# Top Banner

Short banners that slide in from the top of the screen, queue one at a time and can be swiped up to dismiss.

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

Source: https://uim.suiss.app/docs/interactions/top-banner

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

```tsx
import { WifiSlashIcon } from "phosphor-react-native"
import * as React from "react"
import { View } from "react-native"
import { TopBannerProvider, useTopBanner } from "@/components/interactions/top-banner"
import { Button } from "@/components/ui/button"
import { Text } from "@/components/ui/text"

function Triggers() {
  const { show, dismiss } = useTopBanner()
  const [log, setLog] = React.useState("")
  return (
    <View className="w-full gap-3">
      <Button
        variant="outline"
        onPress={() =>
          show({
            title: "Message sent",
            description: "Alex will see it the next time they open the app.",
          })
        }
      >
        <Text>Show banner</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() =>
          show({
            icon: WifiSlashIcon,
            title: "You are offline",
            description: "Changes will sync when you reconnect.",
            action: { label: "Retry", onPress: () => setLog("Retry pressed") },
          })
        }
      >
        <Text>Show with icon and action</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() => {
          show({ title: "First of three" })
          show({ title: "Second of three" })
          show({ title: "Third of three" })
        }}
      >
        <Text>Queue three</Text>
      </Button>
      <Button variant="ghost" onPress={() => dismiss()}>
        <Text>Dismiss current</Text>
      </Button>
      <Text role="status" className="text-sm text-label-secondary">
        {log}
      </Text>
    </View>
  )
}

export function TopBannerExample() {
  return (
    <TopBannerProvider>
      <Triggers />
    </TopBannerProvider>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct TopBannerExample: View {
  var body: some View {
    TopBannerStage(timeout: .seconds(4))
  }
}

struct TopBannerStage: View {
  var timeout: Duration = .seconds(600)
  var onMount: (@MainActor (TopBannerManager) -> Void)?

  @State private var manager = TopBannerManager()
  @State private var shown = false

  init(timeout: Duration = .seconds(600), onMount: (@MainActor (TopBannerManager) -> Void)? = nil) {
    self.timeout = timeout
    self.onMount = onMount
  }

  var body: some View {
    TopBannerTriggers(manager: manager)
      .frame(maxHeight: .infinity, alignment: .top)
      .containerRelativeFrame(.vertical) { height, _ in height - 32 }
      .topBanner(manager, timeout: timeout)
      .onAppear {
        guard !shown else { return }
        shown = true
        manager.timeout = timeout
        onMount?(manager)
      }
  }
}

struct TopBannerTriggers: View {
  let manager: TopBannerManager

  @State private var log = ""

  var body: some View {
    VStack(spacing: 12) {
      Button {
        manager.show("Message sent", description: "Alex will see it the next time they open the app.")
      } label: {
        Text("Show banner").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show(
          "You are offline",
          description: "Changes will sync when you reconnect.",
          icon: Ph.wifiSlash.regular,
          action: TopBannerAction("Retry") { log = "Retry pressed" }
        )
      } label: {
        Text("Show with icon and action").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show("First of three")
        manager.show("Second of three")
        manager.show("Third of three")
      } label: {
        Text("Queue three").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.dismiss()
      } label: {
        Text("Dismiss current").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.ghost))
      Text(verbatim: log)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .frame(maxWidth: .infinity, alignment: .leading)
        .accessibilityAddTraits(.updatesFrequently)
    }
  }
}
```

```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.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.WifiSlash
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.TopBannerAction
import com.esuiss.ui.interactions.TopBannerProvider
import com.esuiss.ui.interactions.TopBannerState
import com.esuiss.ui.interactions.rememberTopBannerState
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

@Composable
fun TopBannerExample() {
    TopBannerDemo(timeout = 4000L)
}

@Composable
fun TopBannerDemo(timeout: Long = 600000L, onMount: (TopBannerState.() -> Unit)? = null) {
    val state = rememberTopBannerState(defaultTimeoutMillis = timeout)
    var shown by rememberSaveable { mutableStateOf(false) }
    LaunchedEffect(Unit) {
        if (shown || onMount == null) return@LaunchedEffect
        shown = true
        state.onMount()
    }
    TopBannerProvider(state) {
        TopBannerTriggers(state)
    }
}

@Composable
fun TopBannerTriggers(state: TopBannerState) {
    var log by rememberSaveable { mutableStateOf("") }
    val fill = Modifier.fillMaxWidth()
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Button(
            "Show banner",
            onClick = { state.show("Message sent", description = "Alex will see it the next time they open the app.") },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Show with icon and action",
            onClick = {
                state.show(
                    "You are offline",
                    description = "Changes will sync when you reconnect.",
                    icon = PhosphorIcons.Regular.WifiSlash,
                    action = TopBannerAction("Retry") { log = "Retry pressed" },
                )
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Queue three",
            onClick = {
                state.show("First of three")
                state.show("Second of three")
                state.show("Third of three")
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button("Dismiss current", onClick = { state.dismiss() }, modifier = fill, variant = ButtonVariant.Ghost)
        Text(
            log,
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
        )
    }
}
```

`TopBannerProvider` shows banners requested with `show` from `useTopBanner`. Each banner slides down below the top safe area with a title, an optional description, icon and action button, and hides after 4 seconds by default.

Banners queue and appear one at a time, with a short pause between them. Swiping a banner up past a small distance, or flicking it up, dismisses it; dragging pauses the timer. Use it for brief confirmations and status updates, such as a copied link or a restored connection.

## Installation

```bash title="Terminal"
npx @esuiss/uim@latest add top-banner
```

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

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

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

### Manual

**Uniwind**

1. Install the dependencies:

```bash title="Terminal"
npx expo install cn phosphor-react-native react-native-gesture-handler react-native-reanimated react-native-safe-area-context react-native-svg react-native-worklets
```

2. Add the pieces it builds on: [Button](/docs/components/button), [Icon](/docs/components/icon), [Text](/docs/components/text), and the primitives `components/primitives/portal.tsx`.

