☰

SE Preview on hover

Shows preview of the linked questions/answers on hover

当前为 2020-11-14 提交的版本，查看 最新版本。

  1. // ==UserScript==
  2. // @name           SE Preview on hover
  3. // @description    Shows preview of the linked questions/answers on hover
  4. // @version        1.1.1
  5. // @author         wOxxOm
  6. // @namespace      wOxxOm.scripts
  7. // @license        MIT License
  8. //
  9. // please use only matches for the previewable targets and make sure the domain
  10. // is extractable via [-.\w] so that it starts with . like .stackoverflow.com
  11. // @match          *://*.stackoverflow.com/*
  12. // @match          *://*.superuser.com/*
  13. // @match          *://*.serverfault.com/*
  14. // @match          *://*.askubuntu.com/*
  15. // @match          *://*.stackapps.com/*
  16. // @match          *://*.mathoverflow.net/*
  17. // @match          *://*.stackexchange.com/*
  18. //
  19. // please use only includes for the container sites
  20. // @include        *://www.google.com/search*/
  21. // @include        /https?:\/\/(www\.)?google(\.com?)?(\.\w\w)?\/(webhp|q|.*?[?#]q=|search).*/
  22. // @include        *://*.bing.com/*
  23. // @include        *://*.yahoo.com/*
  24. // @include        /https?:\/\/(\w+\.)*yahoo.(com|\w\w(\.\w\w)?)\/.*/
  25. //
  26. // @require        https://greasyfork.org/scripts/27531/code/LZStringUnsafe.js
  27. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/highlight.min.js
  28. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/autohotkey.min.js
  29. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/autoit.min.js
  30. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/dart.min.js
  31. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/delphi.min.js
  32. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/haskell.min.js
  33. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/moonscript.min.js
  34. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/nsis.min.js
  35. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/powershell.min.js
  36. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/r.min.js
  37. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/vbnet.min.js
  38. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/vbscript-html.min.js
  39. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/vbscript.min.js
  40. // @require        https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/languages/x86asm.min.js
  41. // @resource       HL-style https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/styles/default.min.css
  42. // @resource       HL-style-dark https://cdnjs.cloudflare.com/ajax/libs/highlight.js/10.2.0/styles/atom-one-dark-reasonable.min.css
  43. //
  44. // @grant          GM_addStyle
  45. // @grant          GM_xmlhttpRequest
  46. // @grant          GM_getValue
  47. // @grant          GM_setValue
  48. // @grant          GM_getResourceText
  49. //
  50. // @connect        stackoverflow.com
  51. // @connect        superuser.com
  52. // @connect        serverfault.com
  53. // @connect        askubuntu.com
  54. // @connect        stackapps.com
  55. // @connect        mathoverflow.net
  56. // @connect        stackexchange.com
  57. // @connect        sstatic.net
  58. // @connect        gravatar.com
  59. // @connect        imgur.com
  60. // @connect        self
  61. //
  62. // @noframes
  63. // ==/UserScript==
  64.  
  65. /* global hljs LZStringUnsafe */
  66. 'use strict';
  67.  
  68. Promise.resolve().then(() => {
  69.   Detector.init();
  70.   Security.init();
  71.   Urler.init();
  72.   Cache.init();
  73. });
  74.  
  75. const PREVIEW_DELAY = 200;
  76. const AUTOHIDE_DELAY = 1000;
  77. const BUSY_CURSOR_DELAY = 300;
  78. // 1 minute for the recently active posts, scales up logarithmically
  79. const CACHE_DURATION = 60e3;
  80.  
  81. const PADDING = 24;
  82. const QUESTION_WIDTH = 677; // unconstrained width of a question's .post_text
  83. const ANSWER_WIDTH = 657; // unconstrained width of an answer's .post_text
  84. const WIDTH = Math.max(QUESTION_WIDTH, ANSWER_WIDTH) + PADDING * 2;
  85. const BORDER = 8;
  86. const TOP_BORDER = 24;
  87. const MIN_HEIGHT = 200;
  88. let colors;
  89. const COLORS_LIGHT = {
  90.   body: {
  91.     back: '#ffffff',
  92.     fore: '#000000',
  93.   },
  94.   question: {
  95.     back: '#5894d8',
  96.     fore: '#265184',
  97.     foreInv: '#fff',
  98.   },
  99.   answer: {
  100.     back: '#70c350',
  101.     fore: '#3f7722',
  102.     foreInv: '#fff',
  103.   },
  104.   deleted: {
  105.     back: '#cd9898',
  106.     fore: '#b56767',
  107.     foreInv: '#fff',
  108.   },
  109.   closed: {
  110.     back: '#ffce5d',
  111.     fore: '#c28800',
  112.     foreInv: '#fff',
  113.   },
  114. };
  115. const COLORS_DARK = {
  116.   body: {
  117.     back: '#222222',
  118.     fore: '#cccccc',
  119.   },
  120.   question: {
  121.     back: '#004696',
  122.     fore: '#6abaff',
  123.     foreInv: '#004696',
  124.   },
  125.   answer: {
  126.     back: '#004c1b',
  127.     fore: '#39c466',
  128.     foreInv: '#004c1b',
  129.   },
  130.   deleted: {
  131.     back: '#4d0a0b',
  132.     fore: '#b56767',
  133.     foreInv: '#fff',
  134.   },
  135.   closed: {
  136.     back: '#4b360a',
  137.     fore: '#c28800',
  138.     foreInv: '#fff',
  139.   },
  140. };
  141. const ID = 'SEpreview';
  142. const EXPANDO = Symbol(ID);
  143.  
  144. const pv = {
  145.   /** @type {Target} */
  146.   target: null,
  147.   /** @type {Element} */
  148.   _frame: null,
  149.   /** @type {Element} */
  150.   get frame() {
  151.     if (!this._frame)
  152.       Preview.init();
  153.     if (!document.contains(this._frame))
  154.       document.body.appendChild(this._frame);
  155.     return this._frame;
  156.   },
  157.   set frame(element) {
  158.     this._frame = element;
  159.     return element;
  160.   },
  161.   /** @type {Post} */
  162.   post: {},
  163.   hover: {x: 0, y: 0},
  164.   stylesOverride: '',
  165. };
  166.  
  167. class Detector {
  168.  
  169.   static init() {
  170.     const sites = GM_info.script.matches.map(m => m.match(/[-.\w]+/)[0]);
  171.     const rxsSites = 'https?://(\\w*\\.)*(' +
  172.       GM_info.script.matches
  173.         .map(m => m.match(/^.*?\/\/\W*(\w.*?)\//)[1].replace(/\./g, '\\.'))
  174.         .join('|') +
  175.       ')/';
  176.     Detector.rxPreviewableSite = new RegExp(rxsSites);
  177.     Detector.rxPreviewablePost = new RegExp(rxsSites + '(questions|q|a|posts/comments)/\\d+');
  178.     Detector.pageUrls = getBaseUrls(location, Detector.rxPreviewablePost);
  179.     Detector.isStackExchangePage = Detector.rxPreviewableSite.test(location);
  180.  
  181.     const {
  182.       rxPreviewablePost,
  183.       isStackExchangePage: isSE,
  184.       pageUrls: {base, baseShort},
  185.     } = Detector;
  186.  
