Blame view

node_modules/normalize-wheel/src/ExecutionEnvironment.js 1.1 KB
2a09d1a4   liuqimichale   添加宜春 天水 宣化
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
  /**
   * Copyright (c) 2015, Facebook, Inc.
   * All rights reserved.
   *
   * This source code is licensed under the BSD-style license found in the
   * LICENSE file in the root directory of this source tree. An additional grant
   * of patent rights can be found in the PATENTS file in the same directory.
   *
   * @providesModule ExecutionEnvironment
   */
  
  /*jslint evil: true */
  
  'use strict';
  
  var canUseDOM = !!(
    typeof window !== 'undefined' &&
    window.document &&
    window.document.createElement
  );
  
  /**
   * Simple, lightweight module assisting with the detection and context of
   * Worker. Helps avoid circular dependencies and allows code to reason about
   * whether or not they are in a Worker, even if they never include the main
   * `ReactWorker` dependency.
   */
  var ExecutionEnvironment = {
  
    canUseDOM: canUseDOM,
  
    canUseWorkers: typeof Worker !== 'undefined',
  
    canUseEventListeners:
      canUseDOM && !!(window.addEventListener || window.attachEvent),
  
    canUseViewport: canUseDOM && !!window.screen,
  
    isInWorker: !canUseDOM // For now, this is true - might change in the future.
  
  };
  
  module.exports = ExecutionEnvironment;