3. Copy the source into `components/interactions/top-banner.tsx`:

```tsx title="uniwind/components/interactions/top-banner.tsx"
import { cn } from "cn"
import type { Icon as PhosphorIcon } from "phosphor-react-native"
import * as React from "react"
import { AccessibilityInfo, useWindowDimensions, View } from "react-native"
import { Gesture, GestureDetector } from "react-native-gesture-handler"
import {
  Easing,
  Keyframe,
  ReduceMotion,
  runOnJS,
  useAnimatedStyle,
  useSharedValue,
  withSpring,
  withTiming,
} from "react-native-reanimated"
import { useSafeAreaInsets } from "react-native-safe-area-context"
import { Portal } from "@/components/primitives/portal"
import { AnimatedView } from "@/components/ui/animated-view"
import { Button } from "@/components/ui/button"
import { Icon } from "@/components/ui/icon"
import { Text } from "@/components/ui/text"

type TopBannerOptions = {
  title: React.ReactNode
  description?: React.ReactNode
  icon?: PhosphorIcon
  action?: { label: React.ReactNode; onPress: () => void }
  timeout?: number
}

type TopBannerEntry = TopBannerOptions & { id: number }

type TopBannerContextProps = {
  show: (options: TopBannerOptions) => number
  dismiss: (id?: number) => void
}

const TopBannerContext = React.createContext<TopBannerContextProps | null>(null)

function useTopBanner() {
  const context = React.useContext(TopBannerContext)
  if (!context) {
    throw new Error("useTopBanner must be used within a <TopBannerProvider />")
  }
  return context
}

const MAX_WIDTH = 384

const GAP = 300

const EASING = Easing.bezier(0.32, 0.72, 0, 1)

const ENTERING = new Keyframe({
  0: { opacity: 0, transform: [{ translateY: -80 }, { scale: 0.95 }] },
  100: {
    opacity: 1,
    transform: [{ translateY: 0 }, { scale: 1 }],
    easing: EASING,
  },
})
  .duration(400)
  .reduceMotion(ReduceMotion.System)

const EXITING = new Keyframe({
  0: { opacity: 1, transform: [{ translateY: 0 }, { scale: 1 }] },
  100: {
    opacity: 0,
    transform: [{ translateY: -80 }, { scale: 0.95 }],
    easing: EASING,
  },
})
  .duration(300)
  .reduceMotion(ReduceMotion.System)

let nextId = 0

function wrapText(children: React.ReactNode, className: string) {
  if (typeof children === "string" || typeof children === "number") {
    return <Text className={className}>{children}</Text>
  }
  return children
}

function TopBannerView({
  entry,
  top,
  inset,
  swiped,
  className,
  onSwipe,
  onPause,
  onDismiss,
}: {
  entry: TopBannerEntry
  top: number
  inset: number
  swiped: boolean
  className?: string
  onSwipe: () => void
  onPause: (paused: boolean) => void
  onDismiss: () => void
}) {
  const translateY = useSharedValue(0)
  const height = useSharedValue(0)

  const gesture = React.useMemo(
    () =>
      Gesture.Pan()
        .activeOffsetY([-8, 8])
        .onStart(() => {
          runOnJS(onPause)(true)
        })
        .onUpdate((event) => {
          translateY.value =
            event.translationY < 0
              ? event.translationY
              : event.translationY * 0.2
        })
        .onEnd((event) => {
          if (event.translationY < -32 || event.velocityY < -500) {
            translateY.value = withTiming(
              -(height.value + top + 16),
              { duration: 200, easing: EASING },
              () => {
                runOnJS(onSwipe)()
              }
            )
            return
          }
          translateY.value = withSpring(0, { damping: 20, stiffness: 240 })
          runOnJS(onPause)(false)
        }),
    [translateY, height, top, onSwipe, onPause]
  )

  const animatedStyle = useAnimatedStyle(() => ({
    transform: [{ translateY: translateY.value }],
  }))

  return (
    <AnimatedView
      entering={ENTERING}
      exiting={swiped ? undefined : EXITING}
      className="absolute z-50"
      style={{ top, left: inset, right: inset, pointerEvents: "box-none" }}
    >
      <GestureDetector gesture={gesture}>
        <AnimatedView
          role="alert"
          accessibilityLiveRegion="polite"
          accessibilityActions={[{ name: "dismiss" }]}
          onAccessibilityAction={(event) => {
            if (event.nativeEvent.actionName === "dismiss") onDismiss()
          }}
          onLayout={(event) => {
            height.value = event.nativeEvent.layout.height
          }}
          className={cn(
            "w-full flex-row items-center gap-3 rounded-2xl border border-separator bg-surface-raised p-3.5 shadow-xl dark:bg-surface-secondary",
            className
          )}
          style={animatedStyle}
        >
          {entry.icon ? (
            <Icon as={entry.icon} className="size-6 shrink-0 text-link" />
          ) : null}
          <View className="min-w-0 flex-1 gap-0.5">
            {wrapText(entry.title, "text-sm font-semibold")}
            {entry.description !== undefined
              ? wrapText(entry.description, "text-sm text-label-secondary")
              : null}
          </View>
          {entry.action ? (
            <Button
              variant="tinted"
              size="sm"
              onPress={() => {
                entry.action?.onPress()
                onDismiss()
              }}
            >
              {wrapText(entry.action.label, "font-semibold")}
            </Button>
          ) : null}
        </AnimatedView>
      </GestureDetector>
    </AnimatedView>
  )
}

function TopBannerProvider({
  timeout = 4000,
  className,
  portalHost,
  children,
}: {
  timeout?: number
  className?: string
  portalHost?: string
  children?: React.ReactNode
}) {
  const [queue, setQueue] = React.useState<TopBannerEntry[]>([])
  const [ready, setReady] = React.useState(true)
  const [paused, setPaused] = React.useState(false)
  const [swipedId, setSwipedId] = React.useState<number | null>(null)
  const insets = useSafeAreaInsets()
  const { width } = useWindowDimensions()
  const inset = Math.max(16, (width - MAX_WIDTH) / 2)
  const top = insets.top + 8
  const id = React.useId()
  const current = ready ? queue[0] : undefined

  const show = React.useCallback((options: TopBannerOptions) => {
    nextId += 1
    const entry = { ...options, id: nextId }
    setQueue((items) => [...items, entry])
    return entry.id
  }, [])

  const queueRef = React.useRef(queue)
  queueRef.current = queue

  const dismiss = React.useCallback((entryId?: number) => {
    const first = queueRef.current[0]?.id
    const target = entryId ?? first
    if (target === undefined) return
    if (target === first) {
      setReady(false)
      setPaused(false)
    }
    setQueue((items) => items.filter((item) => item.id !== target))
  }, [])

  React.useEffect(() => {
    if (ready) return
    const timer = setTimeout(() => setReady(true), GAP)
    return () => clearTimeout(timer)
  }, [ready])

  React.useEffect(() => {
    if (!current) return
    if (typeof current.title === "string") {
      AccessibilityInfo.announceForAccessibility(current.title)
    }
  }, [current])

  React.useEffect(() => {
    if (!current || paused) return
    const duration = current.timeout ?? timeout
    if (!Number.isFinite(duration) || duration <= 0) return
    const timer = setTimeout(() => dismiss(current.id), duration)
    return () => clearTimeout(timer)
  }, [current, paused, timeout, dismiss])

  React.useEffect(() => {
    if (swipedId === null) return
    dismiss(swipedId)
    setSwipedId(null)
  }, [swipedId, dismiss])

  const contextValue = React.useMemo(() => ({ show, dismiss }), [show, dismiss])

  return (
    <TopBannerContext.Provider value={contextValue}>
      {children}
      <Portal name={`top-banner-${id}`} hostName={portalHost}>
        <TopBannerContext.Provider value={contextValue}>
          {current ? (
            <TopBannerView
              key={current.id}
              entry={current}
              top={top}
              inset={inset}
              swiped={swipedId === current.id}
              className={className}
              onSwipe={() => setSwipedId(current.id)}
              onPause={setPaused}
              onDismiss={() => dismiss(current.id)}
            />
          ) : null}
        </TopBannerContext.Provider>
      </Portal>
    </TopBannerContext.Provider>
  )
}

export { TopBannerProvider, useTopBanner }
```

4. Update the import paths to match your project.

**NativeWind**

1. Install the dependencies:

```bash title="Terminal"
npx expo install cn phosphor-react-native react-native-gesture-handler react-native-reanimated react-native-safe-area-context react-native-svg react-native-worklets
```

2. Add the pieces it builds on: [Button](/docs/components/button), [Icon](/docs/components/icon), [Text](/docs/components/text), and the primitives `components/primitives/portal.tsx`.

