{ "$schema": "https://ui.shadcn.com/schema/registry-item.json", "name": "horizontal-scroll-stack", "title": "Horizontal Scroll Stack", "author": "AlgorizeTech", "description": "Ask the user to pick one of 6 scroll stack variants: https://avaraui.com/view/scroll-stack. This is the Horizontal scroll stack. Skip the question if the user already named one. A section that converts vertical scrolling into horizontal card movement with a progress indicator. Use it for process timelines and step sequences.", "dependencies": [], "registryDependencies": [ "utils" ], "files": [ { "path": "src/components/custom/blocks/HorizontalScrollStackBlock.tsx", "content": "\"use client\";\n\nimport { cn } from \"@/lib/utils\";\nimport React, { useEffect, useRef, useState } from \"react\";\nimport { cubicBezier } from \"./motion-curves\";\n\n// Stack progress (0 → 1) lives in this custom property on the container,\n// written once per frame by the tween below; cards and bars derive from it.\nconst PROGRESS_VAR = \"--horizontal-scroll-stack-progress\";\nconst PROGRESS_EASE = cubicBezier(0.25, 1, 0.5, 1);\nconst PROGRESS_DURATION = 600;\n\nexport type ScrollStackItem = {\n id: string | number;\n number?: string;\n title: string;\n description: string;\n icon?: React.ReactNode;\n};\n\nexport interface HorizontalScrollStackProps\n extends React.HTMLAttributes {\n items: ScrollStackItem[];\n title?: string;\n subtitle?: string;\n}\n\n// --- CHILD COMPONENT: Stacking Card ---\nfunction StackCard({\n item,\n index,\n total,\n cardWidth,\n gap,\n stackOffset,\n isMobile = false,\n}: {\n item: ScrollStackItem;\n index: number;\n total: number;\n cardWidth: number;\n gap: number;\n stackOffset: number;\n isMobile?: boolean;\n}) {\n const steps = Math.max(1, total - 1);\n const stepSize = 1 / steps;\n const shiftPerStep = cardWidth + gap - stackOffset;\n\n // Card index `index` reaches its stacked position at progress = index * stepSize\n const lockProgress = index * stepSize;\n const finalTranslation = -index * shiftPerStep;\n\n // Linear shift from 0 to lockProgress; stays locked at finalTranslation afterwards.\n // All unstacked cards shift together, keeping equal gap between them to the right.\n const x =\n isMobile || index === 0\n ? undefined\n : `translateX(calc(min(var(${PROGRESS_VAR}, 0), ${lockProgress}) / ${lockProgress} * ${finalTranslation}px))`;\n\n const displayNum = item.number || `0${index + 1}`;\n\n return (\n \n
\n
\n
\n {item.icon}\n
\n \n {displayNum}\n \n
\n\n

