import { attachSpring, motionValue } from "motion" import type { SpringOptions } from "motion" import { createEffect, createSignal, onCleanup } from "solid-js" type Opt = Partial> const eq = (a: Opt | undefined, b: Opt | undefined) => a?.visualDuration === b?.visualDuration && a?.bounce === b?.bounce && a?.stiffness === b?.stiffness && a?.damping === b?.damping && a?.mass === b?.mass && a?.velocity === b?.velocity export function useSpring(target: () => number, options?: Opt | (() => Opt)) { const read = () => (typeof options === "function" ? options() : options) const [value, setValue] = createSignal(target()) const source = motionValue(value()) const spring = motionValue(value()) let config = read() let stop = attachSpring(spring, source, config) let off = spring.on("change", (next: number) => setValue(next)) createEffect(() => { source.set(target()) }) createEffect(() => { if (!options) return const next = read() if (eq(config, next)) return config = next stop() stop = attachSpring(spring, source, next) setValue(spring.get()) }) onCleanup(() => { off() stop() spring.destroy() source.destroy() }) return value }