3. Copy the source into `components/interactions/top-banner.tsx`:

```tsx title="nativewind/components/interactions/top-banner.tsx"
import { cn } from "cn"
import type { Icon as PhosphorIcon } from "phosphor-react-native"
import * as React from "react"
import { AccessibilityInfo, useWindowDimensions, View } from "react-native"
import { Gesture, GestureDetector } from "react-native-gesture-handler"
import {
  Easing,
  Keyframe,
  ReduceMotion,
  runOnJS,
  useAnimatedStyle,
  useSharedValue,
  withSpring,
  withTiming,
} from "react-native-reanimated"
import { useSafeAreaInsets } from "react-native-safe-area-context"
import { Portal } from "@/components/primitives/portal"
import { AnimatedView } from "@/components/ui/animated-view"
import { Button } from "@/components/ui/button"
import { Icon } from "@/components/ui/icon"
import { Text } from "@/components/ui/text"

type TopBannerOptions = {
  title: React.ReactNode
  description?: React.ReactNode
  icon?: PhosphorIcon
  action?: { label: React.ReactNode; onPress: () => void }
  timeout?: number
}

type TopBannerEntry = TopBannerOptions & { id: number }

type TopBannerContextProps = {
  show: (options: TopBannerOptions) => number
  dismiss: (id?: number) => void
}

const TopBannerContext = React.createContext<TopBannerContextProps | null>(null)

function useTopBanner() {
  const context = React.useContext(TopBannerContext)
  if (!context) {
    throw new Error("useTopBanner must be used within a <TopBannerProvider />")
  }
  return context
}

const MAX_WIDTH = 384

const GAP = 300

const EASING = Easing.bezier(0.32, 0.72, 0, 1)

const ENTERING = new Keyframe({
  0: { opacity: 0, transform: [{ translateY: -80 }, { scale: 0.95 }] },
  100: {
    opacity: 1,
    transform: [{ translateY: 0 }, { scale: 1 }],
    easing: EASING,
  },
})
  .duration(400)
  .reduceMotion(ReduceMotion.System)

const EXITING = new Keyframe({
  0: { opacity: 1, transform: [{ translateY: 0 }, { scale: 1 }] },
  100: {
    opacity: 0,
    transform: [{ translateY: -80 }, { scale: 0.95 }],
    easing: EASING,
  },
})
  .duration(300)
  .reduceMotion(ReduceMotion.System)

let nextId = 0

function wrapText(children: React.ReactNode, className: string) {
  if (typeof children === "string" || typeof children === "number") {
    return <Text className={className}>{children}</Text>
  }
  return children
}

function TopBannerView({
  entry,
  top,
  inset,
  swiped,
  className,
  onSwipe,
  onPause,
  onDismiss,
}: {
  entry: TopBannerEntry
  top: number
  inset: number
  swiped: boolean
  className?: string
  onSwipe: () => void
  onPause: (paused: boolean) => void
  onDismiss: () => void
}) {
  const translateY = useSharedValue(0)
  const height = useSharedValue(0)

  const gesture = React.useMemo(
    () =>
      Gesture.Pan()
        .activeOffsetY([-8, 8])
        .onStart(() => {
          runOnJS(onPause)(true)
        })
        .onUpdate((event) => {
          translateY.value =
            event.translationY < 0
              ? event.translationY
              : event.translationY * 0.2
        })
        .onEnd((event) => {
          if (event.translationY < -32 || event.velocityY < -500) {
            translateY.value = withTiming(
              -(height.value + top + 16),
              { duration: 200, easing: EASING },
              () => {
                runOnJS(onSwipe)()
              }
            )
            return
          }
          translateY.value = withSpring(0, { damping: 20, stiffness: 240 })
          runOnJS(onPause)(false)
        }),
    [translateY, height, top, onSwipe, onPause]
  )

  const animatedStyle = useAnimatedStyle(() => ({
    transform: [{ translateY: translateY.value }],
  }))

  return (
    <AnimatedView
      entering={ENTERING}
      exiting={swiped ? undefined : EXITING}
      className="absolute z-50"
      style={{ top, left: inset, right: inset, pointerEvents: "box-none" }}
    >
      <GestureDetector gesture={gesture}>
        <AnimatedView
          role="alert"
          accessibilityLiveRegion="polite"
          accessibilityActions={[{ name: "dismiss" }]}
          onAccessibilityAction={(event) => {
            if (event.nativeEvent.actionName === "dismiss") onDismiss()
          }}
          onLayout={(event) => {
            height.value = event.nativeEvent.layout.height
          }}
          className={cn(
            "w-full flex-row items-center gap-3 rounded-2xl border border-separator bg-surface-raised p-3.5 shadow-xl dark:bg-surface-secondary",
            className
          )}
          style={animatedStyle}
        >
          {entry.icon ? (
            <Icon as={entry.icon} className="size-6 shrink-0 text-link" />
          ) : null}
          <View className="min-w-0 flex-1 gap-0.5">
            {wrapText(entry.title, "text-sm font-semibold")}
            {entry.description !== undefined
              ? wrapText(entry.description, "text-sm text-label-secondary")
              : null}
          </View>
          {entry.action ? (
            <Button
              variant="tinted"
              size="sm"
              onPress={() => {
                entry.action?.onPress()
                onDismiss()
              }}
            >
              {wrapText(entry.action.label, "font-semibold")}
            </Button>
          ) : null}
        </AnimatedView>
      </GestureDetector>
    </AnimatedView>
  )
}

function TopBannerProvider({
  timeout = 4000,
  className,
  portalHost,
  children,
}: {
  timeout?: number
  className?: string
  portalHost?: string
  children?: React.ReactNode
}) {
  const [queue, setQueue] = React.useState<TopBannerEntry[]>([])
  const [ready, setReady] = React.useState(true)
  const [paused, setPaused] = React.useState(false)
  const [swipedId, setSwipedId] = React.useState<number | null>(null)
  const insets = useSafeAreaInsets()
  const { width } = useWindowDimensions()
  const inset = Math.max(16, (width - MAX_WIDTH) / 2)
  const top = insets.top + 8
  const id = React.useId()
  const current = ready ? queue[0] : undefined

  const show = React.useCallback((options: TopBannerOptions) => {
    nextId += 1
    const entry = { ...options, id: nextId }
    setQueue((items) => [...items, entry])
    return entry.id
  }, [])

  const queueRef = React.useRef(queue)
  queueRef.current = queue

  const dismiss = React.useCallback((entryId?: number) => {
    const first = queueRef.current[0]?.id
    const target = entryId ?? first
    if (target === undefined) return
    if (target === first) {
      setReady(false)
      setPaused(false)
    }
    setQueue((items) => items.filter((item) => item.id !== target))
  }, [])

  React.useEffect(() => {
    if (ready) return
    const timer = setTimeout(() => setReady(true), GAP)
    return () => clearTimeout(timer)
  }, [ready])

  React.useEffect(() => {
    if (!current) return
    if (typeof current.title === "string") {
      AccessibilityInfo.announceForAccessibility(current.title)
    }
  }, [current])

  React.useEffect(() => {
    if (!current || paused) return
    const duration = current.timeout ?? timeout
    if (!Number.isFinite(duration) || duration <= 0) return
    const timer = setTimeout(() => dismiss(current.id), duration)
    return () => clearTimeout(timer)
  }, [current, paused, timeout, dismiss])

  React.useEffect(() => {
    if (swipedId === null) return
    dismiss(swipedId)
    setSwipedId(null)
  }, [swipedId, dismiss])

  const contextValue = React.useMemo(() => ({ show, dismiss }), [show, dismiss])

  return (
    <TopBannerContext.Provider value={contextValue}>
      {children}
      <Portal name={`top-banner-${id}`} hostName={portalHost}>
        <TopBannerContext.Provider value={contextValue}>
          {current ? (
            <TopBannerView
              key={current.id}
              entry={current}
              top={top}
              inset={inset}
              swiped={swipedId === current.id}
              className={className}
              onSwipe={() => setSwipedId(current.id)}
              onPause={setPaused}
              onDismiss={() => dismiss(current.id)}
            />
          ) : null}
        </TopBannerContext.Provider>
      </Portal>
    </TopBannerContext.Provider>
  )
}

export { TopBannerProvider, useTopBanner }
```

4. Update the import paths to match your project.

**StyleSheet**

1. Install the dependencies:

```bash title="Terminal"
npx expo install phosphor-react-native react-native-gesture-handler react-native-reanimated react-native-safe-area-context react-native-svg react-native-worklets
```

2. Add the pieces it builds on: [Button](/docs/components/button), [Icon](/docs/components/icon), [Text](/docs/components/text), and the primitives `components/primitives/portal.tsx`.

