react-intersection/lib/IntersectionRoot.js

A React interface for the Intersection Observer API

"use strict";

exports.__esModule = true;
exports["default"] = void 0;

var React = _interopRequireWildcard(require("react"));

var _intersectionObserver = _interopRequireDefault(require("./intersection-observer"));

var _intersectionRootContext = require("./intersection-root-context");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { "default": obj }; }

function _getRequireWildcardCache() { if (typeof WeakMap !== "function") return null; var cache = new WeakMap(); _getRequireWildcardCache = function _getRequireWildcardCache() { return cache; }; return cache; }

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } if (obj === null || typeof obj !== "object" && typeof obj !== "function") { return { "default": obj }; } var cache = _getRequireWildcardCache(); if (cache && cache.has(obj)) { return cache.get(obj); } var newObj = {}; var hasPropertyDescriptor = Object.defineProperty && Object.getOwnPropertyDescriptor; for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) { var desc = hasPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : null; if (desc && (desc.get || desc.set)) { Object.defineProperty(newObj, key, desc); } else { newObj[key] = obj[key]; } } } newObj["default"] = obj; if (cache) { cache.set(obj, newObj); } return newObj; }

function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }

function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }

function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }

var deepCompareArray = function deepCompareArray(a, b) {
  return a.every(function (item, i) {
    return item === b[i];
  });
};

var IntersectionRoot =
/*#__PURE__*/
function (_React$Component) {
  _inheritsLoose(IntersectionRoot, _React$Component);

  function IntersectionRoot(props) {
    var _this;

    _this = _React$Component.call(this, props) || this;

    _defineProperty(_assertThisInitialized(_this), "intersectionObserver", void 0);

    _defineProperty(_assertThisInitialized(_this), "node", React.createRef());

    _this.initIntersectionObserver(_this.props);

    return _this;
  }

  var _proto = IntersectionRoot.prototype;

  _proto.componentDidUpdate = function componentDidUpdate(prevProps) {
    var _this$props = this.props,
        viewport = _this$props.viewport,
        margin = _this$props.margin,
        threshold = _this$props.threshold;
    var thresholdHasChanged = prevProps.threshold && threshold && deepCompareArray(prevProps.threshold, threshold);

    if (prevProps.viewport !== viewport || prevProps.margin !== margin || thresholdHasChanged) {
      this.initIntersectionObserver(this.props);
    }
  };

  _proto.componentWillUnmount = function componentWillUnmount() {
    if (this.intersectionObserver) {
      this.intersectionObserver.disconnect();
    }
  };

  _proto.initIntersectionObserver = function initIntersectionObserver(_ref) {
    var viewport = _ref.viewport,
        margin = _ref.margin,
        threshold = _ref.threshold;
    var root = viewport === true ? null : this.node.current;

    if (root && root instanceof HTMLElement || root === null) {
      var props = {
        root: root,
        rootMargin: margin,
        threshold: threshold
      };

      if (this.intersectionObserver) {
        this.intersectionObserver.reconnect(props);
      } else {
        this.intersectionObserver = new _intersectionObserver["default"](props);
      }
    }
  };

  _proto.render = function render() {
    var _this2 = this;

    var _this$props2 = this.props,
        children = _this$props2.children,
        viewport = _this$props2.viewport;
    var contextValue = {
      observe: function observe(child, onChange) {
        return _this2.intersectionObserver && _this2.intersectionObserver.observe(child, onChange);
      },
      unobserve: function unobserve(child) {
        return _this2.intersectionObserver && _this2.intersectionObserver.unobserve(child);
      }
    };
    return React.createElement(_intersectionRootContext.IntersectionRootContext.Provider, {
      value: contextValue
    }, viewport ? children : React.Children.only(React.cloneElement(children, {
      ref: function ref(node) {
        _this2.node.current = node;
        var ref = children.ref;

        if (typeof ref === 'function') {
          ref(node);
        } else if (ref !== null) {
          ref.current = node;
        }
      }
    })));
  };

  return IntersectionRoot;
}(React.Component);

exports["default"] = IntersectionRoot;

_defineProperty(IntersectionRoot, "defaultProps", {
  viewport: false
});