo(val variant: BubbleVariant, val align: BubbleAlign, val slot: BubbleSlot)

private class BubbleReactionsSlot(val side: BubbleReactionsSide, val align: BubbleAlign)

private val LocalBubble = compositionLocalOf<BubbleInfo?> { null }

internal val LocalBubbleAlign = compositionLocalOf { BubbleAlign.Start }

private val TailPath = PathParser().parsePathString("M7 0H20V4A16 16 0 0 1 4 20H0V19.54A10 10 0 0 0 7 10Z").toPath()

@Composable
internal fun BubbleStack(
    modifier: Modifier,
    spacing: Dp,
    alignEnd: Boolean,
    content: @Composable () -> Unit,
) {
    Layout(content = content, modifier = modifier) { measurables, constraints ->
        val loose = constraints.copy(minWidth = 0, minHeight = 0)
        val placeables = measurables.map { it.measure(loose) }
        val slots = measurables.map { it.layoutId as? BubbleSlot }
        slots.forEachIndexed { index, slot ->
            if (slot != null) {
                val next = slots.getOrNull(index + 1)
                slot.tailed = next == null || next.align != slot.align
            }
        }
        val gap = spacing.roundToPx()
        val width = if (constraints.hasBoundedWidth) constraints.maxWidth else placeables.maxOfOrNull { it.width } ?: 0
        val height = placeables.sumOf { it.height } + gap * (placeables.size - 1).coerceAtLeast(0)
        layout(width, constraints.constrainHeight(height)) {
            var y = 0
            placeables.forEachIndexed { index, placeable ->
                val end = alignEnd || slots[index]?.align == BubbleAlign.End
                placeable.placeRelative(if (end) width - placeable.width else 0, y)
                y += placeable.height + gap
            }
        }
    }
}

@Composable
fun BubbleGroup(
    modifier: Modifier = Modifier,
    content: @Composable () -> Unit,
) {
    BubbleStack(modifier, 8.dp, alignEnd = false, content = content)
}

@Composable
fun Bubble(
    modifier: Modifier = Modifier,
    variant: BubbleVariant = BubbleVariant.Default,
    align: BubbleAlign = LocalBubbleAlign.current,
    content: @Composable () -> Unit,
) {
    val slot = remember { BubbleSlot() }
    SideEffect { slot.align = align }
    val message = LocalMessage.current
    if (variant == BubbleVariant.Ghost && message != null) {
        DisposableEffect(message) {
            message.ghosts += 1
            onDispose { message.ghosts -= 1 }
        }
    }
    val fraction = if (variant == BubbleVariant.Ghost) 1f else 0.8f
    val end = align == BubbleAlign.End
    CompositionLocalProvider(LocalBubble provides BubbleInfo(variant, align, slot)) {
        Layout(content = content, modifier = modifier.layoutId(slot)) { measurables, constraints ->
            val maxWidth = if (constraints.hasBoundedWidth) (constraints.maxWidth * fraction).roundToInt() else Constraints.Infinity
            val gap = 4.dp.roundToPx()
            val inset = 12.dp.roundToPx()
            val reserve = 20.dp.roundToPx()
            val childConstraints = Constraints(maxWidth = maxWidth, maxHeight = constraints.maxHeight)
            val items = measurables.filter { it.layoutId !is BubbleReactionsSlot }.map { it.measure(childConstraints) }
            val reactions = measurables.filter { it.layoutId is BubbleReactionsSlot }.map {
                it.layoutId as BubbleReactionsSlot to it.measure(Constraints(maxWidth = maxWidth))
            }
            val columnWidth = items.maxOfOrNull { it.width } ?: 0
            val columnHeight = items.sumOf { it.height } + gap * (items.size - 1).coerceAtLeast(0)
            val top = if (reactions.any { it.first.side == BubbleReactionsSide.Top }) reserve else 0
            val bottom = if (reactions.any { it.first.side == BubbleReactionsSide.Bottom }) reserve else 0
            val width = constraints.constrainWidth(columnWidth)
            layout(width, constraints.constrainHeight(top + columnHeight + bottom)) {
                var y = top
                items.forEach { placeable ->
                    placeable.placeRelative(if (end) width - placeable.width else 0, y)
                    y += placeable.height + gap
                }
                reactions.forEach { (data, placeable) ->
                    val x = if (data.align == BubbleAlign.End) width - inset - placeable.width else inset
                    val ry = if (data.side == BubbleReactionsSide.Bottom) {
                        top + columnHeight - placeable.height / 4
                    } else {
                        top - placeable.height * 3 / 4
                    }
                    placeable.placeRelative(x, ry, 1f)
                }
            }
        }
    }
}