  187.     // array of target elements accumulated in mutation observer
  188.     // cleared in attachHoverListener
  189.     const moQueue = [];
  190.  
  191.     onMutation([{
  192.       addedNodes: [document.body],
  193.     }]);
  194.  
  195.     new MutationObserver(onMutation)
  196.       .observe(document.body, {
  197.         childList: true,
  198.         subtree: true,
  199.       });
  200.  
  201.     Detector.init = true;
  202.  
  203.     function onMutation(mutations) {
  204.       const alreadyScheduled = moQueue.length > 0;
  205.       for (const {addedNodes} of mutations) {
  206.         for (const n of addedNodes) {
  207.           if (!n.localName)
  208.             continue;
  209.           if (n.localName === 'a') {
  210.             moQueue.push(n);
  211.             continue;
  212.           }
  213.           // not using ..spreading since there could be 100k links for all we know
  214.           // and that might exceed JS engine stack limit which can be pretty low
  215.           const targets = n.getElementsByTagName('a');
  216.           for (let k = 0, len = targets.length; k < len; k++)
  217.             moQueue.push(targets[k]);
  218.           if (!isSE)
  219.             continue;
  220.           if (n.classList.contains('question-summary')) {
  221.             moQueue.push(...n.getElementsByClassName('answered'));
  222.             moQueue.push(...n.getElementsByClassName('answered-accepted'));
  223.             continue;
  224.           }
  225.           for (const el of n.getElementsByClassName('question-summary')) {
  226.             moQueue.push(...el.getElementsByClassName('answered'));
  227.             moQueue.push(...el.getElementsByClassName('answered-accepted'));
  228.           }
  229.         }
  230.       }
  231.       if (!alreadyScheduled && moQueue.length)
  232.         setTimeout(hoverize);
  233.     }
  234.  
  235.     function hoverize() {
  236.       for (const el of moQueue) {
  237.         if (el[EXPANDO] instanceof Target)
  238.           continue;
  239.         if (el.localName === 'a') {
  240.           if (isSE && el.classList.contains('js-share-link'))
  241.             continue;
  242.           const previewable = isPreviewable(el) || !isSE && isEmbeddedUrlPreviewable(el);
  243.           if (!previewable)
  244.             continue;
  245.           const url = Urler.makeHttps(el.href);
  246.           if (url.startsWith(base) || url.startsWith(baseShort))
  247.             continue;
  248.         }
  249.         Target.createHoverable(el);
  250.       }
  251.       moQueue.length = 0;
  252.     }
  253.  
  254.     function isPreviewable(a) {
  255.       let href = false;
  256.       const host = '.' + a.hostname;
  257.       const hostLen = host.length;
  258.       for (const stackSite of sites) {
  259.         if (host[hostLen - stackSite.length] === '.' &&
  260.             host.endsWith(stackSite) &&
  261.             rxPreviewablePost.test(href || (href = a.href)))
  262.           return true;
  263.       }
  264.     }
  265.  
  266.     function isEmbeddedUrlPreviewable(a) {
  267.       const url = a.href;
  268.       let i = url.indexOf('http', 1);
  269.       if (i < 0)
  270.         return false;
  271.       i = (
  272.         url.indexOf('http://', i) + 1 ||
  273.         url.indexOf('https://', i) + 1 ||
  274.         url.indexOf('http%3A%2F%2F', i) + 1 ||
  275.         url.indexOf('https%3A%2F%2F', i) + 1
  276.       ) - 1;
  277.       if (i < 0)
  278.         return false;
  279.       const j = url.indexOf('&', i);
  280.       const embeddedUrl = url.slice(i, j > 0 ? j : undefined);
  281.       return rxPreviewablePost.test(embeddedUrl);
  282.     }
  283.  
  284.     function getBaseUrls(url, rx) {
  285.       if (!rx.test(url))
  286.         return {};
  287.       const base = Urler.makeHttps(RegExp.lastMatch);
  288.       return {
  289.         base,
  290.         baseShort: base.replace('/questions/', '/q/'),
  291.       };
  292.     }
  293.   }
  294. }
  295.  
  296. /**
  297.  * @property {Element} element
  298.  * @property {Boolean} isLink
  299.  * @property {String}  url
  300.  * @property {Number}  timer
  301.  * @property {Number}  timerCursor
  302.  * @property {String}  savedCursor
  303.  */
  304. class Target {
  305.  
  306.   /** @param {Element} el */
  307.   static createHoverable(el) {
  308.     const target = new Target(el);
  309.     Object.defineProperty(el, EXPANDO, {value: target});
  310.     el.removeAttribute('title');
  311.     el.addEventListener('mouseover', Target._onMouseOver);
  312.     return target;
  313.   }
  314.  
  315.   /** @param {Element} el */
  316.   constructor(el) {
  317.     this.element = el;
  318.     this.isLink = el.localName === 'a';
  319.   }
  320.  
  321.   release() {
  322.     $.off('mousemove', this.element, Target._onMove);
  323.     $.off('mouseout', this.element, Target._onHoverEnd);
  324.     $.off('mousedown', this.element, Target._onHoverEnd);
  325.  
  326.     for (const k in this) {
  327.       if (k.startsWith('timer') && this[k] >= 1) {
  328.         clearTimeout(this[k]);
  329.         this[k] = 0;
  330.       }
  331.     }
  332.     BusyCursor.hide(this);
  333.     pv.target = null;
  334.   }
  335.  
  336.   get url() {
  337.     const el = this.element;
  338.     if (this.isLink)
  339.       return el.href;
  340.     const a = $('a', el.closest('.question-summary'));
  341.     if (a)
  342.       return a.href;
  343.   }
  344.  
  345.   /** @param {MouseEvent} e */
  346.   static _onMouseOver(e) {
  347.     if (Util.hasKeyModifiers(e))
  348.       return;
  349.     const self = /** @type {Target} */ this[EXPANDO];
  350.     if (self === Preview.target && Preview.shown() ||
  351.         self === pv.target)
  352.       return;
  353.  
  354.     if (pv.target)
  355.       pv.target.release();
  356.     pv.target = self;
  357.  
  358.     pv.hover.x = e.pageX;
  359.     pv.hover.y = e.pageY;
  360.  
  361.     $.on('mousemove', this, Target._onMove);
  362.     $.on('mouseout', this, Target._onHoverEnd);
  363.     $.on('mousedown', this, Target._onHoverEnd);
  364.  
  365.     Target._restartTimer(self);
  366.   }
  367.  
  368.   /** @param {MouseEvent} e */
  369.   static _onHoverEnd(e) {
  370.     if (e.type === 'mouseout' && e.target !== this)
  371.       return;
  372.     const self = /** @type {Target} */ this[EXPANDO];
  373.     if (pv.xhr && pv.target === self) {
  374.       pv.xhr.abort();
  375.       pv.xhr = null;
  376.     }
  377.     self.release();
  378.     self.timer = setTimeout(Target._onAbortTimer, AUTOHIDE_DELAY, self);
  379.   }
  380.  
  381.   /** @param {MouseEvent} e */
  382.   static _onMove(e) {
  383.     const stoppedMoving =
  384.       Math.abs(pv.hover.x - e.pageX) < 2 &&
  385.       Math.abs(pv.hover.y - e.pageY) < 2;
  386.     if (stoppedMoving) {
  387.       pv.hover.x = e.pageX;
  388.       pv.hover.y = e.pageY;
  389.       Target._restartTimer(this[EXPANDO]);
  390.     }
  391.   }
  392.  
