# Undo Bar

A floating bar at the bottom of the screen that offers Undo for a few seconds after a destructive action.

Undo Bar 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/undo-bar

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

```tsx
import { TrashIcon } from "phosphor-react-native"
import * as React from "react"
import { View } from "react-native"
import { UndoBarProvider, useUndoBar } from "@/components/interactions/undo-bar"
import { Button } from "@/components/ui/button"
import { Icon } from "@/components/ui/icon"
import { Text } from "@/components/ui/text"

const initialNotes = [
  { id: 1, title: "Groceries", preview: "Milk, eggs, bread, coffee" },
  { id: 2, title: "Trip ideas", preview: "Lisbon, Porto, the coast road" },
  { id: 3, title: "Book list", preview: "Three novels for the summer" },
  { id: 4, title: "Meeting notes", preview: "Ship the beta on Friday" },
]

type Note = (typeof initialNotes)[number]

function useNotes() {
  const [notes, setNotes] = React.useState(initialNotes)
  const [log, setLog] = React.useState("Delete a note.")
  const { show } = useUndoBar()

  const remove = (note: Note) => {
    const index = notes.findIndex((item) => item.id === note.id)
    setNotes((current) => current.filter((item) => item.id !== note.id))
    setLog(`Removed “${note.title}”`)
    show({
      title: `“${note.title}” deleted`,
      onUndo: () => {
        setNotes((current) => {
          const next = [...current]
          next.splice(Math.min(index, next.length), 0, note)
          return next
        })
        setLog(`Restored “${note.title}”`)
      },
      onCommit: () => setLog(`Deleted “${note.title}” permanently`),
    })
  }

  return { notes, remove, log }
}

function NoteText({ note }: { note: Note }) {
  return (
    <View className="min-w-0 flex-1 py-2">
      <Text numberOfLines={1} className="font-semibold">
        {note.title}
      </Text>
      <Text numberOfLines={1} className="text-sm text-label-secondary">
        {note.preview}
      </Text>
    </View>
  )
}

function NotesList({ deleteFirst = false }: { deleteFirst?: boolean }) {
  const { notes, remove, log } = useNotes()
  const removeRef = React.useRef(remove)
  const deletedRef = React.useRef(false)
  removeRef.current = remove

  React.useEffect(() => {
    if (!deleteFirst || deletedRef.current) return
    deletedRef.current = true
    removeRef.current(initialNotes[0])
  }, [deleteFirst])

  return (
    <View className="w-full gap-3">
      <View className="overflow-hidden rounded-2xl border border-separator">
        {notes.map((note, index) => (
          <View
            key={note.id}
            className={
              index > 0
                ? "flex-row items-center gap-3 border-t border-separator py-1 ps-4 pe-1"
                : "flex-row items-center gap-3 py-1 ps-4 pe-1"
            }
          >
            <NoteText note={note} />
            <Button
              variant="ghost"
              size="icon-lg"
              accessibilityLabel={`Delete ${note.title}`}
              onPress={() => remove(note)}
            >
              <Icon as={TrashIcon} className="size-5" />
            </Button>
          </View>
        ))}
      </View>
      <Text role="status" className="text-sm text-label-secondary">
        {log}
      </Text>
    </View>
  )
}

export function UndoBarExample() {
  return (
    <UndoBarProvider>
      <NotesList />
    </UndoBarProvider>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct UndoBarExample: View {
  var body: some View {
    UndoBarStage(timeout: .seconds(5)) { UndoBarNotes() }
  }
}

struct UndoBarNote: Identifiable, Equatable {
  let id: Int
  let title: String
  let preview: String
}

let undoBarInitialNotes = [
  UndoBarNote(id: 1, title: "Groceries", preview: "Milk, eggs, bread, coffee"),
  UndoBarNote(id: 2, title: "Trip ideas", preview: "Lisbon, Porto, the coast road"),
  UndoBarNote(id: 3, title: "Book list", preview: "Three novels for the summer"),
  UndoBarNote(id: 4, title: "Meeting notes", preview: "Ship the beta on Friday"),
]

struct UndoBarStage<Content: View>: View {
  let timeout: Duration
  @ViewBuilder let content: () -> Content

  @State private var manager = UndoBarManager()

  var body: some View {
    content()
      .frame(maxHeight: .infinity, alignment: .top)
      .containerRelativeFrame(.vertical) { height, _ in height - 32 }
      .undoBar(manager, timeout: timeout)
  }
}

struct UndoBarNoteText: View {
  let note: UndoBarNote

  var body: some View {
    VStack(alignment: .leading, spacing: 0) {
      Text(verbatim: note.title)
        .textStyle(.base, weight: .semibold)
        .foregroundStyle(Color.label)
        .lineLimit(1)
      Text(verbatim: note.preview)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .lineLimit(1)
    }
    .padding(.vertical, 8)
    .frame(maxWidth: .infinity, alignment: .leading)
  }
}

struct UndoBarNotes: View {
  var deleteFirst = false
  var swipe = false

  @State private var notes = undoBarInitialNotes
  @State private var log = "Delete a note."
  @State private var deleted = false
  @Environment(\.undoBarManager) private var manager

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
    VStack(alignment: .leading, spacing: 12) {
      VStack(spacing: 0) {
        ForEach(Array(notes.enumerated()), id: \.element.id) { index, note in
          row(note)
            .overlay(alignment: .top) {
              if index > 0 {
                Color.separator.frame(height: 1)
              }
            }
        }
      }
      .clipShape(shape)
      .overlay { shape.strokeBorder(Color.separator) }
      Text(verbatim: log)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .accessibilityAddTraits(.updatesFrequently)
    }
    .onAppear {
      guard deleteFirst, !deleted else { return }
      deleted = true
      remove(undoBarInitialNotes[0])
    }
  }

  @ViewBuilder
  func row(_ note: UndoBarNote) -> some View {
    if swipe {
      SwipeActions {
        UndoBarNoteText(note: note)
          .padding(.horizontal, 16)
          .padding(.vertical, 4)
      } trailing: {
        SwipeAction("Delete", icon: Ph.trash.fill, variant: .destructive, fullSwipe: true) {
          remove(note)
        }
      }
    } else {
      HStack(spacing: 12) {
        UndoBarNoteText(note: note)
        Button {
          remove(note)
        } label: {
          Ph.trash.regular.frame(width: 20, height: 20)
        }
        .buttonStyle(.variant(.ghost, size: .iconLg))
        .accessibilityLabel(Text(verbatim: "Delete \(note.title)"))
      }
      .padding(.leading, 16)
      .padding(.trailing, 4)
      .padding(.vertical, 4)
    }
  }

  func remove(_ note: UndoBarNote) {
    let index = notes.firstIndex(of: note) ?? 0
    notes.removeAll { $0.id == note.id }
    log = "Removed “\(note.title)”"
    manager.show(
      "“\(note.title)” deleted",
      onUndo: {
        notes.insert(note, at: min(index, notes.count))
        log = "Restored “\(note.title)”"
      },
      onCommit: {
        log = "Deleted “\(note.title)” permanently"
      }
    )
  }
}
```

```kotlin
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.key
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.fill.Trash
import com.adamglin.phosphoricons.regular.Trash
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonSize
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Icon
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.UndoBarProvider
import com.esuiss.ui.interactions.UndoBarState
import com.esuiss.ui.interactions.rememberUndoBarState
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

@Composable
fun UndoBarExample() {
    UndoBarDemo(timeout = 5000L) { state -> UndoBarNotesList(state) }
}

class UndoBarNote(val id: Int, val title: String, val preview: String)

val undoBarInitialNotes = listOf(
    UndoBarNote(1, "Groceries", "Milk, eggs, bread, coffee"),
    UndoBarNote(2, "Trip ideas", "Lisbon, Porto, the coast road"),
    UndoBarNote(3, "Book list", "Three novels for the summer"),
    UndoBarNote(4, "Meeting notes", "Ship the beta on Friday"),
)

class UndoBarNotes(
    val notes: List<UndoBarNote>,
    val log: String,
    val remove: (UndoBarNote) -> Unit,
)

@Composable
fun UndoBarDemo(timeout: Long, content: @Composable (UndoBarState) -> Unit) {
    val state = rememberUndoBarState()
    UndoBarProvider(state, timeoutMillis = timeout) {
        content(state)
    }
}

@Composable
fun rememberUndoBarNotes(state: UndoBarState): UndoBarNotes {
    var ids by rememberSaveable { mutableStateOf(undoBarInitialNotes.map { it.id }) }
    var log by rememberSaveable { mutableStateOf("Delete a note.") }
    val notes = ids.mapNotNull { id -> undoBarInitialNotes.firstOrNull { it.id == id } }
    return UndoBarNotes(notes, log) { note ->
        val index = ids.indexOf(note.id)
        ids = ids - note.id
        log = "Removed “${note.title}”"
        state.show(
            title = "“${note.title}” deleted",
            onUndo = {
                ids = ids.toMutableList().apply { add(minOf(index, size), note.id) }
                log = "Restored “${note.title}”"
            },
            onCommit = { log = "Deleted “${note.title}” permanently" },
        )
    }
}

@Composable
fun UndoBarNoteText(note: UndoBarNote, modifier: Modifier = Modifier) {
    Column(modifier.padding(vertical = 8.dp)) {
        Text(
            note.title,
            style = Typography.base.copy(fontWeight = FontWeight.SemiBold),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
        )
        Text(
            note.preview,
            style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
        )
    }
}

@Composable
fun UndoBarFrame(notes: UndoBarNotes, row: @Composable (UndoBarNote) -> Unit) {
    val colors = EsuissTheme.colors
    val shape = RoundedCornerShape(Radius.xl2)
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Column(
            Modifier
                .fillMaxWidth()
                .clip(shape)
                .border(1.dp, colors.separator, shape),
        ) {
            notes.notes.forEachIndexed { index, note ->
                key(note.id) {
                    if (index > 0) Box(Modifier.fillMaxWidth().height(1.dp).background(colors.separator))
                    row(note)
                }
            }
        }
        Text(
            notes.log,
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = colors.labelSecondary),
        )
    }
}

@Composable
fun UndoBarNotesList(state: UndoBarState, deleteFirst: Boolean = false) {
    val notes = rememberUndoBarNotes(state)
    var deleted by rememberSaveable { mutableStateOf(false) }
    LaunchedEffect(Unit) {
        if (!deleteFirst || deleted) return@LaunchedEffect
        deleted = true
        notes.remove(undoBarInitialNotes.first())
    }
    UndoBarFrame(notes) { note ->
        Row(
            modifier = Modifier.fillMaxWidth().padding(start = 16.dp, end = 4.dp, top = 4.dp, bottom = 4.dp),
            horizontalArrangement = Arrangement.spacedBy(12.dp),
            verticalAlignment = Alignment.CenterVertically,
        ) {
            UndoBarNoteText(note, Modifier.weight(1f))
            Button(onClick = { notes.remove(note) }, variant = ButtonVariant.Ghost, size = ButtonSize.IconLg) {
                Icon(PhosphorIcons.Regular.Trash, contentDescription = "Delete ${note.title}", size = 20.dp)
            }
        }
    }
}
```

`UndoBarProvider` shows a pill-shaped bar above the bottom safe area when `show` is called from `useUndoBar`. It holds a message, a countdown ring and an Undo button, and slides up into view.

If the user presses Undo, `onUndo` runs. If the countdown runs out, `onCommit` runs. Only one bar shows at a time: calling `show` again commits the previous action first. The countdown pauses while the app is in the background and resumes with the time left. Use it after deleting, archiving or moving items.