@Composable
fun BubbleContent(
    modifier: Modifier = Modifier,
    onClick: (() -> Unit)? = null,
    onLongPress: (() -> Unit)? = null,
    content: @Composable () -> Unit,
) {
    val colors = EsuissTheme.colors
    val info = LocalBubble.current
    val variant = info?.variant ?: BubbleVariant.Default
    val align = info?.align ?: LocalBubbleAlign.current
    val slot = info?.slot
    val haptics = rememberHaptics()
    val interaction = remember { MutableInteractionSource() }
    val clicked by interaction.collectIsPressedAsState()
    var holding by remember { mutableStateOf(false) }
    val pressed = clicked || holding
    val background = bubbleBackground(variant, colors, pressed)
    val foreground = bubbleForeground(variant, colors)
    val ghost = variant == BubbleVariant.Ghost
    val shape = if (ghost) RectangleShape else RoundedCornerShape(Radius.xl2)
    val tailing = variant != BubbleVariant.Ghost && variant != BubbleVariant.Outline
    val longPress = onLongPress?.let { action ->
        {
            haptics.perform(HapticFeedbackType.LongPress)
            action()
        }
    }
    val gestures = when {
        onClick != null -> Modifier.combinedClickable(
            interactionSource = interaction,
            indication = null,
            onLongClick = longPress,
            onClick = onClick,
        )
        longPress != null -> Modifier
            .pointerInput(Unit) {
                detectTapGestures(
                    onPress = {
                        holding = true
                        tryAwaitRelease()
                        holding = false
                    },
                    onLongPress = { longPress() },
                )
            }
            .semantics {
                onLongClick {
                    longPress()
                    true
                }
            }
        else -> Modifier
    }
    Box(
        modifier = modifier
            .drawBehind {
                if (tailing && (slot?.tailed ?: true)) {
                    val unit = 1.dp.toPx()
                    val end = (align == BubbleAlign.End) != (layoutDirection == LayoutDirection.Rtl)
                    val left = if (end) size.width + 6.9f * unit else -6.9f * unit
                    val top = size.height + unit - 20f * unit
                    withTransform({
                        translate(left, top)
                        scale(if (end) -unit else unit, unit, Offset.Zero)
                    }) {
                        drawPath(TailPath, background)
                    }
                }
            }
            .background(background, shape)
            .then(if (variant == BubbleVariant.Outline) Modifier.border(1.dp, colors.separator, shape) else Modifier)
            .then(gestures)
            .then(if (ghost) Modifier else Modifier.padding(horizontal = 15.dp, vertical = 7.dp)),
    ) {
        CompositionLocalProvider(
            LocalContentStyle provides Typography.base.copy(color = foreground),
            LocalContentColor provides foreground,
        ) {
            content()
        }
    }
}

@Composable
fun BubbleContent(
    text: String,
    modifier: Modifier = Modifier,
    onClick: (() -> Unit)? = null,
    onLongPress: (() -> Unit)? = null,
) {
    BubbleContent(modifier, onClick, onLongPress) {
        BasicText(text, style = LocalContentStyle.current)
    }
}

@Composable
fun BubbleReactions(
    modifier: Modifier = Modifier,
    side: BubbleReactionsSide = BubbleReactionsSide.Bottom,
    align: BubbleAlign = BubbleAlign.End,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    Row(
        modifier = modifier
            .layoutId(BubbleReactionsSlot(side, align))
            .drawBehind {
                val ring = 3.dp.toPx()
                drawRoundRect(
                    color = colors.surface,
                    topLeft = Offset(-ring, -ring),
                    size = Size(size.width + ring * 2, size.height + ring * 2),
                    cornerRadius = CornerRadius(size.height / 2 + ring),
                )
            }
            .background(colors.surfaceSecondary, CircleShape)
            .padding(horizontal = 6.dp, vertical = 2.dp),
        horizontalArrangement = Arrangement.spacedBy(4.dp, Alignment.CenterHorizontally),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        CompositionLocalProvider(
            LocalContentStyle provides Typography.sm.copy(color = colors.label),
            LocalContentColor provides colors.label,
            LocalIconSize provides 16.dp,
        ) {
            content()
        }
    }
}

@Composable
fun BubbleReactions(
    text: String,
    modifier: Modifier = Modifier,
    side: BubbleReactionsSide = BubbleReactionsSide.Bottom,
    align: BubbleAlign = BubbleAlign.End,
) {
    BubbleReactions(modifier, side, align) {
        BasicText(text, style = LocalContentStyle.current, maxLines = 1)
    }
}

private fun bubbleBackground(variant: BubbleVariant, colors: Colors, pressed: Boolean): Color =
    if (variant == BubbleVariant.Ghost) bubbleFill(variant, colors, pressed) else bubbleFill(variant, colors, pressed).compositeOver(colors.surface)

private fun bubbleFill(variant: BubbleVariant, colors: Colors, pressed: Boolean): Color = when (variant) {
    BubbleVariant.Default -> if (pressed) colors.accentPressed else colors.accent
    BubbleVariant.Secondary -> if (pressed) colors.controlPressed else colors.control
    BubbleVariant.Muted -> if (pressed) lerp(colors.surfaceSecondary, colors.label, 0.05f) else colors.surfaceSecondary
    BubbleVariant.Tinted -> colors.accent.copy(alpha = if (pressed) 0.2f else 0.12f)
    BubbleVariant.Outline -> if (pressed) colors.control else colors.surface
    BubbleVariant.Ghost -> if (pressed) colors.itemPressed else Color.Transparent
    BubbleVariant.Destructive -> if (pressed) colors.dangerSurfacePressed else colors.dangerSurface
}