  393.   /** @param {Target} self */
  394.   static _restartTimer(self) {
  395.     if (self.timer)
  396.       clearTimeout(self.timer);
  397.     self.timer = setTimeout(Target._onTimer, PREVIEW_DELAY, self);
  398.   }
  399.  
  400.   /** @param {Target} self */
  401.   static _onTimer(self) {
  402.     self.timer = 0;
  403.     const el = self.element;
  404.     if (!el.matches(':hover')) {
  405.       self.release();
  406.       return;
  407.     }
  408.     $.off('mousemove', el, Target._onMove);
  409.  
  410.     if (self.url)
  411.       Preview.start(self);
  412.   }
  413.  
  414.   /** @param {Target} self */
  415.   static _onAbortTimer(self) {
  416.     if ((self === pv.target || self === Preview.target) &&
  417.         pv.frame && !pv.frame.matches(':hover')) {
  418.       pv.target = null;
  419.       Preview.hide({fade: true});
  420.     }
  421.   }
  422. }
  423.  
  424.  
  425. class BusyCursor {
  426.  
  427.   /** @param {Target} target */
  428.   static schedule(target) {
  429.     target.timerCursor = setTimeout(BusyCursor._onTimer, BUSY_CURSOR_DELAY, target);
  430.   }
  431.  
  432.   /** @param {Target} target */
  433.   static hide(target) {
  434.     if (target.timerCursor) {
  435.       clearTimeout(target.timerCursor);
  436.       target.timerCursor = 0;
  437.     }
  438.     const style = target.element.style;
  439.     if (style.cursor === 'wait')
  440.       style.cursor = target.savedCursor;
  441.   }
  442.  
  443.   /** @param {Target} target */
  444.   static _onTimer(target) {
  445.     target.timerCursor = 0;
  446.     target.savedCursor = target.element.style.cursor;
  447.     $.setStyle(target.element, ['cursor', 'wait']);
  448.   }
  449. }
  450.  
  451.  
  452. class Preview {
  453.  
  454.   static init() {
  455.     pv.frame = $.create(`#${ID}`, {parent: document.body});
  456.     pv.shadow = pv.frame.attachShadow({mode: 'open'});
  457.     pv.body = $.create(`body#${ID}-body`, {parent: pv.shadow});
  458.  
  459.     const WRAP_AROUND = '(or wrap around to the question)';
  460.     const TITLE_PREV = 'Previous answer\n' + WRAP_AROUND;
  461.     const TITLE_NEXT = 'Next answer\n' + WRAP_AROUND;
  462.     const TITLE_ENTER = 'Return to the question\n(Enter was Return initially)';
  463.  
  464.     pv.answersTitle =
  465.       $.create(`#${ID}-answers-title`, [
  466.         'Answers:',
  467.         $.create('p', [
  468.           'Use ',
  469.           $.create('b', {title: TITLE_PREV}),
  470.           $.create('b', {title: TITLE_NEXT, attributes: {mirrored: ''}}),
  471.           $.create('label', {title: TITLE_ENTER}, 'Enter'),
  472.           ' to switch entries',
  473.         ]),
  474.       ]);
  475.  
  476.     $.on('keydown', pv.frame, Preview.onKey);
  477.     $.on('keyup', pv.frame, Util.consumeEsc);
  478.  
  479.     $.on('mouseover', pv.body, ScrollLock.enable);
  480.     $.on('click', pv.body, Preview.onClick);
  481.  
  482.     Sizer.init();
  483.     Styles.init();
  484.     Preview.init = true;
  485.   }
  486.  
  487.   /** @param {Target} target */
  488.   static async start(target) {
  489.     Preview.target = target;
  490.  
  491.     if (!Security.checked)
  492.       Security.check();
  493.  
  494.     const {url} = target;
  495.  
  496.     let data = Cache.read(url);
  497.     if (data) {
  498.       const r = await Urler.get(url, {method: 'HEAD'});
  499.       const postTime = Util.getResponseDate(r.responseHeaders);
  500.       if (postTime >= data.time)
  501.         data = null;
  502.     }
  503.  
  504.     if (!data) {
  505.       BusyCursor.schedule(target);
  506.       const {finalUrl, responseText: html} = await Urler.get(target.url);
  507.       data = {finalUrl, html, unsaved: true};
  508.       BusyCursor.hide(target);
  509.     }
  510.  
  511.     data.url = url;
  512.     data.showAnswer = !target.isLink;
  513.  
  514.     if (!Preview.prepare(data))
  515.       Preview.target = null;
  516.     else if (data.unsaved && data.lastActivity >= 1)
  517.       Preview.save(data);
  518.   }
  519.  
  520.   static save({url, finalUrl, html, lastActivity}) {
  521.     const inactiveDays = Math.max(0, (Date.now() - lastActivity) / (24 * 3600e3));
  522.     const cacheDuration = CACHE_DURATION * Math.pow(Math.log(inactiveDays + 1) + 1, 2);
  523.     setTimeout(Cache.write, 1000, {url, finalUrl, html, cacheDuration});
  524.   }
  525.  
  526.   // data is mutated: its lastActivity property is assigned!
  527.   static prepare(data) {
  528.     const {finalUrl, html, showAnswer, doc = Util.parseHtml(html)} = data;
  529.  
  530.     if (!doc || !doc.head)
  531.       return Util.error('no HEAD in the document received for', finalUrl);
  532.  
  533.     if (!$('base', doc))
  534.       $.create('base', {href: finalUrl, parent: doc.head});
  535.  
  536.     let answerId;
  537.     if (showAnswer) {
  538.       const el = $('[id^="answer-"]', doc);
  539.       answerId = el && el.id.match(/\d+/)[0];
  540.     } else {
  541.       answerId = finalUrl.match(/questions\/\d+\/[^/]+\/(\d+)|$/)[1];
  542.     }
  543.     const selector = answerId ? '#answer-' + answerId : '#question';
  544.     const core = $(`${selector} .${answerId ? 'answer' : 'post'}cell`, doc);
  545.     if (!core)
  546.       return Util.error('No parsable post found', doc);
  547.  