## Installation

```bash title="Terminal"
npx @esuiss/uim@latest add undo-bar
```

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

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

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

### Manual

**Uniwind**

1. Install the dependencies:

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

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

3. Copy the source into `components/interactions/undo-bar.tsx`:

```tsx title="uniwind/components/interactions/undo-bar.tsx"
import { cn } from "cn"
import * as React from "react"
import {
  AccessibilityInfo,
  AppState,
  I18nManager,
  useWindowDimensions,
  View,
} from "react-native"
import {
  cancelAnimation,
  Easing,
  Keyframe,
  ReduceMotion,
  type SharedValue,
  useAnimatedStyle,
  useSharedValue,
  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 { Text } from "@/components/ui/text"

type UndoBarOptions = {
  title: React.ReactNode
  actionLabel?: React.ReactNode
  onUndo: () => void
  onCommit?: () => void
}

type UndoBarEntry = UndoBarOptions & { id: number }

type UndoBarContextProps = {
  show: (options: UndoBarOptions) => void
  undo: () => void
  dismiss: () => void
}

const UndoBarContext = React.createContext<UndoBarContextProps | null>(null)

function useUndoBar() {
  const context = React.useContext(UndoBarContext)
  if (!context) {
    throw new Error("useUndoBar must be used within an <UndoBarProvider />")
  }
  return context
}

const MAX_WIDTH = 384

const RING_SIZE = 18

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 CountdownRing({ progress }: { progress: SharedValue<number> }) {
  const half = RING_SIZE / 2
  const endStyle = useAnimatedStyle(() => ({
    transform: [{ rotate: `${Math.min(progress.value * 360, 180)}deg` }],
  }))
  const startStyle = useAnimatedStyle(() => ({
    transform: [{ rotate: `${Math.max(progress.value * 360 - 180, 0)}deg` }],
  }))
  return (
    <View
      accessibilityElementsHidden
      importantForAccessibility="no-hide-descendants"
      className="size-5 shrink-0 items-center justify-center"
      style={I18nManager.isRTL ? { transform: [{ scaleX: -1 }] } : undefined}
    >
      <View style={{ width: RING_SIZE, height: RING_SIZE }}>
        <View className="absolute top-0 left-0 size-full rounded-full border-2 border-separator" />
        <View
          className="absolute top-0 overflow-hidden"
          style={{ left: half, width: half, height: RING_SIZE }}
        >
          <AnimatedView
            className="absolute top-0"
            style={[
              { left: -half, width: RING_SIZE, height: RING_SIZE },
              endStyle,
            ]}
          >
            <View
              className="overflow-hidden"
              style={{ width: half, height: RING_SIZE }}
            >
              <View
                className="rounded-full border-2 border-label-secondary"
                style={{ width: RING_SIZE, height: RING_SIZE }}
              />
            </View>
          </AnimatedView>
        </View>
        <View
          className="absolute top-0 left-0 overflow-hidden"
          style={{ width: half, height: RING_SIZE }}
        >
          <AnimatedView
            className="absolute top-0 left-0"
            style={[{ width: RING_SIZE, height: RING_SIZE }, startStyle]}
          >
            <View
              className="absolute top-0 overflow-hidden"
              style={{ left: half, width: half, height: RING_SIZE }}
            >
              <View
                className="absolute top-0 rounded-full border-2 border-label-secondary"
                style={{ left: -half, width: RING_SIZE, height: RING_SIZE }}
              />
            </View>
          </AnimatedView>
        </View>
      </View>
    </View>
  )
}

function UndoBarProvider({
  timeout = 5000,
  className,
  portalHost,
  children,
}: {
  timeout?: number
  className?: string
  portalHost?: string
  children?: React.ReactNode
}) {
  const [entry, setEntry] = React.useState<UndoBarEntry | null>(null)
  const [active, setActive] = React.useState(AppState.currentState === "active")
  const entryRef = React.useRef<UndoBarEntry | null>(null)
  const remainingRef = React.useRef({ id: 0, duration: timeout })
  const progress = useSharedValue(1)
  const insets = useSafeAreaInsets()
  const { width } = useWindowDimensions()
  const inset = Math.max(16, (width - MAX_WIDTH) / 2)
  const id = React.useId()

  const settle = React.useCallback((undo: boolean) => {
    const current = entryRef.current
    if (!current) return
    entryRef.current = null
    setEntry(null)
    if (undo) current.onUndo()
    else current.onCommit?.()
  }, [])

  const show = React.useCallback(
    (options: UndoBarOptions) => {
      entryRef.current?.onCommit?.()
      nextId += 1
      const next = { ...options, id: nextId }
      entryRef.current = next
      remainingRef.current = { id: next.id, duration: timeout }
      setEntry(next)
      if (typeof options.title === "string") {
        AccessibilityInfo.announceForAccessibility(options.title)
      }
    },
    [timeout]
  )

  const undo = React.useCallback(() => settle(true), [settle])
  const dismiss = React.useCallback(() => settle(false), [settle])

  React.useEffect(() => {
    const subscription = AppState.addEventListener("change", (state) =>
      setActive(state === "active")
    )
    return () => subscription.remove()
  }, [])

  React.useEffect(() => {
    if (!entry) return
    if (!active) {
      cancelAnimation(progress)
      return
    }
    const remaining =
      remainingRef.current.id === entry.id
        ? remainingRef.current.duration
        : timeout
    const started = Date.now()
    progress.value = remaining / timeout
    progress.value = withTiming(0, {
      duration: remaining,
      easing: Easing.linear,
      reduceMotion: ReduceMotion.Never,
    })
    const timer = setTimeout(dismiss, remaining)
    return () => {
      clearTimeout(timer)
      if (remainingRef.current.id !== entry.id) return
      remainingRef.current = {
        id: entry.id,
        duration: Math.max(0, remaining - (Date.now() - started)),
      }
    }
  }, [entry, active, timeout, dismiss, progress])

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

  return (
    <UndoBarContext.Provider value={contextValue}>
      {children}
      <Portal name={`undo-bar-${id}`} hostName={portalHost}>
        {entry ? (
          <AnimatedView
            key={entry.id}
            entering={ENTERING}
            exiting={EXITING}
            className="absolute z-50"
            style={{
              left: inset,
              right: inset,
              bottom: Math.max(16, insets.bottom),
              pointerEvents: "box-none",
            }}
          >
            <View
              role="group"
              accessibilityLiveRegion="polite"
              className={cn(
                "h-13 w-full flex-row items-center gap-3 rounded-full border border-separator bg-surface-raised ps-4 pe-1 shadow-xl dark:bg-surface-secondary",
                className
              )}
            >
              <CountdownRing progress={progress} />
              <View className="min-w-0 flex-1">
                {typeof entry.title === "string" ||
                typeof entry.title === "number" ? (
                  <Text numberOfLines={1} className="text-sm font-medium">
                    {entry.title}
                  </Text>
                ) : (
                  entry.title
                )}
              </View>
              <Button variant="plain" size="lg" className="px-4" onPress={undo}>
                {typeof entry.actionLabel === "string" ||
                typeof entry.actionLabel === "number" ||
                entry.actionLabel === undefined ? (
                  <Text className="font-semibold">
                    {entry.actionLabel ?? "Undo"}
                  </Text>
                ) : (
                  entry.actionLabel
                )}
              </Button>
            </View>
          </AnimatedView>
        ) : null}
      </Portal>
    </UndoBarContext.Provider>
  )
}

export { UndoBarProvider, useUndoBar }
```

4. Update the import paths to match your project.

**NativeWind**

1. Install the dependencies:

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

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

3. Copy the source into `components/interactions/undo-bar.tsx`:

```tsx title="nativewind/components/interactions/undo-bar.tsx"
import { cn } from "cn"
import * as React from "react"
import {
  AccessibilityInfo,
  AppState,
  I18nManager,
  useWindowDimensions,
  View,
} from "react-native"
import {
  cancelAnimation,
  Easing,
  Keyframe,
  ReduceMotion,
  type SharedValue,
  useAnimatedStyle,
  useSharedValue,
  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 { Text } from "@/components/ui/text"

type UndoBarOptions = {
  title: React.ReactNode
  actionLabel?: React.ReactNode
  onUndo: () => void
  onCommit?: () => void
}

type UndoBarEntry = UndoBarOptions & { id: number }

type UndoBarContextProps = {
  show: (options: UndoBarOptions) => void
  undo: () => void
  dismiss: () => void
}

const UndoBarContext = React.createContext<UndoBarContextProps | null>(null)

function useUndoBar() {
  const context = React.useContext(UndoBarContext)
  if (!context) {
    throw new Error("useUndoBar must be used within an <UndoBarProvider />")
  }
  return context
}

const MAX_WIDTH = 384

const RING_SIZE = 18

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 CountdownRing({ progress }: { progress: SharedValue<number> }) {
  const half = RING_SIZE / 2
  const endStyle = useAnimatedStyle(() => ({
    transform: [{ rotate: `${Math.min(progress.value * 360, 180)}deg` }],
  }))
  const startStyle = useAnimatedStyle(() => ({
    transform: [{ rotate: `${Math.max(progress.value * 360 - 180, 0)}deg` }],
  }))
  return (
    <View
      accessibilityElementsHidden
      importantForAccessibility="no-hide-descendants"
      className="size-5 shrink-0 items-center justify-center"
      style={I18nManager.isRTL ? { transform: [{ scaleX: -1 }] } : undefined}
    >
      <View style={{ width: RING_SIZE, height: RING_SIZE }}>
        <View className="absolute top-0 left-0 size-full rounded-full border-2 border-separator" />
        <View
          className="absolute top-0 overflow-hidden"
          style={{ left: half, width: half, height: RING_SIZE }}
        >
          <AnimatedView
            className="absolute top-0"
            style={[
              { left: -half, width: RING_SIZE, height: RING_SIZE },
              endStyle,
            ]}
          >
            <View
              className="overflow-hidden"
              style={{ width: half, height: RING_SIZE }}
            >
              <View
                className="rounded-full border-2 border-label-secondary"
                style={{ width: RING_SIZE, height: RING_SIZE }}
              />
            </View>
          </AnimatedView>
        </View>
        <View
          className="absolute top-0 left-0 overflow-hidden"
          style={{ width: half, height: RING_SIZE }}
        >
          <AnimatedView
            className="absolute top-0 left-0"
            style={[{ width: RING_SIZE, height: RING_SIZE }, startStyle]}
          >
            <View
              className="absolute top-0 overflow-hidden"
              style={{ left: half, width: half, height: RING_SIZE }}
            >
              <View
                className="absolute top-0 rounded-full border-2 border-label-secondary"
                style={{ left: -half, width: RING_SIZE, height: RING_SIZE }}
              />
            </View>
          </AnimatedView>
        </View>
      </View>
    </View>
  )
}

function UndoBarProvider({
  timeout = 5000,
  className,
  portalHost,
  children,
}: {
  timeout?: number
  className?: string
  portalHost?: string
  children?: React.ReactNode
}) {
  const [entry, setEntry] = React.useState<UndoBarEntry | null>(null)
  const [active, setActive] = React.useState(AppState.currentState === "active")
  const entryRef = React.useRef<UndoBarEntry | null>(null)
  const remainingRef = React.useRef({ id: 0, duration: timeout })
  const progress = useSharedValue(1)
  const insets = useSafeAreaInsets()
  const { width } = useWindowDimensions()
  const inset = Math.max(16, (width - MAX_WIDTH) / 2)
  const id = React.useId()

  const settle = React.useCallback((undo: boolean) => {
    const current = entryRef.current
    if (!current) return
    entryRef.current = null
    setEntry(null)
    if (undo) current.onUndo()
    else current.onCommit?.()
  }, [])

  const show = React.useCallback(
    (options: UndoBarOptions) => {
      entryRef.current?.onCommit?.()
      nextId += 1
      const next = { ...options, id: nextId }
      entryRef.current = next
      remainingRef.current = { id: next.id, duration: timeout }
      setEntry(next)
      if (typeof options.title === "string") {
        AccessibilityInfo.announceForAccessibility(options.title)
      }
    },
    [timeout]
  )

  const undo = React.useCallback(() => settle(true), [settle])
  const dismiss = React.useCallback(() => settle(false), [settle])

  React.useEffect(() => {
    const subscription = AppState.addEventListener("change", (state) =>
      setActive(state === "active")
    )
    return () => subscription.remove()
  }, [])

  React.useEffect(() => {
    if (!entry) return
    if (!active) {
      cancelAnimation(progress)
      return
    }
    const remaining =
      remainingRef.current.id === entry.id
        ? remainingRef.current.duration
        : timeout
    const started = Date.now()
    progress.value = remaining / timeout
    progress.value = withTiming(0, {
      duration: remaining,
      easing: Easing.linear,
      reduceMotion: ReduceMotion.Never,
    })
    const timer = setTimeout(dismiss, remaining)
    return () => {
      clearTimeout(timer)
      if (remainingRef.current.id !== entry.id) return
      remainingRef.current = {
        id: entry.id,
        duration: Math.max(0, remaining - (Date.now() - started)),
      }
    }
  }, [entry, active, timeout, dismiss, progress])

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

  return (
    <UndoBarContext.Provider value={contextValue}>
      {children}
      <Portal name={`undo-bar-${id}`} hostName={portalHost}>
        {entry ? (
          <AnimatedView
            key={entry.id}
            entering={ENTERING}
            exiting={EXITING}
            className="absolute z-50"
            style={{
              left: inset,
              right: inset,
              bottom: Math.max(16, insets.bottom),
              pointerEvents: "box-none",
            }}
          >
            <View
              role="group"
              accessibilityLiveRegion="polite"
              className={cn(
                "h-[3.25rem] w-full flex-row items-center gap-3 rounded-full border border-separator bg-surface-raised ps-4 pe-1 shadow-xl dark:bg-surface-secondary",
                className
              )}
            >
              <CountdownRing progress={progress} />
              <View className="min-w-0 flex-1">
                {typeof entry.title === "string" ||
                typeof entry.title === "number" ? (
                  <Text numberOfLines={1} className="text-sm font-medium">
                    {entry.title}
                  </Text>
                ) : (
                  entry.title
                )}
              </View>
              <Button variant="plain" size="lg" className="px-4" onPress={undo}>
                {typeof entry.actionLabel === "string" ||
                typeof entry.actionLabel === "number" ||
                entry.actionLabel === undefined ? (
                  <Text className="font-semibold">
                    {entry.actionLabel ?? "Undo"}
                  </Text>
                ) : (
                  entry.actionLabel
                )}
              </Button>
            </View>
          </AnimatedView>
        ) : null}
      </Portal>
    </UndoBarContext.Provider>
  )
}

export { UndoBarProvider, useUndoBar }
```