3. Copy the source into `components/interactions/top-banner.tsx`:

```tsx title="stylesheet/components/interactions/top-banner.tsx"
import type { Icon as PhosphorIcon } from "phosphor-react-native"
import * as React from "react"
import {
  AccessibilityInfo,
  type StyleProp,
  StyleSheet,
  type TextStyle,
  useWindowDimensions,
  View,
  type ViewStyle,
} from "react-native"
import { Gesture, GestureDetector } from "react-native-gesture-handler"
import {
  Easing,
  Keyframe,
  ReduceMotion,
  runOnJS,
  useAnimatedStyle,
  useSharedValue,
  withSpring,
  withTiming,
} from "react-native-reanimated"
import { useSafeAreaInsets } from "react-native-safe-area-context"
import { Portal } from "@/components/primitives/portal"
import { AnimatedView } from "@/components/ui/animated-view"
import { Button } from "@/components/ui/button"
import { Icon } from "@/components/ui/icon"
import { Text } from "@/components/ui/text"
import { fontSize, radius, shadow, useTheme } from "@/components/ui/theme"

type TopBannerOptions = {
  title: React.ReactNode
  description?: React.ReactNode
  icon?: PhosphorIcon
  action?: { label: React.ReactNode; onPress: () => void }
  timeout?: number
}

type TopBannerEntry = TopBannerOptions & { id: number }

type TopBannerContextProps = {
  show: (options: TopBannerOptions) => number
  dismiss: (id?: number) => void
}

const TopBannerContext = React.createContext<TopBannerContextProps | null>(null)

function useTopBanner() {
  const context = React.useContext(TopBannerContext)
  if (!context) {
    throw new Error("useTopBanner must be used within a <TopBannerProvider />")
  }
  return context
}

const MAX_WIDTH = 384

const GAP = 300

const EASING = Easing.bezier(0.32, 0.72, 0, 1)

const ENTERING = new Keyframe({
  0: { opacity: 0, transform: [{ translateY: -80 }, { scale: 0.95 }] },
  100: {
    opacity: 1,
    transform: [{ translateY: 0 }, { scale: 1 }],
    easing: EASING,
  },
})
  .duration(400)
  .reduceMotion(ReduceMotion.System)

const EXITING = new Keyframe({
  0: { opacity: 1, transform: [{ translateY: 0 }, { scale: 1 }] },
  100: {
    opacity: 0,
    transform: [{ translateY: -80 }, { scale: 0.95 }],
    easing: EASING,
  },
})
  .duration(300)
  .reduceMotion(ReduceMotion.System)

let nextId = 0

const styles = StyleSheet.create({
  frame: { position: "absolute", zIndex: 50 },
  banner: {
    width: "100%",
    flexDirection: "row",
    alignItems: "center",
    gap: 12,
    borderRadius: radius["2xl"],
    borderWidth: 1,
    padding: 14,
    ...shadow.xl,
  },
  icon: { flexShrink: 0 },
  body: { minWidth: 0, flex: 1, gap: 2 },
  title: { ...fontSize.sm, fontWeight: "600" },
  description: { ...fontSize.sm },
  action: { fontWeight: "600" },
})

function wrapText(children: React.ReactNode, style: TextStyle) {
  if (typeof children === "string" || typeof children === "number") {
    return <Text style={style}>{children}</Text>
  }
  return children
}

function TopBannerView({
  entry,
  top,
  inset,
  swiped,
  style,
  onSwipe,
  onPause,
  onDismiss,
}: {
  entry: TopBannerEntry
  top: number
  inset: number
  swiped: boolean
  style?: StyleProp<ViewStyle>
  onSwipe: () => void
  onPause: (paused: boolean) => void
  onDismiss: () => void
}) {
  const { colors, isDark } = useTheme()
  const translateY = useSharedValue(0)
  const height = useSharedValue(0)

  const gesture = React.useMemo(
    () =>
      Gesture.Pan()
        .activeOffsetY([-8, 8])
        .onStart(() => {
          runOnJS(onPause)(true)
        })
        .onUpdate((event) => {
          translateY.value =
            event.translationY < 0
              ? event.translationY
              : event.translationY * 0.2
        })
        .onEnd((event) => {
          if (event.translationY < -32 || event.velocityY < -500) {
            translateY.value = withTiming(
              -(height.value + top + 16),
              { duration: 200, easing: EASING },
              () => {
                runOnJS(onSwipe)()
              }
            )
            return
          }
          translateY.value = withSpring(0, { damping: 20, stiffness: 240 })
          runOnJS(onPause)(false)
        }),
    [translateY, height, top, onSwipe, onPause]
  )

  const animatedStyle = useAnimatedStyle(() => ({
    transform: [{ translateY: translateY.value }],
  }))

  return (
    <AnimatedView
      entering={ENTERING}
      exiting={swiped ? undefined : EXITING}
      style={[
        styles.frame,
        { top, left: inset, right: inset, pointerEvents: "box-none" },
      ]}
    >
      <GestureDetector gesture={gesture}>
        <AnimatedView
          role="alert"
          accessibilityLiveRegion="polite"
          accessibilityActions={[{ name: "dismiss" }]}
          onAccessibilityAction={(event) => {
            if (event.nativeEvent.actionName === "dismiss") onDismiss()
          }}
          onLayout={(event) => {
            height.value = event.nativeEvent.layout.height
          }}
          style={[
            styles.banner,
            {
              borderColor: colors.separator,
              backgroundColor: isDark
                ? colors.surfaceSecondary
                : colors.surfaceRaised,
            },
            style,
            animatedStyle,
          ]}
        >
          {entry.icon ? (
            <Icon
              as={entry.icon}
              size={24}
              color={colors.link}
              style={styles.icon}
            />
          ) : null}
          <View style={styles.body}>
            {wrapText(entry.title, styles.title)}
            {entry.description !== undefined
              ? wrapText(entry.description, {
                  ...styles.description,
                  color: colors.labelSecondary,
                })
              : null}
          </View>
          {entry.action ? (
            <Button
              variant="tinted"
              size="sm"
              onPress={() => {
                entry.action?.onPress()
                onDismiss()
              }}
            >
              {wrapText(entry.action.label, styles.action)}
            </Button>
          ) : null}
        </AnimatedView>
      </GestureDetector>
    </AnimatedView>
  )
}

function TopBannerProvider({
  timeout = 4000,
  style,
  portalHost,
  children,
}: {
  timeout?: number
  style?: StyleProp<ViewStyle>
  portalHost?: string
  children?: React.ReactNode
}) {
  const [queue, setQueue] = React.useState<TopBannerEntry[]>([])
  const [ready, setReady] = React.useState(true)
  const [paused, setPaused] = React.useState(false)
  const [swipedId, setSwipedId] = React.useState<number | null>(null)
  const insets = useSafeAreaInsets()
  const { width } = useWindowDimensions()
  const inset = Math.max(16, (width - MAX_WIDTH) / 2)
  const top = insets.top + 8
  const id = React.useId()
  const current = ready ? queue[0] : undefined

  const show = React.useCallback((options: TopBannerOptions) => {
    nextId += 1
    const entry = { ...options, id: nextId }
    setQueue((items) => [...items, entry])
    return entry.id
  }, [])

  const queueRef = React.useRef(queue)
  queueRef.current = queue

  const dismiss = React.useCallback((entryId?: number) => {
    const first = queueRef.current[0]?.id
    const target = entryId ?? first
    if (target === undefined) return
    if (target === first) {
      setReady(false)
      setPaused(false)
    }
    setQueue((items) => items.filter((item) => item.id !== target))
  }, [])

  React.useEffect(() => {
    if (ready) return
    const timer = setTimeout(() => setReady(true), GAP)
    return () => clearTimeout(timer)
  }, [ready])

  React.useEffect(() => {
    if (!current) return
    if (typeof current.title === "string") {
      AccessibilityInfo.announceForAccessibility(current.title)
    }
  }, [current])

  React.useEffect(() => {
    if (!current || paused) return
    const duration = current.timeout ?? timeout
    if (!Number.isFinite(duration) || duration <= 0) return
    const timer = setTimeout(() => dismiss(current.id), duration)
    return () => clearTimeout(timer)
  }, [current, paused, timeout, dismiss])

  React.useEffect(() => {
    if (swipedId === null) return
    dismiss(swipedId)
    setSwipedId(null)
  }, [swipedId, dismiss])

  const contextValue = React.useMemo(() => ({ show, dismiss }), [show, dismiss])

  return (
    <TopBannerContext.Provider value={contextValue}>
      {children}
      <Portal name={`top-banner-${id}`} hostName={portalHost}>
        <TopBannerContext.Provider value={contextValue}>
          {current ? (
            <TopBannerView
              key={current.id}
              entry={current}
              top={top}
              inset={inset}
              swiped={swipedId === current.id}
              style={style}
              onSwipe={() => setSwipedId(current.id)}
              onPause={setPaused}
              onDismiss={() => dismiss(current.id)}
            />
          ) : null}
        </TopBannerContext.Provider>
      </Portal>
    </TopBannerContext.Provider>
  )
}

export { TopBannerProvider, useTopBanner }
```

4. Update the import paths to match your project.

**SwiftUI**

1. Target iOS 17 or later.

2. Add the Swift package to your app:

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

3. Copy the theme files every view uses:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

4. Copy the source and every file it uses:

```swift title="swift/Interactions/TopBanner.swift"
import Observation
import PhosphorSwift
import SwiftUI

public struct TopBannerAction: Sendable {
  public let title: LocalizedStringResource
  public let action: @MainActor @Sendable () -> Void

  public init(_ title: LocalizedStringResource, action: @escaping @MainActor @Sendable () -> Void) {
    self.title = title
    self.action = action
  }
}

public struct TopBannerItem: Identifiable, @unchecked Sendable {
  public let id: UUID
  public let title: LocalizedStringResource
  public let description: LocalizedStringResource?
  public let icon: Image?
  public let action: TopBannerAction?
  public let duration: Duration?
}

@Observable
public final class TopBannerManager: @unchecked Sendable {
  public static let shared = TopBannerManager()

  public private(set) var queue: [TopBannerItem] = []
  public var timeout: Duration = .seconds(4)

  @ObservationIgnored private var timer: Task<Void, Never>?
  @ObservationIgnored private var scheduled: UUID?

  public init() {}

  public var current: TopBannerItem? { queue.first }

  @MainActor @discardableResult
  public func show(
    _ title: LocalizedStringResource,
    description: LocalizedStringResource? = nil,
    icon: Image? = nil,
    action: TopBannerAction? = nil,
    duration: Duration? = nil
  ) -> UUID {
    let item = TopBannerItem(
      id: UUID(),
      title: title,
      description: description,
      icon: icon,
      action: action,
      duration: duration
    )
    queue.append(item)
    advance()
    return item.id
  }

  @MainActor
  public func dismiss(_ id: UUID? = nil) {
    guard let target = id ?? queue.first?.id else { return }
    queue.removeAll { $0.id == target }
    advance()
  }

  @MainActor
  public func dismissAll() {
    queue.removeAll()
    advance()
  }

  @MainActor
  private func advance() {
    guard let item = queue.first else {
      timer?.cancel()
      timer = nil
      scheduled = nil
      return
    }
    guard scheduled != item.id else { return }
    timer?.cancel()
    scheduled = item.id
    let title = String(localized: item.title)
    let detail = item.description.map { String(localized: $0) }
    AccessibilityNotification.Announcement([title, detail].compactMap { $0 }.joined(separator: ". ")).post()
    let wait = item.duration ?? timeout
    timer = Task { @MainActor [weak self] in
      try? await Task.sleep(for: wait)
      guard !Task.isCancelled, let self, self.queue.first?.id == item.id else { return }
      self.dismiss(item.id)
    }
  }
}

extension EnvironmentValues {
  @Entry public var topBannerManager: TopBannerManager = .shared
}

extension View {
  public func topBanner(_ manager: TopBannerManager = .shared, timeout: Duration = .seconds(4)) -> some View {
    overlay(alignment: .top) {
      TopBannerRegion(manager: manager)
    }
    .environment(\.topBannerManager, manager)
    .onAppear { manager.timeout = timeout }
    .onChange(of: timeout) { _, value in manager.timeout = value }
  }
}

struct TopBannerRegion: View {
  let manager: TopBannerManager

  @Environment(\.accessibilityReduceMotion) private var reduceMotion

  var body: some View {
    ZStack(alignment: .top) {
      if let item = manager.current {
        TopBannerCard(item: item) { manager.dismiss(item.id) }
          .id(item.id)
          .transition(reduceMotion ? .opacity : .move(edge: .top).combined(with: .opacity))
      }
    }
    .animation(reduceMotion ? .linear(duration: 0.2) : .timingCurve(0.32, 0.72, 0, 1, duration: 0.4), value: manager.current?.id)
  }
}

struct TopBannerCard: View {
  let item: TopBannerItem
  let onDismiss: () -> Void

  @State private var drag: CGFloat = 0
  @Environment(\.colorScheme) private var colorScheme

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
    let dark = colorScheme == .dark
    HStack(spacing: 12) {
      if let icon = item.icon {
        icon
          .frame(width: 20, height: 20)
          .foregroundStyle(Color.link)
          .frame(width: 36, height: 36)
          .background(Color.accentSurface, in: Circle())
          .accessibilityHidden(true)
      }
      VStack(alignment: .leading, spacing: 2) {
        Text(item.title)
          .scaledFont(.sm, weight: .semibold)
          .foregroundStyle(Color.label)
        if let description = item.description {
          Text(description)
            .scaledFont(.sm)
            .foregroundStyle(Color.labelSecondary)
            .lineLimit(3)
        }
      }
      .lineLimit(2)
      .fixedSize(horizontal: false, vertical: true)
      .frame(maxWidth: .infinity, alignment: .leading)
      if let action = item.action {
        Button {
          action.action()
          onDismiss()
        } label: {
          Text(action.title)
        }
        .buttonStyle(.variant(.tinted, size: .sm))
      }
    }
    .padding(.horizontal, 14)
    .padding(.vertical, 12)
    .frame(maxWidth: 512)
    .background {
      shape
        .fill(Color.surfaceRaised)
        .shadow(dark ? .lg : Shadow(color: .black.opacity(0.14), radius: 16, y: 8))
    }
    .overlay {
      if !dark { shape.strokeBorder(Color.label.opacity(0.05)) }
    }
    .padding(.horizontal, 12)
    .padding(.top, 4)
    .offset(y: min(drag, 0) + max(drag, 0) / 6)
    .gesture(
      DragGesture(minimumDistance: 8)
        .onChanged { value in
          drag = value.translation.height
        }
        .onEnded { value in
          if drag < -24 || value.predictedEndTranslation.height < -80 {
            onDismiss()
          } else {
            withAnimation(.spring(duration: 0.3)) { drag = 0 }
          }
        }
    )
    .accessibilityElement(children: .contain)
    .accessibilityAction(.escape, onDismiss)
    .accessibilityAction(named: Text("Dismiss"), onDismiss)
  }
}
```

