import { each, is, useIsomorphicLayoutEffect } from '@react-spring/shared' import { Lookup } from '@react-spring/types' import { Valid } from '../types/common' import { PickAnimated, SpringValues } from '../types' import { SpringRef } from '../SpringRef' import { Controller } from '../Controller' import { UseSpringProps } from './useSpring' import { useSprings } from './useSprings' import { replaceRef } from '../helpers' export type UseTrailProps = UseSpringProps export function useTrail( length: number, props: ( i: number, ctrl: Controller ) => UseTrailProps | (Props & Valid>), deps?: readonly any[] ): PickAnimated extends infer State ? State extends Lookup ? [SpringValues[], SpringRef] : never : never /** * This hook is an abstraction around `useSprings` and is designed to * automatically orchestrate the springs to stagger one after the other * * ```jsx * export const MyComponent = () => { * const trails = useTrail(3, {opacity: 0}) * * return trails.map(styles => ) * } * ``` * * @param length – The number of springs you want to create * @param propsArg – The props to pass to the internal `useSprings` hook, * therefore is the same as `useSprings`. * * @public */ export function useTrail( length: number, props: UseTrailProps | (Props & Valid>) ): SpringValues>[] /** * This hook is an abstraction around `useSprings` and is designed to * automatically orchestrate the springs to stagger one after the other * * ```jsx * export const MyComponent = () => { * const trails = useTrail(3, {opacity: 0}, []) * * return trails.map(styles => ) * } * ``` * * @param length – The number of springs you want to create * @param propsArg – The props to pass to the internal `useSprings` hook, * therefore is the same as `useSprings`. * @param deps – The optional array of dependencies to pass to the internal * `useSprings` hook, therefore is the same as `useSprings`. * * @public */ export function useTrail( length: number, props: UseTrailProps | (Props & Valid>), deps: readonly any[] ): PickAnimated extends infer State ? State extends Lookup ? [SpringValues[], SpringRef] : never : never export function useTrail( length: number, propsArg: unknown, deps?: readonly any[] ) { const propsFn = is.fun(propsArg) && propsArg if (propsFn && !deps) deps = [] // The trail is reversed when every render-based update is reversed. let reverse = true let passedRef: SpringRef | undefined = undefined const result = useSprings( length, (i, ctrl) => { const props = propsFn ? propsFn(i, ctrl) : propsArg passedRef = props.ref reverse = reverse && props.reverse return props }, // Ensure the props function is called when no deps exist. // This works around the 3 argument rule. deps || [{}] ) useIsomorphicLayoutEffect(() => { /** * Run through the ref passed by the `useSprings` hook. */ each(result[1].current, (ctrl, i) => { const parent = result[1].current[i + (reverse ? 1 : -1)] /** * If there's a passed ref then we replace the ctrl ref with it */ replaceRef(ctrl, passedRef) /** * And if there's a ctrl ref then we update instead of start * which means nothing is fired until the start method * of said passedRef is called. */ if (ctrl.ref) { if (parent) { ctrl.update({ to: parent.springs }) } return } if (parent) { ctrl.start({ to: parent.springs }) } else { ctrl.start() } }) }, deps) if (propsFn || arguments.length == 3) { const ref = passedRef ?? result[1] ref['_getProps'] = (propsArg, ctrl, i) => { const props = is.fun(propsArg) ? propsArg(i, ctrl) : propsArg if (props) { const parent = ref.current[i + (props.reverse ? 1 : -1)] if (parent) props.to = parent.springs return props } } return result } return result[0] }