4. Update the import paths to match your project.

**StyleSheet**

1. Install the dependencies:

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

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

3. Copy the source into `components/interactions/undo-bar.tsx`:

```tsx title="stylesheet/components/interactions/undo-bar.tsx"
import * as React from "react"
import {
  AccessibilityInfo,
  AppState,
  I18nManager,
  type StyleProp,
  StyleSheet,
  useWindowDimensions,
  View,
  type ViewStyle,
} from "react-native"
import {
  cancelAnimation,
  Easing,
  Keyframe,
  ReduceMotion,
  type SharedValue,
  useAnimatedStyle,
  useSharedValue,
  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 { Text } from "@/components/ui/text"
import {
  fontSize,
  radius,
  shadow,
  type ThemeColors,
  useTheme,
} from "@/components/ui/theme"

type UndoBarOptions = {
  title: React.ReactNode
  actionLabel?: React.ReactNode
  onUndo: () => void
  onCommit?: () => void
}

type UndoBarEntry = UndoBarOptions & { id: number }

type UndoBarContextProps = {
  show: (options: UndoBarOptions) => void
  undo: () => void
  dismiss: () => void
}

const UndoBarContext = React.createContext<UndoBarContextProps | null>(null)

function useUndoBar() {
  const context = React.useContext(UndoBarContext)
  if (!context) {
    throw new Error("useUndoBar must be used within an <UndoBarProvider />")
  }
  return context
}

const MAX_WIDTH = 384

const RING_SIZE = 18

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({
  ringBox: {
    width: 20,
    height: 20,
    flexShrink: 0,
    alignItems: "center",
    justifyContent: "center",
  },
  ring: { width: RING_SIZE, height: RING_SIZE },
  circle: {
    width: RING_SIZE,
    height: RING_SIZE,
    borderRadius: radius.full,
    borderWidth: 2,
  },
  frame: { position: "absolute", zIndex: 50 },
  bar: {
    height: 52,
    width: "100%",
    flexDirection: "row",
    alignItems: "center",
    gap: 12,
    borderRadius: radius.full,
    borderWidth: 1,
    paddingStart: 16,
    paddingEnd: 4,
    ...shadow.xl,
  },
  titleBox: { minWidth: 0, flex: 1 },
  title: { ...fontSize.sm, fontWeight: "500" },
  action: { paddingHorizontal: 16 },
  actionText: { fontWeight: "600" },
})

function CountdownRing({
  progress,
  colors,
}: {
  progress: SharedValue<number>
  colors: ThemeColors
}) {
  const half = RING_SIZE / 2
  const endStyle = useAnimatedStyle(() => ({
    transform: [{ rotate: `${Math.min(progress.value * 360, 180)}deg` }],
  }))
  const startStyle = useAnimatedStyle(() => ({
    transform: [{ rotate: `${Math.max(progress.value * 360 - 180, 0)}deg` }],
  }))
  const arc = [styles.circle, { borderColor: colors.labelSecondary }]
  return (
    <View
      accessibilityElementsHidden
      importantForAccessibility="no-hide-descendants"
      style={[
        styles.ringBox,
        I18nManager.isRTL ? { transform: [{ scaleX: -1 }] } : undefined,
      ]}
    >
      <View style={styles.ring}>
        <View
          style={[
            StyleSheet.absoluteFill,
            styles.circle,
            { borderColor: colors.separator },
          ]}
        />
        <View
          style={{
            position: "absolute",
            top: 0,
            left: half,
            width: half,
            height: RING_SIZE,
            overflow: "hidden",
          }}
        >
          <AnimatedView
            style={[
              {
                position: "absolute",
                top: 0,
                left: -half,
                width: RING_SIZE,
                height: RING_SIZE,
              },
              endStyle,
            ]}
          >
            <View
              style={{ width: half, height: RING_SIZE, overflow: "hidden" }}
            >
              <View style={arc} />
            </View>
          </AnimatedView>
        </View>
        <View
          style={{
            position: "absolute",
            top: 0,
            left: 0,
            width: half,
            height: RING_SIZE,
            overflow: "hidden",
          }}
        >
          <AnimatedView
            style={[
              {
                position: "absolute",
                top: 0,
                left: 0,
                width: RING_SIZE,
                height: RING_SIZE,
              },
              startStyle,
            ]}
          >
            <View
              style={{
                position: "absolute",
                top: 0,
                left: half,
                width: half,
                height: RING_SIZE,
                overflow: "hidden",
              }}
            >
              <View
                style={[arc, { position: "absolute", top: 0, left: -half }]}
              />
            </View>
          </AnimatedView>
        </View>
      </View>
    </View>
  )
}

function UndoBarProvider({
  timeout = 5000,
  style,
  portalHost,
  children,
}: {
  timeout?: number
  style?: StyleProp<ViewStyle>
  portalHost?: string
  children?: React.ReactNode
}) {
  const { colors, isDark } = useTheme()
  const [entry, setEntry] = React.useState<UndoBarEntry | null>(null)
  const [active, setActive] = React.useState(AppState.currentState === "active")
  const entryRef = React.useRef<UndoBarEntry | null>(null)
  const remainingRef = React.useRef({ id: 0, duration: timeout })
  const progress = useSharedValue(1)
  const insets = useSafeAreaInsets()
  const { width } = useWindowDimensions()
  const inset = Math.max(16, (width - MAX_WIDTH) / 2)
  const id = React.useId()

  const settle = React.useCallback((undo: boolean) => {
    const current = entryRef.current
    if (!current) return
    entryRef.current = null
    setEntry(null)
    if (undo) current.onUndo()
    else current.onCommit?.()
  }, [])

  const show = React.useCallback(
    (options: UndoBarOptions) => {
      entryRef.current?.onCommit?.()
      nextId += 1
      const next = { ...options, id: nextId }
      entryRef.current = next
      remainingRef.current = { id: next.id, duration: timeout }
      setEntry(next)
      if (typeof options.title === "string") {
        AccessibilityInfo.announceForAccessibility(options.title)
      }
    },
    [timeout]
  )

  const undo = React.useCallback(() => settle(true), [settle])
  const dismiss = React.useCallback(() => settle(false), [settle])

  React.useEffect(() => {
    const subscription = AppState.addEventListener("change", (state) =>
      setActive(state === "active")
    )
    return () => subscription.remove()
  }, [])

  React.useEffect(() => {
    if (!entry) return
    if (!active) {
      cancelAnimation(progress)
      return
    }
    const remaining =
      remainingRef.current.id === entry.id
        ? remainingRef.current.duration
        : timeout
    const started = Date.now()
    progress.value = remaining / timeout
    progress.value = withTiming(0, {
      duration: remaining,
      easing: Easing.linear,
      reduceMotion: ReduceMotion.Never,
    })
    const timer = setTimeout(dismiss, remaining)
    return () => {
      clearTimeout(timer)
      if (remainingRef.current.id !== entry.id) return
      remainingRef.current = {
        id: entry.id,
        duration: Math.max(0, remaining - (Date.now() - started)),
      }
    }
  }, [entry, active, timeout, dismiss, progress])

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

  return (
    <UndoBarContext.Provider value={contextValue}>
      {children}
      <Portal name={`undo-bar-${id}`} hostName={portalHost}>
        {entry ? (
          <AnimatedView
            key={entry.id}
            entering={ENTERING}
            exiting={EXITING}
            style={[
              styles.frame,
              {
                left: inset,
                right: inset,
                bottom: Math.max(16, insets.bottom),
                pointerEvents: "box-none",
              },
            ]}
          >
            <View
              role="group"
              accessibilityLiveRegion="polite"
              style={[
                styles.bar,
                {
                  borderColor: colors.separator,
                  backgroundColor: isDark
                    ? colors.surfaceSecondary
                    : colors.surfaceRaised,
                },
                style,
              ]}
            >
              <CountdownRing progress={progress} colors={colors} />
              <View style={styles.titleBox}>
                {typeof entry.title === "string" ||
                typeof entry.title === "number" ? (
                  <Text numberOfLines={1} style={styles.title}>
                    {entry.title}
                  </Text>
                ) : (
                  entry.title
                )}
              </View>
              <Button
                variant="plain"
                size="lg"
                style={styles.action}
                onPress={undo}
              >
                {typeof entry.actionLabel === "string" ||
                typeof entry.actionLabel === "number" ||
                entry.actionLabel === undefined ? (
                  <Text style={styles.actionText}>
                    {entry.actionLabel ?? "Undo"}
                  </Text>
                ) : (
                  entry.actionLabel
                )}
              </Button>
            </View>
          </AnimatedView>
        ) : null}
      </Portal>
    </UndoBarContext.Provider>
  )
}

export { UndoBarProvider, useUndoBar }
```

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/UndoBar.swift"
import Observation
import SwiftUI

public struct UndoBarEntry: Identifiable, Sendable {
  public let id: UUID
  public let title: LocalizedStringResource
  public let actionLabel: LocalizedStringResource?
  let onUndo: @MainActor @Sendable () -> Void
  let onCommit: (@MainActor @Sendable () -> Void)?
}

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

  public private(set) var entry: UndoBarEntry?
  public var timeout: Duration = .seconds(5)
  private(set) var paused = false

