{"$schema":"https://ui.shadcn.com/schema/registry-item.json","name":"message","type":"registry:component","title":"Message","description":"Composable conversation primitives for message rows, grouped bubbles, avatars, metadata, live markers, and a mount-only trailing-edge pop-up for newly sent rows.","author":"AgentUI","dependencies":["clsx","lucide-react","motion","tailwind-merge"],"registryDependencies":[],"files":[{"path":"components/agents/message.tsx","type":"registry:component","target":"@components/agents/message.tsx","content":"\"use client\";\n// www.agentui.pro/components/agents/message\n\nimport { motion, useReducedMotion } from \"motion/react\";\nimport {\n type ComponentPropsWithRef,\n createContext,\n type ReactNode,\n useContext,\n} from \"react\";\nimport { EASE_OUT } from \"@/lib/ease\";\nimport { cn } from \"@/lib/utils\";\nimport { MessageSideContext } from \"@/components/agents/message-context\";\n\nexport {\n MessageBubble,\n MessageBubbleCollapsible,\n MessageBubbleContent,\n MessageBubbleGroup,\n} from \"@/components/agents/message-bubble\";\nexport { MessageScroller } from \"@/components/agents/message-scroller\";\nexport type { MessageScrollerProps } from \"@/components/agents/message-scroller\";\n\nexport type MessageFrom = \"user\" | \"assistant\";\n\ninterface MessageContextValue {\n from: MessageFrom;\n}\n\nconst MessageContext = createContext({\n from: \"assistant\",\n});\n\nexport interface MessageProps\n extends Omit, \"children\"> {\n from: MessageFrom;\n /** Plays a trailing-edge pop-up once when this message row mounts. */\n animateIn?: boolean;\n children: ReactNode;\n}\n\nexport interface MessageGroupProps extends ComponentPropsWithRef<\"div\"> {\n spacing?: \"compact\" | \"default\";\n}\n\nexport interface MessageAvatarProps extends ComponentPropsWithRef<\"div\"> {\n /** Keep an empty avatar slot so grouped messages remain aligned. */\n placeholder?: boolean;\n}\n\nexport type MessageContentProps = ComponentPropsWithRef<\"div\">;\nexport type MessageHeaderProps = ComponentPropsWithRef<\"div\">;\nexport type MessageFooterProps = ComponentPropsWithRef<\"div\">;\n\nexport type MessageMarkerProps = ComponentPropsWithRef<\"div\">;\n\nexport interface MessageTypingProps extends ComponentPropsWithRef<\"span\"> {\n label?: string;\n}\n\n// A sent row should rise from the live edge without changing measured layout.\nconst MESSAGE_POP_UP = {\n type: \"spring\",\n stiffness: 480,\n damping: 32,\n mass: 0.62,\n} as const;\n\nexport function Message({\n from,\n animateIn = false,\n children,\n className,\n initial,\n animate,\n transition,\n exit,\n style,\n ...props\n}: MessageProps) {\n const reduce = useReducedMotion() ?? false;\n\n return (\n \n \n \n {children}\n \n \n \n );\n}\n\nexport function MessageGroup({\n spacing = \"compact\",\n className,\n ...props\n}: MessageGroupProps) {\n return (\n \n );\n}\n\nexport function MessageAvatar({\n placeholder = false,\n children,\n className,\n ...props\n}: MessageAvatarProps) {\n return (\n \n {children}\n \n );\n}\n\nexport function MessageContent({ className, ...props }: MessageContentProps) {\n const { from } = useContext(MessageContext);\n\n return (\n \n );\n}\n\nexport function MessageHeader({ className, ...props }: MessageHeaderProps) {\n const { from } = useContext(MessageContext);\n\n return (\n \n );\n}\n\nexport function MessageFooter({ className, ...props }: MessageFooterProps) {\n const { from } = useContext(MessageContext);\n\n return (\n \n );\n}\n\nexport function MessageMarker({ className, ...props }: MessageMarkerProps) {\n return (\n \n );\n}\n\nexport function MessageTyping({\n label = \"Responding\",\n className,\n ...props\n}: MessageTypingProps) {\n const reduce = useReducedMotion() ?? false;\n\n return (\n \n {label}\n {[0, 1, 2].map((index) => (\n \n ))}\n \n );\n}\n"},{"path":"components/agents/message-bubble.tsx","type":"registry:component","target":"@components/agents/message-bubble.tsx","content":"\"use client\";\n\nimport { ChevronDown } from \"lucide-react\";\nimport {\n type HTMLMotionProps,\n motion,\n useReducedMotion,\n} from \"motion/react\";\nimport {\n cloneElement,\n type ComponentPropsWithRef,\n createContext,\n type ReactElement,\n type ReactNode,\n type Ref,\n useCallback,\n useContext,\n useId,\n useState,\n} from \"react\";\nimport {\n EASE_OUT,\n SPRING_LAYOUT,\n SPRING_SWAP,\n} from \"@/lib/ease\";\nimport { cn } from \"@/lib/utils\";\nimport { MessageSideContext } from \"@/components/agents/message-context\";\n\nexport type MessageBubbleVariant =\n | \"solid\"\n | \"soft\"\n | \"tint\"\n | \"outline\"\n | \"ghost\"\n | \"danger\";\nexport type MessageBubbleAlign = \"start\" | \"end\";\n\ninterface MessageBubbleContextValue {\n align?: MessageBubbleAlign;\n animateIn: boolean;\n variant: MessageBubbleVariant;\n}\n\nconst MessageBubbleContext = createContext({\n animateIn: true,\n variant: \"soft\",\n});\nconst MessageBubbleLayoutContext = createContext<() => void>(() => {});\n\nexport interface MessageBubbleProps\n extends Omit, \"children\"> {\n variant?: MessageBubbleVariant;\n /** Defaults to the surrounding Message alignment when omitted. */\n align?: MessageBubbleAlign;\n /** Plays the bubble entrance once when this component mounts. */\n animateIn?: boolean;\n children?: ReactNode;\n}\n\nexport interface MessageBubbleContentProps\n extends ComponentPropsWithRef<\"div\"> {\n /** Replaces the content element while preserving bubble styling. */\n render?: ReactElement;\n}\n\nexport interface MessageBubbleGroupProps extends ComponentPropsWithRef<\"div\"> {\n spacing?: \"compact\" | \"default\";\n}\n\nexport interface MessageBubbleCollapsibleProps\n extends ComponentPropsWithRef<\"div\"> {\n open?: boolean;\n defaultOpen?: boolean;\n onOpenChange?: (open: boolean) => void;\n collapsedLines?: 2 | 3 | 4 | 5 | 6;\n moreLabel?: ReactNode;\n lessLabel?: ReactNode;\n contentClassName?: string;\n triggerClassName?: string;\n children?: ReactNode;\n}\n\nfunction mergeRefs(...refs: Array | undefined>) {\n return (node: T | null) => {\n for (const ref of refs) {\n if (typeof ref === \"function\") ref(node);\n else if (ref) ref.current = node;\n }\n };\n}\n\nconst BUBBLE_CONTENT_REVEAL = {\n duration: 0.12,\n ease: EASE_OUT,\n delay: 0.04,\n} as const;\n\n// Sent bubbles should pop into place quickly with one restrained overshoot.