1/**
2@license
3Copyright (c) 2016 The Polymer Project Authors. All rights reserved.
4This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
5The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
6The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
7Code distributed by Google as part of the polymer project is also
8subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
9*/
10
11/*
12Example library for adding document-level styles to ShadyCSS
13
14After DOMContentLoaded, synchronously add all document document level styles.
15Then, start a MutationObserver for dynamically added styles.
16
17Caveat: ShadyCSS will add a `scope` attribute to styles it controls, so do not add those styles.
18*/
19(function() {
20  'use strict';
21
22  const CustomStyleInterface = window.ShadyCSS.CustomStyleInterface;
23
24  function shouldAddDocumentStyle(n) {
25    return n.nodeType === Node.ELEMENT_NODE && n.localName === 'style' && !n.hasAttribute('scope');
26  }
27
28  function handler(mxns) {
29    for (let i = 0; i < mxns.length; i++) {
30      let mxn = mxns[i];
31      for (let j = 0; j < mxn.addedNodes.length; j++) {
32        let n = mxn.addedNodes[j];
33        if (shouldAddDocumentStyle(n)) {
34          CustomStyleInterface.addCustomStyle(n);
35        }
36      }
37    }
38  }
39
40  const observer = new MutationObserver(handler);
41
42  document.addEventListener('DOMContentLoaded', () => {
43    const candidates = document.querySelectorAll('custom-style');
44    for (let i = 0; i < candidates.length; i++) {
45      const candidate = candidates[i];
46      if (shouldAddDocumentStyle(candidate)) {
47        CustomStyleInterface.addCustomStyle(candidate);
48      }
49    }
50    observer.observe(document, {childList: true, subtree: true});
51  });
52
53  window.documentStyleFlush = () => {handler(observer.takeRecords())};
54})();