\n \n );\n});\n\nexport default Marquee;\n","import { ObserverInstanceCallback } from './index';\n\nconst observerMap = new Map<\n string,\n {\n id: string;\n observer: IntersectionObserver;\n elements: Map>;\n }\n>();\n\nconst RootIds: WeakMap = new WeakMap();\nlet rootId = 0;\n\nlet unsupportedValue: boolean | undefined = undefined;\n\n/**\n * What should be the default behavior if the IntersectionObserver is unsupported?\n * Ideally the polyfill has been loaded, you can have the following happen:\n * - `undefined`: Throw an error\n * - `true` or `false`: Set the `inView` value to this regardless of intersection state\n * **/\nexport function defaultFallbackInView(inView: boolean | undefined) {\n unsupportedValue = inView;\n}\n\n/**\n * Generate a unique ID for the root element\n * @param root\n */\nfunction getRootId(root: IntersectionObserverInit['root']) {\n if (!root) return '0';\n if (RootIds.has(root)) return RootIds.get(root);\n rootId += 1;\n RootIds.set(root, rootId.toString());\n return RootIds.get(root);\n}\n\n/**\n * Convert the options to a string Id, based on the values.\n * Ensures we can reuse the same observer when observing elements with the same options.\n * @param options\n */\nexport function optionsToId(options: IntersectionObserverInit) {\n return Object.keys(options)\n .sort()\n .filter((key) => options[key] !== undefined)\n .map((key) => {\n return `${key}_${\n key === 'root' ? getRootId(options.root) : options[key]\n }`;\n })\n .toString();\n}\n\nfunction createObserver(options: IntersectionObserverInit) {\n // Create a unique ID for this observer instance, based on the root, root margin and threshold.\n let id = optionsToId(options);\n let instance = observerMap.get(id);\n\n if (!instance) {\n // Create a map of elements this observer is going to observe. Each element has a list of callbacks that should be triggered, once it comes into view.\n const elements = new Map>();\n let thresholds: number[] | readonly number[];\n\n const observer = new IntersectionObserver((entries) => {\n entries.forEach((entry) => {\n // While it would be nice if you could just look at isIntersecting to determine if the component is inside the viewport, browsers can't agree on how to use it.\n // -Firefox ignores `threshold` when considering `isIntersecting`, so it will never be false again if `threshold` is > 0\n const inView =\n entry.isIntersecting &&\n thresholds.some((threshold) => entry.intersectionRatio >= threshold);\n\n // @ts-ignore support IntersectionObserver v2\n if (options.trackVisibility && typeof entry.isVisible === 'undefined') {\n // The browser doesn't support Intersection Observer v2, falling back to v1 behavior.\n // @ts-ignore\n entry.isVisible = inView;\n }\n\n elements.get(entry.target)?.forEach((callback) => {\n callback(inView, entry);\n });\n });\n }, options);\n\n // Ensure we have a valid thresholds array. If not, use the threshold from the options\n thresholds =\n observer.thresholds ||\n (Array.isArray(options.threshold)\n ? options.threshold\n : [options.threshold || 0]);\n\n instance = {\n id,\n observer,\n elements,\n };\n\n observerMap.set(id, instance);\n }\n\n return instance;\n}\n\n/**\n * @param element - DOM Element to observe\n * @param callback - Callback function to trigger when intersection status changes\n * @param options - Intersection Observer options\n * @param fallbackInView - Fallback inView value.\n * @return Function - Cleanup function that should be triggered to unregister the observer\n */\nexport function observe(\n element: Element,\n callback: ObserverInstanceCallback,\n options: IntersectionObserverInit = {},\n fallbackInView = unsupportedValue,\n) {\n if (\n typeof window.IntersectionObserver === 'undefined' &&\n fallbackInView !== undefined\n ) {\n const bounds = element.getBoundingClientRect();\n callback(fallbackInView, {\n isIntersecting: fallbackInView,\n target: element,\n intersectionRatio:\n typeof options.threshold === 'number' ? options.threshold : 0,\n time: 0,\n boundingClientRect: bounds,\n intersectionRect: bounds,\n rootBounds: bounds,\n });\n return () => {\n // Nothing to cleanup\n };\n }\n // An observer with the same options can be reused, so lets use this fact\n const { id, observer, elements } = createObserver(options);\n\n // Register the callback listener for this element\n let callbacks = elements.get(element) || [];\n if (!elements.has(element)) {\n elements.set(element, callbacks);\n }\n\n callbacks.push(callback);\n observer.observe(element);\n\n return function unobserve() {\n // Remove the callback from the callback list\n callbacks.splice(callbacks.indexOf(callback), 1);\n\n if (callbacks.length === 0) {\n // No more callback exists for element, so destroy it\n elements.delete(element);\n observer.unobserve(element);\n }\n\n if (elements.size === 0) {\n // No more elements are being observer by this instance, so destroy it\n observer.disconnect();\n observerMap.delete(id);\n }\n };\n}\n","import * as React from 'react';\nimport { IntersectionObserverProps, PlainChildrenProps } from './index';\nimport { observe } from './observe';\n\ntype State = {\n inView: boolean;\n entry?: IntersectionObserverEntry;\n};\n\nfunction isPlainChildren(\n props: IntersectionObserverProps | PlainChildrenProps,\n): props is PlainChildrenProps {\n return typeof props.children !== 'function';\n}\n\n/**\n ## Render props\n\n To use the `` component, you pass it a function. It will be called\n whenever the state changes, with the new value of `inView`. In addition to the\n `inView` prop, children also receive a `ref` that should be set on the\n containing DOM element. This is the element that the IntersectionObserver will\n monitor.\n\n If you need it, you can also access the\n [`IntersectionObserverEntry`](https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserverEntry)\n on `entry`, giving you access to all the details about the current intersection\n state.\n\n ```jsx\n import { InView } from 'react-intersection-observer';\n\n const Component = () => (\n \n {({ inView, ref, entry }) => (\n
\n
{`Header inside viewport ${inView}.`}
\n
\n )}\n \n );\n\n export default Component;\n ```\n\n ## Plain children\n\n You can pass any element to the ``, and it will handle creating the\n wrapping DOM element. Add a handler to the `onChange` method, and control the\n state in your own component. Any extra props you add to `` will be\n passed to the HTML element, allowing you set the `className`, `style`, etc.\n\n ```jsx\n import { InView } from 'react-intersection-observer';\n\n const Component = () => (\n console.log('Inview:', inView)}>\n
Plain children are always rendered. Use onChange to monitor state.