\nconst BUBBLE_POP = {\n type: \"spring\",\n stiffness: 520,\n damping: 27,\n mass: 0.52,\n} as const;\n\nexport function MessageBubble({\n variant = \"soft\",\n align,\n animateIn = false,\n className,\n children,\n initial,\n animate,\n exit,\n transition,\n layout,\n ...props\n}: MessageBubbleProps) {\n const reduce = useReducedMotion() ?? false;\n const messageSide = useContext(MessageSideContext);\n const resolvedAlign = align ?? messageSide ?? \"start\";\n\n return (\n \n \n {children}\n \n \n );\n}\n\nfunction bubbleContentClass(\n variant: MessageBubbleVariant,\n interactive: boolean,\n) {\n return cn(\n \"relative z-0 min-w-9 max-w-[82%] rounded-2xl px-3.5 py-2.5 text-sm leading-6 text-foreground\",\n \"[&_a]:font-medium [&_a]:underline [&_a]:underline-offset-4 [&_code]:rounded [&_code]:bg-background/60 [&_code]:px-1 [&_code]:py-0.5 [&_code]:font-mono [&_code]:text-[0.9em] [&_ol]:my-2 [&_ol]:list-decimal [&_ol]:pl-5 [&_p+p]:mt-2 [&_pre]:my-2 [&_pre]:overflow-x-auto [&_pre]:rounded-xl [&_pre]:bg-background/60 [&_pre]:p-3 [&_ul]:my-2 [&_ul]:list-disc [&_ul]:pl-5\",\n variant === \"solid\" && \"text-background\",\n variant === \"ghost\" && \"w-full max-w-none rounded-none px-0 py-0\",\n variant === \"danger\" && \"text-destructive\",\n interactive &&\n \"cursor-pointer text-left outline-none transition-[background-color,color,transform] duration-150 hover:brightness-[0.98] focus-visible:ring-2 focus-visible:ring-ring active:scale-[0.99]\",\n );\n}\n\nfunction bubbleSurfaceClass(\n variant: MessageBubbleVariant,\n align: MessageBubbleAlign,\n) {\n return cn(\n \"pointer-events-none absolute inset-0 -z-10 rounded-[inherit]\",\n align === \"end\" ? \"origin-bottom-right\" : \"origin-bottom-left\",\n variant === \"solid\" && \"bg-foreground\",\n variant === \"soft\" && \"bg-muted\",\n variant === \"tint\" && \"bg-primary/10\",\n variant === \"outline\" && \"border border-border/70 bg-background\",\n variant === \"danger\" && \"bg-destructive/10\",\n );\n}\n\nexport function MessageBubbleContent({\n render,\n className,\n children,\n ref,\n ...props\n}: MessageBubbleContentProps) {\n const reduce = useReducedMotion() ?? false;\n const { align = \"start\", animateIn, variant } =\n useContext(MessageBubbleContext);\n const [layoutVersion, setLayoutVersion] = useState(0);\n const notifyLayout = useCallback(\n () => setLayoutVersion((version) => version + 1),\n [],\n );\n const interactive =\n render?.type === \"button\" || render?.type === \"a\";\n const classes = cn(bubbleContentClass(variant, interactive), className);\n const composedChildren = (\n <>\n {variant !== \"ghost\" ? (\n \n ) : null}\n \n \n {children}\n \n \n \n );\n\n if (render) {\n const child = render as ReactElement<\n Record & { className?: string; ref?: Ref }\n >;\n\n return cloneElement(child, {\n ...props,\n ref: mergeRefs(child.props.ref, ref as Ref | undefined),\n className: cn(classes, child.props.className),\n children: composedChildren,\n \"data-slot\": \"message-bubble-content\",\n });\n }\n\n return (\n \n {composedChildren}\n \n );\n}\n\nexport function MessageBubbleGroup({\n spacing = \"compact\",\n className,\n ...props\n}: MessageBubbleGroupProps) {\n return (\n \n );\n}\n\nconst LINE_CLAMP_CLASS = {\n 2: \"line-clamp-2\",\n 3: \"line-clamp-3\",\n 4: \"line-clamp-4\",\n 5: \"line-clamp-5\",\n 6: \"line-clamp-6\",\n} as const;\n\nexport function MessageBubbleCollapsible({\n open,\n defaultOpen = false,\n onOpenChange,\n collapsedLines = 4,\n moreLabel = \"Show more\",\n lessLabel = \"Show less\",\n contentClassName,\n triggerClassName,\n className,\n children,\n ...props\n}: MessageBubbleCollapsibleProps) {\n const reduce = useReducedMotion() ?? false;\n const contentId = useId();\n const notifyLayout = useContext(MessageBubbleLayoutContext);\n const [internalOpen, setInternalOpen] = useState(defaultOpen);\n const currentOpen = open ?? internalOpen;\n\n const setOpen = useCallback(\n (next: boolean) => {\n notifyLayout();\n if (open === undefined) setInternalOpen(next);\n onOpenChange?.(next);\n },\n [notifyLayout, onOpenChange, open],\n );\n\n return (\n \n \n {children}\n \n setOpen(!currentOpen)}\n className={cn(\n \"mt-2 inline-flex h-7 items-center gap-1 rounded-full px-2 text-xs font-medium text-muted-foreground outline-none transition-colors hover:bg-muted hover:text-foreground focus-visible:ring-2 focus-visible:ring-ring\",\n triggerClassName,\n )}\n >\n {currentOpen ? lessLabel : moreLabel}\n \n \n \n \n \n );\n}\n"},{"path":"components/agents/message-context.tsx","type":"registry:component","target":"@components/agents/message-context.tsx","content":"\"use client\";\n\nimport { createContext } from \"react\";\n\nexport type MessageSide = \"start\" | \"end\";\n\nexport const MessageSideContext = createContext(\n undefined,\n);\n"},{"path":"components/agents/message-scroller.tsx","type":"registry:component","target":"@components/agents/message-scroller.tsx","content":"\"use client\";\n\nimport { useReducedMotion } from \"motion/react\";\nimport {\n type ComponentPropsWithRef,\n type Ref,\n useCallback,\n useEffect,\n useLayoutEffect,\n useRef,\n useState,\n} from \"react\";\nimport {\n PreviewRail,\n type PreviewRailItem,\n} from \"@/components/motion/preview-rail\";\nimport { cn } from \"@/lib/utils\";\n\nconst PREVIEW_TITLE_LENGTH = 56;\nconst PREVIEW_DESCRIPTION_LENGTH = 88;\n\nfunction truncateMessageText(text: string, limit: number) {\n if (text.length <= limit) return text;\n const excerpt = text.slice(0, limit);\n const boundary = excerpt.lastIndexOf(\" \");\n return `${excerpt.slice(0, boundary > limit * 0.65 ? boundary : limit).trim()}…`;\n}\n\nfunction getMessageText(message: HTMLElement) {\n const surface =\n message.querySelector('[data-slot=\"message-bubble-content\"]') ??\n message.querySelector('[data-slot=\"message-content\"]') ??