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

enum ButtonGroupSpace: Hashable {
  case group
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

private struct ButtonGroupClip: ViewModifier {
  let shape: AnyShape?

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

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

  @Environment(\.buttonGroup) private var group

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

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

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

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

public struct ButtonGroupSeparator: View {
  let orientation: Axis

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

  public var body: some View {
    let vertical = orientation == .vertical
    Rectangle()
      .fill(Color.label.opacity(0.2))
      .frame(width: vertical ? 1 : nil, height: vertical ? nil : 1)
      .padding(vertical ? .vertical : .horizontal, 9)
      .frame(maxWidth: vertical ? nil : .infinity, maxHeight: vertical ? .infinity : nil)
      .padding(vertical ? .trailing : .bottom, -1)
      .zIndex(1)
      .accessibilityHidden(true)
  }
}
```

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

public struct FieldTitle: View {
  let text: Text

  @Environment(\.isEnabled) private var isEnabled

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

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

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

public struct FieldDescription: View {
  let text: Text

  @Environment(\.fieldSetInset) private var inset

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

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

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

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

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

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

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

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

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

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

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

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

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

struct FieldSetInsetKey: PreferenceKey {
  static let defaultValue = false

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

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

  @State private var inset = false

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

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

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

  let text: Text
  let variant: Variant

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

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

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

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

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

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

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

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

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

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

extension EnvironmentValues {
  @Entry public var hapticsEnabled = true
}

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

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

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

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

  @Environment(\.hapticsEnabled) private var enabled

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

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

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

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

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

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

  @State private var count = 0

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

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

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

public struct Separator: View {
  let orientation: Axis

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

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

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

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

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

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

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

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

private struct TextVariantModifier: ViewModifier {
  let variant: TextVariant

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

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

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

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

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

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

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

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

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

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

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

5. Add the files to your app target.

**Jetpack Compose**

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

```kotlin title="build.gradle.kts"
implementation(platform("androidx.compose:compose-bom:2026.09.00"))
implementation("androidx.compose.foundation:foundation")
implementation("androidx.compose.ui:ui")
```

2. Copy the theme files every view uses:

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

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

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

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

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

val LocalColors = staticCompositionLocalOf { LightColors }

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

    val typography: Typography
        get() = Typography

    val radius: Radius
        get() = Radius

    val shadows: Shadows
        get() = Shadows
}

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

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

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

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

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

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

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

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

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

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

3. Copy the source and every file it uses:

```kt title="kotlin/interactions/TopBanner.kt"
package com.esuiss.ui.interactions

import androidx.compose.animation.core.Animatable
import androidx.compose.animation.core.tween
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.gestures.Orientation
import androidx.compose.foundation.gestures.draggable
import androidx.compose.foundation.gestures.rememberDraggableState
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.WindowInsets
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.layout.statusBars
import androidx.compose.foundation.layout.width
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.Immutable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.Stable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.key
import androidx.compose.runtime.mutableIntStateOf
import androidx.compose.runtime.mutableStateListOf
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.graphicsLayer
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.layout.onGloballyPositioned
import androidx.compose.ui.layout.onSizeChanged
import androidx.compose.ui.layout.positionOnScreen
import androidx.compose.ui.platform.LocalDensity
import androidx.compose.ui.platform.LocalWindowInfo
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.dismiss
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.unit.Dp
import androidx.compose.ui.unit.IntOffset
import androidx.compose.ui.unit.IntRect
import androidx.compose.ui.unit.IntSize
import androidx.compose.ui.unit.LayoutDirection
import androidx.compose.ui.unit.dp
import androidx.compose.ui.window.Popup
import androidx.compose.ui.window.PopupPositionProvider
import androidx.compose.ui.window.PopupProperties
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonSize
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.FormEasing
import com.esuiss.ui.components.Icon
import com.esuiss.ui.components.formReducedMotion
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Shadows
import com.esuiss.ui.theme.Typography
import com.esuiss.ui.theme.shadow
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch

private val TopBannerMaxWidth = 420.dp

class TopBannerAction(val label: String, val onClick: () -> Unit)

@Immutable
internal class TopBannerEntry(
    val id: Long,
    val title: String,
    val description: String?,
    val icon: ImageVector?,
    val action: TopBannerAction?,
    val timeoutMillis: Long,
)

@Stable
class TopBannerState internal constructor(private val defaultTimeoutMillis: Long) {
    private var nextId = 0L
    private val queue = mutableStateListOf<TopBannerEntry>()
    internal var leaving by mutableStateOf(false)

    internal val current: TopBannerEntry?
        get() = queue.firstOrNull()

    fun show(
        title: String,
        description: String? = null,
        icon: ImageVector? = null,
        action: TopBannerAction? = null,
        timeoutMillis: Long = defaultTimeoutMillis,
    ): Long {
        nextId += 1
        queue.add(TopBannerEntry(nextId, title, description, icon, action, timeoutMillis))
        return nextId
    }

    fun dismiss() {
        if (queue.isNotEmpty()) leaving = true
    }

    internal fun removeCurrent() {
        if (queue.isNotEmpty()) queue.removeAt(0)
        leaving = false
    }
}

@Composable
fun rememberTopBannerState(defaultTimeoutMillis: Long = 4000): TopBannerState =
    remember { TopBannerState(defaultTimeoutMillis) }

private class TopBannerPosition : PopupPositionProvider {
    override fun calculatePosition(
        anchorBounds: IntRect,
        windowSize: IntSize,
        layoutDirection: LayoutDirection,
        popupContentSize: IntSize,
    ): IntOffset = IntOffset((windowSize.width - popupContentSize.width) / 2, 0)
}

@Composable
fun TopBannerProvider(
    state: TopBannerState,
    modifier: Modifier = Modifier,
    content: @Composable () -> Unit,
) {
    content()
    val entry = state.current ?: return
    val density = LocalDensity.current
    val top = WindowInsets.statusBars.getTop(density)
    val container = LocalWindowInfo.current.containerSize
    val available = with(density) { container.width.toDp() } - 32.dp
    val width = if (container.width > 0 && available < TopBannerMaxWidth) available else TopBannerMaxWidth
    val provider = remember { TopBannerPosition() }
    Popup(
        popupPositionProvider = provider,
        properties = PopupProperties(focusable = false, dismissOnBackPress = false, dismissOnClickOutside = false),
    ) {
        key(entry.id) {
            TopBannerCard(
                entry = entry,
                state = state,
                topInset = with(density) { top.toDp() },
                width = width,
                modifier = modifier,
            )
        }
    }
}