\n \n );\n\n export default Component;\n ```\n */\nexport class InView extends React.Component<\n IntersectionObserverProps | PlainChildrenProps,\n State\n> {\n static displayName = 'InView';\n static defaultProps = {\n threshold: 0,\n triggerOnce: false,\n initialInView: false,\n };\n\n constructor(props: IntersectionObserverProps | PlainChildrenProps) {\n super(props);\n this.state = {\n inView: !!props.initialInView,\n entry: undefined,\n };\n }\n\n componentDidUpdate(prevProps: IntersectionObserverProps) {\n // If a IntersectionObserver option changed, reinit the observer\n if (\n prevProps.rootMargin !== this.props.rootMargin ||\n prevProps.root !== this.props.root ||\n prevProps.threshold !== this.props.threshold ||\n prevProps.skip !== this.props.skip ||\n prevProps.trackVisibility !== this.props.trackVisibility ||\n prevProps.delay !== this.props.delay\n ) {\n this.unobserve();\n this.observeNode();\n }\n }\n\n componentWillUnmount() {\n this.unobserve();\n this.node = null;\n }\n\n node: Element | null = null;\n _unobserveCb: (() => void) | null = null;\n\n observeNode() {\n if (!this.node || this.props.skip) return;\n const {\n threshold,\n root,\n rootMargin,\n trackVisibility,\n delay,\n fallbackInView,\n } = this.props;\n\n this._unobserveCb = observe(\n this.node,\n this.handleChange,\n {\n threshold,\n root,\n rootMargin,\n // @ts-ignore\n trackVisibility,\n // @ts-ignore\n delay,\n },\n fallbackInView,\n );\n }\n\n unobserve() {\n if (this._unobserveCb) {\n this._unobserveCb();\n this._unobserveCb = null;\n }\n }\n\n handleNode = (node?: Element | null) => {\n if (this.node) {\n // Clear the old observer, before we start observing a new element\n this.unobserve();\n\n if (!node && !this.props.triggerOnce && !this.props.skip) {\n // Reset the state if we get a new node, and we aren't ignoring updates\n this.setState({ inView: !!this.props.initialInView, entry: undefined });\n }\n }\n\n this.node = node ? node : null;\n this.observeNode();\n };\n\n handleChange = (inView: boolean, entry: IntersectionObserverEntry) => {\n if (inView && this.props.triggerOnce) {\n // If `triggerOnce` is true, we should stop observing the element.\n this.unobserve();\n }\n if (!isPlainChildren(this.props)) {\n // Store the current State, so we can pass it to the children in the next render update\n // There's no reason to update the state for plain children, since it's not used in the rendering.\n this.setState({ inView, entry });\n }\n if (this.props.onChange) {\n // If the user is actively listening for onChange, always trigger it\n this.props.onChange(inView, entry);\n }\n };\n\n render() {\n if (!isPlainChildren(this.props)) {\n const { inView, entry } = this.state;\n return this.props.children({ inView, entry, ref: this.handleNode });\n }\n\n const {\n children,\n as,\n triggerOnce,\n threshold,\n root,\n rootMargin,\n onChange,\n skip,\n trackVisibility,\n delay,\n initialInView,\n fallbackInView,\n ...props\n } = this.props;\n\n return React.createElement(\n as || 'div',\n { ref: this.handleNode, ...props },\n children,\n );\n }\n}\n","import * as React from 'react';\nimport { InViewHookResponse, IntersectionOptions } from './index';\nimport { useEffect } from 'react';\nimport { observe } from './observe';\n\ntype State = {\n inView: boolean;\n entry?: IntersectionObserverEntry;\n};\n\n/**\n * React Hooks make it easy to monitor the `inView` state of your components. Call\n * the `useInView` hook with the (optional) [options](#options) you need. It will\n * return an array containing a `ref`, the `inView` status and the current\n * [`entry`](https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserverEntry).\n * Assign the `ref` to the DOM element you want to monitor, and the hook will\n * report the status.\n *\n * @example\n * ```jsx\n * import React from 'react';\n * import { useInView } from 'react-intersection-observer';\n *\n * const Component = () => {\n * const { ref, inView, entry } = useInView({\n * threshold: 0,\n * });\n *\n * return (\n *