\n message;\n return (surface.textContent ?? \"\").replace(/\\s+/g, \" \").trim();\n}\n\nfunction getMessagePreview(\n message: HTMLElement,\n assistantResponse?: HTMLElement,\n) {\n const text = getMessageText(message);\n if (!text) {\n return { label: \"Message\", description: undefined };\n }\n\n if (text.length <= PREVIEW_TITLE_LENGTH) {\n const responseText = assistantResponse\n ? getMessageText(assistantResponse)\n : \"\";\n return {\n label: text,\n description: responseText\n ? truncateMessageText(responseText, PREVIEW_DESCRIPTION_LENGTH)\n : undefined,\n };\n }\n\n const titleExcerpt = text.slice(0, PREVIEW_TITLE_LENGTH);\n const titleBoundary = titleExcerpt.lastIndexOf(\" \");\n const titleEnd =\n titleBoundary > PREVIEW_TITLE_LENGTH * 0.65\n ? titleBoundary\n : PREVIEW_TITLE_LENGTH;\n const label = `${text.slice(0, titleEnd).trim()}…`;\n const responseText = assistantResponse\n ? getMessageText(assistantResponse)\n : text.slice(titleEnd).trim();\n return {\n label,\n description: responseText\n ? truncateMessageText(responseText, PREVIEW_DESCRIPTION_LENGTH)\n : undefined,\n };\n}\n\nexport interface MessageScrollerProps extends ComponentPropsWithRef<\"div\"> {\n /** Keep streamed output pinned while the reader remains near the end. */\n followOutput?: boolean;\n /** Distance from the end that still counts as following the output. */\n followThreshold?: number;\n /** Smoothly follow growing content. */\n smooth?: boolean;\n /** Reports when the reader leaves or returns to the live edge. */\n onFollowChange?: (following: boolean) => void;\n /** Accessible label for the scrollable transcript. */\n label?: string;\n /** Marks the transcript as waiting for more streamed content. */\n busy?: boolean;\n /** Adds a compact rail for navigating between rendered Message rows. */\n navigation?: \"rail\";\n /** Accessible label for the optional message navigation rail. */\n navigationLabel?: string;\n viewportClassName?: string;\n contentClassName?: string;\n railClassName?: string;\n viewportRef?: Ref;\n viewportProps?: Omit<\n ComponentPropsWithRef<\"section\">,\n \"children\" | \"className\" | \"ref\"\n >;\n contentProps?: Omit<\n ComponentPropsWithRef<\"div\">,\n \"children\" | \"className\" | \"ref\"\n >;\n}\n\nexport function MessageScroller({\n followOutput = true,\n followThreshold = 56,\n smooth = true,\n onFollowChange,\n label = \"Conversation\",\n busy,\n navigation,\n navigationLabel = \"Message navigation\",\n viewportClassName,\n contentClassName,\n railClassName,\n viewportRef: externalViewportRef,\n viewportProps,\n contentProps,\n className,\n children,\n ...props\n}: MessageScrollerProps) {\n const reduce = useReducedMotion() ?? false;\n const viewportRef = useRef(null);\n const contentRef = useRef(null);\n const followingRef = useRef(followOutput);\n const programmaticScrollRef = useRef(false);\n const scrollTimerRef = useRef(undefined);\n const frameRef = useRef(undefined);\n const railFrameRef = useRef(undefined);\n const railIdRef = useRef(new WeakMap());\n const railIdCounterRef = useRef(0);\n const railTargetsRef = useRef(new Map());\n const [railItems, setRailItems] = useState([]);\n const [activeRailId, setActiveRailId] = useState(\"\");\n const [railOverflowing, setRailOverflowing] = useState(false);\n const {\n onScroll: onViewportScroll,\n onWheel: onViewportWheel,\n onTouchStart: onViewportTouchStart,\n onKeyDown: onViewportKeyDown,\n ...restViewportProps\n } = viewportProps ?? {};\n\n const setViewportRef = useCallback(\n (node: HTMLElement | null) => {\n viewportRef.current = node;\n if (typeof externalViewportRef === \"function\") {\n externalViewportRef(node);\n } else if (externalViewportRef) {\n externalViewportRef.current = node;\n }\n },\n [externalViewportRef],\n );\n\n const setFollowing = useCallback(\n (next: boolean) => {\n if (followingRef.current === next) return;\n followingRef.current = next;\n onFollowChange?.(next);\n },\n [onFollowChange],\n );\n\n const updateActiveRailItem = useCallback(() => {\n if (navigation !== \"rail\") return;\n const viewport = viewportRef.current;\n const targets = [...railTargetsRef.current.entries()];\n if (!viewport || targets.length === 0) return;\n\n const viewportRect = viewport.getBoundingClientRect();\n if (viewport.scrollTop <= followThreshold) {\n const firstId = targets[0]?.[0] ?? \"\";\n setActiveRailId((current) => (current === firstId ? current : firstId));\n return;\n }\n\n const distanceFromEnd =\n viewport.scrollHeight - viewport.scrollTop - viewport.clientHeight;\n if (distanceFromEnd <= followThreshold) {\n const lastId = targets.at(-1)?.[0] ?? \"\";\n setActiveRailId((current) => (current === lastId ? current : lastId));\n return;\n }\n\n const viewportCenter = viewportRect.top + viewportRect.height / 2;\n let nearestId = targets[0]?.[0] ?? \"\";\n let nearestDistance = Number.POSITIVE_INFINITY;\n\n for (const [id, element] of targets) {\n const rect = element.getBoundingClientRect();\n const messageCenter = rect.top + rect.height / 2;\n const distance = Math.abs(messageCenter - viewportCenter);\n if (distance < nearestDistance) {\n nearestDistance = distance;\n nearestId = id;\n }\n }\n\n setActiveRailId((current) =>\n current === nearestId ? current : nearestId,\n );\n }, [followThreshold, navigation]);\n\n const syncRailItems = useCallback(() => {\n if (navigation !== \"rail\") return;\n const content = contentRef.current;\n const viewport = viewportRef.current;\n if (!content || !viewport) return;\n\n const messages = Array.from(\n content.querySelectorAll('[data-slot=\"message\"]'),\n );\n const targets = new Map();\n const nextItems = messages.map((message, index) => {\n let id = railIdRef.current.get(message);\n if (!id) {\n railIdCounterRef.current += 1;\n id = `message-rail-${railIdCounterRef.current}`;\n railIdRef.current.set(message, id);\n }\n targets.set(id, message);\n const sender = message.dataset.from ?? \"conversation\";\n const assistantResponse =\n sender === \"user\"\n ? messages\n .slice(index + 1)\n .find((candidate) => candidate.dataset.from === \"assistant\")\n : undefined;\n const preview = getMessagePreview(message, assistantResponse);\n\n return {\n id,\n label: preview.label,\n description: preview.description,\n ariaLabel: `Go to ${sender} message ${index + 1} of ${messages.length}`,\n };\n });\n\n railTargetsRef.current = targets;\n setRailItems((current) => {\n const unchanged =\n current.length === nextItems.length &&\n current.every(\n (item, index) =>\n item.id === nextItems[index]?.id &&\n item.label === nextItems[index]?.label &&\n item.description === nextItems[index]?.description &&\n item.ariaLabel === nextItems[index]?.ariaLabel,\n );\n return unchanged ? current : nextItems;\n });\n setRailOverflowing(\n viewport.scrollHeight > viewport.clientHeight + 1 && messages.length > 1,\n );\n }, [navigation]);\n\n const scheduleRailSync = useCallback(() => {\n if (navigation !