  @ObservationIgnored private var started = Date()
  @ObservationIgnored private var elapsed: TimeInterval = 0
  @ObservationIgnored private var timer: Task<Void, Never>?

  public init() {}

  @MainActor
  public func show(
    _ title: LocalizedStringResource,
    actionLabel: LocalizedStringResource? = nil,
    onUndo: @escaping @MainActor @Sendable () -> Void,
    onCommit: (@MainActor @Sendable () -> Void)? = nil
  ) {
    let previous = entry
    entry = UndoBarEntry(id: UUID(), title: title, actionLabel: actionLabel, onUndo: onUndo, onCommit: onCommit)
    previous?.onCommit?()
    elapsed = 0
    started = Date()
    if !paused { schedule() }
    AccessibilityNotification.Announcement(String(localized: title)).post()
  }

  @MainActor
  public func undo() {
    settle(undo: true)
  }

  @MainActor
  public func dismiss() {
    settle(undo: false)
  }

  @MainActor
  func pause() {
    guard !paused else { return }
    paused = true
    elapsed += Date().timeIntervalSince(started)
    timer?.cancel()
    timer = nil
  }

  @MainActor
  func resume() {
    guard paused else { return }
    paused = false
    started = Date()
    if entry != nil { schedule() }
  }

  func progress(at date: Date) -> Double {
    let total = Double(timeout.components.seconds) + Double(timeout.components.attoseconds) / 1e18
    guard total > 0 else { return 1 }
    let spent = elapsed + (paused ? 0 : date.timeIntervalSince(started))
    return min(max(spent / total, 0), 1)
  }

  @MainActor
  private func settle(undo: Bool) {
    guard let current = entry else { return }
    timer?.cancel()
    timer = nil
    entry = nil
    if undo {
      current.onUndo()
    } else {
      current.onCommit?()
    }
  }

  @MainActor
  private func schedule() {
    timer?.cancel()
    guard let id = entry?.id else { return }
    let remaining = timeout - .milliseconds(Int(elapsed * 1000))
    timer = Task { @MainActor [weak self] in
      try? await Task.sleep(for: max(remaining, .zero))
      guard !Task.isCancelled, let self, self.entry?.id == id else { return }
      self.dismiss()
    }
  }
}

extension EnvironmentValues {
  @Entry public var undoBarManager: UndoBarManager = .shared
}

extension View {
  public func undoBar(_ manager: UndoBarManager = .shared, timeout: Duration = .seconds(5)) -> some View {
    overlay(alignment: .bottom) {
      UndoBarRegion(manager: manager)
    }
    .environment(\.undoBarManager, manager)
    .onAppear { manager.timeout = timeout }
    .onChange(of: timeout) { _, value in manager.timeout = value }
  }
}

struct UndoBarRegion: View {
  let manager: UndoBarManager

  @Environment(\.scenePhase) private var scenePhase
  @Environment(\.accessibilityReduceMotion) private var reduceMotion

  var body: some View {
    ZStack(alignment: .bottom) {
      if let entry = manager.entry {
        UndoBarView(manager: manager, entry: entry)
          .id(entry.id)
          .transition(
            reduceMotion
              ? .opacity
              : .asymmetric(
                insertion: .offset(y: 68).combined(with: .scale(scale: 0.95, anchor: .bottom)).combined(with: .opacity),
                removal: .offset(y: 68).combined(with: .scale(scale: 0.95, anchor: .bottom)).combined(with: .opacity)
              )
          )
      }
    }
    .animation(.timingCurve(0.32, 0.72, 0, 1, duration: 0.4), value: manager.entry?.id)
    .onChange(of: scenePhase, initial: true) { _, phase in
      if phase == .active {
        manager.resume()
      } else {
        manager.pause()
      }
    }
  }
}

struct UndoBarView: View {
  let manager: UndoBarManager
  let entry: UndoBarEntry

  var body: some View {
    FloatingBar(visible: true, maxWidth: 384) {
      HStack(spacing: 12) {
        TimelineView(.animation(minimumInterval: nil, paused: manager.paused)) { context in
          UndoBarRing(progress: manager.progress(at: context.date))
        }
        Text(entry.title)
          .scaledFont(.sm, weight: .medium)
          .lineLimit(1)
          .truncationMode(.tail)
          .frame(maxWidth: .infinity, alignment: .leading)
        Button {
          manager.undo()
        } label: {
          Text(entry.actionLabel ?? "Undo").fontWeight(.semibold)
        }
        .buttonStyle(VariantButtonStyle(.plain, size: .lg, metrics: ButtonMetrics(horizontalPadding: 16, spacing: 6, iconSize: 16, textStyle: .base)))
      }
      .padding(.leading, 16)
      .padding(.trailing, 4)
    }
    .accessibilityElement(children: .contain)
    .accessibilityAction(.escape) { manager.dismiss() }
  }
}

struct UndoBarRing: View {
  let progress: Double

  var body: some View {
    ZStack {
      Circle()
        .stroke(Color.separator, lineWidth: 2)
      Circle()
        .trim(from: 0, to: 1 - progress)
        .stroke(Color.labelSecondary, style: StrokeStyle(lineWidth: 2, lineCap: .round))
        .rotationEffect(.degrees(-90))
    }
    .frame(width: 16, height: 16)
    .frame(width: 20, height: 20)
    .accessibilityHidden(true)
  }
}
```

```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)
  }
}
```

```swift title="swift/Interactions/SelectionList.swift"
import PhosphorSwift
import SwiftUI

struct SelectionModel<Value: Hashable> {
  var editing = false
  var selected: Set<Value> = []
  var order: [Value] = []

  mutating func toggle(_ value: Value) {
    if selected.contains(value) {
      selected.remove(value)
    } else {
      selected.insert(value)
    }
  }

  mutating func selectAll() {
    selected = Set(order)
  }

  mutating func clear() {
    selected = []
  }

  mutating func setEditing(_ value: Bool) {
    editing = value
    if !value { selected = [] }
  }
}

struct SelectionListContext {
  var editing: Bool
  var count: Int
  var total: Int
  var isSelected: (AnyHashable) -> Bool
  var toggle: (AnyHashable) -> Void
  var setEditing: (Bool) -> Void
  var selectAll: () -> Void
  var clear: () -> Void
}

extension EnvironmentValues {
  @Entry var selectionList: SelectionListContext?
}

struct SelectionListValuesKey: PreferenceKey {
  static var defaultValue: [AnyHashable] { [] }

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

let selectionListAnimation = Animation.timingCurve(0.32, 0.72, 0, 1, duration: 0.4)

public struct SelectionListProxy {
  let context: SelectionListContext

  public var isEditing: Bool { context.editing }
  public var count: Int { context.count }
  public var total: Int { context.total }

  public func setEditing(_ value: Bool) {
    context.setEditing(value)
  }

  public func selectAll() {
    context.selectAll()
  }

  public func clear() {
    context.clear()
  }
}

public struct SelectionList<Value: Hashable, Content: View>: View {
  let editingBinding: Binding<Bool>?
  let selectionBinding: Binding<Set<Value>>?
  let content: Content

  @State private var localEditing: Bool
  @State private var localSelection: Set<Value>
  @State private var order: [Value] = []
  @Environment(\.accessibilityReduceMotion) private var reduceMotion

  public init(
    isEditing: Binding<Bool>? = nil,
    selection: Binding<Set<Value>>? = nil,
    defaultEditing: Bool = false,
    defaultSelection: Set<Value> = [],
    @ViewBuilder content: () -> Content
  ) {
    editingBinding = isEditing
    selectionBinding = selection
    _localEditing = State(initialValue: defaultEditing)
    _localSelection = State(initialValue: defaultSelection)
    self.content = content()
  }

  private var model: SelectionModel<Value> {
    SelectionModel(
      editing: editingBinding?.wrappedValue ?? localEditing,
      selected: selectionBinding?.wrappedValue ?? localSelection,
      order: order
    )
  }

  private func update(_ change: (inout SelectionModel<Value>) -> Void) {
    var next = model
    change(&next)
    if next.selected != model.selected {
      if let selectionBinding {
        selectionBinding.wrappedValue = next.selected
      } else {
        localSelection = next.selected
      }
    }
    if next.editing != model.editing {
      let apply = {
        if let editingBinding {
          editingBinding.wrappedValue = next.editing
        } else {
          localEditing = next.editing
        }
      }
      if reduceMotion {
        apply()
      } else {
        withAnimation(selectionListAnimation, apply)
      }
    }
  }

  public var body: some View {
    let current = model
    let context = SelectionListContext(
      editing: current.editing,
      count: current.selected.count,
      total: order.count,
      isSelected: { value in (value.base as? Value).map(current.selected.contains) ?? false },
      toggle: { value in
        guard let value = value.base as? Value else { return }
        update { $0.toggle(value) }
      },
      setEditing: { value in update { $0.setEditing(value) } },
      selectAll: { update { $0.selectAll() } },
      clear: { update { $0.clear() } }
    )
    content
      .environment(\.selectionList, context)
      .onPreferenceChange(SelectionListValuesKey.self) { values in
        order = values.compactMap { $0.base as? Value }
      }
      .accessibilityAction(.escape) {
        if current.editing { context.setEditing(false) }
      }
  }
}

public struct SelectionListTrigger<Label: View>: View {
  let label: Label?

  @Environment(\.selectionList) private var list

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

  public var body: some View {
    let editing = list?.editing ?? false
    Button {
      list?.setEditing(!editing)
    } label: {
      if let label {
        label
      } else {
        Text(editing ? "Done" : "Select").fontWeight(.semibold)
      }
    }
    .buttonStyle(.variant(.plain))
    .fontWeight(.semibold)
    .accessibilityAddTraits(editing ? .isSelected : [])
  }
}

extension SelectionListTrigger where Label == Text {
  public init() {
    label = nil
  }

  public init(_ title: LocalizedStringKey) {
    label = Text(title).fontWeight(.semibold)
  }
}

public struct SelectionListItem<Value: Hashable, Content: View>: View {
  let value: Value
  let content: Content

  @Environment(\.selectionList) private var list

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

  public var body: some View {
    let editing = list?.editing ?? false
    let checked = list?.isSelected(AnyHashable(value)) ?? false
    HStack(spacing: 0) {
      SelectionListIndicator(editing: editing, checked: checked)
      content
        .frame(maxWidth: .infinity, alignment: .leading)
        .allowsHitTesting(!editing)
    }
    .background(checked ? Color.itemSelected : .clear)
    .contentShape(Rectangle())
    .onTapGesture {
      guard editing else { return }
      list?.toggle(AnyHashable(value))
    }
    .animation(.timingCurve(0.32, 0.72, 0, 1, duration: 0.2), value: checked)
    .preference(key: SelectionListValuesKey.self, value: [AnyHashable(value)])
    .modifier(SelectionItemAccessibility(editing: editing, checked: checked) {
      list?.toggle(AnyHashable(value))
    })
  }
}

private struct SelectionItemAccessibility: ViewModifier {
  let editing: Bool
  let checked: Bool
  let toggle: () -> Void

  func body(content: Content) -> some View {
    if editing {
      content
        .accessibilityElement(children: .combine)
        .accessibilityAddTraits(checked ? [.isButton, .isSelected] : .isButton)
        .accessibilityAction { toggle() }
    } else {
      content
    }
  }
}

struct SelectionListIndicator: View {
  let editing: Bool
  let checked: Bool

  var body: some View {
    ZStack {
      Circle()
        .strokeBorder(checked ? Color.accent : .labelTertiary, lineWidth: 1.5)
      if checked {
        Circle().fill(Color.accent)
        Ph.check.bold
          .frame(width: 14, height: 14)
          .foregroundStyle(Color.onAccent)
          .transition(.scale)
      }
    }
    .frame(width: 22, height: 22)
    .scaleEffect(editing ? 1 : 0.5)
    .padding(.leading, 16)
    .frame(width: editing ? 40 : 0, alignment: .leading)
    .opacity(editing ? 1 : 0)
    .clipped()
    .accessibilityHidden(true)
  }
}

public struct SelectionListBar<Content: View>: View {
  let content: (SelectionListProxy) -> Content

  @Environment(\.selectionList) private var list

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

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

  public var body: some View {
    let editing = list?.editing ?? false
    FloatingBar(visible: editing) {
      HStack(spacing: 8) {
        if let list {
          content(SelectionListProxy(context: list))
        }
      }
      .padding(.horizontal, 6)
    }
    .accessibilityElement(children: .contain)
  }
}

public struct SelectionListCount: View {
  let text: Text?

