import { getClippingParents, computeRect, pointInsideRect, Rect } from '@fullcalendar/core' import { ElementScrollGeomCache } from './scroll-geom-cache' /* When this class is instantiated, it records the offset of an element (relative to the document topleft), and continues to monitor scrolling, updating the cached coordinates if it needs to. Does not access the DOM after instantiation, so highly performant. Also keeps track of all scrolling/overflow:hidden containers that are parents of the given element and an determine if a given point is inside the combined clipping rectangle. */ export default class OffsetTracker { // ElementOffsetTracker scrollCaches: ElementScrollGeomCache[] origRect: Rect constructor(el: HTMLElement) { this.origRect = computeRect(el) // will work fine for divs that have overflow:hidden this.scrollCaches = getClippingParents(el).map(function(el) { return new ElementScrollGeomCache(el, true) // listen=true }) } destroy() { for (let scrollCache of this.scrollCaches) { scrollCache.destroy() } } computeLeft() { let left = this.origRect.left for (let scrollCache of this.scrollCaches) { left += scrollCache.origScrollLeft - scrollCache.getScrollLeft() } return left } computeTop() { let top = this.origRect.top for (let scrollCache of this.scrollCaches) { top += scrollCache.origScrollTop - scrollCache.getScrollTop() } return top } isWithinClipping(pageX: number, pageY: number): boolean { let point = { left: pageX, top: pageY } for (let scrollCache of this.scrollCaches) { if ( !isIgnoredClipping(scrollCache.getEventTarget()) && !pointInsideRect(point, scrollCache.clientRect) ) { return false } } return true } } // certain clipping containers should never constrain interactions, like and // https://github.com/fullcalendar/fullcalendar/issues/3615 function isIgnoredClipping(node: EventTarget) { let tagName = (node as HTMLElement).tagName return tagName === 'HTML' || tagName === 'BODY' }