  548.     const isQuestion = !answerId;
  549.     const status = isQuestion && $('[role="status"]', core);
  550.     const isClosed = status && $('[href*="closed"]', status);
  551.     const isDeleted = Boolean(core.closest('.deleted-answer'));
  552.     const type = [
  553.       isQuestion && 'question' || 'answer',
  554.       isDeleted && 'deleted',
  555.       isClosed && 'closed',
  556.     ].filter(Boolean).join(' ');
  557.     const answers = $.all('.answer', doc);
  558.     const comments = $(`${selector} .comments`, doc);
  559.     const commentsParent = comments.parentElement;
  560.     const showMoreComments = $(`${selector} .js-show-link.comments-link`, doc);
  561.     const lastActivity = Util.tryCatch(Util.extractTime, $('a[href*="?lastactivity"]', core)) ||
  562.                          Date.now();
  563.     Object.assign(pv, {
  564.       finalUrl,
  565.       finalUrlOfQuestion: Urler.makeCacheable(finalUrl),
  566.     });
  567.     /** @typedef Post
  568.      * @property {Document}  doc
  569.      * @property {String}    html
  570.      * @property {String}    selector
  571.      * @property {String}    type
  572.      * @property {String}    id
  573.      * @property {String}    title
  574.      * @property {Boolean}   isQuestion
  575.      * @property {Boolean}   isDeleted
  576.      * @property {Number}    lastActivity
  577.      * @property {Number}    numAnswers
  578.      * @property {Element}   core
  579.      * @property {Element}   comments
  580.      * @property {Element[]} answers
  581.      * @property {Element[]} renderParts
  582.      */
  583.     Object.assign(pv.post, {
  584.       doc,
  585.       html,
  586.       core,
  587.       selector,
  588.       answers,
  589.       comments,
  590.       type,
  591.       isQuestion,
  592.       isDeleted,
  593.       lastActivity,
  594.       id: isQuestion ? Urler.getFirstNumber(finalUrl) : answerId,
  595.       title: $('meta[property="og:title"]', doc).content,
  596.       numAnswers: answers.length,
  597.       renderParts: [
  598.         // including the parent so the right CSS kicks in
  599.         core,
  600.         commentsParent,
  601.       ],
  602.     });
  603.  
  604.     $.remove('script', doc);
  605.     // remove the comment actions block
  606.     $.remove('.comment-form, [id^="comments-link-"], .hover-only-label', commentsParent);
  607.     if (!commentsParent.contains(showMoreComments))
  608.       commentsParent.appendChild(showMoreComments);
  609.  
  610.     Promise.all([
  611.       pv.frame,
  612.       Preview.addStyles(),
  613.       Security.ready(),
  614.     ]).then(Preview.show);
  615.  
  616.     data.lastActivity = lastActivity;
  617.     return true;
  618.   }
  619.  
  620.   static show() {
  621.     Render.all();
  622.  
  623.     const style = getComputedStyle(pv.frame);
  624.     if (style.opacity !== '1' || style.display !== 'block') {
  625.       $.setStyle(pv.frame, ['display', 'block']);
  626.       setTimeout($.setStyle, 0, pv.frame, ['opacity', '1']);
  627.     }
  628.  
  629.     pv.parts.focus();
  630.   }
  631.  
  632.   static hide({fade = false} = {}) {
  633.     if (Preview.target) {
  634.       Preview.target.release();
  635.       Preview.target = null;
  636.     }
  637.  
  638.     pv.body.onmouseover = null;
  639.     pv.body.onclick = null;
  640.     pv.body.onkeydown = null;
  641.  
  642.     if (fade) {
  643.       Util.fadeOut(pv.frame)
  644.         .then(Preview.eraseBoxIfHidden);
  645.     } else {
  646.       $.setStyle(pv.frame,
  647.         ['opacity', '0'],
  648.         ['display', 'none']);
  649.       Preview.eraseBoxIfHidden();
  650.     }
  651.   }
  652.  
  653.   static shown() {
  654.     return pv.frame.style.opacity === '1';
  655.   }
  656.  
  657.   /** @param {KeyboardEvent} e */
  658.   static onKey(e) {
  659.     switch (e.key) {
  660.       case 'Escape':
  661.         Preview.hide({fade: true});
  662.         break;
  663.       case 'ArrowUp':
  664.       case 'PageUp':
  665.         if (pv.parts.scrollTop)
  666.           return;
  667.         break;
  668.       case 'ArrowDown':
  669.       case 'PageDown': {
  670.         const {scrollTop: t, clientHeight: h, scrollHeight} = pv.parts;
  671.         if (t + h < scrollHeight)
  672.           return;
  673.         break;
  674.       }
  675.       case 'ArrowLeft':
  676.       case 'ArrowRight': {
  677.         if (!pv.post.numAnswers)
  678.           return;
  679.         // current is 0 if isQuestion, 1 is the first answer
  680.         const answers = $.all(`#${ID}-answers a`);
  681.         const current = pv.post.numAnswers ?
  682.           answers.indexOf($('.SEpreviewed')) + 1 :
  683.           pv.post.isQuestion ? 0 : 1;
  684.         const num = pv.post.numAnswers + 1;
  685.         const dir = e.key === 'ArrowLeft' ? -1 : 1;
  686.         const toShow = (current + dir + num) % num;
  687.         const a = toShow ? answers[toShow - 1] : $(`#${ID}-title`);
  688.         a.click();
  689.         break;
  690.       }
  691.       case 'Enter':
  692.         if (pv.post.isQuestion)
  693.           return;
  694.         $(`#${ID}-title`).click();
  695.         break;
  696.       default:
  697.         return;
  698.     }
  699.     e.preventDefault();
  700.   }
  701.  
  702.   /** @param {MouseEvent} e */
  703.   static onClick(e) {
  704.     if (e.target.id === `${ID}-close`) {
  705.       Preview.hide();
  706.       return;
  707.     }
  708.  
  709.     const link = e.target.closest('a');
  710.     if (!link)
  711.       return;
  712.  
  713.     if (link.matches('.js-show-link.comments-link')) {
  714.       Util.fadeOut(link, 0.5);
  715.       Preview.loadComments();
  716.       e.preventDefault();
  717.       return;
  718.     }
  719.  
  720.     if (e.button ||
  721.         Util.hasKeyModifiers(e) ||
  722.         !link.matches('.SEpreviewable')) {
  723.       link.target = '_blank';
  724.       return;
  725.     }
  726.  
  727.     e.preventDefault();
  728.  
  729.     const {doc} = pv.post;
  730.     if (link.id === `${ID}-title`)
  731.       Preview.prepare({doc, finalUrl: pv.finalUrlOfQuestion});
  732.     else if (link.matches(`#${ID}-answers a`))
  733.       Preview.prepare({doc, finalUrl: pv.finalUrlOfQuestion + '/' + Urler.getFirstNumber(link)});
  734.     else
  735.       Preview.start(new Target(link));
  736.   }
  737.  
  738.   static eraseBoxIfHidden() {
  739.     if (!Preview.shown())
  740.       pv.body.textContent = '';
  741.   }
  742.  
  743.   static setHeight(height) {
  744.     const currentHeight = pv.frame.clientHeight;
  745.     const borderHeight = pv.frame.offsetHeight - currentHeight;
  746.     const newHeight = Math.max(MIN_HEIGHT, Math.min(innerHeight - borderHeight, height));
  747.     if (newHeight !== currentHeight)
  748.       $.setStyle(pv.frame, ['height', newHeight + 'px']);
  749.   }
  750.  
  751.   static async addStyles() {
  752.     const isDark = matchMedia('(prefers-color-scheme: dark)').matches;
  753.     colors = isDark ? COLORS_DARK : COLORS_LIGHT;
  754.     pv.body.className = isDark ? 'theme-dark' : '';
  755.     Styles.init(isDark);
  756.  
  757.     let last = $.create(`style#${ID}-styles.${Styles.REUSABLE}`, {
  758.       textContent: pv.stylesOverride,
  759.       before: pv.shadow.firstChild,
  760.     });
  761.  
  762.     if (!pv.styles) {
  763.       pv.styles = new Map();
  764.       pv.stylesScaled = new Set();
  765.     }
  766.  
  767.     const toDownload = [];
  768.     const sourceElements = $.all('link[rel="stylesheet"], style', pv.post.doc);
  769.  