  @Environment(\.selectionList) private var list

  public init() {
    text = nil
  }

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

  public var body: some View {
    let count = list?.count ?? 0
    Group {
      if let text {
        text
      } else if count == 0 {
        Text("Select items")
      } else {
        Text("\(count) selected")
      }
    }
    .scaledFont(.sm, weight: .medium)
    .monospacedDigit()
    .lineLimit(1)
    .multilineTextAlignment(.center)
    .foregroundStyle(Color.label)
    .frame(maxWidth: .infinity)
    .contentTransition(.numericText())
    .accessibilityAddTraits(.updatesFrequently)
  }
}

struct FloatingBar<Content: View>: View {
  let visible: Bool
  var maxWidth: CGFloat = 448
  @ViewBuilder let content: () -> Content

  @State private var bottomInset: CGFloat = 0
  @Environment(\.colorScheme) private var colorScheme
  @Environment(\.accessibilityReduceMotion) private var reduceMotion

  var body: some View {
    let dark = colorScheme == .dark
    content()
      .frame(maxWidth: .infinity, minHeight: 52, maxHeight: 52)
      .foregroundStyle(Color.label)
      .background {
        Capsule()
          .fill(.ultraThinMaterial)
          .overlay {
            Capsule().fill(dark ? Color.surfaceSecondary.opacity(0.75) : Color.surfaceRaised.opacity(0.8))
          }
          .shadow(Shadow(color: .black.opacity(dark ? 0.3 : 0.12), radius: 14, y: 10))
      }
      .overlay {
        Capsule().strokeBorder(Color.separator)
      }
      .frame(maxWidth: maxWidth)
      .padding(.horizontal, 16)
      .padding(.bottom, 16)
      .scaleEffect(visible || reduceMotion ? 1 : 0.95, anchor: .bottom)
      .offset(y: min(16, bottomInset) + (visible || reduceMotion ? 0 : 52 + 16 + bottomInset))
      .background {
        Color.clear
          .onGeometryChange(for: CGFloat.self) { $0.safeAreaInsets.bottom } action: { bottomInset = $0 }
      }
      .opacity(visible ? 1 : 0)
      .allowsHitTesting(visible)
      .accessibilityHidden(!visible)
  }
}
```

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/UndoBar.kt"
package com.esuiss.ui.interactions

import androidx.compose.animation.core.Animatable
import androidx.compose.animation.core.LinearEasing
import androidx.compose.animation.core.tween
import androidx.compose.foundation.Canvas
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.PaddingValues
import androidx.compose.foundation.layout.size
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.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.StrokeCap
import androidx.compose.ui.graphics.drawscope.Stroke
import androidx.compose.ui.graphics.drawscope.scale
import androidx.compose.ui.platform.LocalLayoutDirection
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.LayoutDirection
import androidx.compose.ui.unit.dp
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonSize
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.LocalContentStyle
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Typography

@Immutable
internal class UndoBarEntry(
    val id: Long,
    val title: String,
    val actionLabel: String?,
    val onUndo: () -> Unit,
    val onCommit: (() -> Unit)?,
)

@Stable
class UndoBarState {
    private var nextId = 0L
    private var entry by mutableStateOf<UndoBarEntry?>(null)
    internal var visible by mutableStateOf(false)
        private set
    private var pending: UndoBarEntry? = null

    internal val current: UndoBarEntry?
        get() = entry

    fun show(
        title: String,
        onUndo: () -> Unit,
        actionLabel: String? = null,
        onCommit: (() -> Unit)? = null,
    ) {
        pending?.onCommit?.invoke()
        nextId += 1
        val next = UndoBarEntry(nextId, title, actionLabel, onUndo, onCommit)
        pending = next
        entry = next
        visible = true
    }

    fun undo() {
        settle(true)
    }

    fun dismiss() {
        settle(false)
    }

    private fun settle(undo: Boolean) {
        val active = pending ?: return
        pending = null
        visible = false
        if (undo) active.onUndo() else active.onCommit?.invoke()
    }
}

@Composable
fun rememberUndoBarState(): UndoBarState = remember { UndoBarState() }

@Composable
fun UndoBarProvider(
    state: UndoBarState,
    modifier: Modifier = Modifier,
    timeoutMillis: Long = 5000,
    content: @Composable () -> Unit,
) {
    content()
    val entry = state.current ?: return
    val visible = state.visible
    val progress = remember { Animatable(0f) }
    LaunchedEffect(entry.id, visible, timeoutMillis) {
        if (!visible) return@LaunchedEffect
        progress.snapTo(0f)
        progress.animateTo(1f, tween(timeoutMillis.toInt(), easing = LinearEasing))
        state.dismiss()
    }
    val colors = EsuissTheme.colors
    FloatingBar(
        visible = visible,
        maxWidth = 384.dp,
        contentPadding = PaddingValues(start = 16.dp, end = 4.dp),
        horizontalArrangement = Arrangement.spacedBy(12.dp),
        modifier = modifier.semantics { liveRegion = LiveRegionMode.Polite },
    ) {
        val rtl = LocalLayoutDirection.current == LayoutDirection.Rtl
        Canvas(modifier = Modifier.size(20.dp)) {
            val stroke = 2.dp.toPx()
            val radius = 8.dp.toPx()
            val topLeft = Offset(center.x - radius, center.y - radius)
            val arc = Size(radius * 2, radius * 2)
            drawCircle(colors.separator, radius, style = Stroke(stroke))
            scale(if (rtl) -1f else 1f, 1f) {
                drawArc(
                    color = colors.labelSecondary,
                    startAngle = -90f + progress.value * 360f,
                    sweepAngle = (1f - progress.value) * 360f,
                    useCenter = false,
                    topLeft = topLeft,
                    size = arc,
                    style = Stroke(stroke, cap = StrokeCap.Round),
                )
            }
        }
        BasicText(
            entry.title,
            modifier = Modifier.weight(1f),
            style = Typography.sm.copy(color = colors.label, fontWeight = FontWeight.Medium),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
        )
        Button(onClick = { state.undo() }, variant = ButtonVariant.Plain, size = ButtonSize.Lg) {
            BasicText(
                entry.actionLabel ?: "Undo",
                style = LocalContentStyle.current.copy(fontWeight = FontWeight.SemiBold),
                maxLines = 1,
            )
        }
    }
}
```

```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),
    )
}
```

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

import androidx.compose.animation.AnimatedVisibility
import androidx.compose.animation.core.MutableTransitionState
import androidx.compose.animation.core.tween
import androidx.compose.animation.fadeIn
import androidx.compose.animation.fadeOut
import androidx.compose.animation.scaleIn
import androidx.compose.animation.scaleOut
import androidx.compose.animation.slideInVertically
import androidx.compose.animation.slideOutVertically
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.PaddingValues
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.RowScope
import androidx.compose.foundation.layout.WindowInsets
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.safeDrawing
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.CompositionLocalProvider
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.platform.LocalDensity
import androidx.compose.ui.platform.LocalWindowInfo
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.FormEasing
import com.esuiss.ui.components.LocalContentColor
import com.esuiss.ui.components.LocalContentStyle
import com.esuiss.ui.components.formReducedMotion
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Shadows
import com.esuiss.ui.theme.Typography
import com.esuiss.ui.theme.shadow

private val FloatingBarPadding = 16.dp

private class FloatingBarPosition(
    private val bottomLimit: Int,
    private val padding: Int,
) : PopupPositionProvider {
    override fun calculatePosition(
        anchorBounds: IntRect,
        windowSize: IntSize,
        layoutDirection: LayoutDirection,
        popupContentSize: IntSize,
    ): IntOffset {
        val bottom = minOf(windowSize.height, bottomLimit)
        return IntOffset(
            (windowSize.width - popupContentSize.width) / 2,
            bottom - popupContentSize.height + padding,
        )
    }
}

@Composable
internal fun FloatingBar(
    visible: Boolean,
    maxWidth: Dp,
    contentPadding: PaddingValues,
    horizontalArrangement: Arrangement.Horizontal,
    modifier: Modifier = Modifier,
    content: @Composable RowScope.() -> Unit,
) {
    val transition = remember { MutableTransitionState(false) }
    transition.targetState = visible
    if (!transition.currentState && !transition.targetState) return
    val density = LocalDensity.current
    val colors = EsuissTheme.colors
    val reduced = formReducedMotion()
    val container = LocalWindowInfo.current.containerSize
    val safeBottom = WindowInsets.safeDrawing.getBottom(density)
    val margin = with(density) { FloatingBarPadding.roundToPx() }
    val bottomLimit = if (container.height > 0) container.height - maxOf(margin, safeBottom) else Int.MAX_VALUE
    val available = with(density) { container.width.toDp() } - FloatingBarPadding * 2
    val width = if (container.width > 0 && available < maxWidth) available else maxWidth
    val provider = remember(bottomLimit, margin) { FloatingBarPosition(bottomLimit, margin) }
    val slide = with(density) { FloatingBarPadding.roundToPx() }
    Popup(
        popupPositionProvider = provider,
        properties = PopupProperties(focusable = false, dismissOnBackPress = false, dismissOnClickOutside = false),
    ) {
        Box(modifier = Modifier.padding(FloatingBarPadding)) {
            AnimatedVisibility(
                visibleState = transition,
                enter = if (reduced) {
                    fadeIn(tween(400))
                } else {
                    fadeIn(tween(400, easing = FormEasing)) +
                        scaleIn(tween(400, easing = FormEasing), initialScale = 0.95f) +
                        slideInVertically(tween(400, easing = FormEasing)) { it + slide }
                },
                exit = if (reduced) {
                    fadeOut(tween(300))
                } else {
                    fadeOut(tween(300, easing = FormEasing)) +
                        scaleOut(tween(300, easing = FormEasing), targetScale = 0.95f) +
                        slideOutVertically(tween(300, easing = FormEasing)) { it + slide }
                },
            ) {
                val background = if (colors.isDark) colors.surfaceSecondary.copy(alpha = 0.75f) else colors.surfaceRaised.copy(alpha = 0.8f)
                Row(
                    modifier = modifier
                        .width(width)
                        .height(52.dp)
                        .shadow(Shadows.lg, CircleShape)
                        .clip(CircleShape)
                        .background(background, CircleShape)
                        .border(1.dp, colors.separator, CircleShape)
                        .padding(contentPadding),
                    horizontalArrangement = horizontalArrangement,
                    verticalAlignment = Alignment.CenterVertically,
                ) {
                    CompositionLocalProvider(
                        LocalContentStyle provides Typography.sm.copy(color = colors.label),
                        LocalContentColor provides colors.label,
                    ) {
                        content()
                    }
                }
            }
        }
    }
}
```

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

## Usage

```tsx
import { UndoBarProvider } from "@/components/interactions/undo-bar"
```

```tsx
<UndoBarProvider>
  <NotesList />
</UndoBarProvider>
```

Wrap the screen or app in `UndoBarProvider`. After removing an item from the UI, call `show({ title, onUndo, onCommit?, actionLabel? })`: restore the item in `onUndo`, and do the permanent work, such as a server delete, in `onCommit`.

`useUndoBar` also returns `undo`, which runs the current undo, and `dismiss`, which commits and hides the bar.

## Examples

### Showing

The bar shown right after deleting a note, with a long timeout.

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