== \"rail\") return;\n if (railFrameRef.current) cancelAnimationFrame(railFrameRef.current);\n railFrameRef.current = requestAnimationFrame(() => {\n syncRailItems();\n updateActiveRailItem();\n });\n }, [navigation, syncRailItems, updateActiveRailItem]);\n\n const scrollToEnd = useCallback((behavior: ScrollBehavior) => {\n const viewport = viewportRef.current;\n if (!viewport) return;\n\n programmaticScrollRef.current = true;\n if (typeof viewport.scrollTo === \"function\") {\n viewport.scrollTo({ top: viewport.scrollHeight, behavior });\n } else {\n viewport.scrollTop = viewport.scrollHeight;\n }\n if (scrollTimerRef.current) window.clearTimeout(scrollTimerRef.current);\n scrollTimerRef.current = window.setTimeout(() => {\n programmaticScrollRef.current = false;\n }, behavior === \"smooth\" ? 320 : 0);\n }, []);\n\n const handleScroll = useCallback(() => {\n const viewport = viewportRef.current;\n if (!viewport || programmaticScrollRef.current) return;\n\n const distance =\n viewport.scrollHeight - viewport.scrollTop - viewport.clientHeight;\n setFollowing(distance <= followThreshold);\n updateActiveRailItem();\n }, [followThreshold, setFollowing, updateActiveRailItem]);\n\n const leaveLiveEdge = useCallback(() => {\n programmaticScrollRef.current = false;\n }, []);\n\n useLayoutEffect(() => {\n followingRef.current = followOutput;\n if (!followOutput) return;\n\n frameRef.current = requestAnimationFrame(() => scrollToEnd(\"auto\"));\n return () => {\n if (frameRef.current) cancelAnimationFrame(frameRef.current);\n };\n }, [followOutput, scrollToEnd]);\n\n useEffect(() => {\n const content = contentRef.current;\n if (!content || typeof ResizeObserver === \"undefined\") return;\n\n const observer = new ResizeObserver(() => {\n scheduleRailSync();\n if (!followOutput || !followingRef.current) return;\n scrollToEnd(reduce || !smooth ? \"auto\" : \"smooth\");\n });\n observer.observe(content);\n\n return () => observer.disconnect();\n }, [followOutput, reduce, scheduleRailSync, scrollToEnd, smooth]);\n\n useEffect(() => {\n if (navigation !== \"rail\") {\n railTargetsRef.current.clear();\n setRailItems([]);\n setRailOverflowing(false);\n return;\n }\n\n const content = contentRef.current;\n const viewport = viewportRef.current;\n if (!content || !viewport) return;\n\n scheduleRailSync();\n const mutationObserver =\n typeof MutationObserver === \"undefined\"\n ? null\n : new MutationObserver(scheduleRailSync);\n mutationObserver?.observe(content, {\n childList: true,\n characterData: true,\n subtree: true,\n });\n\n const resizeObserver =\n typeof ResizeObserver === \"undefined\"\n ? null\n : new ResizeObserver(scheduleRailSync);\n resizeObserver?.observe(content);\n resizeObserver?.observe(viewport);\n\n return () => {\n mutationObserver?.disconnect();\n resizeObserver?.disconnect();\n };\n }, [navigation, scheduleRailSync]);\n\n useEffect(\n () => () => {\n if (scrollTimerRef.current) window.clearTimeout(scrollTimerRef.current);\n if (frameRef.current) cancelAnimationFrame(frameRef.current);\n if (railFrameRef.current) cancelAnimationFrame(railFrameRef.current);\n },\n [],\n );\n\n const scrollToRailItem = useCallback(\n (item: PreviewRailItem) => {\n const viewport = viewportRef.current;\n const target = railTargetsRef.current.get(item.id);\n if (!viewport || !target) return;\n\n const lastItem = railItems.at(-1)?.id === item.id;\n setActiveRailId(item.id);\n if (lastItem) {\n setFollowing(true);\n scrollToEnd(reduce || !smooth ? \"auto\" : \"smooth\");\n return;\n }\n\n setFollowing(false);\n programmaticScrollRef.current = true;\n const viewportRect = viewport.getBoundingClientRect();\n const targetRect = target.getBoundingClientRect();\n const top =\n viewport.scrollTop +\n targetRect.top -\n viewportRect.top -\n (viewport.clientHeight - targetRect.height) / 2;\n const behavior = reduce || !smooth ? \"auto\" : \"smooth\";\n\n if (typeof viewport.scrollTo === \"function\") {\n viewport.scrollTo({ top, behavior });\n } else {\n viewport.scrollTop = top;\n }\n if (scrollTimerRef.current) window.clearTimeout(scrollTimerRef.current);\n scrollTimerRef.current = window.setTimeout(() => {\n programmaticScrollRef.current = false;\n }, behavior === \"smooth\" ? 320 : 0);\n },\n [railItems, reduce, scrollToEnd, setFollowing, smooth],\n );\n\n const viewport = (\n {\n handleScroll();\n onViewportScroll?.(event);\n }}\n onWheel={(event) => {\n leaveLiveEdge();\n onViewportWheel?.(event);\n }}\n onTouchStart={(event) => {\n leaveLiveEdge();\n onViewportTouchStart?.(event);\n }}\n onKeyDown={(event) => {\n if ([\"ArrowUp\", \"PageUp\", \"Home\"].includes(event.key)) {\n leaveLiveEdge();\n }\n onViewportKeyDown?.(event);\n }}\n className={cn(\n \"h-full overflow-y-auto overscroll-contain outline-none [overflow-anchor:none] focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-ring\",\n navigation === \"rail\"\n ? \"[-ms-overflow-style:none] [scrollbar-width:none] [&::-webkit-scrollbar]:hidden\"\n : \"[scrollbar-gutter:stable]\",\n viewportClassName,\n navigation === \"rail\" && railOverflowing && \"pr-10\",\n )}\n >\n \n {children}\n \n \n );\n\n return (\n \n {navigation === \"rail\" ? (\n \n {viewport}\n \n ) : (\n viewport\n )}\n \n );\n}\n"},{"path":"lib/ease.ts","type":"registry:lib","target":"@lib/ease.ts","content":"// Shared motion tokens. Easing curves mirror the CSS custom properties in\n// globals.css; springs are the canonical physics used across components.