@aimake/nanod/lib/_util/throttleByAnimationFrame.js

## 设计模式 NANO DESIGN 是面向于企业级中台化应用的解决方案。服务于 ToB 和 ToE 类型的单页应用，应用于各产品中从而产出了一套设计及前端规范。

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports["default"] = throttleByAnimationFrame;
exports.throttleByAnimationFrameDecorator = throttleByAnimationFrameDecorator;

var _raf = _interopRequireDefault(require("raf"));

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

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

function _nonIterableSpread() {
  throw new TypeError("Invalid attempt to spread non-iterable instance");
}

function _iterableToArray(iter) {
  if (Symbol.iterator in Object(iter) || Object.prototype.toString.call(iter) === "[object Arguments]") return Array.from(iter);
}

function _arrayWithoutHoles(arr) {
  if (Array.isArray(arr)) {
    for (var i = 0, arr2 = new Array(arr.length); i < arr.length; i++) {
      arr2[i] = arr[i];
    }return arr2;
  }
}

function throttleByAnimationFrame(fn) {
  var requestId;

  var later = function later(args) {
    return function () {
      requestId = null;
      fn.apply(void 0, _toConsumableArray(args));
    };
  };

  var throttled = function throttled() {
    if (requestId == null) {
      for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
        args[_key] = arguments[_key];
      }

      requestId = (0, _raf["default"])(later(args));
    }
  };

  throttled.cancel = function () {
    return _raf["default"].cancel(requestId);
  };

  return throttled;
}

function throttleByAnimationFrameDecorator() {
  return function (target, key, descriptor) {
    var fn = descriptor.value;
    var definingProperty = false;
    return {
      configurable: true,
      get: function get() {
        if (definingProperty || this === target.prototype || this.hasOwnProperty(key)) {
          return fn;
        }

        var boundFn = throttleByAnimationFrame(fn.bind(this));
        definingProperty = true;
        Object.defineProperty(this, key, {
          value: boundFn,
          configurable: true,
          writable: true
        });
        definingProperty = false;
        return boundFn;
      }
    };
  };
}