```tsx
import { TrashIcon } from "phosphor-react-native"
import * as React from "react"
import { View } from "react-native"
import { UndoBarProvider, useUndoBar } from "@/components/interactions/undo-bar"
import { Button } from "@/components/ui/button"
import { Icon } from "@/components/ui/icon"
import { Text } from "@/components/ui/text"

const initialNotes = [
  { id: 1, title: "Groceries", preview: "Milk, eggs, bread, coffee" },
  { id: 2, title: "Trip ideas", preview: "Lisbon, Porto, the coast road" },
  { id: 3, title: "Book list", preview: "Three novels for the summer" },
  { id: 4, title: "Meeting notes", preview: "Ship the beta on Friday" },
]

type Note = (typeof initialNotes)[number]

function useNotes() {
  const [notes, setNotes] = React.useState(initialNotes)
  const [log, setLog] = React.useState("Delete a note.")
  const { show } = useUndoBar()

  const remove = (note: Note) => {
    const index = notes.findIndex((item) => item.id === note.id)
    setNotes((current) => current.filter((item) => item.id !== note.id))
    setLog(`Removed “${note.title}”`)
    show({
      title: `“${note.title}” deleted`,
      onUndo: () => {
        setNotes((current) => {
          const next = [...current]
          next.splice(Math.min(index, next.length), 0, note)
          return next
        })
        setLog(`Restored “${note.title}”`)
      },
      onCommit: () => setLog(`Deleted “${note.title}” permanently`),
    })
  }

  return { notes, remove, log }
}

function NoteText({ note }: { note: Note }) {
  return (
    <View className="min-w-0 flex-1 py-2">
      <Text numberOfLines={1} className="font-semibold">
        {note.title}
      </Text>
      <Text numberOfLines={1} className="text-sm text-label-secondary">
        {note.preview}
      </Text>
    </View>
  )
}

function NotesList({ deleteFirst = false }: { deleteFirst?: boolean }) {
  const { notes, remove, log } = useNotes()
  const removeRef = React.useRef(remove)
  const deletedRef = React.useRef(false)
  removeRef.current = remove

  React.useEffect(() => {
    if (!deleteFirst || deletedRef.current) return
    deletedRef.current = true
    removeRef.current(initialNotes[0])
  }, [deleteFirst])

  return (
    <View className="w-full gap-3">
      <View className="overflow-hidden rounded-2xl border border-separator">
        {notes.map((note, index) => (
          <View
            key={note.id}
            className={
              index > 0
                ? "flex-row items-center gap-3 border-t border-separator py-1 ps-4 pe-1"
                : "flex-row items-center gap-3 py-1 ps-4 pe-1"
            }
          >
            <NoteText note={note} />
            <Button
              variant="ghost"
              size="icon-lg"
              accessibilityLabel={`Delete ${note.title}`}
              onPress={() => remove(note)}
            >
              <Icon as={TrashIcon} className="size-5" />
            </Button>
          </View>
        ))}
      </View>
      <Text role="status" className="text-sm text-label-secondary">
        {log}
      </Text>
    </View>
  )
}

export function UndoBarShowingExample() {
  return (
    <UndoBarProvider timeout={60000}>
      <NotesList deleteFirst />
    </UndoBarProvider>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct UndoBarShowingExample: View {
  var body: some View {
    UndoBarStage(timeout: .seconds(60)) { UndoBarNotes(deleteFirst: true) }
  }
}

struct UndoBarNote: Identifiable, Equatable {
  let id: Int
  let title: String
  let preview: String
}

let undoBarInitialNotes = [
  UndoBarNote(id: 1, title: "Groceries", preview: "Milk, eggs, bread, coffee"),
  UndoBarNote(id: 2, title: "Trip ideas", preview: "Lisbon, Porto, the coast road"),
  UndoBarNote(id: 3, title: "Book list", preview: "Three novels for the summer"),
  UndoBarNote(id: 4, title: "Meeting notes", preview: "Ship the beta on Friday"),
]

struct UndoBarStage<Content: View>: View {
  let timeout: Duration
  @ViewBuilder let content: () -> Content

  @State private var manager = UndoBarManager()

  var body: some View {
    content()
      .frame(maxHeight: .infinity, alignment: .top)
      .containerRelativeFrame(.vertical) { height, _ in height - 32 }
      .undoBar(manager, timeout: timeout)
  }
}

struct UndoBarNoteText: View {
  let note: UndoBarNote

  var body: some View {
    VStack(alignment: .leading, spacing: 0) {
      Text(verbatim: note.title)
        .textStyle(.base, weight: .semibold)
        .foregroundStyle(Color.label)
        .lineLimit(1)
      Text(verbatim: note.preview)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .lineLimit(1)
    }
    .padding(.vertical, 8)
    .frame(maxWidth: .infinity, alignment: .leading)
  }
}

struct UndoBarNotes: View {
  var deleteFirst = false
  var swipe = false

  @State private var notes = undoBarInitialNotes
  @State private var log = "Delete a note."
  @State private var deleted = false
  @Environment(\.undoBarManager) private var manager

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
    VStack(alignment: .leading, spacing: 12) {
      VStack(spacing: 0) {
        ForEach(Array(notes.enumerated()), id: \.element.id) { index, note in
          row(note)
            .overlay(alignment: .top) {
              if index > 0 {
                Color.separator.frame(height: 1)
              }
            }
        }
      }
      .clipShape(shape)
      .overlay { shape.strokeBorder(Color.separator) }
      Text(verbatim: log)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .accessibilityAddTraits(.updatesFrequently)
    }
    .onAppear {
      guard deleteFirst, !deleted else { return }
      deleted = true
      remove(undoBarInitialNotes[0])
    }
  }

  @ViewBuilder
  func row(_ note: UndoBarNote) -> some View {
    if swipe {
      SwipeActions {
        UndoBarNoteText(note: note)
          .padding(.horizontal, 16)
          .padding(.vertical, 4)
      } trailing: {
        SwipeAction("Delete", icon: Ph.trash.fill, variant: .destructive, fullSwipe: true) {
          remove(note)
        }
      }
    } else {
      HStack(spacing: 12) {
        UndoBarNoteText(note: note)
        Button {
          remove(note)
        } label: {
          Ph.trash.regular.frame(width: 20, height: 20)
        }
        .buttonStyle(.variant(.ghost, size: .iconLg))
        .accessibilityLabel(Text(verbatim: "Delete \(note.title)"))
      }
      .padding(.leading, 16)
      .padding(.trailing, 4)
      .padding(.vertical, 4)
    }
  }

  func remove(_ note: UndoBarNote) {
    let index = notes.firstIndex(of: note) ?? 0
    notes.removeAll { $0.id == note.id }
    log = "Removed “\(note.title)”"
    manager.show(
      "“\(note.title)” deleted",
      onUndo: {
        notes.insert(note, at: min(index, notes.count))
        log = "Restored “\(note.title)”"
      },
      onCommit: {
        log = "Deleted “\(note.title)” permanently"
      }
    )
  }
}
```

```kotlin
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.key
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.fill.Trash
import com.adamglin.phosphoricons.regular.Trash
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonSize
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Icon
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.UndoBarProvider
import com.esuiss.ui.interactions.UndoBarState
import com.esuiss.ui.interactions.rememberUndoBarState
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

@Composable
fun UndoBarShowingExample() {
    UndoBarDemo(timeout = 60000L) { state -> UndoBarNotesList(state, deleteFirst = true) }
}

class UndoBarNote(val id: Int, val title: String, val preview: String)

val undoBarInitialNotes = listOf(
    UndoBarNote(1, "Groceries", "Milk, eggs, bread, coffee"),
    UndoBarNote(2, "Trip ideas", "Lisbon, Porto, the coast road"),
    UndoBarNote(3, "Book list", "Three novels for the summer"),
    UndoBarNote(4, "Meeting notes", "Ship the beta on Friday"),
)

class UndoBarNotes(
    val notes: List<UndoBarNote>,
    val log: String,
    val remove: (UndoBarNote) -> Unit,
)

@Composable
fun UndoBarDemo(timeout: Long, content: @Composable (UndoBarState) -> Unit) {
    val state = rememberUndoBarState()
    UndoBarProvider(state, timeoutMillis = timeout) {
        content(state)
    }
}

@Composable
fun rememberUndoBarNotes(state: UndoBarState): UndoBarNotes {
    var ids by rememberSaveable { mutableStateOf(undoBarInitialNotes.map { it.id }) }
    var log by rememberSaveable { mutableStateOf("Delete a note.") }
    val notes = ids.mapNotNull { id -> undoBarInitialNotes.firstOrNull { it.id == id } }
    return UndoBarNotes(notes, log) { note ->
        val index = ids.indexOf(note.id)
        ids = ids - note.id
        log = "Removed “${note.title}”"
        state.show(
            title = "“${note.title}” deleted",
            onUndo = {
                ids = ids.toMutableList().apply { add(minOf(index, size), note.id) }
                log = "Restored “${note.title}”"
            },
            onCommit = { log = "Deleted “${note.title}” permanently" },
        )
    }
}

@Composable
fun UndoBarNoteText(note: UndoBarNote, modifier: Modifier = Modifier) {
    Column(modifier.padding(vertical = 8.dp)) {
        Text(
            note.title,
            style = Typography.base.copy(fontWeight = FontWeight.SemiBold),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
        )
        Text(
            note.preview,
            style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
        )
    }
}

@Composable
fun UndoBarFrame(notes: UndoBarNotes, row: @Composable (UndoBarNote) -> Unit) {
    val colors = EsuissTheme.colors
    val shape = RoundedCornerShape(Radius.xl2)
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Column(
            Modifier
                .fillMaxWidth()
                .clip(shape)
                .border(1.dp, colors.separator, shape),
        ) {
            notes.notes.forEachIndexed { index, note ->
                key(note.id) {
                    if (index > 0) Box(Modifier.fillMaxWidth().height(1.dp).background(colors.separator))
                    row(note)
                }
            }
        }
        Text(
            notes.log,
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = colors.labelSecondary),
        )
    }
}

@Composable
fun UndoBarNotesList(state: UndoBarState, deleteFirst: Boolean = false) {
    val notes = rememberUndoBarNotes(state)
    var deleted by rememberSaveable { mutableStateOf(false) }
    LaunchedEffect(Unit) {
        if (!deleteFirst || deleted) return@LaunchedEffect
        deleted = true
        notes.remove(undoBarInitialNotes.first())
    }
    UndoBarFrame(notes) { note ->
        Row(
            modifier = Modifier.fillMaxWidth().padding(start = 16.dp, end = 4.dp, top = 4.dp, bottom = 4.dp),
            horizontalArrangement = Arrangement.spacedBy(12.dp),
            verticalAlignment = Alignment.CenterVertically,
        ) {
            UndoBarNoteText(note, Modifier.weight(1f))
            Button(onClick = { notes.remove(note) }, variant = ButtonVariant.Ghost, size = ButtonSize.IconLg) {
                Icon(PhosphorIcons.Regular.Trash, contentDescription = "Delete ${note.title}", size = 20.dp)
            }
        }
    }
}
```

### Longer timeout

Uses a 10 second `timeout`.

![Preview](https://uim.suiss.app/previews/interactions-undo-bar--longer-timeout.light.webp)