\n// Strong custom variants — defaults like `ease-in`/`ease-out` feel weak.\n\nexport const EASE_OUT = [0.16, 1, 0.3, 1] as const;\nexport const EASE_IN_OUT = [0.77, 0, 0.175, 1] as const;\nexport const EASE_DRAWER = [0.32, 0.72, 0, 1] as const;\n\n/** CSS string form of EASE_OUT for inline style transitions. */\nexport const EASE_OUT_CSS = \"cubic-bezier(0.16, 1, 0.3, 1)\";\n\n/** Press feedback on buttons and other tappable surfaces. */\nexport const SPRING_PRESS = {\n type: \"spring\",\n stiffness: 500,\n damping: 30,\n mass: 0.6,\n} as const;\n\n/** Content swaps — label/icon slots trading places inside a control. */\nexport const SPRING_SWAP = {\n type: \"spring\",\n stiffness: 460,\n damping: 30,\n mass: 0.55,\n} as const;\n\n/** Overlay panel entrances — modals and sheets summoned by pointer. */\nexport const SPRING_PANEL = {\n type: \"spring\",\n stiffness: 420,\n damping: 40,\n mass: 0.5,\n} as const;\n\n/** Shared-layout glides — pills, indicators and panels morphing between positions. */\nexport const SPRING_LAYOUT = {\n type: \"spring\",\n stiffness: 360,\n damping: 32,\n mass: 0.6,\n} as const;\n\n/** Cursor-follow physics for decorative mouse tracking (magnetic, tilt, dock). */\nexport const SPRING_MOUSE = {\n stiffness: 200,\n damping: 15,\n mass: 0.3,\n} as const;\n\n/** Dragged handles and fills (sliders) — critically damped `useSpring` config,\n * so the value follows the pointer butterily and never rebounds off an end. */\nexport const SPRING_GLIDE = {\n stiffness: 700,\n damping: 50,\n mass: 0.5,\n} as const;\n"},{"path":"lib/utils.ts","type":"registry:lib","target":"@lib/utils.ts","content":"import { clsx, type ClassValue } from \"clsx\"\nimport { twMerge } from \"tailwind-merge\"\n\nexport function cn(...inputs: ClassValue[]) {\n return twMerge(clsx(inputs))\n}\n"},{"path":"components/motion/preview-rail.tsx","type":"registry:component","target":"@components/motion/preview-rail.tsx","content":"\"use client\";\n\nimport { AnimatePresence, motion, useReducedMotion } from \"motion/react\";\nimport {\n type MouseEvent,\n type PointerEvent,\n type ReactNode,\n useCallback,\n useId,\n useRef,\n useState,\n} from \"react\";\nimport { EASE_OUT, SPRING_LAYOUT } from \"@/lib/ease\";\nimport { useDismiss } from \"@/lib/hooks/use-dismiss\";\nimport { useHoverGesture } from \"@/lib/hooks/use-hover-gesture\";\nimport { useTapGesture } from \"@/lib/hooks/use-tap-gesture\";\nimport { cn } from \"@/lib/utils\";\n\nexport interface PreviewRailItem {\n id: string;\n label: string;\n ariaLabel?: string;\n description?: ReactNode;\n href?: string;\n target?: \"_blank\" | \"_self\" | \"_parent\" | \"_top\";\n rel?: string;\n}\n\nexport interface PreviewRailProps {\n items: PreviewRailItem[];\n label?: string;\n orientation?: \"vertical\" | \"horizontal\";\n activeId?: string;\n defaultActiveId?: string;\n onActiveChange?: (id: string) => void;\n onItemSelect?: (item: PreviewRailItem) => void;\n renderPreview?: (item: PreviewRailItem) => ReactNode;\n showPreview?: boolean;\n previewSide?: \"before\" | \"after\";\n highlightActive?: boolean;\n itemSize?: number;\n children?: ReactNode;\n className?: string;\n railClassName?: string;\n previewContainerClassName?: string;\n previewClassName?: string;\n}\n\nfunction DefaultPreview({ item }: { item: PreviewRailItem }) {\n return (\n \n \n {item.label}\n

\n {item.description ? (\n \n {item.description}\n \n ) : null}\n \n );\n}\n\nexport function PreviewRail({\n items,\n label = \"Section navigation\",\n orientation = \"vertical\",\n activeId,\n defaultActiveId,\n onActiveChange,\n onItemSelect,\n renderPreview,\n showPreview = true,\n previewSide = \"after\",\n highlightActive = false,\n itemSize = 24,\n children,\n className,\n railClassName,\n previewContainerClassName,\n previewClassName,\n}: PreviewRailProps) {\n const uid = useId();\n const reduce = useReducedMotion();\n const rootRef = useRef(null);\n const [internalActiveId, setInternalActiveId] = useState(\n defaultActiveId ?? items[0]?.id ?? \"\",\n );\n const [hoveredId, setHoveredId] = useState(null);\n // A finger cannot hover, so a tap lights the tick instead. Kept apart from\n // the hovered one: they end in different ways, and a stray mouse move must\n // not clear a tick the keyboard or a tap chose.\n const [pinnedId, setPinnedId] = useState(null);\n const [focusedId, setFocusedId] = useState(null);\n // A click carries no pointerType, so the pointerdown before it is what says\n // whether the activation was a tap. Keyboard activation has none at all.\n const tap = useTapGesture();\n const hover = useHoverGesture();\n\n const clearPinned = useCallback(() => setPinnedId(null), []);\n\n // The next tap outside the rail stands in for the pointer leaving it. The\n // card is a preview, so that tap passes through to whatever it landed on.\n useDismiss(pinnedId !== null, clearPinned, rootRef);\n\n const requestedActiveId = activeId ?? internalActiveId;\n const selectedId = items.some((item) => item.id === requestedActiveId)\n ? requestedActiveId\n : (items[0]?.id ?? \"\");\n const displayedId = hoveredId ?? pinnedId ?? focusedId ?? \"\";\n const highlightedId = displayedId || (highlightActive ? selectedId : \"\");\n const displayedIndex = items.findIndex((item) => item.id === highlightedId);\n const rowTemplate = items.length\n ? `repeat(${items.length}, ${itemSize}px)`\n : undefined;\n const isHorizontal = orientation === \"horizontal\";\n\n const selectItem = (id: string) => {\n if (activeId === undefined) setInternalActiveId(id);\n onActiveChange?.(id);\n };\n\n return (\n {\n // Both tick sources leave with the focus: a tap does not always land\n // focus, but when it does, tabbing away must not strand the card.\n if (!event.currentTarget.contains(event.relatedTarget)) {\n setFocusedId(null);\n setPinnedId(null);\n }\n }}\n className={cn(\n \"isolate relative flex w-full overflow-visible\",\n isHorizontal\n ? \"min-h-64 flex-col items-center justify-center\"\n : \"min-h-80\",\n className,\n )}\n >\n {\n // A touch pointer leaves on lift, which would clear the tick the tap\n // just chose — that one is cleared by the outside tap instead.