private fun bubbleForeground(variant: BubbleVariant, colors: Colors): Color = when (variant) {
    BubbleVariant.Default -> colors.onAccent
    BubbleVariant.Destructive -> colors.danger
    else -> colors.label
}
```

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

import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.clickable
import androidx.compose.foundation.interaction.MutableInteractionSource
import androidx.compose.foundation.interaction.collectIsPressedAsState
import androidx.compose.foundation.layout.Arrangement
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.size
import androidx.compose.foundation.shape.CircleShape
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.getValue
import androidx.compose.runtime.remember
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.semantics.Role
import androidx.compose.ui.text.TextStyle
import androidx.compose.ui.text.style.TextDecoration
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.dp
import com.esuiss.ui.theme.Colors
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

enum class ButtonVariant { Default, Outline, Secondary, Tinted, Ghost, Plain, Destructive, Link }

enum class ButtonSize(
    val height: Dp,
    val horizontalPadding: Dp,
    val spacing: Dp,
    val iconSize: Dp,
    val blockRadius: Dp,
    val isIcon: Boolean,
) {
    Default(36.dp, 16.dp, 6.dp, 16.dp, Radius.md, false),
    Xs(24.dp, 11.dp, 4.dp, 12.dp, Radius.sm, false),
    Sm(32.dp, 12.dp, 4.dp, 16.dp, Radius.md, false),
    Lg(44.dp, 22.dp, 6.dp, 16.dp, Radius.lg, false),
    Xl(56.dp, 31.dp, 8.dp, 16.dp, Radius.xl, false),
    Icon(36.dp, 0.dp, 6.dp, 16.dp, Radius.md, true),
    IconXs(24.dp, 0.dp, 4.dp, 12.dp, Radius.sm, true),
    IconSm(32.dp, 0.dp, 4.dp, 16.dp, Radius.md, true),
    IconLg(44.dp, 0.dp, 6.dp, 16.dp, Radius.lg, true),
    IconXl(56.dp, 0.dp, 8.dp, 16.dp, Radius.xl, true),
    ;

    val textStyle: TextStyle
        get() = when (this) {
            Xs, IconXs -> Typography.xs2
            Lg, Xl -> Typography.base
            else -> Typography.sm
        }
}

@Composable
fun Button(
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    variant: ButtonVariant = ButtonVariant.Default,
    size: ButtonSize = ButtonSize.Default,
    block: Boolean = false,
    enabled: Boolean = true,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val interaction = remember { MutableInteractionSource() }
    val pressed by interaction.collectIsPressedAsState()
    val foreground = buttonForeground(variant, colors, enabled)
    val group = LocalButtonGroup.current?.takeIf { variant != ButtonVariant.Ghost && variant != ButtonVariant.Plain }
    RegisterButtonGroupOutline(group, variant == ButtonVariant.Outline)
    val shape = group.itemShape(if (block) RoundedCornerShape(size.blockRadius) else CircleShape)
    val sizing = when {
        block -> Modifier.fillMaxWidth().height(size.height)
        size.isIcon -> Modifier.size(size.height)
        else -> Modifier.height(size.height)
    }

    Row(
        modifier = modifier
            .then(sizing)
            .clip(shape)
            .background(buttonBackground(variant, colors, pressed && enabled, enabled), shape)
            .then(
                when {
                    variant != ButtonVariant.Outline -> Modifier
                    group != null -> Modifier.buttonGroupEdge(group, colors.separator)
                    else -> Modifier.border(1.dp, colors.separator, shape)
                },
            )
            .clickable(
                interactionSource = interaction,
                indication = null,
                enabled = enabled,
                role = Role.Button,
                onClick = onClick,
            )
            .padding(horizontal = size.horizontalPadding),
        horizontalArrangement = Arrangement.spacedBy(size.spacing, Alignment.CenterHorizontally),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        CompositionLocalProvider(
            LocalButtonGroup provides null,
            LocalContentStyle provides size.textStyle.copy(
                color = foreground,
                textDecoration = if (variant == ButtonVariant.Link && pressed && enabled) {
                    TextDecoration.Underline
                } else {
                    null
                },
            ),
            LocalContentColor provides foreground,
            LocalIconSize provides size.iconSize,
        ) {
            content()
        }
    }
}

@Composable
fun Button(
    text: String,
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    variant: ButtonVariant = ButtonVariant.Default,
    size: ButtonSize = ButtonSize.Default,
    block: Boolean = false,
    enabled: Boolean = true,
) {
    Button(onClick, modifier, variant, size, block, enabled) {
        BasicText(text, style = LocalContentStyle.current, maxLines = 1)
    }
}

private fun buttonForeground(variant: ButtonVariant, colors: Colors, enabled: Boolean): Color =
    when (variant) {
        ButtonVariant.Default -> colors.onAccent
        ButtonVariant.Outline, ButtonVariant.Secondary, ButtonVariant.Ghost ->
            if (enabled) colors.label else colors.labelQuaternary
        ButtonVariant.Tinted, ButtonVariant.Plain ->
            if (enabled) colors.link else colors.link.copy(alpha = 0.4f)
        ButtonVariant.Destructive ->
            if (enabled) colors.danger else colors.danger.copy(alpha = 0.4f)
        ButtonVariant.Link -> if (enabled) colors.link else colors.labelQuaternary
    }

private fun buttonBackground(variant: ButtonVariant, colors: Colors, pressed: Boolean, enabled: Boolean): Color =
    when (variant) {
        ButtonVariant.Default -> when {
            !enabled -> colors.accentDisabled
            pressed -> colors.accentPressed
            else -> colors.accent
        }
        ButtonVariant.Outline -> when {
            pressed -> colors.itemPressed
            colors.isDark -> Color.Transparent
            else -> colors.surface
        }
        ButtonVariant.Secondary -> when {
            !enabled -> colors.controlDisabled
            pressed -> colors.controlPressed
            else -> colors.control
        }
        ButtonVariant.Tinted -> if (pressed) colors.accentSurfacePressed else colors.accentSurface
        ButtonVariant.Ghost -> if (pressed) colors.itemPressed else Color.Transparent
        ButtonVariant.Plain -> if (pressed) colors.itemPressed else Color.Transparent
        ButtonVariant.Destructive -> if (pressed) colors.dangerSurfacePressed else colors.dangerSurface
        ButtonVariant.Link -> Color.Transparent
    }
```

