{ "$schema": "https://ui.shadcn.com/schema/registry-item.json", "name": "testimonial-wall", "type": "registry:ui", "title": "Testimonial Wall", "description": "Masonry of quotes drifting in opposite columns that ease to a stop under the pointer.", "categories": [ "marketing" ], "dependencies": [ "motion" ], "registryDependencies": [ "https://www.stealth.pm/r/tokens.json", "https://www.stealth.pm/r/cn.json", "https://www.stealth.pm/r/motion.json", "https://www.stealth.pm/r/use-controllable-state.json" ], "files": [ { "path": "components/ui/testimonial-wall.tsx", "content": "\"use client\";\nimport { AnimatePresence, motion } from \"motion/react\";\nimport { useCallback, useEffect, useMemo, useRef, useState, useSyncExternalStore } from \"react\";\nimport { cn } from \"@/lib/cn\";\nimport { spring, swap } from \"@/lib/motion\";\nimport { useControllableState } from \"@/lib/use-controllable-state\";\n\nexport type Testimonial = {\n /** Stable key. Falls back to the name. */\n id?: string;\n /** The quote. Wrap the line that sells it in and it steps up to the primary color. */\n quote: React.ReactNode;\n name: string;\n /** Role and company, e.g. \"Staff engineer, Northwind\". */\n role?: string;\n /** Square image URL. Initials show until it loads, and if it never does. */\n avatar?: string;\n};\n\n/** Cards and columns share one gap, so the loop's seam is invisible. */\nconst GAP = 12;\n/** Narrowest a column gets before the wall drops one. */\nconst MIN_COLUMN = 216;\n/** Each column runs at a slightly different pace, so the wall never moves in lockstep. */\nconst PACE = [1, 0.84, 1.12, 0.93];\n/** How long the wall takes to settle when it slows for a reader, and to pick up again. */\nconst SLOW_MS = 170;\nconst RESUME_MS = 360;\n\n// Reduced motion changes the markup (a scrollable region instead of a loop), so it\n// reads \"no preference\" while hydrating and switches to the real value right after.\nconst reducedQuery = \"(prefers-reduced-motion: reduce)\";\nfunction subscribeReduced(onChange: () => void) {\n const mq = window.matchMedia(reducedQuery);\n mq.addEventListener(\"change\", onChange);\n return () => mq.removeEventListener(\"change\", onChange);\n}\nfunction usePrefersReducedMotion() {\n return useSyncExternalStore(subscribeReduced, () => window.matchMedia(reducedQuery).matches, () => false);\n}\n\n/**\n * Deals items into columns, each to the currently shortest one, estimating height\n * from the quote's length. Deterministic, so server and client agree.\n */\nfunction distribute(items: Testimonial[], count: number) {\n const cols: { item: Testimonial; index: number }[][] = Array.from({ length: count }, () => []);\n const heights = new Array(count).fill(0);\n items.forEach((item, index) => {\n let target = 0;\n for (let c = 1; c < count; c++) if (heights[c] < heights[target] - 1) target = c;\n cols[target].push({ item, index });\n heights[target] += 96 + (typeof item.quote === \"string\" ? item.quote.length : 140) * 0.55;\n });\n return cols;\n}\n\nexport type TestimonialWallProps = Omit, \"children\"> & {\n items: Testimonial[];\n /** The most columns it will use. It drops to fewer as its container narrows (about 216px each). */\n columns?: 1 | 2 | 3 | 4;\n /** Pixels per second for the average column. */\n speed?: number;\n /** Height of the visible window. */\n height?: number | string;\n /** Whether the columns run. Hover and touch-and-hold still pause them for a moment. */\n playing?: boolean;\n defaultPlaying?: boolean;\n onPlayingChange?: (playing: boolean) => void;\n /** Show the pause button in the corner. Motion longer than five seconds needs one; hide it only if you render your own. */\n showControl?: boolean;\n pauseLabel?: string;\n playLabel?: string;\n /** Draw your own card. Defaults to TestimonialCard. */\n renderItem?: (item: Testimonial, index: number) => React.ReactNode;\n};\n\n/**\n * A masonry of testimonials in columns that drift in opposite directions, looping\n * without a seam. A pointer resting on it slows every column to a stop so the card\n * under it can be read, and they ease back up when it leaves. Off screen, in a\n * hidden tab or under reduced motion nothing moves; with reduced motion the wall\n * becomes a plain scrollable region instead.