\n if (hover.leave(event)) setHoveredId(null);\n }}\n style={\n isHorizontal\n ? { gridTemplateColumns: rowTemplate }\n : { gridTemplateRows: rowTemplate }\n }\n className={cn(\n \"relative z-10 grid shrink-0\",\n isHorizontal\n ? \"h-12 w-fit max-w-full self-center justify-center\"\n : \"w-12 content-center\",\n railClassName,\n )}\n >\n {items.map((item, index) => {\n const selected = item.id === selectedId;\n const highlighted = item.id === highlightedId;\n const distance =\n displayedIndex < 0 ? Number.POSITIVE_INFINITY : Math.abs(index - displayedIndex);\n const scale = highlighted\n ? 1\n : distance === 1\n ? 0.68\n : distance === 2\n ? 0.44\n : 0.25;\n\n const itemContent = (\n <>\n \n \n );\n\n const sharedClassName = cn(\n \"relative flex text-muted-foreground focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background\",\n isHorizontal\n ? \"h-12 w-6 items-end justify-center\"\n : \"h-6 w-12 items-center\",\n );\n const sharedStyle = isHorizontal\n ? { width: itemSize }\n : { height: itemSize };\n const handlePointerEnter = (event: PointerEvent) => {\n if (hover.enter(event)) setHoveredId(item.id);\n };\n const handlePointerDown = (event: PointerEvent) => {\n tap.start(event, pinnedId === item.id);\n setFocusedId(null);\n };\n // A gesture the platform takes away sends no click, and a key press\n // starts an activation that never had a pointer behind it: either\n // one leaves a record the next click would read as a tap of its own.\n const dropGesture = () => tap.drop();\n const handleFocus = (currentTarget: HTMLElement) => {\n if (currentTarget.matches(\":focus-visible\")) {\n setFocusedId(item.id);\n }\n };\n const handleSelect = (event: MouseEvent) => {\n const gesture = tap.take();\n const tapped =\n gesture !== null && gesture.pointerType !== \"mouse\";\n\n if (tapped) {\n // A link would otherwise show its preview and leave the page in\n // the same tap, so the card is never read: the first tap lights\n // the tick, the second follows the link.\n if (item.href && !gesture.state) {\n event.preventDefault();\n setPinnedId(item.id);\n return;\n }\n setPinnedId(item.id);\n }\n\n selectItem(item.id);\n onItemSelect?.(item);\n };\n\n return item.href ? (\n handleFocus(event.currentTarget)}\n onClick={handleSelect}\n style={sharedStyle}\n className={sharedClassName}\n >\n {itemContent}\n \n ) : (\n handleFocus(event.currentTarget)}\n onClick={handleSelect}\n style={sharedStyle}\n className={sharedClassName}\n >\n {itemContent}\n \n );\n })}\n \n\n {showPreview ? (\n \n {items.map((item) => (\n \n {item.id === displayedId ? (\n \n \n \n \n {renderPreview ? (\n renderPreview(item)\n ) : (\n \n )}\n \n \n \n \n ) : null}\n \n ))}\n \n ) : null}\n\n {children ? (\n
{children}
\n ) : null}\n \n );\n}\n"},{"path":"lib/hooks/use-dismiss.ts","type":"registry:hook","target":"@lib/hooks/use-dismiss.ts","content":"\"use client\";\n\nimport { type RefObject, useEffect } from \"react\";\n\n/**\n * What the dismissing gesture does to the control it landed on.\n *\n * `\"pass-through\"` is the platform norm (native popover light-dismiss): the\n * tap closes the overlay *and* activates whatever was under it. Use\n * `\"consume\"` where the open overlay sits over or beside controls that would\n * be costly to trigger by accident — the dismissal then swallows the\n * activation too, so the gesture only closes.\n */\nexport type DismissBehavior = \"pass-through\" | \"consume\";\n\nexport interface DismissOptions {\n /** Default `\"pass-through\"`. */\n behavior?: DismissBehavior;\n /** Dismiss on Escape as well. Default true. */\n escape?: boolean;\n /** Return true for an outside target that should *not* dismiss. Must be stable. */\n ignore?: (target: Element) => boolean;\n}\n\n/**\n * What every currently open dismiss scope counts as inside itself. A consumed\n * dismissal reads this to tell a stray gesture from one that belongs to an\n * overlay in front of it: overlays have no shared z-order to consult, but the\n * one the gesture landed in has said as much by registering it.\n */\nconst openScopes = new Set<(target: Element) => boolean>();\n\nfunction claimedByAnotherScope(\n self: (target: Element) => boolean,\n target: Element,\n) {\n for (const scope of openScopes) {\n if (scope !== self && scope(target)) return true;\n }\n return false;\n}\n\n// preventDefault on pointerdown does not suppress the click that follows, so\n// consuming a gesture means swallowing that click itself. The swallower\n// deliberately outlives the effect that installed it — the dismissal it\n// belongs to has already unmounted or re-rendered by the time the click lands.\n// It releases on that click, or on the next gesture if the pointer is dragged\n// away and no click ever arrives, so it can never eat a later one. A keydown\n// releases it too: a gesture that ends with neither a click nor a cancel would\n// otherwise leave it armed, and the click Enter synthesizes on some focused\n// control is not the one this dismissal was owed.\nfunction consumeActivation(source: Event) {\n const swallow = (event: MouseEvent) => {\n event.preventDefault();\n event.stopPropagation();\n release();\n };\n const restart = (event: Event) => {\n if (event !== source) release();\n };\n const release = () => {\n window.removeEventListener(\"click\", swallow, true);\n window.removeEventListener(\"pointerdown\", restart, true);\n window.removeEventListener(\"pointercancel\", restart, true);\n window.removeEventListener(\"keydown\", release, true);\n };\n window.addEventListener(\"click\", swallow, true);\n window.addEventListener(\"pointerdown\", restart, true);\n window.addEventListener(\"pointercancel\", restart, true);\n window.addEventListener(\"keydown\", release, true);\n}\n\n/**\n * Close an open overlay on Escape or a pointerdown outside `ref`. Pass `null`\n * for `ref` when what counts as inside isn't one element, and say so with\n * `ignore` instead.