@Composable
private fun TopBannerCard(
    entry: TopBannerEntry,
    state: TopBannerState,
    topInset: Dp,
    width: Dp,
    modifier: Modifier,
) {
    val colors = EsuissTheme.colors
    val density = LocalDensity.current
    val scope = rememberCoroutineScope()
    val reduced = formReducedMotion()
    var height by remember { mutableIntStateOf(0) }
    val travel = remember { Animatable(1f) }
    val drag = remember { Animatable(0f) }
    val gap = with(density) { 8.dp.toPx() }
    LaunchedEffect(Unit) {
        travel.animateTo(0f, tween(if (reduced) 0 else 400, easing = FormEasing))
    }
    var holding by remember { mutableStateOf(false) }
    LaunchedEffect(entry.id, entry.timeoutMillis, holding) {
        if (entry.timeoutMillis <= 0 || holding) return@LaunchedEffect
        delay(entry.timeoutMillis)
        state.dismiss()
    }
    LaunchedEffect(state.leaving) {
        if (!state.leaving) return@LaunchedEffect
        travel.animateTo(1f, tween(if (reduced) 0 else 250, easing = FormEasing))
        state.removeCurrent()
    }
    val dragState = rememberDraggableState { delta ->
        scope.launch { drag.snapTo((drag.value + delta).coerceAtMost(with(density) { 12.dp.toPx() })) }
    }
    val shape = RoundedCornerShape(Radius.xl2)
    var origin by remember { mutableStateOf<Float?>(null) }
    val inset = origin?.let { with(density) { (topInset.toPx() - it).coerceAtLeast(0f).toDp() } } ?: topInset
    Box(
        modifier = Modifier
            .onGloballyPositioned { origin = it.positionOnScreen().y }
            .padding(top = inset + 8.dp, start = 16.dp, end = 16.dp, bottom = 24.dp),
    ) {
        Row(
            modifier = modifier
                .width(width)
                .onSizeChanged { height = it.height }
                .graphicsLayer {
                    translationY = -travel.value * (height + gap + inset.toPx()) + drag.value
                    alpha = if (reduced) 1f - travel.value else 1f
                }
                .shadow(Shadows.lg, shape)
                .background(colors.surfaceRaised, shape)
                .border(1.dp, colors.label.copy(alpha = if (colors.isDark) 0.1f else 0.05f), shape)
                .draggable(
                    state = dragState,
                    orientation = Orientation.Vertical,
                    onDragStarted = { holding = true },
                    onDragStopped = { velocity ->
                        holding = false
                        if (drag.value < -with(density) { 32.dp.toPx() } || velocity < -1000f) {
                            state.dismiss()
                        } else {
                            drag.animateTo(0f, tween(200))
                        }
                    },
                )
                .semantics {
                    liveRegion = LiveRegionMode.Polite
                    dismiss {
                        state.dismiss()
                        true
                    }
                }
                .padding(start = 14.dp, end = 14.dp, top = 12.dp, bottom = 12.dp),
            horizontalArrangement = Arrangement.spacedBy(12.dp),
            verticalAlignment = Alignment.CenterVertically,
        ) {
            if (entry.icon != null) {
                Box(
                    modifier = Modifier
                        .size(36.dp)
                        .background(colors.accentSurface, CircleShape),
                    contentAlignment = Alignment.Center,
                ) {
                    Icon(entry.icon, contentDescription = null, size = 20.dp, tint = colors.link)
                }
            }
            Column(modifier = Modifier.weight(1f), verticalArrangement = Arrangement.spacedBy(2.dp)) {
                BasicText(entry.title, style = Typography.sm.copy(color = colors.label, fontWeight = FontWeight.SemiBold))
                if (entry.description != null) {
                    BasicText(entry.description, style = Typography.sm.copy(color = colors.labelSecondary))
                }
            }
            if (entry.action != null) {
                Button(
                    text = entry.action.label,
                    onClick = {
                        entry.action.onClick()
                        state.dismiss()
                    },
                    variant = ButtonVariant.Tinted,
                    size = ButtonSize.Sm,
                )
            }
        }
    }
}
```

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

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

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

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

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

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

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

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

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

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

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

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

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

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

## Usage

```tsx
import { TopBannerProvider } from "@/components/interactions/top-banner"
```

```tsx
<TopBannerProvider>
  <Triggers />
</TopBannerProvider>
```

Wrap the app in `TopBannerProvider`, then call `show({ title, description?, icon?, action?, timeout? })` from `useTopBanner`. `show` returns an id that you can pass to `dismiss`; calling `dismiss()` with no id dismisses the current banner.

`icon` is a Phosphor icon component. `action` is `{ label, onPress }`; pressing it runs `onPress` and dismisses the banner. Pass a `timeout` of `0` or `Infinity` to keep a banner until dismissed.

## Examples

### Showing

A banner with a title and description, shown on mount.

![Preview](https://uim.suiss.app/previews/interactions-top-banner--showing.light.webp)

```tsx
import { WifiSlashIcon } from "phosphor-react-native"
import * as React from "react"
import { View } from "react-native"
import { TopBannerProvider, useTopBanner } from "@/components/interactions/top-banner"
import { Button } from "@/components/ui/button"
import { Text } from "@/components/ui/text"

function Triggers() {
  const { show, dismiss } = useTopBanner()
  const [log, setLog] = React.useState("")
  return (
    <View className="w-full gap-3">
      <Button
        variant="outline"
        onPress={() =>
          show({
            title: "Message sent",
            description: "Alex will see it the next time they open the app.",
          })
        }
      >
        <Text>Show banner</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() =>
          show({
            icon: WifiSlashIcon,
            title: "You are offline",
            description: "Changes will sync when you reconnect.",
            action: { label: "Retry", onPress: () => setLog("Retry pressed") },
          })
        }
      >
        <Text>Show with icon and action</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() => {
          show({ title: "First of three" })
          show({ title: "Second of three" })
          show({ title: "Third of three" })
        }}
      >
        <Text>Queue three</Text>
      </Button>
      <Button variant="ghost" onPress={() => dismiss()}>
        <Text>Dismiss current</Text>
      </Button>
      <Text role="status" className="text-sm text-label-secondary">
        {log}
      </Text>
    </View>
  )
}

function ShowOnMount({
  options,
}: {
  options: Parameters<ReturnType<typeof useTopBanner>["show"]>[0]
}) {
  const { show } = useTopBanner()
  const shownRef = React.useRef(false)
  const optionsRef = React.useRef(options)

  React.useEffect(() => {
    if (shownRef.current) return
    shownRef.current = true
    show(optionsRef.current)
  }, [show])

  return <Triggers />
}

export function TopBannerShowingExample() {
  return (
    <TopBannerProvider timeout={600000}>
      <ShowOnMount
        options={{
          title: "Message sent",
          description: "Alex will see it the next time they open the app.",
        }}
      />
    </TopBannerProvider>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct TopBannerShowingExample: View {
  var body: some View {
    TopBannerStage { manager in
      manager.show("Message sent", description: "Alex will see it the next time they open the app.")
    }
  }
}

struct TopBannerStage: View {
  var timeout: Duration = .seconds(600)
  var onMount: (@MainActor (TopBannerManager) -> Void)?

  @State private var manager = TopBannerManager()
  @State private var shown = false

  init(timeout: Duration = .seconds(600), onMount: (@MainActor (TopBannerManager) -> Void)? = nil) {
    self.timeout = timeout
    self.onMount = onMount
  }

  var body: some View {
    TopBannerTriggers(manager: manager)
      .frame(maxHeight: .infinity, alignment: .top)
      .containerRelativeFrame(.vertical) { height, _ in height - 32 }
      .topBanner(manager, timeout: timeout)
      .onAppear {
        guard !shown else { return }
        shown = true
        manager.timeout = timeout
        onMount?(manager)
      }
  }
}

struct TopBannerTriggers: View {
  let manager: TopBannerManager

  @State private var log = ""

  var body: some View {
    VStack(spacing: 12) {
      Button {
        manager.show("Message sent", description: "Alex will see it the next time they open the app.")
      } label: {
        Text("Show banner").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show(
          "You are offline",
          description: "Changes will sync when you reconnect.",
          icon: Ph.wifiSlash.regular,
          action: TopBannerAction("Retry") { log = "Retry pressed" }
        )
      } label: {
        Text("Show with icon and action").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show("First of three")
        manager.show("Second of three")
        manager.show("Third of three")
      } label: {
        Text("Queue three").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.dismiss()
      } label: {
        Text("Dismiss current").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.ghost))
      Text(verbatim: log)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .frame(maxWidth: .infinity, alignment: .leading)
        .accessibilityAddTraits(.updatesFrequently)
    }
  }
}
```

```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.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.WifiSlash
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.TopBannerAction
import com.esuiss.ui.interactions.TopBannerProvider
import com.esuiss.ui.interactions.TopBannerState
import com.esuiss.ui.interactions.rememberTopBannerState
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

@Composable
fun TopBannerShowingExample() {
    TopBannerDemo { show("Message sent", description = "Alex will see it the next time they open the app.") }
}

@Composable
fun TopBannerDemo(timeout: Long = 600000L, onMount: (TopBannerState.() -> Unit)? = null) {
    val state = rememberTopBannerState(defaultTimeoutMillis = timeout)
    var shown by rememberSaveable { mutableStateOf(false) }
    LaunchedEffect(Unit) {
        if (shown || onMount == null) return@LaunchedEffect
        shown = true
        state.onMount()
    }
    TopBannerProvider(state) {
        TopBannerTriggers(state)
    }
}

@Composable
fun TopBannerTriggers(state: TopBannerState) {
    var log by rememberSaveable { mutableStateOf("") }
    val fill = Modifier.fillMaxWidth()
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Button(
            "Show banner",
            onClick = { state.show("Message sent", description = "Alex will see it the next time they open the app.") },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Show with icon and action",
            onClick = {
                state.show(
                    "You are offline",
                    description = "Changes will sync when you reconnect.",
                    icon = PhosphorIcons.Regular.WifiSlash,
                    action = TopBannerAction("Retry") { log = "Retry pressed" },
                )
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Queue three",
            onClick = {
                state.show("First of three")
                state.show("Second of three")
                state.show("Third of three")
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button("Dismiss current", onClick = { state.dismiss() }, modifier = fill, variant = ButtonVariant.Ghost)
        Text(
            log,
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
        )
    }
}
```

### With icon

A banner with a leading icon.

![Preview](https://uim.suiss.app/previews/interactions-top-banner--with-icon.light.webp)