\n */\nexport function TestimonialWall({\n items,\n columns = 3,\n speed = 18,\n height = 480,\n playing: playingProp,\n defaultPlaying = true,\n onPlayingChange,\n showControl = true,\n pauseLabel = \"Pause testimonials\",\n playLabel = \"Play testimonials\",\n renderItem = (item) => ,\n className,\n style,\n \"aria-label\": ariaLabel = \"Testimonials\",\n ...rest\n}: TestimonialWallProps) {\n const [playing, setPlaying] = useControllableState({ value: playingProp, defaultValue: defaultPlaying, onChange: onPlayingChange });\n const reduce = usePrefersReducedMotion();\n const [section, setSection] = useState(null);\n const [fit, setFit] = useState(columns);\n const [hovered, setHovered] = useState(false);\n const [holding, setHolding] = useState(false);\n const [visible, setVisible] = useState(true);\n const [pageHidden, setPageHidden] = useState(false);\n\n // How many columns fit, and whether anyone can see the wall at all.\n useEffect(() => {\n if (!section) return;\n const ro = new ResizeObserver(([e]) => setFit(Math.max(1, Math.floor((e.contentRect.width + GAP) / (MIN_COLUMN + GAP)))));\n ro.observe(section);\n const io = new IntersectionObserver(([e]) => setVisible(e.isIntersecting));\n io.observe(section);\n const onVis = () => setPageHidden(document.hidden);\n document.addEventListener(\"visibilitychange\", onVis);\n return () => {\n ro.disconnect();\n io.disconnect();\n document.removeEventListener(\"visibilitychange\", onVis);\n };\n }, [section]);\n\n const count = Math.max(1, Math.min(columns, fit, items.length));\n const cols = useMemo(() => distribute(items, count), [items, count]);\n\n const animating = !reduce;\n const moving = animating && playing && !hovered && !holding && visible && !pageHidden;\n // Leaving the screen or the tab stops dead; a reader arriving gets the ease.\n const instant = !visible || pageHidden;\n\n // One rate for every column, eased toward 0 or 1 on its own frame loop. Setting\n // playbackRate keeps each animation's current time, so nothing ever jumps.\n const anims = useRef(new Set());\n const rate = useRef(0);\n const register = useCallback((anim: Animation) => {\n anim.playbackRate = rate.current;\n anims.current.add(anim);\n return () => void anims.current.delete(anim);\n }, []);\n\n useEffect(() => {\n if (!animating) return;\n const target = moving ? 1 : 0;\n const apply = () => anims.current.forEach((a) => (a.playbackRate = rate.current));\n if (instant) {\n rate.current = target;\n apply();\n return;\n }\n const tau = target ? RESUME_MS / 3 : SLOW_MS / 3;\n let raf = 0;\n let last = performance.now();\n const tick = (now: number) => {\n rate.current += (target - rate.current) * (1 - Math.exp(-(now - last) / tau));\n last = now;\n if (Math.abs(target - rate.current) < 0.004) rate.current = target;\n apply();\n if (rate.current !== target) raf = requestAnimationFrame(tick);\n };\n raf = requestAnimationFrame(tick);\n return () => cancelAnimationFrame(raf);\n }, [animating, moving, instant]);\n\n if (!items.length) return null;\n\n return (\n \n e.pointerType === \"mouse\" && setHovered(true)}\n onPointerLeave={() => setHovered(false)}\n // On touch, a finger resting on the wall holds it still; a scroll cancels the hold.\n onPointerDown={(e) => e.pointerType !== \"mouse\" && setHolding(true)}\n onPointerUp={() => setHolding(false)}\n onPointerCancel={() => setHolding(false)}\n className={cn(\n // Bleeds 12px each side so card shadows are not clipped by the overflow.\n \"-mx-3 flex min-w-0 gap-3 px-3 outline-none\",\n reduce\n ? \"peer overflow-y-auto overscroll-contain [mask-image:linear-gradient(to_bottom,var(--fg)_calc(100%-40px),transparent)]\"\n : \"overflow-hidden [mask-image:linear-gradient(to_bottom,transparent,var(--fg)_14%,var(--fg)_86%,transparent)]\",\n )}\n style={{ height }}\n >\n {cols.map((col, i) => (\n \n ))}\n \n\n {/* The mask would clip an outline drawn on the scroller itself, so the ring is a sibling. */}\n {reduce && (\n