  770.     for (const {href, textContent, localName} of sourceElements) {
  771.       const isLink = localName === 'link';
  772.       const id = ID + '-style-' + (isLink ? href : await Util.sha256(textContent));
  773.       const el = pv.styles.get(id);
  774.       if (!el && isLink)
  775.         toDownload.push(Urler.get({url: href, context: id}));
  776.       last = $.create('style', {
  777.         id,
  778.         className: Styles.REUSABLE,
  779.         textContent: isLink ? $.text(el) : textContent,
  780.         after: last,
  781.       });
  782.       pv.styles.set(id, last);
  783.     }
  784.  
  785.     const downloaded = await Promise.all(toDownload);
  786.  
  787.     for (const {responseText, context: id} of downloaded)
  788.       Styles.applyRemScale(id, responseText);
  789.  
  790.     if (!pv.remScale) {
  791.       pv.remScale = parseFloat(getComputedStyle(pv.body).fontSize) /
  792.                     parseFloat(getComputedStyle(document.documentElement).fontSize);
  793.       if (pv.remScale !== 1)
  794.         for (const id of pv.styles.keys())
  795.           Styles.applyRemScale(id);
  796.     }
  797.   }
  798.  
  799.   static async loadComments() {
  800.     const list = $(`#${pv.post.comments.id} .comments-list`);
  801.     const url = new URL(pv.finalUrl).origin +
  802.                 '/posts/' + pv.post.comments.id.match(/\d+/)[0] + '/comments';
  803.     list.innerHTML = (await Urler.get(url)).responseText;
  804.     $.remove('.hover-only-label', list);
  805.  
  806.     const oldIds = new Set([...list.children].map(e => e.id));
  807.     for (const cmt of list.children) {
  808.       if (!oldIds.has(cmt.id))
  809.         cmt.classList.add('new-comment-highlight');
  810.     }
  811.  
  812.     $.setStyle(list.closest('.comments'), ['display', 'block']);
  813.     Render.previewableLinks(list);
  814.     Render.hoverableUsers(list);
  815.   }
  816. }
  817.  
  818.  
  819. class Render {
  820.  
  821.   static all() {
  822.     pv.frame.classList.toggle(`${ID}-hasAnswerShelf`, pv.post.numAnswers > 0);
  823.     pv.frame.setAttribute(`${ID}-type`, pv.post.type);
  824.     pv.body.setAttribute(`${ID}-type`, pv.post.type);
  825.  
  826.     $.create(`a#${ID}-title.SEpreviewable`, {
  827.       href: pv.finalUrlOfQuestion,
  828.       textContent: pv.post.title,
  829.       parent: pv.body,
  830.     });
  831.  
  832.     $.create(`#${ID}-close`, {
  833.       title: 'Or press Esc key while the preview is focused (also when just shown)',
  834.       parent: pv.body,
  835.     });
  836.  
  837.     $.create(`#${ID}-meta`, {
  838.       parent: pv.body,
  839.       onmousedown: Sizer.onMouseDown,
  840.       children: [
  841.         Render._votes(),
  842.         pv.post.isQuestion
  843.           ? Render._questionMeta()
  844.           : Render._answerMeta(),
  845.       ],
  846.     });
  847.  
  848.     Render.previewableLinks(pv.post.doc);
  849.  
  850.     pv.post.answerShelf = pv.post.answers.map(Render._answer);
  851.     if (Security.noImages)
  852.       Security.embedImages(...pv.post.renderParts);
  853.  
  854.     pv.parts = $.create(`#${ID}-parts`, {
  855.       className: pv.post.isDeleted ? 'deleted-answer' : '',
  856.       tabIndex: 0,
  857.       scrollTop: 0,
  858.       parent: pv.body,
  859.       children: pv.post.renderParts,
  860.     });
  861.  
  862.     Render.hoverableUsers(pv.parts);
  863.  
  864.     if (pv.post.numAnswers) {
  865.       $.create(`#${ID}-answers`, {parent: pv.body}, [
  866.         pv.answersTitle,
  867.         pv.post.answerShelf,
  868.       ]);
  869.     } else {
  870.       $.remove(`#${ID}-answers`, pv.body);
  871.     }
  872.  
  873.     // delinkify/remove non-functional items in post-menu
  874.     $.remove('.js-share-link, .flag-post-link', pv.body);
  875.     for (const a of $.all('.post-menu a:not(.edit-post)')) {
  876.       if (a.children.length)
  877.         $.create('span', {before: a}, a.childNodes);
  878.       a.remove();
  879.     }
  880.  
  881.     // add a timeline link
  882.     $.appendChildren($('.post-menu'), [
  883.       $.create('span.lsep'),
  884.       $.create('a', {href: `/posts/${pv.post.id}/timeline`}, 'timeline'),
  885.     ]);
  886.  
  887.     // prettify code blocks
  888.     hljs.configure({
  889.       languages: $.all('.post-taglist .post-tag', pv.post.doc).map($.text),
  890.     });
  891.     $.all('pre > code').forEach(el => {
  892.       el = el.parentElement;
  893.       el.className = el.className.replace(/((?:^|\s)lang-)bsh(?=\s|$)/, '$1powershell');
  894.       hljs.highlightBlock(el);
  895.     });
  896.  
  897.     const leftovers = $.all('style, link, script, .post-menu .lsep + .lsep');
  898.     for (const el of leftovers) {
  899.       if (el.classList.contains(Styles.REUSABLE))
  900.         el.classList.remove(Styles.REUSABLE);
  901.       else
  902.         el.remove();
  903.     }
  904.  
  905.     pv.post.html = null;
  906.     pv.post.core = null;
  907.     pv.post.renderParts = null;
  908.     pv.post.answers = null;
  909.     pv.post.answerShelf = null;
  910.   }
  911.  
  912.   /** @param {Element} container */
  913.   static previewableLinks(container) {
  914.     for (const a of $.all('a:not(.SEpreviewable)', container)) {
  915.       let href = a.getAttribute('href');
  916.       if (!href)
  917.         continue;
  918.       if (!href.includes('://')) {
  919.         href = a.href;
  920.         a.setAttribute('href', href);
  921.       }
  922.       if (Detector.rxPreviewablePost.test(href)) {
  923.         a.removeAttribute('title');
  924.         a.classList.add('SEpreviewable');
  925.       }
  926.     }
  927.   }
  928.  
  929.   /** @param {Element} container */
  930.   static hoverableUsers(container) {
  931.     for (const a of $.all('a[href*="/users/"]', container)) {
  932.       if (Detector.rxPreviewableSite.test(a.href) &&
  933.           a.pathname.match(/^\/users\/\d+/)) {
  934.         a.onmouseover = UserCard.onUserLinkHovered;
  935.         a.classList.add(`${ID}-userLink`);
  936.       }
  937.     }
  938.   }
  939.  
