zarm/lib/use-in-viewport/index.js

基于 React 的移动端UI库

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;

var _defineProperty2 = _interopRequireDefault(require("@babel/runtime/helpers/defineProperty"));

var _slicedToArray2 = _interopRequireDefault(require("@babel/runtime/helpers/slicedToArray"));

require("intersection-observer");

var _react = require("react");

var _getTargetElement = require("../utils/getTargetElement");

function ownKeys(e, r) { var t = Object.keys(e); if (Object.getOwnPropertySymbols) { var o = Object.getOwnPropertySymbols(e); r && (o = o.filter(function (r) { return Object.getOwnPropertyDescriptor(e, r).enumerable; })), t.push.apply(t, o); } return t; }

function _objectSpread(e) { for (var r = 1; r < arguments.length; r++) { var t = null != arguments[r] ? arguments[r] : {}; r % 2 ? ownKeys(Object(t), !0).forEach(function (r) { (0, _defineProperty2.default)(e, r, t[r]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(e, Object.getOwnPropertyDescriptors(t)) : ownKeys(Object(t)).forEach(function (r) { Object.defineProperty(e, r, Object.getOwnPropertyDescriptor(t, r)); }); } return e; }

function _createForOfIteratorHelper(r, e) { var t = "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"]; if (!t) { if (Array.isArray(r) || (t = _unsupportedIterableToArray(r)) || e && r && "number" == typeof r.length) { t && (r = t); var _n = 0, F = function F() {}; return { s: F, n: function n() { return _n >= r.length ? { done: !0 } : { done: !1, value: r[_n++] }; }, e: function e(r) { throw r; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var o, a = !0, u = !1; return { s: function s() { t = t.call(r); }, n: function n() { var r = t.next(); return a = r.done, r; }, e: function e(r) { u = !0, o = r; }, f: function f() { try { a || null == t.return || t.return(); } finally { if (u) throw o; } } }; }

function _unsupportedIterableToArray(r, a) { if (r) { if ("string" == typeof r) return _arrayLikeToArray(r, a); var t = {}.toString.call(r).slice(8, -1); return "Object" === t && r.constructor && (t = r.constructor.name), "Map" === t || "Set" === t ? Array.from(r) : "Arguments" === t || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(t) ? _arrayLikeToArray(r, a) : void 0; } }

function _arrayLikeToArray(r, a) { (null == a || a > r.length) && (a = r.length); for (var e = 0, n = Array(a); e < a; e++) { n[e] = r[e]; } return n; }

function useInViewport(target, options) {
  var _useState = (0, _react.useState)(false),
      _useState2 = (0, _slicedToArray2.default)(_useState, 2),
      isIntersecting = _useState2[0],
      setIsIntersecting = _useState2[1];

  (0, _react.useEffect)(function () {
    var el = (0, _getTargetElement.getTargetElement)(target);

    if (el) {
      var observer = new IntersectionObserver(function (entries) {
        // eslint-disable-next-line no-restricted-syntax
        var _iterator = _createForOfIteratorHelper(entries),
            _step;

        try {
          for (_iterator.s(); !(_step = _iterator.n()).done;) {
            var entry = _step.value;
            setIsIntersecting(entry.isIntersecting);
          }
        } catch (err) {
          _iterator.e(err);
        } finally {
          _iterator.f();
        }
      }, _objectSpread(_objectSpread({}, options), {}, {
        root: (0, _getTargetElement.getTargetElement)(options === null || options === void 0 ? void 0 : options.root)
      }));
      observer.observe(el);
      return function () {
        observer.disconnect();
      };
    }
  }, []);
  return [isIntersecting];
}

var _default = useInViewport;
exports.default = _default;