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

import androidx.compose.foundation.background
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.CornerSize
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
import androidx.compose.runtime.DisposableEffect
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.Stable
import androidx.compose.runtime.compositionLocalOf
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.draw.drawBehind
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.RectangleShape
import androidx.compose.ui.graphics.Shape
import androidx.compose.ui.graphics.drawOutline
import androidx.compose.ui.graphics.drawscope.Stroke
import androidx.compose.ui.graphics.drawscope.translate
import androidx.compose.ui.graphics.takeOrElse
import androidx.compose.ui.layout.Layout
import androidx.compose.ui.layout.Placeable
import androidx.compose.ui.layout.layout
import androidx.compose.ui.layout.layoutId
import androidx.compose.ui.layout.onPlaced
import androidx.compose.ui.platform.LocalLayoutDirection
import androidx.compose.ui.semantics.isTraversalGroup
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.Constraints
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.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

enum class ButtonGroupOrientation { Horizontal, Vertical }

@Stable
internal class ButtonGroupState(val orientation: ButtonGroupOrientation) {
    var nested by mutableIntStateOf(0)
    var outlined by mutableIntStateOf(0)
}

internal val LocalButtonGroup = compositionLocalOf<ButtonGroupState?> { null }

internal object ButtonGroupFill

private object ButtonGroupDivider

internal fun ButtonGroupState?.itemShape(default: Shape): Shape = if (this == null) default else RectangleShape

@Immutable
internal class ButtonGroupItem(val shape: Shape, val modifier: Modifier)

@Composable
internal fun rememberButtonGroupItem(group: ButtonGroupState?, default: Shape): ButtonGroupItem {
    var edges by remember { mutableIntStateOf(0) }
    val horizontal = group?.orientation != ButtonGroupOrientation.Vertical
    val rtl = LocalLayoutDirection.current == LayoutDirection.Rtl
    val shape = remember(edges, horizontal) {
        val round = if (horizontal) CornerSize(50) else CornerSize(Radius.xl2)
        val square = CornerSize(0)
        val start = if (edges and 1 != 0) round else square
        val end = if (edges and 2 != 0) round else square
        if (horizontal) {
            RoundedCornerShape(topStart = start, topEnd = end, bottomEnd = end, bottomStart = start)
        } else {
            RoundedCornerShape(topStart = start, topEnd = start, bottomEnd = end, bottomStart = end)
        }
    }
    if (group == null || group.nested > 0) return ButtonGroupItem(default, Modifier)
    return ButtonGroupItem(
        shape = shape,
        modifier = Modifier.onPlaced { coordinates ->
            val parent = coordinates.parentLayoutCoordinates ?: return@onPlaced
            val bounds = parent.localBoundingBoxOf(coordinates, clipBounds = false)
            val first: Boolean
            val last: Boolean
            if (horizontal) {
                val left = bounds.left <= 0.5f
                val right = bounds.right >= parent.size.width - 0.5f
                first = if (rtl) right else left
                last = if (rtl) left else right
            } else {
                first = bounds.top <= 0.5f
                last = bounds.bottom >= parent.size.height - 0.5f
            }
            edges = (if (first) 1 else 0) or (if (last) 2 else 0)
        },
    )
}

internal fun Modifier.buttonGroupEdge(group: ButtonGroupState?, color: Color): Modifier {
    if (group == null) return this
    return drawBehind {
        val stroke = 1.dp.toPx()
        if (group.orientation == ButtonGroupOrientation.Horizontal) {
            val x = if (layoutDirection == LayoutDirection.Rtl) 0f else size.width - stroke
            drawRect(color, Offset(x, 0f), Size(stroke, size.height))
        } else {
            drawRect(color, Offset(0f, size.height - stroke), Size(size.width, stroke))
        }
    }
}

@Composable
internal fun RegisterButtonGroupOutline(group: ButtonGroupState?, outlined: Boolean) {
    DisposableEffect(group, outlined) {
        if (group != null && outlined) group.outlined += 1
        onDispose {
            if (group != null && outlined) group.outlined -= 1
        }
    }
}