```tsx
import { BellIcon, WifiSlashIcon } from "phosphor-react-native"
import * as React from "react"
import { View } from "react-native"
import { TopBannerProvider, useTopBanner } from "@/components/interactions/top-banner"
import { Button } from "@/components/ui/button"
import { Text } from "@/components/ui/text"

function Triggers() {
  const { show, dismiss } = useTopBanner()
  const [log, setLog] = React.useState("")
  return (
    <View className="w-full gap-3">
      <Button
        variant="outline"
        onPress={() =>
          show({
            title: "Message sent",
            description: "Alex will see it the next time they open the app.",
          })
        }
      >
        <Text>Show banner</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() =>
          show({
            icon: WifiSlashIcon,
            title: "You are offline",
            description: "Changes will sync when you reconnect.",
            action: { label: "Retry", onPress: () => setLog("Retry pressed") },
          })
        }
      >
        <Text>Show with icon and action</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() => {
          show({ title: "First of three" })
          show({ title: "Second of three" })
          show({ title: "Third of three" })
        }}
      >
        <Text>Queue three</Text>
      </Button>
      <Button variant="ghost" onPress={() => dismiss()}>
        <Text>Dismiss current</Text>
      </Button>
      <Text role="status" className="text-sm text-label-secondary">
        {log}
      </Text>
    </View>
  )
}

function ShowOnMount({
  options,
}: {
  options: Parameters<ReturnType<typeof useTopBanner>["show"]>[0]
}) {
  const { show } = useTopBanner()
  const shownRef = React.useRef(false)
  const optionsRef = React.useRef(options)

  React.useEffect(() => {
    if (shownRef.current) return
    shownRef.current = true
    show(optionsRef.current)
  }, [show])

  return <Triggers />
}

export function TopBannerWithIconExample() {
  return (
    <TopBannerProvider timeout={600000}>
      <ShowOnMount
        options={{
          icon: BellIcon,
          title: "Reminders are on",
          description: "We will remind you 10 minutes before each event.",
        }}
      />
    </TopBannerProvider>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct TopBannerWithIconExample: View {
  var body: some View {
    TopBannerStage { manager in
      manager.show(
        "Reminders are on",
        description: "We will remind you 10 minutes before each event.",
        icon: Ph.bell.regular
      )
    }
  }
}

struct TopBannerStage: View {
  var timeout: Duration = .seconds(600)
  var onMount: (@MainActor (TopBannerManager) -> Void)?

  @State private var manager = TopBannerManager()
  @State private var shown = false

  init(timeout: Duration = .seconds(600), onMount: (@MainActor (TopBannerManager) -> Void)? = nil) {
    self.timeout = timeout
    self.onMount = onMount
  }

  var body: some View {
    TopBannerTriggers(manager: manager)
      .frame(maxHeight: .infinity, alignment: .top)
      .containerRelativeFrame(.vertical) { height, _ in height - 32 }
      .topBanner(manager, timeout: timeout)
      .onAppear {
        guard !shown else { return }
        shown = true
        manager.timeout = timeout
        onMount?(manager)
      }
  }
}

struct TopBannerTriggers: View {
  let manager: TopBannerManager

  @State private var log = ""

  var body: some View {
    VStack(spacing: 12) {
      Button {
        manager.show("Message sent", description: "Alex will see it the next time they open the app.")
      } label: {
        Text("Show banner").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show(
          "You are offline",
          description: "Changes will sync when you reconnect.",
          icon: Ph.wifiSlash.regular,
          action: TopBannerAction("Retry") { log = "Retry pressed" }
        )
      } label: {
        Text("Show with icon and action").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show("First of three")
        manager.show("Second of three")
        manager.show("Third of three")
      } label: {
        Text("Queue three").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.dismiss()
      } label: {
        Text("Dismiss current").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.ghost))
      Text(verbatim: log)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .frame(maxWidth: .infinity, alignment: .leading)
        .accessibilityAddTraits(.updatesFrequently)
    }
  }
}
```

```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.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.Bell
import com.adamglin.phosphoricons.regular.WifiSlash
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.TopBannerAction
import com.esuiss.ui.interactions.TopBannerProvider
import com.esuiss.ui.interactions.TopBannerState
import com.esuiss.ui.interactions.rememberTopBannerState
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

@Composable
fun TopBannerWithIconExample() {
    TopBannerDemo {
        show(
            "Reminders are on",
            description = "We will remind you 10 minutes before each event.",
            icon = PhosphorIcons.Regular.Bell,
        )
    }
}

@Composable
fun TopBannerDemo(timeout: Long = 600000L, onMount: (TopBannerState.() -> Unit)? = null) {
    val state = rememberTopBannerState(defaultTimeoutMillis = timeout)
    var shown by rememberSaveable { mutableStateOf(false) }
    LaunchedEffect(Unit) {
        if (shown || onMount == null) return@LaunchedEffect
        shown = true
        state.onMount()
    }
    TopBannerProvider(state) {
        TopBannerTriggers(state)
    }
}

@Composable
fun TopBannerTriggers(state: TopBannerState) {
    var log by rememberSaveable { mutableStateOf("") }
    val fill = Modifier.fillMaxWidth()
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Button(
            "Show banner",
            onClick = { state.show("Message sent", description = "Alex will see it the next time they open the app.") },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Show with icon and action",
            onClick = {
                state.show(
                    "You are offline",
                    description = "Changes will sync when you reconnect.",
                    icon = PhosphorIcons.Regular.WifiSlash,
                    action = TopBannerAction("Retry") { log = "Retry pressed" },
                )
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Queue three",
            onClick = {
                state.show("First of three")
                state.show("Second of three")
                state.show("Third of three")
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button("Dismiss current", onClick = { state.dismiss() }, modifier = fill, variant = ButtonVariant.Ghost)
        Text(
            log,
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
        )
    }
}
```

### With action

A banner with an action button.

![Preview](https://uim.suiss.app/previews/interactions-top-banner--with-action.light.webp)

```tsx
import { CloudArrowUpIcon, WifiSlashIcon } from "phosphor-react-native"
import * as React from "react"
import { View } from "react-native"
import { TopBannerProvider, useTopBanner } from "@/components/interactions/top-banner"
import { Button } from "@/components/ui/button"
import { Text } from "@/components/ui/text"

function Triggers() {
  const { show, dismiss } = useTopBanner()
  const [log, setLog] = React.useState("")
  return (
    <View className="w-full gap-3">
      <Button
        variant="outline"
        onPress={() =>
          show({
            title: "Message sent",
            description: "Alex will see it the next time they open the app.",
          })
        }
      >
        <Text>Show banner</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() =>
          show({
            icon: WifiSlashIcon,
            title: "You are offline",
            description: "Changes will sync when you reconnect.",
            action: { label: "Retry", onPress: () => setLog("Retry pressed") },
          })
        }
      >
        <Text>Show with icon and action</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() => {
          show({ title: "First of three" })
          show({ title: "Second of three" })
          show({ title: "Third of three" })
        }}
      >
        <Text>Queue three</Text>
      </Button>
      <Button variant="ghost" onPress={() => dismiss()}>
        <Text>Dismiss current</Text>
      </Button>
      <Text role="status" className="text-sm text-label-secondary">
        {log}
      </Text>
    </View>
  )
}

function ShowOnMount({
  options,
}: {
  options: Parameters<ReturnType<typeof useTopBanner>["show"]>[0]
}) {
  const { show } = useTopBanner()
  const shownRef = React.useRef(false)
  const optionsRef = React.useRef(options)

  React.useEffect(() => {
    if (shownRef.current) return
    shownRef.current = true
    show(optionsRef.current)
  }, [show])

  return <Triggers />
}

export function TopBannerWithActionExample() {
  return (
    <TopBannerProvider timeout={600000}>
      <ShowOnMount
        options={{
          icon: CloudArrowUpIcon,
          title: "Upload paused",
          description: "3 photos are waiting for Wi-Fi.",
          action: { label: "Resume", onPress: () => {} },
        }}
      />
    </TopBannerProvider>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct TopBannerWithActionExample: View {
  var body: some View {
    TopBannerStage { manager in
      manager.show(
        "Upload paused",
        description: "3 photos are waiting for Wi-Fi.",
        icon: Ph.cloudArrowUp.regular,
        action: TopBannerAction("Resume") {}
      )
    }
  }
}

struct TopBannerStage: View {
  var timeout: Duration = .seconds(600)
  var onMount: (@MainActor (TopBannerManager) -> Void)?

