framer-motion
Version:
A simple and powerful JavaScript animation library
71 lines (68 loc) • 2.16 kB
JavaScript
import { useContext, useId, useEffect, useCallback } from 'react';
import { PresenceContext } from '../../context/PresenceContext.mjs';
/**
* When a component is the child of `AnimatePresence`, it can use `usePresence`
* to access information about whether it's still present in the React tree.
*
* ```jsx
* import { usePresence } from "framer-motion"
*
* export const Component = () => {
* const [isPresent, safeToRemove] = usePresence()
*
* useEffect(() => {
* !isPresent && setTimeout(safeToRemove, 1000)
* }, [isPresent])
*
* return <div />
* }
* ```
*
* If `isPresent` is `false`, it means that a component has been removed the tree, but
* `AnimatePresence` won't really remove it until `safeToRemove` has been called.
*
* @public
*/
function usePresence(subscribe = true) {
const context = useContext(PresenceContext);
if (context === null)
return [true, null];
const { isPresent, onExitComplete, register } = context;
// It's safe to call the following hooks conditionally (after an early return) because the context will always
// either be null or non-null for the lifespan of the component.
const id = useId();
useEffect(() => {
if (subscribe) {
return register(id);
}
}, [subscribe]);
const safeToRemove = useCallback(() => subscribe && onExitComplete && onExitComplete(id), [id, onExitComplete, subscribe]);
return !isPresent && onExitComplete ? [false, safeToRemove] : [true];
}
/**
* Similar to `usePresence`, except `useIsPresent` simply returns whether or not the component is present.
* There is no `safeToRemove` function.
*
* ```jsx
* import { useIsPresent } from "framer-motion"
*
* export const Component = () => {
* const isPresent = useIsPresent()
*
* useEffect(() => {
* !isPresent && console.log("I've been removed!")
* }, [isPresent])
*
* return <div />
* }
* ```
*
* @public
*/
function useIsPresent() {
return isPresent(useContext(PresenceContext));
}
function isPresent(context) {
return context === null ? true : context.isPresent;
}
export { isPresent, useIsPresent, usePresence };