  940.   /** @param {Element} el */
  941.   static _answer(el) {
  942.     const shortUrl = $('.js-share-link', el).href.replace(/(\d+)\/\d+/, '$1');
  943.     const extraClasses =
  944.       (el.matches(pv.post.selector) ? ' SEpreviewed' : '') +
  945.       (el.matches('.deleted-answer') ? ' deleted-answer' : '') +
  946.       (el.matches('.accepted-answer') ? ` ${ID}-accepted` : '');
  947.     const author = $('.post-signature:last-child', el);
  948.     const title =
  949.       $.text('.user-details a', author) +
  950.       ' (rep ' +
  951.       $.text('.reputation-score', author) +
  952.       ')\n' +
  953.       $.text('.user-action-time', author);
  954.     let gravatar = $('img, .anonymous-gravatar, .community-wiki', author);
  955.     if (gravatar && Security.noImages)
  956.       Security.embedImages(gravatar);
  957.     if (gravatar && gravatar.src)
  958.       gravatar = $.create('img', {src: gravatar.src});
  959.     const a = $.create('a', {
  960.       href: shortUrl,
  961.       title: title,
  962.       className: 'SEpreviewable' + extraClasses,
  963.       textContent: $.text('.js-vote-count', el).replace(/^0$/, '\xA0') + ' ',
  964.       children: gravatar,
  965.     });
  966.     return [a, ' '];
  967.   }
  968.  
  969.   static _votes() {
  970.     const votes = $.text('.js-vote-count', pv.post.core.closest('.post-layout'));
  971.     if (Number(votes))
  972.       return $.create('b', `${votes} vote${Math.abs(votes) >= 2 ? 's' : ''}`);
  973.   }
  974.   static _questionMeta() {
  975.     try {
  976.       return [...$('time', pv.post.doc).closest('.grid').children]
  977.         .map(el => el.textContent.trim())
  978.         .map((s, i) => (i ? s.toLowerCase() : s))
  979.         .join(', ');
  980.     } catch (e) {
  981.       return '';
  982.     }
  983.   }
  984.  
  985.   static _answerMeta() {
  986.     return $.all('.user-action-time', pv.post.core.closest('.answer'))
  987.       .reverse()
  988.       .map($.text)
  989.       .join(', ');
  990.   }
  991. }
  992.  
  993.  
  994. class UserCard {
  995.  
  996.   _fadeIn() {
  997.     this._retakeId(this);
  998.     $.setStyle(this.element,
  999.       ['opacity', '0'],
  1000.       ['display', 'block']);
  1001.     this.timer = setTimeout(() => {
  1002.       if (this.timer)
  1003.         $.setStyle(this.element, ['opacity', '1']);
  1004.     });
  1005.   }
  1006.  
  1007.   _retakeId() {
  1008.     if (this.element.id !== 'user-menu') {
  1009.       const oldCard = $('#user-menu');
  1010.       if (oldCard)
  1011.         oldCard.id = oldCard.style.display = '';
  1012.       this.element.id = 'user-menu';
  1013.     }
  1014.   }
  1015.  
  1016.   // 'this' is the hoverable link enclosing the user's name/avatar
  1017.   static onUserLinkHovered() {
  1018.     clearTimeout(this[EXPANDO]);
  1019.     this[EXPANDO] = setTimeout(UserCard._show, PREVIEW_DELAY * 2, this);
  1020.   }
  1021.  
  1022.   /** @param {HTMLAnchorElement} a */
  1023.   static async _show(a) {
  1024.     if (!a.matches(':hover'))
  1025.       return;
  1026.     const el = a.nextElementSibling;
  1027.     const card = el && el.matches(`.${ID}-userCard`) && el[EXPANDO] ||
  1028.                  await UserCard._create(a);
  1029.     card._fadeIn();
  1030.   }
  1031.  
  1032.   /** @param {HTMLAnchorElement} a */
  1033.   static async _create(a) {
  1034.     const url = a.origin + '/users/user-info/' + Urler.getFirstNumber(a);
  1035.     let {html} = Cache.read(url) || {};
  1036.     if (!html) {
  1037.       html = (await Urler.get(url)).responseText;
  1038.       Cache.write({url, html, cacheDuration: CACHE_DURATION * 100});
  1039.     }
  1040.  
  1041.     const dom = Util.parseHtml(html);
  1042.     if (Security.noImages)
  1043.       Security.embedImages(dom);
  1044.  
  1045.     const b = a.getBoundingClientRect();
  1046.     const pb = pv.parts.getBoundingClientRect();
  1047.     const left = Math.min(b.left - 20, pb.right - 350) - pb.left + 'px';
  1048.     const isClipped = b.bottom + 100 > pb.bottom;
  1049.  
  1050.     const el = $.create(`#user-menu-tmp.${ID}-userCard`, {
  1051.       attributes: {
  1052.         style: `left: ${left} !important;` +
  1053.                (isClipped ? 'margin-top: -5rem !important;' : ''),
  1054.       },
  1055.       onmouseout: UserCard._onMouseOut,
  1056.       children: dom.body.children,
  1057.       after: a,
  1058.     });
  1059.  
  1060.     const card = new UserCard(el);
  1061.     Object.defineProperty(el, EXPANDO, {value: card});
  1062.     card.element = el;
  1063.     return card;
  1064.   }
  1065.  
  1066.   /** @param {MouseEvent} e */
  1067.   static _onMouseOut(e) {
  1068.     if (this.matches(':hover') ||
  1069.         this.style.opacity === '0' /* fading out already */)
  1070.       return;
  1071.  
  1072.     const self = /** @type {UserCard} */ this[EXPANDO];
  1073.     clearTimeout(self.timer);
  1074.     self.timer = 0;
  1075.  
  1076.     Util.fadeOut(this);
  1077.   }
  1078. }
  1079.  
  1080.  
  1081. class Sizer {
  1082.  
  1083.   static init() {
  1084.     Preview.setHeight(GM_getValue('height', innerHeight / 3) >> 0);
  1085.   }
  1086.  
  1087.   /** @param {MouseEvent} e */
  1088.   static onMouseDown(e) {
  1089.     if (e.button !== 0 || Util.hasKeyModifiers(e))
  1090.       return;
  1091.     Sizer._heightDelta = innerHeight - e.clientY - pv.frame.clientHeight;
  1092.     $.on('mousemove', document, Sizer._onMouseMove);
  1093.     $.on('mouseup', document, Sizer._onMouseUp);
  1094.   }
  1095.  
  1096.   /** @param {MouseEvent} e */
  1097.   static _onMouseMove(e) {
  1098.     Preview.setHeight(innerHeight - e.clientY - Sizer._heightDelta);
  1099.     getSelection().removeAllRanges();
  1100.   }
  1101.  
  1102.   /** @param {MouseEvent} e */
  1103.   static _onMouseUp(e) {
  1104.     GM_setValue('height', pv.frame.clientHeight);
  1105.     $.off('mouseup', document, Sizer._onMouseUp);
  1106.     $.off('mousemove', document, Sizer._onMouseMove);
  1107.   }
  1108. }
  1109.  
  1110.  
  1111. class ScrollLock {
  1112.  
  1113.   static enable() {
  1114.     if (ScrollLock.active)
  1115.       return;
  1116.     ScrollLock.active = true;
  1117.     ScrollLock.x = scrollX;
  1118.     ScrollLock.y = scrollY;
  1119.     $.on('mouseover', document.body, ScrollLock._onMouseOver);
  1120.     $.on('scroll', document, ScrollLock._onScroll);
  1121.   }
  1122.  
  1123.   static disable() {
  1124.     ScrollLock.active = false;
  1125.     $.off('mouseover', document.body, ScrollLock._onMouseOver);
  1126.     $.off('scroll', document, ScrollLock._onScroll);
  1127.   }
  1128.  
