@zohodesk/components/lib/Popup/intersectionObserver.js

In this Package, we Provide Some Basic Components to Build Web App

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.addIntersectionObserver = addIntersectionObserver;
exports.removeIntersectionObserver = removeIntersectionObserver;

function _toConsumableArray(arr) { return _arrayWithoutHoles(arr) || _iterableToArray(arr) || _unsupportedIterableToArray(arr) || _nonIterableSpread(); }

function _nonIterableSpread() { throw new TypeError("Invalid attempt to spread non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); }

function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(o); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); }

function _iterableToArray(iter) { if (typeof Symbol !== "undefined" && iter[Symbol.iterator] != null || iter["@@iterator"] != null) return Array.from(iter); }

function _arrayWithoutHoles(arr) { if (Array.isArray(arr)) return _arrayLikeToArray(arr); }

function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) { arr2[i] = arr[i]; } return arr2; }

var observerCallbacks = null;
var intersectionObserver = null;

function handleObserverCallbacks(entries) {
  entries.forEach(function (entry) {
    var oldCallbacks = observerCallbacks.get(entry.target);

    if (Array.isArray(oldCallbacks) && oldCallbacks.length) {
      oldCallbacks.forEach(function (callback) {
        callback && callback(entry);
      });
    }
  });
}

function addIntersectionObserver(element, callback, options) {
  if (!!element && typeof callback == 'function') {
    if (intersectionObserver === null && observerCallbacks === null) {
      intersectionObserver = new IntersectionObserver(function (entries) {
        handleObserverCallbacks(entries);
      }, options);
      observerCallbacks = new Map();
    }

    intersectionObserver.observe(element);
    var oldCallbacks = observerCallbacks.get(element) || [];
    observerCallbacks.set(element, [].concat(_toConsumableArray(oldCallbacks), [callback]));
  }
}

function removeIntersectionObserver(element, callback) {
  if (!!element && typeof callback == 'function') {
    var oldCallbacks = observerCallbacks ? observerCallbacks.get(element) : null;

    if (Array.isArray(oldCallbacks)) {
      var callbacks = oldCallbacks.filter(function (handler) {
        return handler !== callback;
      });

      if (intersectionObserver && callbacks.length === 0) {
        observerCallbacks["delete"](element);
        intersectionObserver.unobserve(element);
      }
    }

    if (intersectionObserver && observerCallbacks && observerCallbacks.size === 0) {
      intersectionObserver.disconnect();
      intersectionObserver = null;
      observerCallbacks = null;
    }
  }
}