@Composable
fun ButtonGroup(
    modifier: Modifier = Modifier,
    orientation: ButtonGroupOrientation = ButtonGroupOrientation.Horizontal,
    content: @Composable () -> Unit,
) {
    val parent = LocalButtonGroup.current
    DisposableEffect(parent) {
        parent?.let { it.nested += 1 }
        onDispose { parent?.let { it.nested -= 1 } }
    }
    val state = remember(orientation) { ButtonGroupState(orientation) }
    val colors = EsuissTheme.colors
    val joined = state.nested == 0
    val horizontal = orientation == ButtonGroupOrientation.Horizontal
    val shape = if (horizontal) CircleShape else RoundedCornerShape(Radius.xl2)
    val outline = colors.separator
    Layout(
        content = {
            CompositionLocalProvider(LocalButtonGroup provides state, content = content)
        },
        modifier = modifier
            .semantics { isTraversalGroup = true }
            .then(
                if (joined) {
                    Modifier
                        .clip(shape)
                        .drawWithContent {
                            drawContent()
                            if (state.outlined > 0) {
                                val stroke = 1.dp.toPx()
                                val inset = stroke / 2
                                val path = shape.createOutline(
                                    Size(size.width - stroke, size.height - stroke),
                                    layoutDirection,
                                    this,
                                )
                                translate(inset, inset) {
                                    drawOutline(path, outline, style = Stroke(stroke))
                                }
                            }
                        }
                } else {
                    Modifier
                },
            ),
    ) { measurables, constraints ->
        val gap = if (joined) 0 else 8.dp.roundToPx()
        val items = measurables.filter { it.layoutId != ButtonGroupDivider }
        if (horizontal) {
            val height = if (constraints.hasFixedHeight) {
                constraints.maxHeight
            } else {
                constraints.constrainHeight(items.maxOfOrNull { it.maxIntrinsicHeight(Constraints.Infinity) } ?: 0)
            }
            val fills = measurables.count { it.layoutId == ButtonGroupFill }
            val placeables = arrayOfNulls<Placeable>(measurables.size)
            var used = 0
            measurables.forEachIndexed { index, measurable ->
                if (measurable.layoutId != ButtonGroupFill) {
                    val placeable = measurable.measure(Constraints(minHeight = height, maxHeight = height))
                    placeables[index] = placeable
                    used += placeable.width
                }
            }
            val gaps = gap * (items.size - 1).coerceAtLeast(0)
            val remaining = if (constraints.hasBoundedWidth) {
                (constraints.maxWidth - used - gaps).coerceAtLeast(0)
            } else {
                0
            }
            measurables.forEachIndexed { index, measurable ->
                if (measurable.layoutId == ButtonGroupFill) {
                    val placeable = if (constraints.hasBoundedWidth) {
                        val width = remaining / fills
                        measurable.measure(Constraints(width, width, height, height))
                    } else {
                        measurable.measure(Constraints(minHeight = height, maxHeight = height))
                    }
                    placeables[index] = placeable
                    used += placeable.width
                }
            }
            val width = constraints.constrainWidth(used + gaps)
            layout(width, height) {
                var x = 0
                measurables.forEachIndexed { index, measurable ->
                    val placeable = placeables[index] ?: return@forEachIndexed
                    val divider = measurable.layoutId == ButtonGroupDivider
                    placeable.placeRelative(x, 0, zIndex = if (divider) 1f else 0f)
                    if (!divider) x += placeable.width + gap
                }
            }
        } else {
            val width = if (constraints.hasFixedWidth) {
                constraints.maxWidth
            } else {
                constraints.constrainWidth(items.maxOfOrNull { it.maxIntrinsicWidth(Constraints.Infinity) } ?: 0)
            }
            val placeables = measurables.map { it.measure(Constraints(minWidth = width, maxWidth = width)) }
            val gaps = gap * (items.size - 1).coerceAtLeast(0)
            val height = constraints.constrainHeight(
                placeables.filterIndexed { index, _ -> measurables[index].layoutId != ButtonGroupDivider }.sumOf { it.height } + gaps,
            )
            layout(width, height) {
                var y = 0
                measurables.forEachIndexed { index, measurable ->
                    val divider = measurable.layoutId == ButtonGroupDivider
                    placeables[index].placeRelative(0, y, zIndex = if (divider) 1f else 0f)
                    if (!divider) y += placeables[index].height + gap
                }
            }
        }
    }
}

@Composable
fun ButtonGroupText(
    modifier: Modifier = Modifier,
    content: @Composable RowScope.() -> Unit,
) {
    val colors = EsuissTheme.colors
    val shape = LocalButtonGroup.current.itemShape(CircleShape)
    Row(
        modifier = modifier
            .clip(shape)
            .background(colors.control, shape)
            .padding(horizontal = 10.dp),
        horizontalArrangement = Arrangement.spacedBy(8.dp),
        verticalAlignment = Alignment.CenterVertically,
    ) {
        CompositionLocalProvider(
            LocalButtonGroup provides null,
            LocalContentStyle provides Typography.sm.copy(color = colors.label),
            LocalContentColor provides colors.label,
            LocalIconSize provides 16.dp,
        ) {
            content()
        }
    }
}

@Composable
fun ButtonGroupSeparator(
    modifier: Modifier = Modifier,
    orientation: Orientation = Orientation.Vertical,
    color: Color = Color.Unspecified,
) {
    val line = color.takeOrElse { EsuissTheme.colors.label.copy(alpha = 0.2f) }
    Box(
        modifier = modifier
            .layoutId(ButtonGroupDivider)
            .then(
                if (orientation == Orientation.Vertical) {
                    Modifier.layout { measurable, constraints ->
                        val placeable = measurable.measure(constraints.copy(minWidth = 0, maxWidth = 0))
                        layout(0, placeable.height) { placeable.place(0, 0) }
                    }
                } else {
                    Modifier.layout { measurable, constraints ->
                        val placeable = measurable.measure(constraints.copy(minHeight = 0, maxHeight = 0))
                        layout(placeable.width, 0) { placeable.place(0, 0) }
                    }
                },
            )
            .drawBehind {
                val stroke = 1.dp.toPx()
                val inset = 9.dp.toPx()
                if (orientation == Orientation.Vertical) {
                    val x = if (layoutDirection == LayoutDirection.Rtl) -stroke else 0f
                    drawRect(line, Offset(x, inset), Size(stroke, (size.height - inset * 2).coerceAtLeast(0f)))
                } else {
                    drawRect(line, Offset(inset, 0f), Size((size.width - inset * 2).coerceAtLeast(0f), stroke))
                }
            },
    )
}
```

```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/Haptics.kt"
package com.esuiss.ui.components

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

val LocalHapticsEnabled = staticCompositionLocalOf { true }

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

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

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

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

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

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

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

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

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

import androidx.compose.foundation.Canvas
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.gestures.awaitEachGesture
import androidx.compose.foundation.gestures.awaitFirstDown
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.text.BasicText
import androidx.compose.runtime.Composable
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateListOf
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberUpdatedState
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.ImageBitmap
import androidx.compose.ui.graphics.Path
import androidx.compose.ui.graphics.PathEffect
import androidx.compose.ui.graphics.StrokeCap
import androidx.compose.ui.graphics.StrokeJoin
import androidx.compose.ui.graphics.drawscope.CanvasDrawScope
import androidx.compose.ui.graphics.drawscope.DrawScope
import androidx.compose.ui.graphics.drawscope.Stroke
import androidx.compose.ui.graphics.Canvas as GraphicsCanvas
import androidx.compose.ui.input.pointer.pointerInput
import androidx.compose.ui.layout.layout
import androidx.compose.ui.input.pointer.positionChange
import androidx.compose.ui.semantics.CustomAccessibilityAction
import androidx.compose.ui.semantics.contentDescription
import androidx.compose.ui.semantics.customActions
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.semantics.stateDescription
import androidx.compose.ui.unit.Density
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.LayoutDirection
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 java.util.Locale