  1129.   static _onMouseOver() {
  1130.     if (ScrollLock.active)
  1131.       ScrollLock.disable();
  1132.   }
  1133.  
  1134.   static _onScroll() {
  1135.     scrollTo(ScrollLock.x, ScrollLock.y);
  1136.   }
  1137. }
  1138.  
  1139.  
  1140. class Security {
  1141.  
  1142.   static init() {
  1143.     if (Detector.isStackExchangePage) {
  1144.       Security.checked = true;
  1145.       Security.check = null;
  1146.     }
  1147.     Security.init = true;
  1148.   }
  1149.  
  1150.   static async check() {
  1151.     Security.noImages = false;
  1152.     Security._resolveOnReady = [];
  1153.     Security._imageCache = new Map();
  1154.  
  1155.     const {headers} = await fetch(location.href, {
  1156.       method: 'HEAD',
  1157.       cache: 'force-cache',
  1158.       mode: 'same-origin',
  1159.       credentials: 'same-origin',
  1160.     });
  1161.     const csp = headers.get('Content-Security-Policy');
  1162.     const imgSrc = /(?:^|[\s;])img-src\s+([^;]+)/i.test(csp) && RegExp.$1.trim();
  1163.     if (imgSrc)
  1164.       Security.noImages = !/(^\s)(\*|https?:)(\s|$)/.test(imgSrc);
  1165.  
  1166.     Security._resolveOnReady.forEach(fn => fn());
  1167.     Security._resolveOnReady = null;
  1168.     Security.checked = true;
  1169.     Security.check = null;
  1170.   }
  1171.  
  1172.   /** @return Promise<void> */
  1173.   static ready() {
  1174.     return Security.checked ?
  1175.       Promise.resolve() :
  1176.       new Promise(done => Security._resolveOnReady.push(done));
  1177.   }
  1178.  
  1179.   static embedImages(...containers) {
  1180.     for (const container of containers) {
  1181.       if (!container)
  1182.         continue;
  1183.       if (Util.isIterable(container)) {
  1184.         Security.embedImages(...container);
  1185.         continue;
  1186.       }
  1187.       if (container.localName === 'img') {
  1188.         Security._embedImage(container);
  1189.         continue;
  1190.       }
  1191.       for (const img of container.getElementsByTagName('img'))
  1192.         Security._embedImage(img);
  1193.     }
  1194.   }
  1195.  
  1196.   static _embedImage(img) {
  1197.     const src = img.src;
  1198.     if (!src || src.startsWith('data:'))
  1199.       return;
  1200.     const data = Security._imageCache.get(src);
  1201.     const alreadyFetching = Array.isArray(data);
  1202.     if (alreadyFetching) {
  1203.       data.push(img);
  1204.     } else if (data) {
  1205.       img.src = data;
  1206.       return;
  1207.     } else {
  1208.       Security._imageCache.set(src, [img]);
  1209.       Security._fetchImage(src);
  1210.     }
  1211.     $.setStyle(img, ['visibility', 'hidden']);
  1212.     img.dataset.src = src;
  1213.     img.removeAttribute('src');
  1214.   }
  1215.  
  1216.   static async _fetchImage(src) {
  1217.     const r = await Urler.get({url: src, responseType: 'blob'});
  1218.     const type = Util.getResponseMimeType(r.responseHeaders);
  1219.     const blob = r.response;
  1220.     const blobType = blob.type;
  1221.     let dataUri = await Util.blobToBase64(blob);
  1222.     if (blobType !== type)
  1223.       dataUri = 'data:' + type + dataUri.slice(dataUri.indexOf(';'));
  1224.  
  1225.     const images = Security._imageCache.get(src);
  1226.     Security._imageCache.set(src, dataUri);
  1227.  
  1228.     let detached = false;
  1229.     for (const el of images) {
  1230.       el.src = dataUri;
  1231.       el.style.removeProperty('visibility');
  1232.       if (!detached && el.ownerDocument !== document)
  1233.         detached = true;
  1234.     }
  1235.  
  1236.     if (detached) {
  1237.       for (const el of $.all(`img[data-src="${src}"]`)) {
  1238.         el.src = dataUri;
  1239.         el.style.removeProperty('visibility');
  1240.       }
  1241.     }
  1242.   }
  1243. }
  1244.  
  1245.  
  1246. // eslint-disable-next-line no-redeclare
  1247. class Cache {
  1248.  
  1249.   static init() {
  1250.     Cache.timers = new Map();
  1251.     setTimeout(Cache._cleanup, 10e3);
  1252.   }
  1253.  
  1254.   static read(url) {
  1255.     const keyUrl = Urler.makeCacheable(url);
  1256.     const [time, expires, finalUrl = url] = (localStorage[keyUrl] || '').split('\t');
  1257.     const keyFinalUrl = Urler.makeCacheable(finalUrl);
  1258.     return expires > Date.now() && {
  1259.       time,
  1260.       finalUrl,
  1261.       html: LZStringUnsafe.decompressFromUTF16(localStorage[keyFinalUrl + '\thtml']),
  1262.     };
  1263.   }
  1264.  
  1265.   // standard keyUrl = time,expiry
  1266.   //          keyUrl\thtml = html
  1267.   // redirected keyUrl = time,expiry,finalUrl
  1268.   //            keyFinalUrl = time,expiry
  1269.   //            keyFinalUrl\thtml = html
  1270.   static write({url, finalUrl, html, cacheDuration = CACHE_DURATION}) {
  1271.  
  1272.     cacheDuration = Math.max(CACHE_DURATION, Math.min(0x7FFF0000, cacheDuration >> 0));
  1273.     finalUrl = (finalUrl || url).replace(/[?#].*/, '');
  1274.  
  1275.     const keyUrl = Urler.makeCacheable(url);
  1276.     const keyFinalUrl = Urler.makeCacheable(finalUrl);
  1277.     const lz = LZStringUnsafe.compressToUTF16(html);
  1278.  
  1279.     if (!Util.tryCatch(Cache._writeRaw, keyFinalUrl + '\thtml', lz)) {
  1280.       Cache._cleanup({aggressive: true});
  1281.       if (!Util.tryCatch(Cache._writeRaw, keyFinalUrl + '\thtml', lz))
  1282.         return Util.error('localStorage write error');
  1283.     }
  1284.  
  1285.     const time = Date.now();
  1286.     const expiry = time + cacheDuration;
  1287.     localStorage[keyFinalUrl] = time + '\t' + expiry;
  1288.     if (keyUrl !== keyFinalUrl)
  1289.       localStorage[keyUrl] = time + '\t' + expiry + '\t' + finalUrl;
  1290.  
  1291.     const t = setTimeout(Cache._delete, cacheDuration + 1000,
  1292.       keyUrl,
  1293.       keyFinalUrl,
  1294.       keyFinalUrl + '\thtml');
  1295.  
  1296.     for (const url of [keyUrl, keyFinalUrl]) {
  1297.       clearTimeout(Cache.timers.get(url));
  1298.       Cache.timers.set(url, t);
  1299.     }
  1300.   }
  1301.  
  1302.   static _writeRaw(k, v) {
  1303.     localStorage[k] = v;
  1304.     return true;
  1305.   }
  1306.  
