react-behave/build/cjs/watchResize/watchResize.js

A library of behaviors for React applications.

"use strict";

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

var _lodash = _interopRequireDefault(require("lodash.throttle"));

var _resizeObserverPolyfill = _interopRequireDefault(require("resize-observer-polyfill"));

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

// Corresponds to 1 frame
var DEFAULT_RESIZE_INTERVAL = 16;

function watchResize(target, cb) {
  var _ref = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {},
      _ref$resizeInterval = _ref.resizeInterval,
      resizeInterval = _ref$resizeInterval === void 0 ? DEFAULT_RESIZE_INTERVAL : _ref$resizeInterval;

  function handleResize(entries) {
    if (entries.length) {
      cb(entries[0].contentRect);
    }
  }

  var observer = (0, _lodash["default"])(handleResize, resizeInterval);
  var resizeObserver = new _resizeObserverPolyfill["default"](observer);
  resizeObserver.observe(target);
  return function () {
    observer.cancel();
    resizeObserver.unobserve(target);
  };
}