```tsx
import { TrashIcon } from "phosphor-react-native"
import * as React from "react"
import { View } from "react-native"
import { UndoBarProvider, useUndoBar } from "@/components/interactions/undo-bar"
import { Button } from "@/components/ui/button"
import { Icon } from "@/components/ui/icon"
import { Text } from "@/components/ui/text"

const initialNotes = [
  { id: 1, title: "Groceries", preview: "Milk, eggs, bread, coffee" },
  { id: 2, title: "Trip ideas", preview: "Lisbon, Porto, the coast road" },
  { id: 3, title: "Book list", preview: "Three novels for the summer" },
  { id: 4, title: "Meeting notes", preview: "Ship the beta on Friday" },
]

type Note = (typeof initialNotes)[number]

function useNotes() {
  const [notes, setNotes] = React.useState(initialNotes)
  const [log, setLog] = React.useState("Delete a note.")
  const { show } = useUndoBar()

  const remove = (note: Note) => {
    const index = notes.findIndex((item) => item.id === note.id)
    setNotes((current) => current.filter((item) => item.id !== note.id))
    setLog(`Removed “${note.title}”`)
    show({
      title: `“${note.title}” deleted`,
      onUndo: () => {
        setNotes((current) => {
          const next = [...current]
          next.splice(Math.min(index, next.length), 0, note)
          return next
        })
        setLog(`Restored “${note.title}”`)
      },
      onCommit: () => setLog(`Deleted “${note.title}” permanently`),
    })
  }

  return { notes, remove, log }
}

function NoteText({ note }: { note: Note }) {
  return (
    <View className="min-w-0 flex-1 py-2">
      <Text numberOfLines={1} className="font-semibold">
        {note.title}
      </Text>
      <Text numberOfLines={1} className="text-sm text-label-secondary">
        {note.preview}
      </Text>
    </View>
  )
}

function NotesList({ deleteFirst = false }: { deleteFirst?: boolean }) {
  const { notes, remove, log } = useNotes()
  const removeRef = React.useRef(remove)
  const deletedRef = React.useRef(false)
  removeRef.current = remove

  React.useEffect(() => {
    if (!deleteFirst || deletedRef.current) return
    deletedRef.current = true
    removeRef.current(initialNotes[0])
  }, [deleteFirst])

  return (
    <View className="w-full gap-3">
      <View className="overflow-hidden rounded-2xl border border-separator">
        {notes.map((note, index) => (
          <View
            key={note.id}
            className={
              index > 0
                ? "flex-row items-center gap-3 border-t border-separator py-1 ps-4 pe-1"
                : "flex-row items-center gap-3 py-1 ps-4 pe-1"
            }
          >
            <NoteText note={note} />
            <Button
              variant="ghost"
              size="icon-lg"
              accessibilityLabel={`Delete ${note.title}`}
              onPress={() => remove(note)}
            >
              <Icon as={TrashIcon} className="size-5" />
            </Button>
          </View>
        ))}
      </View>
      <Text role="status" className="text-sm text-label-secondary">
        {log}
      </Text>
    </View>
  )
}

export function UndoBarLongerTimeoutExample() {
  return (
    <UndoBarProvider timeout={10000}>
      <NotesList />
    </UndoBarProvider>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct UndoBarLongerTimeoutExample: View {
  var body: some View {
    UndoBarStage(timeout: .seconds(10)) { UndoBarNotes() }
  }
}

struct UndoBarNote: Identifiable, Equatable {
  let id: Int
  let title: String
  let preview: String
}

let undoBarInitialNotes = [
  UndoBarNote(id: 1, title: "Groceries", preview: "Milk, eggs, bread, coffee"),
  UndoBarNote(id: 2, title: "Trip ideas", preview: "Lisbon, Porto, the coast road"),
  UndoBarNote(id: 3, title: "Book list", preview: "Three novels for the summer"),
  UndoBarNote(id: 4, title: "Meeting notes", preview: "Ship the beta on Friday"),
]

struct UndoBarStage<Content: View>: View {
  let timeout: Duration
  @ViewBuilder let content: () -> Content

  @State private var manager = UndoBarManager()

  var body: some View {
    content()
      .frame(maxHeight: .infinity, alignment: .top)
      .containerRelativeFrame(.vertical) { height, _ in height - 32 }
      .undoBar(manager, timeout: timeout)
  }
}

struct UndoBarNoteText: View {
  let note: UndoBarNote

  var body: some View {
    VStack(alignment: .leading, spacing: 0) {
      Text(verbatim: note.title)
        .textStyle(.base, weight: .semibold)
        .foregroundStyle(Color.label)
        .lineLimit(1)
      Text(verbatim: note.preview)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .lineLimit(1)
    }
    .padding(.vertical, 8)
    .frame(maxWidth: .infinity, alignment: .leading)
  }
}

struct UndoBarNotes: View {
  var deleteFirst = false
  var swipe = false

  @State private var notes = undoBarInitialNotes
  @State private var log = "Delete a note."
  @State private var deleted = false
  @Environment(\.undoBarManager) private var manager

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
    VStack(alignment: .leading, spacing: 12) {
      VStack(spacing: 0) {
        ForEach(Array(notes.enumerated()), id: \.element.id) { index, note in
          row(note)
            .overlay(alignment: .top) {
              if index > 0 {
                Color.separator.frame(height: 1)
              }
            }
        }
      }
      .clipShape(shape)
      .overlay { shape.strokeBorder(Color.separator) }
      Text(verbatim: log)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .accessibilityAddTraits(.updatesFrequently)
    }
    .onAppear {
      guard deleteFirst, !deleted else { return }
      deleted = true
      remove(undoBarInitialNotes[0])
    }
  }

  @ViewBuilder
  func row(_ note: UndoBarNote) -> some View {
    if swipe {
      SwipeActions {
        UndoBarNoteText(note: note)
          .padding(.horizontal, 16)
          .padding(.vertical, 4)
      } trailing: {
        SwipeAction("Delete", icon: Ph.trash.fill, variant: .destructive, fullSwipe: true) {
          remove(note)
        }
      }
    } else {
      HStack(spacing: 12) {
        UndoBarNoteText(note: note)
        Button {
          remove(note)
        } label: {
          Ph.trash.regular.frame(width: 20, height: 20)
        }
        .buttonStyle(.variant(.ghost, size: .iconLg))
        .accessibilityLabel(Text(verbatim: "Delete \(note.title)"))
      }
      .padding(.leading, 16)
      .padding(.trailing, 4)
      .padding(.vertical, 4)
    }
  }

  func remove(_ note: UndoBarNote) {
    let index = notes.firstIndex(of: note) ?? 0
    notes.removeAll { $0.id == note.id }
    log = "Removed “\(note.title)”"
    manager.show(
      "“\(note.title)” deleted",
      onUndo: {
        notes.insert(note, at: min(index, notes.count))
        log = "Restored “\(note.title)”"
      },
      onCommit: {
        log = "Deleted “\(note.title)” permanently"
      }
    )
  }
}
```

```kotlin
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.LaunchedEffect
import androidx.compose.runtime.getValue
import androidx.compose.runtime.key
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.saveable.rememberSaveable
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Regular
import com.adamglin.phosphoricons.fill.Trash
import com.adamglin.phosphoricons.regular.Trash
import com.esuiss.ui.components.Button
import com.esuiss.ui.components.ButtonSize
import com.esuiss.ui.components.ButtonVariant
import com.esuiss.ui.components.Icon
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.UndoBarProvider
import com.esuiss.ui.interactions.UndoBarState
import com.esuiss.ui.interactions.rememberUndoBarState
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

@Composable
fun UndoBarLongerTimeoutExample() {
    UndoBarDemo(timeout = 10000L) { state -> UndoBarNotesList(state) }
}

class UndoBarNote(val id: Int, val title: String, val preview: String)

val undoBarInitialNotes = listOf(
    UndoBarNote(1, "Groceries", "Milk, eggs, bread, coffee"),
    UndoBarNote(2, "Trip ideas", "Lisbon, Porto, the coast road"),
    UndoBarNote(3, "Book list", "Three novels for the summer"),
    UndoBarNote(4, "Meeting notes", "Ship the beta on Friday"),
)

class UndoBarNotes(
    val notes: List<UndoBarNote>,
    val log: String,
    val remove: (UndoBarNote) -> Unit,
)

@Composable
fun UndoBarDemo(timeout: Long, content: @Composable (UndoBarState) -> Unit) {
    val state = rememberUndoBarState()
    UndoBarProvider(state, timeoutMillis = timeout) {
        content(state)
    }
}

@Composable
fun rememberUndoBarNotes(state: UndoBarState): UndoBarNotes {
    var ids by rememberSaveable { mutableStateOf(undoBarInitialNotes.map { it.id }) }
    var log by rememberSaveable { mutableStateOf("Delete a note.") }
    val notes = ids.mapNotNull { id -> undoBarInitialNotes.firstOrNull { it.id == id } }
    return UndoBarNotes(notes, log) { note ->
        val index = ids.indexOf(note.id)
        ids = ids - note.id
        log = "Removed “${note.title}”"
        state.show(
            title = "“${note.title}” deleted",
            onUndo = {
                ids = ids.toMutableList().apply { add(minOf(index, size), note.id) }
                log = "Restored “${note.title}”"
            },
            onCommit = { log = "Deleted “${note.title}” permanently" },
        )
    }
}

@Composable
fun UndoBarNoteText(note: UndoBarNote, modifier: Modifier = Modifier) {
    Column(modifier.padding(vertical = 8.dp)) {
        Text(
            note.title,
            style = Typography.base.copy(fontWeight = FontWeight.SemiBold),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
        )
        Text(
            note.preview,
            style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
        )
    }
}

@Composable
fun UndoBarFrame(notes: UndoBarNotes, row: @Composable (UndoBarNote) -> Unit) {
    val colors = EsuissTheme.colors
    val shape = RoundedCornerShape(Radius.xl2)
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Column(
            Modifier
                .fillMaxWidth()
                .clip(shape)
                .border(1.dp, colors.separator, shape),
        ) {
            notes.notes.forEachIndexed { index, note ->
                key(note.id) {
                    if (index > 0) Box(Modifier.fillMaxWidth().height(1.dp).background(colors.separator))
                    row(note)
                }
            }
        }
        Text(
            notes.log,
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = colors.labelSecondary),
        )
    }
}

@Composable
fun UndoBarNotesList(state: UndoBarState, deleteFirst: Boolean = false) {
    val notes = rememberUndoBarNotes(state)
    var deleted by rememberSaveable { mutableStateOf(false) }
    LaunchedEffect(Unit) {
        if (!deleteFirst || deleted) return@LaunchedEffect
        deleted = true
        notes.remove(undoBarInitialNotes.first())
    }
    UndoBarFrame(notes) { note ->
        Row(
            modifier = Modifier.fillMaxWidth().padding(start = 16.dp, end = 4.dp, top = 4.dp, bottom = 4.dp),
            horizontalArrangement = Arrangement.spacedBy(12.dp),
            verticalAlignment = Alignment.CenterVertically,
        ) {
            UndoBarNoteText(note, Modifier.weight(1f))
            Button(onClick = { notes.remove(note) }, variant = ButtonVariant.Ghost, size = ButtonSize.IconLg) {
                Icon(PhosphorIcons.Regular.Trash, contentDescription = "Delete ${note.title}", size = 20.dp)
            }
        }
    }
}
```

### With swipe actions

Shows the bar after a swipe-to-delete in a list with swipe actions.

![Preview](https://uim.suiss.app/previews/interactions-undo-bar--with-swipe-actions.light.webp)