\n *\n * The pointerdown listener is capture-phase: a bubble-phase one is blinded by\n * any handler in between that stops propagation, and an overlay cannot know\n * what it is layered over. `onDismiss` and `ignore` must be stable (wrap in\n * useCallback) so the listeners aren't re-bound every render while open.\n */\nexport function useDismiss(\n open: boolean,\n onDismiss: () => void,\n ref: RefObject | null,\n {\n behavior = \"pass-through\",\n escape: dismissOnEscape = true,\n ignore,\n }: DismissOptions = {},\n) {\n useEffect(() => {\n if (!open) return;\n const inside = (target: Element) =>\n Boolean(ref?.current?.contains(target)) || Boolean(ignore?.(target));\n const onKey = (event: KeyboardEvent) => {\n if (dismissOnEscape && event.key === \"Escape\") onDismiss();\n };\n const onPointer = (event: PointerEvent) => {\n const target = event.target as Element | null;\n if (!target || inside(target)) return;\n // Outside this overlay, but inside one that is also open: the gesture is\n // that overlay's to answer, and swallowing its click from behind would\n // cost the user the control they actually aimed at.\n if (behavior === \"consume\" && !claimedByAnotherScope(inside, target)) {\n consumeActivation(event);\n }\n onDismiss();\n };\n openScopes.add(inside);\n window.addEventListener(\"keydown\", onKey);\n window.addEventListener(\"pointerdown\", onPointer, true);\n return () => {\n openScopes.delete(inside);\n window.removeEventListener(\"keydown\", onKey);\n window.removeEventListener(\"pointerdown\", onPointer, true);\n };\n }, [open, onDismiss, ref, behavior, dismissOnEscape, ignore]);\n}\n"},{"path":"lib/hooks/use-hover-gesture.ts","type":"registry:hook","target":"@lib/hooks/use-hover-gesture.ts","content":"\"use client\";\n\nimport { useMemo, useRef } from \"react\";\nimport { isHoveringPointer } from \"@/lib/touch\";\n\ninterface BoundaryEvent {\n pointerId: number;\n pointerType: string;\n buttons: number;\n}\n\nexport interface HoverGesture {\n /** True when this enter starts a hover: the pointer arrived resting, not pressing. */\n enter: (event: BoundaryEvent) => boolean;\n /** True when this leave ends a hover that entered as one. */\n leave: (event: BoundaryEvent) => boolean;\n}\n\n/**\n * Pairs a surface's enter with its leave, per pointer.\n *\n * `isHoveringPointer` answers the question the *enter* asks — is this pointer\n * resting on the surface or pressing it — and both boundary cases go wrong if\n * the leave is asked the same question again:\n *\n * - A pen with no hover never rests. It arrives in contact, taps, and the spec\n * then requires its boundary events after `pointerup`, so the leave carries\n * `buttons: 0` and reads as a mouse gliding off. Hover teardown then undid\n * the tap — the panel the pen had just opened closed under it.\n * - A mouse pressed on the surface and dragged off leaves with `buttons: 1`.\n * Skipping teardown there strands the surface open: the release happens\n * outside, and no second leave ever comes.\n *\n * So the state a hover holds is released by the pointer that took it, whatever\n * the buttons say at the boundary, and a pointer that arrived in contact never\n * took it in the first place. Contact is the exception tracked here, not\n * hover: a leave from a pointer this surface never saw enter — mounted under\n * the cursor, say — still counts, since the alternative is state with no way\n * out.\n */\nexport function useHoverGesture(): HoverGesture {\n const contact = useRef(new Set());\n\n return useMemo(\n () => ({\n enter: (event) => {\n if (isHoveringPointer(event)) {\n contact.current.delete(event.pointerId);\n return true;\n }\n contact.current.add(event.pointerId);\n return false;\n },\n leave: (event) => {\n const arrivedInContact = contact.current.delete(event.pointerId);\n return !arrivedInContact && event.pointerType !== \"touch\";\n },\n }),\n [],\n );\n}\n"},{"path":"lib/hooks/use-tap-gesture.ts","type":"registry:hook","target":"@lib/hooks/use-tap-gesture.ts","content":"\"use client\";\n\nimport { useMemo, useRef } from \"react\";\n\n/** What a pointerdown recorded, read back by the click that ends its gesture. */\nexport interface TapRecord {\n /** Which input started the gesture. */\n pointerType: string;\n /** What the surface was showing when it started. */\n state: S;\n}\n\nexport interface TapGesture {\n /** Record the gesture a pointerdown starts, with the state it starts in. */\n start: (event: { pointerType: string }, state: S) => void;\n /** Read the record and clear it. `null` when no pointer is behind this click. */\n take: () => TapRecord | null;\n /** Drop the record: this gesture will never spend it on a click. */\n drop: () => void;\n}\n\n/**\n * The pointer gesture behind a click, recorded where the click cannot report\n * it. A `click` carries no `pointerType` in the engines that matter, so the\n * `pointerdown` before it is the only thing that says which input activated\n * the control — and whether one did at all, since keyboard activation\n * synthesizes a click with no pointer behind it.\n *\n * State goes in with the record because a click reports that no better: a\n * browser that focuses a control on contact can open the very panel the tap\n * was meant to open, and reading \"is it open\" at click time then undoes it.\n * What the gesture started against is what it acts on.\n *\n * The record is spent by one click and dropped by everything else, because a\n * record that outlives its gesture is worse than none:\n *\n * - A scroll or an OS gesture takes the touch away — `pointercancel`, no click\n * ever — and the finger would sit in the record until some later click.\n * - That later click is often `Enter` on a keyboard, which arrives with no\n * pointerdown of its own and would inherit the abandoned finger. A keydown\n * is the start of a keyboard activation and never part of a tap, so it drops\n * the record too.\n *\n * Both ends have to be wired by the surface: `drop` on `onPointerCancel` and\n * on `onKeyDown`.