@Immutable
class SignatureStroke(val points: List<Offset>)

fun List<SignatureStroke>.toPath(scale: Float = 1f): Path {
    val path = Path()
    forEach { stroke ->
        val points = stroke.points
        if (points.isEmpty()) return@forEach
        val first = points.first() * scale
        path.moveTo(first.x, first.y)
        if (points.size == 1) {
            path.lineTo(first.x + 0.01f, first.y)
            return@forEach
        }
        for (i in 1 until points.size) {
            val previous = points[i - 1] * scale
            val current = points[i] * scale
            val middle = (previous + current) / 2f
            if (i == 1) path.lineTo(middle.x, middle.y) else path.quadraticTo(previous.x, previous.y, middle.x, middle.y)
        }
        val last = points.last() * scale
        path.lineTo(last.x, last.y)
    }
    return path
}

fun List<SignatureStroke>.toSvg(width: Float, height: Float, strokeWidth: Float = 3f, color: String = "#000000"): String {
    fun format(value: Float) = String.format(Locale.US, "%.1f", value)
    val paths = joinToString("") { stroke ->
        val points = stroke.points
        if (points.isEmpty()) return@joinToString ""
        val data = StringBuilder("M${format(points[0].x)} ${format(points[0].y)}")
        if (points.size == 1) data.append(" l0.01 0")
        for (i in 1 until points.size) {
            val previous = points[i - 1]
            val middle = (previous + points[i]) / 2f
            if (i == 1) data.append(" L${format(middle.x)} ${format(middle.y)}")
            else data.append(" Q${format(previous.x)} ${format(previous.y)} ${format(middle.x)} ${format(middle.y)}")
        }
        if (points.size > 1) data.append(" L${format(points.last().x)} ${format(points.last().y)}")
        "<path d=\"$data\"/>"
    }
    return "<svg xmlns=\"http://www.w3.org/2000/svg\" viewBox=\"0 0 ${format(width)} ${format(height)}\" width=\"${format(width)}\" height=\"${format(height)}\">" +
        "<g fill=\"none\" stroke=\"$color\" stroke-width=\"${format(strokeWidth)}\" stroke-linecap=\"round\" stroke-linejoin=\"round\">$paths</g></svg>"
}

fun List<SignatureStroke>.toImageBitmap(
    width: Dp,
    height: Dp,
    density: Density,
    color: Color = Color.Black,
    strokeWidth: Dp = 3.dp,
    background: Color = Color.Transparent,
): ImageBitmap {
    val bitmap = with(density) { ImageBitmap(width.roundToPx().coerceAtLeast(1), height.roundToPx().coerceAtLeast(1)) }
    val scope = CanvasDrawScope()
    val size = Size(bitmap.width.toFloat(), bitmap.height.toFloat())
    scope.draw(density, LayoutDirection.Ltr, GraphicsCanvas(bitmap), size) {
        if (background != Color.Transparent) drawRect(background)
        drawSignature(this@toImageBitmap, density.density, color, strokeWidth.toPx())
    }
    return bitmap
}

private fun DrawScope.drawSignature(strokes: List<SignatureStroke>, scale: Float, color: Color, width: Float) {
    drawPath(strokes.toPath(scale), color, style = Stroke(width, cap = StrokeCap.Round, join = StrokeJoin.Round))
}

@Composable
fun SignaturePad(
    modifier: Modifier = Modifier,
    value: List<SignatureStroke>? = null,
    onValueChange: ((List<SignatureStroke>) -> Unit)? = null,
    defaultValue: List<SignatureStroke> = emptyList(),
    strokeWidth: Dp = 3.dp,
    enabled: Boolean = true,
    placeholder: String = "Sign here",
    clearLabel: String = "Clear",
    showClearButton: Boolean = true,
) {
    val colors = EsuissTheme.colors
    var uncontrolled by remember { mutableStateOf(defaultValue) }
    val strokes = value ?: uncontrolled
    val latest by rememberUpdatedState(strokes)
    val change by rememberUpdatedState<(List<SignatureStroke>) -> Unit>({ next ->
        if (value == null) uncontrolled = next
        onValueChange?.invoke(next)
    })
    val live = remember { mutableStateListOf<Offset>() }
    val empty = strokes.isEmpty() && live.isEmpty()
    val shape = RoundedCornerShape(Radius.xl)
    val ink = if (enabled) colors.label else colors.labelQuaternary
    val guide = colors.separatorStrong
    Box(
        modifier = modifier
            .fillMaxWidth()
            .height(200.dp)
            .clip(shape)
            .background(if (enabled) colors.surface else colors.controlDisabled, shape)
            .border(1.dp, colors.separator, shape)
            .semantics {
                contentDescription = "Signature pad"
                stateDescription = if (strokes.isEmpty()) "Empty" else "Signed"
                if (enabled && strokes.isNotEmpty()) {
                    customActions = listOf(
                        CustomAccessibilityAction(clearLabel) {
                            change(emptyList())
                            true
                        },
                    )
                }
            },
    ) {
        Canvas(
            modifier = Modifier
                .matchParentSize()
                .then(
                    if (!enabled) {
                        Modifier
                    } else {
                        Modifier.pointerInput(Unit) {
                            awaitEachGesture {
                                val down = awaitFirstDown()
                                down.consume()
                                val scale = density
                                live.clear()
                                live.add(down.position / scale)
                                while (true) {
                                    val event = awaitPointerEvent()
                                    val pointer = event.changes.firstOrNull { it.id == down.id } ?: break
                                    if (!pointer.pressed) break
                                    if (pointer.positionChange() != Offset.Zero) {
                                        live.add(pointer.position / scale)
                                        pointer.consume()
                                    }
                                }
                                val stroke = SignatureStroke(live.toList())
                                live.clear()
                                change(latest + stroke)
                            }
                        }
                    },
                ),
        ) {
            val inset = 24.dp.toPx()
            val baseline = size.height * 0.72f
            drawLine(
                guide,
                Offset(inset, baseline),
                Offset(size.width - inset, baseline),
                strokeWidth = 1.dp.toPx(),
                pathEffect = PathEffect.dashPathEffect(floatArrayOf(4.dp.toPx(), 4.dp.toPx())),
            )
            val width = strokeWidth.toPx()
            drawSignature(strokes, density, ink, width)
            if (live.isNotEmpty()) drawSignature(listOf(SignatureStroke(live.toList())), density, ink, width)
        }
        if (empty) {
            BasicText(
                placeholder,
                modifier = Modifier.layout { measurable, constraints ->
                    val placeable = measurable.measure(constraints.copy(minWidth = 0, minHeight = 0))
                    layout(constraints.maxWidth, constraints.maxHeight) {
                        placeable.place(24.dp.roundToPx(), (constraints.maxHeight * 0.72f).toInt() + 8.dp.roundToPx())
                    }
                },
                style = Typography.sm.copy(color = colors.labelTertiary),
            )
        }
        if (showClearButton && enabled && strokes.isNotEmpty()) {
            Button(
                text = clearLabel,
                onClick = { change(emptyList()) },
                modifier = Modifier
                    .align(Alignment.TopEnd)
                    .padding(8.dp),
                variant = ButtonVariant.Ghost,
                size = ButtonSize.Sm,
            )
        }
    }
}
```

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

## Usage