  @State private var manager = TopBannerManager()
  @State private var shown = false

  init(timeout: Duration = .seconds(600), onMount: (@MainActor (TopBannerManager) -> Void)? = nil) {
    self.timeout = timeout
    self.onMount = onMount
  }

  var body: some View {
    TopBannerTriggers(manager: manager)
      .frame(maxHeight: .infinity, alignment: .top)
      .containerRelativeFrame(.vertical) { height, _ in height - 32 }
      .topBanner(manager, timeout: timeout)
      .onAppear {
        guard !shown else { return }
        shown = true
        manager.timeout = timeout
        onMount?(manager)
      }
  }
}

struct TopBannerTriggers: View {
  let manager: TopBannerManager

  @State private var log = ""

  var body: some View {
    VStack(spacing: 12) {
      Button {
        manager.show("Message sent", description: "Alex will see it the next time they open the app.")
      } label: {
        Text("Show banner").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show(
          "You are offline",
          description: "Changes will sync when you reconnect.",
          icon: Ph.wifiSlash.regular,
          action: TopBannerAction("Retry") { log = "Retry pressed" }
        )
      } label: {
        Text("Show with icon and action").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show("First of three")
        manager.show("Second of three")
        manager.show("Third of three")
      } label: {
        Text("Queue three").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.dismiss()
      } label: {
        Text("Dismiss current").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.ghost))
      Text(verbatim: log)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .frame(maxWidth: .infinity, alignment: .leading)
        .accessibilityAddTraits(.updatesFrequently)
    }
  }
}
```

```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.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.CloudArrowUp
import com.adamglin.phosphoricons.regular.WifiSlash
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.TopBannerAction
import com.esuiss.ui.interactions.TopBannerProvider
import com.esuiss.ui.interactions.TopBannerState
import com.esuiss.ui.interactions.rememberTopBannerState
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

@Composable
fun TopBannerWithActionExample() {
    TopBannerDemo {
        show(
            "Upload paused",
            description = "3 photos are waiting for Wi-Fi.",
            icon = PhosphorIcons.Regular.CloudArrowUp,
            action = TopBannerAction("Resume") {},
        )
    }
}

@Composable
fun TopBannerDemo(timeout: Long = 600000L, onMount: (TopBannerState.() -> Unit)? = null) {
    val state = rememberTopBannerState(defaultTimeoutMillis = timeout)
    var shown by rememberSaveable { mutableStateOf(false) }
    LaunchedEffect(Unit) {
        if (shown || onMount == null) return@LaunchedEffect
        shown = true
        state.onMount()
    }
    TopBannerProvider(state) {
        TopBannerTriggers(state)
    }
}

@Composable
fun TopBannerTriggers(state: TopBannerState) {
    var log by rememberSaveable { mutableStateOf("") }
    val fill = Modifier.fillMaxWidth()
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Button(
            "Show banner",
            onClick = { state.show("Message sent", description = "Alex will see it the next time they open the app.") },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Show with icon and action",
            onClick = {
                state.show(
                    "You are offline",
                    description = "Changes will sync when you reconnect.",
                    icon = PhosphorIcons.Regular.WifiSlash,
                    action = TopBannerAction("Retry") { log = "Retry pressed" },
                )
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Queue three",
            onClick = {
                state.show("First of three")
                state.show("Second of three")
                state.show("Third of three")
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button("Dismiss current", onClick = { state.dismiss() }, modifier = fill, variant = ButtonVariant.Ghost)
        Text(
            log,
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
        )
    }
}
```

### Title only

A banner with only a title.

![Preview](https://uim.suiss.app/previews/interactions-top-banner--title-only.light.webp)

```tsx
import { WifiSlashIcon } from "phosphor-react-native"
import * as React from "react"
import { View } from "react-native"
import { TopBannerProvider, useTopBanner } from "@/components/interactions/top-banner"
import { Button } from "@/components/ui/button"
import { Text } from "@/components/ui/text"

function Triggers() {
  const { show, dismiss } = useTopBanner()
  const [log, setLog] = React.useState("")
  return (
    <View className="w-full gap-3">
      <Button
        variant="outline"
        onPress={() =>
          show({
            title: "Message sent",
            description: "Alex will see it the next time they open the app.",
          })
        }
      >
        <Text>Show banner</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() =>
          show({
            icon: WifiSlashIcon,
            title: "You are offline",
            description: "Changes will sync when you reconnect.",
            action: { label: "Retry", onPress: () => setLog("Retry pressed") },
          })
        }
      >
        <Text>Show with icon and action</Text>
      </Button>
      <Button
        variant="outline"
        onPress={() => {
          show({ title: "First of three" })
          show({ title: "Second of three" })
          show({ title: "Third of three" })
        }}
      >
        <Text>Queue three</Text>
      </Button>
      <Button variant="ghost" onPress={() => dismiss()}>
        <Text>Dismiss current</Text>
      </Button>
      <Text role="status" className="text-sm text-label-secondary">
        {log}
      </Text>
    </View>
  )
}

function ShowOnMount({
  options,
}: {
  options: Parameters<ReturnType<typeof useTopBanner>["show"]>[0]
}) {
  const { show } = useTopBanner()
  const shownRef = React.useRef(false)
  const optionsRef = React.useRef(options)

  React.useEffect(() => {
    if (shownRef.current) return
    shownRef.current = true
    show(optionsRef.current)
  }, [show])

  return <Triggers />
}

export function TopBannerTitleOnlyExample() {
  return (
    <TopBannerProvider timeout={600000}>
      <ShowOnMount options={{ title: "Copied to clipboard" }} />
    </TopBannerProvider>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct TopBannerTitleOnlyExample: View {
  var body: some View {
    TopBannerStage { manager in
      manager.show("Copied to clipboard")
    }
  }
}

struct TopBannerStage: View {
  var timeout: Duration = .seconds(600)
  var onMount: (@MainActor (TopBannerManager) -> Void)?

  @State private var manager = TopBannerManager()
  @State private var shown = false

  init(timeout: Duration = .seconds(600), onMount: (@MainActor (TopBannerManager) -> Void)? = nil) {
    self.timeout = timeout
    self.onMount = onMount
  }

  var body: some View {
    TopBannerTriggers(manager: manager)
      .frame(maxHeight: .infinity, alignment: .top)
      .containerRelativeFrame(.vertical) { height, _ in height - 32 }
      .topBanner(manager, timeout: timeout)
      .onAppear {
        guard !shown else { return }
        shown = true
        manager.timeout = timeout
        onMount?(manager)
      }
  }
}

struct TopBannerTriggers: View {
  let manager: TopBannerManager

  @State private var log = ""

  var body: some View {
    VStack(spacing: 12) {
      Button {
        manager.show("Message sent", description: "Alex will see it the next time they open the app.")
      } label: {
        Text("Show banner").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show(
          "You are offline",
          description: "Changes will sync when you reconnect.",
          icon: Ph.wifiSlash.regular,
          action: TopBannerAction("Retry") { log = "Retry pressed" }
        )
      } label: {
        Text("Show with icon and action").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.show("First of three")
        manager.show("Second of three")
        manager.show("Third of three")
      } label: {
        Text("Queue three").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.outline))
      Button {
        manager.dismiss()
      } label: {
        Text("Dismiss current").frame(maxWidth: .infinity)
      }
      .buttonStyle(.variant(.ghost))
      Text(verbatim: log)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .frame(maxWidth: .infinity, alignment: .leading)
        .accessibilityAddTraits(.updatesFrequently)
    }
  }
}
```

```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.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.regular.WifiSlash
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.TopBannerAction
import com.esuiss.ui.interactions.TopBannerProvider
import com.esuiss.ui.interactions.TopBannerState
import com.esuiss.ui.interactions.rememberTopBannerState
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

@Composable
fun TopBannerTitleOnlyExample() {
    TopBannerDemo { show("Copied to clipboard") }
}

@Composable
fun TopBannerDemo(timeout: Long = 600000L, onMount: (TopBannerState.() -> Unit)? = null) {
    val state = rememberTopBannerState(defaultTimeoutMillis = timeout)
    var shown by rememberSaveable { mutableStateOf(false) }
    LaunchedEffect(Unit) {
        if (shown || onMount == null) return@LaunchedEffect
        shown = true
        state.onMount()
    }
    TopBannerProvider(state) {
        TopBannerTriggers(state)
    }
}

@Composable
fun TopBannerTriggers(state: TopBannerState) {
    var log by rememberSaveable { mutableStateOf("") }
    val fill = Modifier.fillMaxWidth()
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Button(
            "Show banner",
            onClick = { state.show("Message sent", description = "Alex will see it the next time they open the app.") },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Show with icon and action",
            onClick = {
                state.show(
                    "You are offline",
                    description = "Changes will sync when you reconnect.",
                    icon = PhosphorIcons.Regular.WifiSlash,
                    action = TopBannerAction("Retry") { log = "Retry pressed" },
                )
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button(
            "Queue three",
            onClick = {
                state.show("First of three")
                state.show("Second of three")
                state.show("Third of three")
            },
            modifier = fill,
            variant = ButtonVariant.Outline,
        )
        Button("Dismiss current", onClick = { state.dismiss() }, modifier = fill, variant = ButtonVariant.Ghost)
        Text(
            log,
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
        )
    }
}
```

## API Reference

### TopBannerProvider

Holds the banner queue and renders the current banner in a portal.

## Accessibility

- The banner has the `alert` role and is a polite live region.
- A string title is announced when the banner appears.
- The banner has a `dismiss` accessibility action.

## Notes

- Banners are up to 384 points wide and centered.
- The card uses `bg-surface-raised`, or `bg-surface-secondary` in dark mode, with a `border-separator` outline; the icon uses `text-link`.
- Slide animations respect the system reduce motion setting.