\n {item.title}\n

\n

\n {item.description}\n

\n
\n\n
\n
\n
\n
\n );\n}\n\n// --- CHILD COMPONENT: Progress Indicator Bar ---\nfunction ProgressBarItem({\n index,\n total,\n}: {\n index: number;\n total: number;\n}) {\n const steps = Math.max(1, total - 1);\n\n // Bar `index` fills while progress runs from (index - 1) / steps to\n // index / steps; the first bar is always full.\n const scaleX =\n index === 0\n ? undefined\n : `scaleX(clamp(0, var(${PROGRESS_VAR}, 0) * ${steps} - ${index - 1}, 1))`;\n\n return (\n
\n \n
\n );\n}\n\n// --- MAIN COMPONENT ---\nexport function HorizontalScrollStack({\n items,\n title,\n subtitle,\n className,\n style,\n ...props\n}: HorizontalScrollStackProps) {\n const containerRef = useRef(null);\n\n const [activeStep, setActiveStep] = useState(0);\n const progressRef = useRef(0);\n const lastScrollTimeRef = useRef(0);\n\n const steps = Math.max(1, items.length - 1);\n\n // Smoothly animate progress whenever activeStep changes, always from where\n // it is now, so a new step mid-glide picks up without a jump. Written inline\n // each frame on purpose: the cards' `transition-all` then trails the glide\n // slightly, which is the look the section has always had.\n useEffect(() => {\n const container = containerRef.current;\n const targetProgress = activeStep / steps;\n const from = progressRef.current;\n if (!container || from === targetProgress) return;\n\n let frame = 0;\n let startTime = 0;\n const tick = (now: number) => {\n if (!startTime) startTime = now;\n const t = Math.min((now - startTime) / PROGRESS_DURATION, 1);\n const value = from + (targetProgress - from) * PROGRESS_EASE(t);\n progressRef.current = value;\n container.style.setProperty(PROGRESS_VAR, String(value));\n if (t < 1) frame = requestAnimationFrame(tick);\n };\n frame = requestAnimationFrame(tick);\n return () => cancelAnimationFrame(frame);\n }, [activeStep, steps]);\n\n const [layout, setLayout] = useState({\n cardWidth: 440,\n gap: 32,\n stackOffset: 0,\n });\n const [isMobile, setIsMobile] = useState(false);\n\n useEffect(() => {\n if (typeof window === \"undefined\") return;\n\n const updateLayout = () => {\n const w = window.innerWidth;\n setIsMobile(w < 768);\n\n if (w < 640) {\n setLayout({ cardWidth: Math.max(260, w - 64), gap: 16, stackOffset: 0 });\n } else if (w < 1024) {\n setLayout({ cardWidth: 360, gap: 24, stackOffset: 0 });\n } else {\n setLayout({ cardWidth: 440, gap: 32, stackOffset: 0 });\n }\n };\n\n updateLayout();\n window.addEventListener(\"resize\", updateLayout);\n return () => window.removeEventListener(\"resize\", updateLayout);\n }, []);\n\n // Stepped scroll control: Exactly 1 card per scroll action\n useEffect(() => {\n const container = containerRef.current;\n if (!container) return;\n const doc = container.ownerDocument;\n const win = doc.defaultView ?? window;\n\n const handleWheel = (e: WheelEvent) => {\n if (isMobile) return;\n const rect = container.getBoundingClientRect();\n const isVisibleInViewport =\n rect.top < win.innerHeight * 0.85 && rect.bottom > win.innerHeight * 0.15;\n\n if (!isVisibleInViewport) return;\n\n const now = Date.now();\n const isCooldown = now - lastScrollTimeRef.current < 550;\n\n if (e.deltaY > 0) {\n // Scrolling DOWN\n if (activeStep < steps) {\n e.preventDefault();\n e.stopPropagation();\n if (!isCooldown) {\n lastScrollTimeRef.current = now;\n setActiveStep((prev) => Math.min(steps, prev + 1));\n }\n }\n } else if (e.deltaY < 0) {\n // Scrolling UP\n if (activeStep > 0) {\n e.preventDefault();\n e.stopPropagation();\n if (!isCooldown) {\n lastScrollTimeRef.current = now;\n setActiveStep((prev) => Math.max(0, prev - 1));\n }\n }\n }\n };\n\n win.addEventListener(\"wheel\", handleWheel, { passive: false });\n return () => win.removeEventListener(\"wheel\", handleWheel);\n }, [activeStep, steps, isMobile]);\n\n return (\n \n {isMobile ? (\n
\n {(title || subtitle) && (\n
\n {title && (\n

\n {title}\n

\n )}\n {subtitle && (\n

\n {subtitle}\n

\n )}\n
\n )}\n
\n {items.map((item, index) => (\n \n ))}\n
\n
\n ) : (\n
\n {(title || subtitle) && (\n
\n {title && (\n