```tsx
import { MessageGroup, Message, MessageAvatar, MessageContent, MessageHeader, MessageFooter } from "@/components/ui/message"
```

```tsx
<Message align="start">
  <MessageAvatar>
    <Avatar>
      <AvatarFallback>MK</AvatarFallback>
    </Avatar>
  </MessageAvatar>
  <MessageContent>
    <Bubble variant="muted">
      <BubbleContent>Are we still on for lunch tomorrow?</BubbleContent>
    </Bubble>
  </MessageContent>
</Message>
```

Put a `MessageAvatar` and a `MessageContent` inside each `Message`, and place `Bubble` components, a `MessageHeader` and a `MessageFooter` in `MessageContent`.

Plain strings in `MessageHeader` and `MessageFooter` are wrapped in `Text` for you, so you can pass text directly or mix it with an `Icon`.

When `MessageContent` contains a `MessageFooter`, the avatar shifts up so it lines up with the last bubble instead of the footer.

## Examples

### Align end

A message aligned to the trailing side, as for the current user.

![Preview](https://uim.suiss.app/previews/components-message--align-end.light.webp)

```tsx
import { Bubble, BubbleContent } from "@/components/ui/bubble"
import { Message, MessageContent } from "@/components/ui/message"

export function MessageAlignEndExample() {
  return (
    <Message align="end">
      <MessageContent>
        <Bubble>
          <BubbleContent>Yes, see you at noon.</BubbleContent>
        </Bubble>
      </MessageContent>
    </Message>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct MessageAlignEndExample: View {
  var body: some View {
    Message(align: .end) {
      MessageContent {
        Bubble {
          BubbleContent("Yes, see you at noon.")
        }
      }
    }
  }
}
```

```kotlin
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import com.esuiss.ui.components.Bubble
import com.esuiss.ui.components.BubbleContent
import com.esuiss.ui.components.Message
import com.esuiss.ui.components.MessageAlign
import com.esuiss.ui.components.MessageContent

@Composable
fun MessageAlignEnd() {
    Message(Modifier.fillMaxWidth(), align = MessageAlign.End) {
        MessageContent {
            Bubble {
                BubbleContent("Yes, see you at noon.")
            }
        }
    }
}
```

### With header and footer

A message with a sender name above and a timestamp below.

![Preview](https://uim.suiss.app/previews/components-message--with-header-and-footer.light.webp)

```tsx
import { Avatar, AvatarFallback } from "@/components/ui/avatar"
import { Bubble, BubbleContent } from "@/components/ui/bubble"
import { Message, MessageAvatar, MessageContent, MessageFooter, MessageHeader } from "@/components/ui/message"

export function MessageWithHeaderAndFooterExample() {
  return (
    <Message align="start">
      <MessageAvatar>
        <Avatar>
          <AvatarFallback>JL</AvatarFallback>
        </Avatar>
      </MessageAvatar>
      <MessageContent>
        <MessageHeader>Jordan Lee</MessageHeader>
        <Bubble variant="muted">
          <BubbleContent>
            I pushed the updated designs to the shared folder.
          </BubbleContent>
        </Bubble>
        <MessageFooter>9:41 AM</MessageFooter>
      </MessageContent>
    </Message>
  )
}
```

```swift
import EsuissUI
import SwiftUI

struct MessageWithHeaderAndFooterExample: View {
  var body: some View {
    Message {
      MessageAvatar {
        Avatar { AvatarFallback("JL") }
      }
      MessageContent {
        MessageHeader(verbatim: "Jordan Lee")
        Bubble(variant: .muted) {
          BubbleContent("I pushed the updated designs to the shared folder.")
        }
        MessageFooter(verbatim: "9:41 AM")
      }
    }
  }
}
```

