Save changes Resolves

Send request Rejects · contract to circle

Click to submit — the left one succeeds, the right one fails and offers a retry.

); } ``` ## Accessibility & performance Honors `prefers-reduced-motion` with a designed static frame or fade (never a blank box) and passes `className` through. ## Source (`piston.tsx`) ```tsx "use client"; import { AnimatePresence, motion, type HTMLMotionProps, type Transition } from "motion/react"; import * as React from "react"; import { useReducedMotion } from "@/hooks/use-reduced-motion"; import { cn } from "@/lib/utils"; export type PistonState = "idle" | "pending" | "success" | "error"; export interface PistonProps extends Omit, "onClick" | "children" | "animate" | "transition"> { /** * Async click handler — return a promise and Piston runs the whole * lifecycle for you: pending while in flight, success/error on settle, * back to idle after the dwell. A sync handler leaves the button idle. */ onClick?: (event: React.MouseEvent) => void | Promise; /** * Controlled state. When set, the internal machine is off: Piston renders * exactly this state and you own every transition (onClick still fires). */ state?: PistonState; /** Idle label. @default "Submit" */ children?: React.ReactNode; /** Pending content. @default a neutral spinner */ pendingContent?: React.ReactNode; /** Success content. @default a self-drawing check */ successContent?: React.ReactNode; /** Error / retry label — the button stays live so a click retries. @default "Retry" */ errorContent?: React.ReactNode; /** Contract the button toward a circle while pending. @default false */ contractToCircle?: boolean; /** Seconds the success state dwells before the label returns. @default 1.6 */ successDwell?: number; /** Error shake amplitude multiplier — 0 disables the shake. @default 1 */ shakeIntensity?: number; /** Spring for the axial content slide and the width breath. @default { stiffness: 520, damping: 34 } */ spring?: { stiffness?: number; damping?: number }; /** Really disable the button (not just visually) while pending. @default true */ disabledWhilePending?: boolean; /** The only saturated moments. @default { success: "#34d399", error: "#f87171" } */ colors?: { success?: string; error?: string }; /** Button size. @default "md" */ size?: "sm" | "md" | "lg"; } const SIZES = { sm: { height: 36, padX: 18, radius: 8, text: "text-xs" }, md: { height: 44, padX: 24, radius: 10, text: "text-sm" }, lg: { height: 52, padX: 30, radius: 12, text: "text-base" }, } as const; /** Draws itself with a single stroke, then lands with a 1-frame settle. */ function Check({ color, reduced }: { color: string; reduced: boolean }) { return ( ); } /** Neutral spinner — a rotating ring, or an opacity pulse under reduced motion. */ function Spinner({ reduced }: { reduced: boolean }) { return reduced ? ( ) : ( ); } /** * Piston — a stateful submit button that runs its async lifecycle like a * piston stroke: the label slides out along one axis as the spinner slides * in, the button's width breathing around each state's content — mechanical * and axial, never a fade-in-place. On resolve the spinner gives way to a * check that draws itself in a single stroke and lands with a 1-frame * settle; rejection plays a distinct beat — a shake and an error tint — * and leaves a live retry label. Success and error are the only saturated * moments and both cool back to the neutral chrome. Honest a11y: aria-busy * while pending, a polite live announcement on resolution, and a real * disabled state. Reduced motion: instant state swaps, no shake, spinner * as an opacity pulse only. */ export function Piston({ onClick, state, children, pendingContent, successContent, errorContent, contractToCircle = false, successDwell = 1.6, shakeIntensity = 1, spring, disabledWhilePending = true, colors, size = "md", className, style, disabled, ...rest }: PistonProps) { const reducedMotion = useReducedMotion(); const successColor = colors?.success ?? "#34d399"; const errorColor = colors?.error ?? "#f87171"; const stiffness = spring?.stiffness ?? 520; const damping = spring?.damping ?? 34; const dims = SIZES[size]; const controlled = state !== undefined; const [internal, setInternal] = React.useState("idle"); const status: PistonState = controlled ? state : internal; // Monotonic run token: a click supersedes any in-flight settle or dwell. const runId = React.useRef(0); const dwellTimer = React.useRef(null); const clearDwell = React.useCallback(() => { if (dwellTimer.current !== null) { window.clearTimeout(dwellTimer.current); dwellTimer.current = null; } }, []); React.useEffect(() => clearDwell, [clearDwell]); const handleClick = (event: React.MouseEvent) => { // Never re-enter an in-flight run, even when disabledWhilePending is off. if (status === "pending") return; const result = onClick?.(event); if (controlled) return; if (result && typeof (result as Promise).then === "function") { const id = ++runId.current; clearDwell(); setInternal("pending"); (result as Promise).then( () => { if (id !== runId.current) return; setInternal("success"); dwellTimer.current = window.setTimeout(() => { if (id === runId.current) setInternal("idle"); }, successDwell * 1000); }, () => { if (id === runId.current) setInternal("error"); } ); } }; const content: Record = { idle: children ?? "Submit", pending: pendingContent ?? , success: successContent ?? , error: errorContent ?? "Retry", }; const announcement = status === "success" ? typeof successContent === "string" ? successContent : "Success" : status === "error" ? typeof errorContent === "string" ? `Failed — ${errorContent.toLowerCase()}` : "Something went wrong — press to retry" : ""; const contracted = contractToCircle && status === "pending"; const springT: Transition = reducedMotion ? { duration: 0 } : { type: "spring", stiffness, damping }; // The error beat: a mechanical lateral shake, scaled by intensity. const amp = 6 * shakeIntensity; const shakeX = status === "error" && !reducedMotion && shakeIntensity > 0 ? [0, -amp, amp * 0.85, -amp * 0.6, amp * 0.35, 0] : 0; return ( {/* Soft top light so the neutral face never reads as a flat slab. */} {/* Success tint: flashes saturated on the settle, then cools to neutral. */} {/* Error tint: a distinct flash that cools to a faint standing warning. */} {/* Axial viewport: content strokes vertically through, clipped at the lips. */} {content[status]} {/* Honest resolution announcement for assistive tech. */} {announcement} ); } ```