"use client" import * as React from "react" import { mergeRefs } from "@/lib/merge-refs" import { useMediaQuery } from "@/lib/use-media-query" import { cn } from "@/lib/utils" type TokenRow = { /** The raw value, as written in CSS. */ base: string /** The primitive it is named as, e.g. a palette step. */ primitive: string /** The semantic role that points at the primitive. */ semantic: string /** What the role is for, shown under the semantic chip when `showUse` is set. */ use?: string /** The value and primitive the role resolves to under the dark theme, when they differ. */ dark?: { base: string primitive: string } } const TIERS = ["Base", "Primitive", "Semantic"] as const const SCRAMBLE_CHARS = "_!X$0-+*#" function randomChar() { return SCRAMBLE_CHARS[Math.floor(Math.random() * SCRAMBLE_CHARS.length)] } function subscribeToTheme(onChange: () => void) { const observer = new MutationObserver(onChange) observer.observe(document.documentElement, { attributes: true, attributeFilter: ["class"], }) return () => observer.disconnect() } /** * Whether the `dark` class is on the document, the way next-themes sets it. * `null` until the client has looked, so the first real value is taken as a * baseline rather than a change. */ function useIsDark() { return React.useSyncExternalStore( subscribeToTheme, () => document.documentElement.classList.contains("dark"), () => null ) } function useInView(ref: React.RefObject) { const [inView, setInView] = React.useState(false) React.useEffect(() => { const node = ref.current if (!node) return const observer = new IntersectionObserver(([entry]) => setInView(Boolean(entry?.isIntersecting)) ) observer.observe(node) return () => observer.disconnect() }, [ref]) return inView } /** * Text that holds still until it changes, then spends a moment as noise * before settling on the new value, resolving left to right. Until `live` * is set the text is only a placeholder, so no change is played. */ function ScrambleText({ text, live, reduceMotion, duration = 1000, }: { text: string /** Whether `text` is the real value rather than a server-side guess. */ live: boolean reduceMotion: boolean /** Milliseconds the noise runs for after a change. */ duration?: number }) { const settled = React.useRef(null) const [noise, setNoise] = React.useState(null) React.useEffect(() => { if (!live) return const previous = settled.current settled.current = text if (previous === null || previous === text || reduceMotion) return const startedAt = performance.now() let frame = 0 let lastStep = -1 const loop = (now: number) => { const progress = Math.min((now - startedAt) / duration, 1) const step = Math.floor(progress * (duration / 40)) if (step !== lastStep) { lastStep = step const revealed = Math.floor(progress * text.length) let next = text.slice(0, revealed) for (let i = revealed; i < text.length; i++) { next += text[i] === " " ? " " : randomChar() } setNoise(next) } if (progress < 1) { frame = window.requestAnimationFrame(loop) } else { setNoise(null) } } frame = window.requestAnimationFrame(loop) return () => { window.cancelAnimationFrame(frame) // Stopped part way, by a new value or by motion being turned off: the // noise must not outlive the loop that would have cleared it. setNoise(null) } }, [text, live, duration, reduceMotion]) return ( {text} {noise ?? text} {text} ) } /** * A hairline with a pulse traveling along it. Fills whatever cell it is * in; `vertical` runs it top to bottom for the stacked layout. The pulse is * a Web Animation on the stroke offset, so it needs no keyframes in the * consumer's CSS. */ function Wire({ delay, vertical, active, }: { /** Seconds before this wire's pulse starts, to stagger the rows. */ delay: number vertical: boolean /** Whether the pulse should be running. */ active: boolean }) { const pulse = React.useRef(null) React.useEffect(() => { const node = pulse.current if (!node || !active) return const animation = node.animate( [{ strokeDashoffset: 1.25 }, { strokeDashoffset: -1.25 }], { duration: 3500, delay: delay * 1000, iterations: Infinity } ) return () => animation.cancel() }, [active, delay]) const coords = vertical ? { x1: 4, y1: 0, x2: 4, y2: 100 } : { x1: 0, y1: 4, x2: 100, y2: 4 } return ( ) } function Chip({ color, className, children, }: { color: string className?: string children: React.ReactNode }) { return ( {children} ) } type TokenFlowProps = Omit, "children"> & { /** One color per row, traced from its raw value to the role that uses it. */ rows: TokenRow[] /** Print each row's `use` under its semantic chip. */ showUse?: boolean /** Force a theme instead of following the document's `dark` class. */ theme?: "light" | "dark" /** * `horizontal` wires the tiers left to right, stacking them only on narrow * screens; `vertical` stacks them top to bottom at every width. */ orientation?: "horizontal" | "vertical" } /** * How a color travels through the token tiers: a raw value, the primitive * that names it, and the semantic role that uses it. One row per color, * wired left to right across a dotted plate, with a pulse traveling along * each wire. Rows that carry a `dark` value swap to it when the theme * changes, scrambling for a moment on the way. */ function TokenFlow({ rows, showUse = false, theme, orientation = "horizontal", className, ref, ...props }: TokenFlowProps) { const documentDark = useIsDark() const isDark = theme ? theme === "dark" : documentDark === true const live = theme !== undefined || documentDark !== null const narrow = useMediaQuery("(max-width: 639px)") const horizontal = orientation === "horizontal" const vertical = !horizontal || narrow const reduceMotion = useMediaQuery("(prefers-reduced-motion: reduce)") const plate = React.useRef(null) // A caller's ref would otherwise replace the one that pauses it off screen. const plateRef = React.useMemo(() => mergeRefs(plate, ref), [ref]) const inView = useInView(plate) const pulse = inView && !reduceMotion return (

{TIERS.map((tier, i) => (

{i > 0 ? (

) : null}

{tier}

))}

{rows.map((row, i) => { const value = isDark && row.dark ? row.dark : row return (

{TIERS[0]} {TIERS[1]}

{TIERS[2]} {row.semantic} {showUse && row.use ? ( {row.use} ) : null}

) })}

) } export { TokenFlow, type TokenRow }