```kotlin
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import com.esuiss.ui.components.Avatar
import com.esuiss.ui.components.AvatarFallback
import com.esuiss.ui.components.Bubble
import com.esuiss.ui.components.BubbleContent
import com.esuiss.ui.components.BubbleVariant
import com.esuiss.ui.components.Message
import com.esuiss.ui.components.MessageAvatar
import com.esuiss.ui.components.MessageContent
import com.esuiss.ui.components.MessageFooter
import com.esuiss.ui.components.MessageHeader

@Composable
fun MessageInitials(text: String) {
    MessageAvatar {
        Avatar(fallback = { AvatarFallback(text) })
    }
}

@Composable
fun MessageWithHeaderAndFooter() {
    Message(Modifier.fillMaxWidth()) {
        MessageInitials("JL")
        MessageContent {
            MessageHeader("Jordan Lee")
            Bubble(variant = BubbleVariant.Muted) {
                BubbleContent("I pushed the updated designs to the shared folder.")
            }
            MessageFooter("9:41 AM")
        }
    }
}
```

### Conversation

A `MessageGroup` with an incoming and an outgoing message, including a read receipt footer.

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

```tsx
import { ChecksIcon } from "phosphor-react-native"
import { Avatar, AvatarFallback } from "@/components/ui/avatar"
import { Bubble, BubbleContent } from "@/components/ui/bubble"
import { Icon } from "@/components/ui/icon"
import { Message, MessageAvatar, MessageContent, MessageFooter, MessageGroup } from "@/components/ui/message"
import { Text } from "@/components/ui/text"

export function MessageConversationExample() {
  return (
    <MessageGroup className="gap-4">
      <Message>
        <MessageAvatar>
          <Avatar>
            <AvatarFallback>MK</AvatarFallback>
          </Avatar>
        </MessageAvatar>
        <MessageContent>
          <Bubble variant="muted">
            <BubbleContent>Did the build pass?</BubbleContent>
          </Bubble>
          <Bubble variant="muted">
            <BubbleContent>I want to ship before the weekend.</BubbleContent>
          </Bubble>
        </MessageContent>
      </Message>
      <Message align="end">
        <MessageContent>
          <Bubble>
            <BubbleContent>All green. Merging it now.</BubbleContent>
          </Bubble>
          <MessageFooter className="gap-1">
            <Icon as={ChecksIcon} className="text-accent" />
            <Text>Read 10:02 AM</Text>
          </MessageFooter>
        </MessageContent>
      </Message>
    </MessageGroup>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct MessageConversationExample: View {
  var body: some View {
    MessageGroup(spacing: 16) {
      Message {
        MessageAvatar {
          Avatar { AvatarFallback("MK") }
        }
        MessageContent {
          Bubble(variant: .muted) {
            BubbleContent("Did the build pass?")
          }
          Bubble(variant: .muted) {
            BubbleContent("I want to ship before the weekend.")
          }
        }
      }
      Message(align: .end) {
        MessageContent {
          Bubble {
            BubbleContent("All green. Merging it now.")
          }
          MessageFooter {
            Ph.checks.regular
              .frame(width: 16, height: 16)
              .foregroundStyle(Color.accent)
            Text("Read 10:02 AM")
          }
        }
      }
    }
  }
}
```

```kotlin
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.Checks
import com.esuiss.ui.components.Avatar
import com.esuiss.ui.components.AvatarFallback
import com.esuiss.ui.components.Bubble
import com.esuiss.ui.components.BubbleContent
import com.esuiss.ui.components.BubbleVariant
import com.esuiss.ui.components.Icon
import com.esuiss.ui.components.Message
import com.esuiss.ui.components.MessageAlign
import com.esuiss.ui.components.MessageAvatar
import com.esuiss.ui.components.MessageContent
import com.esuiss.ui.components.MessageFooter
import com.esuiss.ui.components.MessageGroup
import com.esuiss.ui.components.Text
import com.esuiss.ui.theme.EsuissTheme

@Composable
fun MessageInitials(text: String) {
    MessageAvatar {
        Avatar(fallback = { AvatarFallback(text) })
    }
}

@Composable
fun MessageConversation() {
    MessageGroup(Modifier.fillMaxWidth()) {
        Column(verticalArrangement = Arrangement.spacedBy(16.dp)) {
            Message(Modifier.fillMaxWidth()) {
                MessageInitials("MK")
                MessageContent {
                    Bubble(variant = BubbleVariant.Muted) {
                        BubbleContent("Did the build pass?")
                    }
                    Bubble(variant = BubbleVariant.Muted) {
                        BubbleContent("I want to ship before the weekend.")
                    }
                }
            }
            Message(Modifier.fillMaxWidth(), align = MessageAlign.End) {
                MessageContent {
                    Bubble {
                        BubbleContent("All green. Merging it now.")
                    }
                    MessageFooter {
                        Icon(PhosphorIcons.Regular.Checks, contentDescription = null, tint = EsuissTheme.colors.accent)
                        Text("Read 10:02 AM")
                    }
                }
            }
        }
    }
}
```

## API Reference

### MessageGroup

Vertical stack of messages.

### Message

Row that holds the avatar and content and sets the alignment.

### MessageAvatar

Round slot for an avatar, pinned to the bottom of the row.

### MessageContent

Column of bubbles built on `BubbleGroup`.

### MessageHeader

Small secondary text above the bubbles.

### MessageFooter

Small secondary text below the bubbles, aligned with the message side.

## Accessibility

- Messages are plain `View` and `Text` elements, so screen readers read the header, bubble text and footer in order.
- Give avatars without visible text, such as images, an `accessibilityLabel`.

## Notes

- Header and footer text use `text-xs text-label-secondary`, with icons at `size-3.5`.
- The avatar slot uses `bg-surface-secondary`.
- Light and dark colors follow the system appearance.