\n {title}\n

\n )}\n {subtitle && (\n

\n {subtitle}\n

\n )}\n
\n )}\n\n
\n \n {items.map((item, index) => (\n \n ))}\n
\n
\n\n
\n {items.map((_, i) => (\n \n ))}\n
\n \n )}\n \n );\n}\n\nHorizontalScrollStack.displayName = \"HorizontalScrollStack\";\n", "type": "registry:component", "target": "components/custom/blocks/HorizontalScrollStackBlock.tsx" }, { "path": "src/components/custom/blocks/motion-curves.ts", "content": "/**\n * Motion curves with no animation library behind them.\n *\n * The components here ship as CSS, GSAP or Motion builds that must move\n * identically, so the curves are computed once, from the same numbers, and\n * handed to whichever engine runs them:\n *\n * - `cubicBezier(x1, y1, x2, y2)` → an easing function (GSAP accepts any\n * `(progress) => value` as `ease`), exact for Motion's `ease: [..]` arrays\n * and for CSS `cubic-bezier()`.\n * - `spring({ stiffness, damping, mass })` → the analytic solution Motion\n * Motion uses, as an easing function plus the time it takes to settle, or\n * as a CSS `linear()` string for a fixed start and end.\n * - `createSpringFollower` → a value that chases a moving target through the\n * same spring every frame, like Motion's `useSpring`, for pointer-driven\n * motion that no fixed curve can describe.\n */\n\n// ---------------------------------------------------------------------------\n// Cubic bezier\n// ---------------------------------------------------------------------------\n\n/**\n * The CSS / Motion cubic-bezier as a function of progress. Newton-Raphson\n * with a bisection fallback, the same solver browsers use.\n */\nexport function cubicBezier(x1: number, y1: number, x2: number, y2: number) {\n if (x1 === y1 && x2 === y2) return (t: number) => t;\n\n const a = (p1: number, p2: number) => 1 - 3 * p2 + 3 * p1;\n const b = (p1: number, p2: number) => 3 * p2 - 6 * p1;\n const c = (p1: number) => 3 * p1;\n const at = (t: number, p1: number, p2: number) =>\n ((a(p1, p2) * t + b(p1, p2)) * t + c(p1)) * t;\n const slope = (t: number, p1: number, p2: number) =>\n 3 * a(p1, p2) * t * t + 2 * b(p1, p2) * t + c(p1);\n\n const solveX = (x: number) => {\n let t = x;\n for (let i = 0; i < 8; i++) {\n const s = slope(t, x1, x2);\n if (Math.abs(s) < 1e-6) break;\n const err = at(t, x1, x2) - x;\n if (Math.abs(err) < 1e-7) return t;\n t -= err / s;\n }\n let lo = 0;\n let hi = 1;\n t = x;\n for (let i = 0; i < 30 && hi - lo > 1e-7; i++) {\n const value = at(t, x1, x2);\n if (value < x) lo = t;\n else hi = t;\n t = (lo + hi) / 2;\n }\n return t;\n };\n\n return (x: number) => (x <= 0 ? 0 : x >= 1 ? 1 : at(solveX(x), y1, y2));\n}\n\n/** Motion's named eases, as the cubic-beziers they are. */\nexport const MOTION_EASE = {\n linear: [0, 0, 1, 1],\n easeIn: [0.42, 0, 1, 1],\n easeOut: [0, 0, 0.58, 1],\n easeInOut: [0.42, 0, 0.58, 1],\n circIn: [0.55, 0, 1, 0.45],\n circOut: [0.55, 0, 0.45, 1],\n circInOut: [0.85, 0, 0.15, 1],\n backIn: [0.31, 0.01, 0.66, -0.59],\n backOut: [0.33, 1.53, 0.69, 0.99],\n anticipate: [0.66, -0.56, 0.34, 1.35],\n} as const;\n\n/**\n * Motion's default layout transition (`layout` / `layoutId`):\n * `{ duration: 0.45, ease: [0.4, 0, 0.1, 1] }`.\n */\nexport const LAYOUT_TRANSITION = { duration: 0.45, ease: [0.4, 0, 0.1, 1] as const };\n\n// ---------------------------------------------------------------------------\n// Spring\n// ---------------------------------------------------------------------------\n\nexport interface SpringOptions {\n /** Motion default 100. */\n stiffness?: number;\n /** Motion default 10. */\n damping?: number;\n /** Motion default 1. */\n mass?: number;\n /** Starting velocity, in units of the whole distance per second. */\n velocity?: number;\n /** How close to the end counts as settled, as a fraction of the distance. */\n restDelta?: number;\n}\n\n/**\n * Normalised position (0 → 1) of a spring released from 0 towards 1, at time\n * `t` seconds. The closed-form solution Motion's `spring()` generator\n * uses for the under-, critically and over-damped cases.\n */\nexport function springAt(options: SpringOptions = {}) {\n const { stiffness = 100, damping = 10, mass = 1, velocity = 0 } = options;\n const zeta = damping / (2 * Math.sqrt(stiffness * mass));\n const omega0 = Math.sqrt(stiffness / mass);\n // Motion's convention: distance still to cover, velocity toward it negated.\n const delta = 1;\n const v0 = -velocity;\n\n if (zeta < 1) {\n const omegaD = omega0 * Math.sqrt(1 - zeta * zeta);\n return (t: number) => {\n const envelope = Math.exp(-zeta * omega0 * t);\n return (\n 1 -\n envelope *\n (((v0 + zeta * omega0 * delta) / omegaD) * Math.sin(omegaD * t) +\n delta * Math.cos(omegaD * t))\n );\n };\n }\n if (zeta === 1) {\n return (t: number) => 1 - Math.exp(-omega0 * t) * (delta + (v0 + omega0 * delta) * t);\n }\n const omegaD = omega0 * Math.sqrt(zeta * zeta - 1);\n return (t: number) => {\n const envelope = Math.exp(-zeta * omega0 * t);\n const freq = Math.min(omegaD * t, 300);\n return (\n 1 -\n (envelope *\n ((v0 + zeta * omega0 * delta) * Math.sinh(freq) + omegaD * delta * Math.cosh(freq))) /\n omegaD\n );\n };\n}\n\n/** Seconds until the spring stays within `restDelta` of its end. */\nexport function springDuration(options: SpringOptions = {}) {\n const at = springAt(options);\n const restDelta = options.restDelta ?? 