\n */\nexport function useTapGesture(): TapGesture {\n const record = useRef | null>(null);\n\n return useMemo(\n () => ({\n start: (event, state) => {\n record.current = { pointerType: event.pointerType, state };\n },\n take: () => {\n const spent = record.current;\n record.current = null;\n return spent;\n },\n drop: () => {\n record.current = null;\n },\n }),\n [],\n );\n}\n"},{"path":"lib/touch.ts","type":"registry:lib","target":"@lib/touch.ts","content":"// Shared touch primitives. iOS and iPadOS run their own gestures on top of the\n// page — the long-press selection callout and the selection it drags in with\n// it — and they win: once the platform claims a touch it cancels ours\n// mid-gesture, so a press-and-hold or a drag simply dies. Surfaces that own\n// their gesture have to opt out.\n//\n// What the two classes below cover, precisely:\n// - `-webkit-touch-callout: none` stops iOS's long-press callout. WebKit-only:\n// it is not a property other engines have, so it is inert everywhere else.\n// - `user-select: none` stops the long-press selection on every engine,\n// Android included, and stops a drag from painting a selection under the\n// cursor. It is inherited, so it reaches every descendant — which is why the\n// two classes differ only in whether they apply it unconditionally.\n// What neither covers:\n// - Chrome for Android's long-press menu on a link or an image. No CSS\n// suppresses it; a gesture surface that wraps one needs its own\n// `onContextMenu` with `preventDefault()`.\n// - The native drag of an `` or `` descendant. `-webkit-user-drag` is\n// not inherited and plain divs and buttons are not drag sources, so setting\n// it on the surface does nothing — the child itself needs `draggable={false}`.\n\n/**\n * Classes for a surface that *is* the control: a thumb, a drum, a stage, a\n * handle, a hold button. Selection is suppressed on every input, because a\n * drag that highlights the control's own label is wrong on a mouse too.\n * Compose with `touch-none` when the surface also owns the scroll axis — leave\n * it off when the page must still scroll from there.\n */\nexport const TOUCH_GESTURE_CLASS = \"select-none [-webkit-touch-callout:none]\";\n\n/**\n * The same opt-out for a gesture surface that wraps content the consumer owns:\n * a scroller, a context-menu trigger, a sheet header, a list row. Selection is\n * suppressed only where the platform runs its own press gestures — a coarse\n * pointer — so a mouse user can still select and copy that content. If the\n * gesture itself would paint a selection under the cursor, add `select-none`\n * for the duration of the gesture rather than reaching for\n * `TOUCH_GESTURE_CLASS`.\n *\n * `pointer: coarse` describes the *primary* pointer and nothing else, so a\n * hybrid machine reads it wrong in both directions: a tablet with a mouse\n * plugged in keeps touch as primary and loses mouse selection, and a laptop\n * with a touchscreen keeps the mouse as primary and leaves selection live\n * under a finger. No media query can answer per interaction — the query is\n * about the device, and the question is about the gesture in progress. The\n * default stays here because it is right on the machines that are one thing or\n * the other, and losing a selection is a nuisance; where the miss costs a\n * *gesture* instead, the surface pairs it with `holdSelection` on the press.\n */\nexport const TOUCH_GESTURE_CONTENT_CLASS =\n \"[-webkit-touch-callout:none] pointer-coarse:select-none\";\n\n/**\n * Suppress selection on `element` for as long as a gesture is running on it,\n * whatever the primary pointer of the machine happens to be. Returns the\n * release. Inline, so it wins over the class above and is gone again the\n * moment the gesture ends.\n *\n * For the press gestures a native selection would otherwise steal — a\n * long-press that opens a menu. Elsewhere prefer the classes: a surface that\n * takes selection away for the whole session is a surface whose text nobody\n * can copy.\n */\nexport function holdSelection(element: HTMLElement) {\n element.style.setProperty(\"user-select\", \"none\");\n element.style.setProperty(\"-webkit-user-select\", \"none\");\n return () => {\n element.style.removeProperty(\"user-select\");\n element.style.removeProperty(\"-webkit-user-select\");\n };\n}\n\n/**\n * Pointer capture, best effort. WebKit throws `NotFoundError` when the pointer\n * is already gone by the time the handler runs — routine on iOS, where the\n * system can claim the touch first — and an uncaught throw takes the rest of\n * the handler, the gesture included, down with it. Touch pointers carry\n * implicit capture anyway, so losing it is never fatal.\n */\nexport function capturePointer(element: Element, pointerId: number) {\n try {\n element.setPointerCapture(pointerId);\n } catch {\n // Pointer is no longer active — implicit capture still applies on touch.\n }\n}\n\n/** Release a capture taken with `capturePointer`, ignoring a stale pointer. */\nexport function releasePointer(element: Element, pointerId: number) {\n try {\n if (element.hasPointerCapture(pointerId)) {\n element.releasePointerCapture(pointerId);\n }\n } catch {\n // Capture was already dropped by the browser.\n }\n}\n\n/**\n * Whether this event came from a pointer that is *hovering*: not a touch, and\n * not currently pressed. Which input the user is holding right now is not\n * something a device capability can answer — a touchscreen laptop hovers and\n * taps, and iPadOS reports a fine hovering pointer for a finger — so both\n * paths stay live and each handler branches on the event it was given.\n *\n * A pen resting on the glass is making contact, not hovering: `buttons` is the\n * tell, and it sends a pen tap down the same route a finger takes.\n *\n * This answers what an *enter* asks. A leave is the other half of a pair and\n * has to be read against the enter that started it — `useHoverGesture` in\n * `lib/hooks/use-hover-gesture` does that, and hover surfaces should use it\n * rather than asking this question twice.\n */\nexport const isHoveringPointer = (event: {\n pointerType: string;\n buttons: number;\n}) => event.pointerType !== \"touch\" && event.buttons === 0;\n"}]}