```tsx
import { TrashIcon } from "phosphor-react-native"
import * as React from "react"
import { View } from "react-native"
import { SwipeAction, SwipeActions, SwipeActionsActions, SwipeActionsContent } from "@/components/interactions/swipe-actions"
import { UndoBarProvider, useUndoBar } from "@/components/interactions/undo-bar"
import { Icon } from "@/components/ui/icon"
import { Text } from "@/components/ui/text"

const initialNotes = [
  { id: 1, title: "Groceries", preview: "Milk, eggs, bread, coffee" },
  { id: 2, title: "Trip ideas", preview: "Lisbon, Porto, the coast road" },
  { id: 3, title: "Book list", preview: "Three novels for the summer" },
  { id: 4, title: "Meeting notes", preview: "Ship the beta on Friday" },
]

type Note = (typeof initialNotes)[number]

function useNotes() {
  const [notes, setNotes] = React.useState(initialNotes)
  const [log, setLog] = React.useState("Delete a note.")
  const { show } = useUndoBar()

  const remove = (note: Note) => {
    const index = notes.findIndex((item) => item.id === note.id)
    setNotes((current) => current.filter((item) => item.id !== note.id))
    setLog(`Removed “${note.title}”`)
    show({
      title: `“${note.title}” deleted`,
      onUndo: () => {
        setNotes((current) => {
          const next = [...current]
          next.splice(Math.min(index, next.length), 0, note)
          return next
        })
        setLog(`Restored “${note.title}”`)
      },
      onCommit: () => setLog(`Deleted “${note.title}” permanently`),
    })
  }

  return { notes, remove, log }
}

function NoteText({ note }: { note: Note }) {
  return (
    <View className="min-w-0 flex-1 py-2">
      <Text numberOfLines={1} className="font-semibold">
        {note.title}
      </Text>
      <Text numberOfLines={1} className="text-sm text-label-secondary">
        {note.preview}
      </Text>
    </View>
  )
}

function SwipeNotesList() {
  const { notes, remove, log } = useNotes()
  return (
    <View className="w-full gap-3">
      <View className="overflow-hidden rounded-2xl border border-separator">
        {notes.map((note, index) => (
          <View
            key={note.id}
            className={index > 0 ? "border-t border-separator" : undefined}
          >
            <SwipeActions>
              <SwipeActionsContent className="bg-surface px-4 py-1">
                <NoteText note={note} />
              </SwipeActionsContent>
              <SwipeActionsActions side="trailing">
                <SwipeAction
                  variant="destructive"
                  fullSwipe
                  onPress={() => remove(note)}
                >
                  <Icon as={TrashIcon} weight="fill" />
                  <Text>Delete</Text>
                </SwipeAction>
              </SwipeActionsActions>
            </SwipeActions>
          </View>
        ))}
      </View>
      <Text role="status" className="text-sm text-label-secondary">
        {log}
      </Text>
    </View>
  )
}

export function UndoBarWithSwipeActionsExample() {
  return (
    <UndoBarProvider>
      <SwipeNotesList />
    </UndoBarProvider>
  )
}
```

```swift
import EsuissUI
import PhosphorSwift
import SwiftUI

struct UndoBarWithSwipeActionsExample: View {
  var body: some View {
    UndoBarStage(timeout: .seconds(5)) { UndoBarNotes(swipe: true) }
  }
}

struct UndoBarNote: Identifiable, Equatable {
  let id: Int
  let title: String
  let preview: String
}

let undoBarInitialNotes = [
  UndoBarNote(id: 1, title: "Groceries", preview: "Milk, eggs, bread, coffee"),
  UndoBarNote(id: 2, title: "Trip ideas", preview: "Lisbon, Porto, the coast road"),
  UndoBarNote(id: 3, title: "Book list", preview: "Three novels for the summer"),
  UndoBarNote(id: 4, title: "Meeting notes", preview: "Ship the beta on Friday"),
]

struct UndoBarStage<Content: View>: View {
  let timeout: Duration
  @ViewBuilder let content: () -> Content

  @State private var manager = UndoBarManager()

  var body: some View {
    content()
      .frame(maxHeight: .infinity, alignment: .top)
      .containerRelativeFrame(.vertical) { height, _ in height - 32 }
      .undoBar(manager, timeout: timeout)
  }
}

struct UndoBarNoteText: View {
  let note: UndoBarNote

  var body: some View {
    VStack(alignment: .leading, spacing: 0) {
      Text(verbatim: note.title)
        .textStyle(.base, weight: .semibold)
        .foregroundStyle(Color.label)
        .lineLimit(1)
      Text(verbatim: note.preview)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .lineLimit(1)
    }
    .padding(.vertical, 8)
    .frame(maxWidth: .infinity, alignment: .leading)
  }
}

struct UndoBarNotes: View {
  var deleteFirst = false
  var swipe = false

  @State private var notes = undoBarInitialNotes
  @State private var log = "Delete a note."
  @State private var deleted = false
  @Environment(\.undoBarManager) private var manager

  var body: some View {
    let shape = RoundedRectangle(cornerRadius: Radius.xl2, style: .continuous)
    VStack(alignment: .leading, spacing: 12) {
      VStack(spacing: 0) {
        ForEach(Array(notes.enumerated()), id: \.element.id) { index, note in
          row(note)
            .overlay(alignment: .top) {
              if index > 0 {
                Color.separator.frame(height: 1)
              }
            }
        }
      }
      .clipShape(shape)
      .overlay { shape.strokeBorder(Color.separator) }
      Text(verbatim: log)
        .textStyle(.sm)
        .foregroundStyle(Color.labelSecondary)
        .accessibilityAddTraits(.updatesFrequently)
    }
    .onAppear {
      guard deleteFirst, !deleted else { return }
      deleted = true
      remove(undoBarInitialNotes[0])
    }
  }

  @ViewBuilder
  func row(_ note: UndoBarNote) -> some View {
    if swipe {
      SwipeActions {
        UndoBarNoteText(note: note)
          .padding(.horizontal, 16)
          .padding(.vertical, 4)
      } trailing: {
        SwipeAction("Delete", icon: Ph.trash.fill, variant: .destructive, fullSwipe: true) {
          remove(note)
        }
      }
    } else {
      HStack(spacing: 12) {
        UndoBarNoteText(note: note)
        Button {
          remove(note)
        } label: {
          Ph.trash.regular.frame(width: 20, height: 20)
        }
        .buttonStyle(.variant(.ghost, size: .iconLg))
        .accessibilityLabel(Text(verbatim: "Delete \(note.title)"))
      }
      .padding(.leading, 16)
      .padding(.trailing, 4)
      .padding(.vertical, 4)
    }
  }

  func remove(_ note: UndoBarNote) {
    let index = notes.firstIndex(of: note) ?? 0
    notes.removeAll { $0.id == note.id }
    log = "Removed “\(note.title)”"
    manager.show(
      "“\(note.title)” deleted",
      onUndo: {
        notes.insert(note, at: min(index, notes.count))
        log = "Restored “\(note.title)”"
      },
      onCommit: {
        log = "Deleted “\(note.title)” permanently"
      }
    )
  }
}
```

```kotlin
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.key
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.draw.clip
import androidx.compose.ui.semantics.LiveRegionMode
import androidx.compose.ui.semantics.liveRegion
import androidx.compose.ui.semantics.semantics
import androidx.compose.ui.text.font.FontWeight
import androidx.compose.ui.text.style.TextOverflow
import androidx.compose.ui.unit.dp
import com.adamglin.PhosphorIcons
import com.adamglin.phosphoricons.Fill
import com.adamglin.phosphoricons.fill.Trash
import com.adamglin.phosphoricons.regular.Trash
import com.esuiss.ui.components.Text
import com.esuiss.ui.interactions.SwipeAction
import com.esuiss.ui.interactions.SwipeActionVariant
import com.esuiss.ui.interactions.SwipeActions
import com.esuiss.ui.interactions.UndoBarProvider
import com.esuiss.ui.interactions.UndoBarState
import com.esuiss.ui.interactions.rememberUndoBarState
import com.esuiss.ui.theme.EsuissTheme
import com.esuiss.ui.theme.Radius
import com.esuiss.ui.theme.Typography

@Composable
fun UndoBarWithSwipeActionsExample() {
    UndoBarDemo(timeout = 5000L) { state -> UndoBarSwipeNotesList(state) }
}

class UndoBarNote(val id: Int, val title: String, val preview: String)

val undoBarInitialNotes = listOf(
    UndoBarNote(1, "Groceries", "Milk, eggs, bread, coffee"),
    UndoBarNote(2, "Trip ideas", "Lisbon, Porto, the coast road"),
    UndoBarNote(3, "Book list", "Three novels for the summer"),
    UndoBarNote(4, "Meeting notes", "Ship the beta on Friday"),
)

class UndoBarNotes(
    val notes: List<UndoBarNote>,
    val log: String,
    val remove: (UndoBarNote) -> Unit,
)

@Composable
fun UndoBarDemo(timeout: Long, content: @Composable (UndoBarState) -> Unit) {
    val state = rememberUndoBarState()
    UndoBarProvider(state, timeoutMillis = timeout) {
        content(state)
    }
}

@Composable
fun rememberUndoBarNotes(state: UndoBarState): UndoBarNotes {
    var ids by rememberSaveable { mutableStateOf(undoBarInitialNotes.map { it.id }) }
    var log by rememberSaveable { mutableStateOf("Delete a note.") }
    val notes = ids.mapNotNull { id -> undoBarInitialNotes.firstOrNull { it.id == id } }
    return UndoBarNotes(notes, log) { note ->
        val index = ids.indexOf(note.id)
        ids = ids - note.id
        log = "Removed “${note.title}”"
        state.show(
            title = "“${note.title}” deleted",
            onUndo = {
                ids = ids.toMutableList().apply { add(minOf(index, size), note.id) }
                log = "Restored “${note.title}”"
            },
            onCommit = { log = "Deleted “${note.title}” permanently" },
        )
    }
}

@Composable
fun UndoBarNoteText(note: UndoBarNote, modifier: Modifier = Modifier) {
    Column(modifier.padding(vertical = 8.dp)) {
        Text(
            note.title,
            style = Typography.base.copy(fontWeight = FontWeight.SemiBold),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
        )
        Text(
            note.preview,
            style = Typography.sm.copy(color = EsuissTheme.colors.labelSecondary),
            maxLines = 1,
            overflow = TextOverflow.Ellipsis,
        )
    }
}

@Composable
fun UndoBarFrame(notes: UndoBarNotes, row: @Composable (UndoBarNote) -> Unit) {
    val colors = EsuissTheme.colors
    val shape = RoundedCornerShape(Radius.xl2)
    Column(Modifier.fillMaxWidth(), verticalArrangement = Arrangement.spacedBy(12.dp)) {
        Column(
            Modifier
                .fillMaxWidth()
                .clip(shape)
                .border(1.dp, colors.separator, shape),
        ) {
            notes.notes.forEachIndexed { index, note ->
                key(note.id) {
                    if (index > 0) Box(Modifier.fillMaxWidth().height(1.dp).background(colors.separator))
                    row(note)
                }
            }
        }
        Text(
            notes.log,
            modifier = Modifier.semantics { liveRegion = LiveRegionMode.Polite },
            style = Typography.sm.copy(color = colors.labelSecondary),
        )
    }
}

@Composable
fun UndoBarSwipeNotesList(state: UndoBarState) {
    val notes = rememberUndoBarNotes(state)
    UndoBarFrame(notes) { note ->
        SwipeActions(
            trailing = listOf(
                SwipeAction(
                    "Delete",
                    { notes.remove(note) },
                    icon = PhosphorIcons.Fill.Trash,
                    variant = SwipeActionVariant.Destructive,
                    fullSwipe = true,
                ),
            ),
            background = EsuissTheme.colors.surface,
        ) {
            UndoBarNoteText(note, Modifier.fillMaxWidth().padding(horizontal = 16.dp, vertical = 4.dp))
        }
    }
}
```

## API Reference

### UndoBarProvider

Holds the current undo entry and renders the bar in a portal.

## Accessibility

- A string title is announced when the bar appears.
- The bar has the `group` role and is a polite live region.
- The countdown ring is hidden from screen readers.

## Notes

- The bar is up to 384 points wide and centered; it uses `bg-surface-raised`, or `bg-surface-secondary` in dark mode, with a `border-separator` outline.
- The ring drains linearly and runs counterclockwise in right-to-left layouts.
- Slide animations respect the system reduce motion setting; the countdown always runs.