0.001;\n const step = 1 / 240;\n let lastOutside = 0;\n for (let t = 0; t <= 10; t += step) {\n if (Math.abs(1 - at(t)) > restDelta) lastOutside = t;\n else if (t - lastOutside > 0.1) break;\n }\n return Math.max(lastOutside + step, step);\n}\n\n/**\n * A spring as a duration and an easing function over it — what GSAP takes:\n *\n * const { duration, ease } = springEase({ stiffness: 300, damping: 20 });\n * gsap.to(el, { y: 0, duration, ease });\n *\n * Exact for a fixed start and end; a spring that has to react mid-flight to a\n * new target needs `createSpringFollower` instead.\n */\nexport function springEase(options: SpringOptions = {}) {\n const duration = springDuration(options);\n const at = springAt(options);\n return {\n duration,\n ease: (progress: number) => (progress >= 1 ? 1 : at(progress * duration)),\n };\n}\n\n/**\n * A spring as a CSS `linear()` easing and its duration in ms, for\n * `transition` / `animation` with a fixed start and end.\n *\n * const { easing, duration } = springLinear({ stiffness: 400, damping: 30 });\n * el.style.transition = `transform ${duration}ms ${easing}`;\n */\nexport function springLinear(options: SpringOptions = {}, pointsPerSecond = 60) {\n const duration = springDuration(options);\n const at = springAt(options);\n const count = Math.max(Math.ceil(duration * pointsPerSecond), 8);\n const points: string[] = [];\n for (let i = 0; i <= count; i++) {\n const t = (i / count) * duration;\n points.push(String(Math.round((i === count ? 1 : at(t)) * 10000) / 10000));\n }\n return { easing: `linear(${points.join(\", \")})`, duration: Math.round(duration * 1000) };\n}\n\n// ---------------------------------------------------------------------------\n// Spring follower (useSpring equivalent)\n// ---------------------------------------------------------------------------\n\n/** Something that calls back once per frame with the time since the last, in ms. */\nexport interface FrameTicker {\n add: (callback: (deltaMs: number) => void) => () => void;\n}\n\n/** requestAnimationFrame as a ticker — the library-free default. */\nexport const rafTicker: FrameTicker = {\n add(callback) {\n let last = performance.now();\n let frame = requestAnimationFrame(function tick(now) {\n callback(now - last);\n last = now;\n frame = requestAnimationFrame(tick);\n });\n return () => cancelAnimationFrame(frame);\n },\n};\n\nexport interface SpringFollower {\n /** Chase a new target from wherever the value is now, keeping its velocity. */\n set: (target: number) => void;\n /** Move to a value instantly, with no motion. */\n jump: (value: number) => void;\n get: () => number;\n destroy: () => void;\n}\n\n/**\n * A value that follows its target through a spring, integrating the same\n * equation of motion Motion's `useSpring` solves — so a pointer-driven spring\n * reads the same in every build. Runs only while moving; `onUpdate` receives\n * each new value.\n */\nexport function createSpringFollower(\n initial: number,\n onUpdate: (value: number) => void,\n options: SpringOptions & { restSpeed?: number; ticker?: FrameTicker } = {},\n): SpringFollower {\n const { stiffness = 100, damping = 10, mass = 1, ticker = rafTicker } = options;\n const restDelta = options.restDelta ?? 0.01;\n const restSpeed = options.restSpeed ?? 0.01;\n let value = initial;\n let target = initial;\n let velocity = 0;\n let stop: (() => void) | null = null;\n\n const step = (deltaMs: number) => {\n // Fixed 1ms sub-steps keep the integration stable for stiff springs and\n // independent of the frame rate.\n const steps = Math.min(Math.max(Math.round(deltaMs), 1), 250);\n for (let i = 0; i < steps; i++) {\n const force = -stiffness * (value - target) - damping * velocity;\n velocity += (force / mass) * 0.001;\n value += velocity * 0.001;\n }\n if (Math.abs(target - value) < restDelta && Math.abs(velocity) < restSpeed) {\n value = target;\n velocity = 0;\n stop?.();\n stop = null;\n }\n onUpdate(value);\n };\n\n return {\n set(next) {\n target = next;\n if (!stop && value !== target) stop = ticker.add(step);\n },\n jump(next) {\n stop?.();\n stop = null;\n value = target = next;\n velocity = 0;\n onUpdate(value);\n },\n get: () => value,\n destroy() {\n stop?.();\n stop = null;\n },\n };\n}\n", "type": "registry:component", "target": "components/custom/blocks/motion-curves.ts" } ], "docs": "Named export: HorizontalScrollStack. Items take { id, number, title, description, icon? }. Pins the section and maps scroll progress to horizontal travel, so it needs enough page height to complete — and it takes over scrolling while pinned, which is worth testing on touch.", "categories": [ "scroll", "marketing" ], "type": "registry:component" }