  1307.   static _delete(...keys) {
  1308.     for (const k of keys) {
  1309.       delete localStorage[k];
  1310.       Cache.timers.delete(k);
  1311.     }
  1312.   }
  1313.  
  1314.   static _cleanup({aggressive = false} = {}) {
  1315.     for (const k in localStorage) {
  1316.       if ((k.startsWith('http://') || k.startsWith('https://')) &&
  1317.           !k.includes('\t')) {
  1318.         const [, expires, url] = (localStorage[k] || '').split('\t');
  1319.         if (Number(expires) > Date.now() && !aggressive)
  1320.           break;
  1321.         if (url) {
  1322.           delete localStorage[url];
  1323.           Cache.timers.delete(url);
  1324.         }
  1325.         delete localStorage[(url || k) + '\thtml'];
  1326.         delete localStorage[k];
  1327.         Cache.timers.delete(k);
  1328.       }
  1329.     }
  1330.   }
  1331. }
  1332.  
  1333.  
  1334. class Urler {
  1335.  
  1336.   static init() {
  1337.     Urler.xhr = null;
  1338.     Urler.xhrNoSSL = new Set();
  1339.     Urler.init = true;
  1340.   }
  1341.  
  1342.   static getFirstNumber(url) {
  1343.     if (typeof url === 'string')
  1344.       url = new URL(url);
  1345.     return url.pathname.match(/\/(\d+)/)[1];
  1346.   }
  1347.  
  1348.   static makeHttps(url) {
  1349.     if (!url)
  1350.       return '';
  1351.     if (url.startsWith('http:'))
  1352.       return 'https:' + url.slice(5);
  1353.     return url;
  1354.   }
  1355.  
  1356.   // strips queries and hashes and anything after the main part
  1357.   // https://site/questions/NNNNNN/title/
  1358.   static makeCacheable(url) {
  1359.     return url
  1360.       .replace(/(\/q(?:uestions)?\/\d+\/[^/]+).*/, '$1')
  1361.       .replace(/(\/a(?:nswers)?\/\d+).*/, '$1')
  1362.       .replace(/[?#].*$/, '');
  1363.   }
  1364.  
  1365.   static get(options) {
  1366.     if (!options.url)
  1367.       options = {url: options, method: 'GET'};
  1368.     if (!options.method)
  1369.       options = Object.assign({method: 'GET'}, options);
  1370.  
  1371.     let url = options.url;
  1372.     const hostname = new URL(url).hostname;
  1373.  
  1374.     if (Urler.xhrNoSSL.has(hostname)) {
  1375.       url = url.replace(/^https/, 'http');
  1376.     } else {
  1377.       url = Urler.makeHttps(url);
  1378.       const _onerror = options.onerror;
  1379.       options.onerror = () => {
  1380.         options.onerror = _onerror;
  1381.         options.url = url.replace(/^https/, 'http');
  1382.         Urler.xhrNoSSL.add(hostname);
  1383.         return Urler.get(options);
  1384.       };
  1385.     }
  1386.  
  1387.     return new Promise(resolve => {
  1388.       let xhr;
  1389.       options.onload = r => {
  1390.         if (pv.xhr === xhr)
  1391.           pv.xhr = null;
  1392.         resolve(r);
  1393.       };
  1394.       options.url = url;
  1395.       xhr = pv.xhr = GM_xmlhttpRequest(options);
  1396.     });
  1397.   }
  1398. }
  1399.  
  1400.  
  1401. class Util {
  1402.  
  1403.   static tryCatch(fn, ...args) {
  1404.     try {
  1405.       return fn(...args);
  1406.     } catch (e) {}
  1407.   }
  1408.  
  1409.   static isIterable(o) {
  1410.     return typeof o === 'object' && Symbol.iterator in o;
  1411.   }
  1412.  
  1413.   static parseHtml(html) {
  1414.     if (!Util.parser)
  1415.       Util.parser = new DOMParser();
  1416.     return Util.parser.parseFromString(html, 'text/html');
  1417.   }
  1418.  
  1419.   static extractTime(element) {
  1420.     return new Date(element.title).getTime();
  1421.   }
  1422.  
  1423.   static getResponseMimeType(headers) {
  1424.     return headers.match(/^\s*content-type:\s*(.*)|$/mi)[1] ||
  1425.            'image/png';
  1426.   }
  1427.  
  1428.   static getResponseDate(headers) {
  1429.     try {
  1430.       return new Date(headers.match(/^\s*date:\s*(.*)/mi)[1]);
  1431.     } catch (e) {}
  1432.   }
  1433.  
  1434.   static blobToBase64(blob) {
  1435.     return new Promise((resolve, reject) => {
  1436.       const reader = new FileReader();
  1437.       reader.onerror = reject;
  1438.       reader.onload = e => resolve(e.target.result);
  1439.       reader.readAsDataURL(blob);
  1440.     });
  1441.   }
  1442.  
  1443.   static async sha256(str) {
  1444.     if (!pv.utf8encoder)
  1445.       pv.utf8encoder = new TextEncoder('utf-8');
  1446.     const buf = await crypto.subtle.digest('SHA-256', pv.utf8encoder.encode(str));
  1447.     const blob = new Blob([buf]);
  1448.     const url = await Util.blobToBase64(blob);
  1449.     return url.slice(url.indexOf(',') + 1);
  1450.   }
  1451.  
  1452.   /** @param {KeyboardEvent} e */
  1453.   static hasKeyModifiers(e) {
  1454.     return e.ctrlKey || e.altKey || e.shiftKey || e.metaKey;
  1455.   }
  1456.  
  1457.   static fadeOut(el, transition) {
  1458.     return new Promise(resolve => {
  1459.       if (transition) {
  1460.         if (typeof transition === 'number')
  1461.           transition = `opacity ${transition}s ease-in-out`;
  1462.         $.setStyle(el, ['transition', transition]);
  1463.         setTimeout(doFadeOut);
  1464.       } else {
  1465.         doFadeOut();
  1466.       }
  1467.       function doFadeOut() {
  1468.         $.setStyle(el, ['opacity', '0']);
  1469.         $.on('transitionend', el, done);
  1470.         $.on('visibilitychange', el, done);
  1471.       }
  1472.       function done() {
  1473.         $.off('transitionend', el, done);
  1474.         $.off('visibilitychange', el, done);
  1475.         if (el.style.opacity === '0')
  1476.           $.setStyle(el, ['display', 'none']);
  1477.         resolve();
  1478.       }
  1479.     });
  1480.   }
  1481.  
  1482.   /** @param {KeyboardEvent} e */
  1483.   static consumeEsc(e) {
  1484.     if (e.key === 'Escape')
  1485.       e.preventDefault();
  1486.   }
  1487.  
  1488.   static error(...args) {
  1489.     console.error(GM_info.script.name, ...args);
  1490.   }
  1491. }
  1492.  
  1493.  
  1494. class Styles {
  1495.  
  1496.   static init(isDark) {
  1497.     if (Styles.isDark === isDark)
  1498.       return;
  1499.  
  1500.     Styles.isDark = isDark;
  1501.     Styles.REUSABLE = `${ID}-reusable`;
  1502.  
  1503.     const KBD_COLOR = '#0008';
  1504.  
  1505.     // language=HTML
  1506.     const SVG_ARROW = btoa(`
  1507.       <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16">
  1508.         <path stroke="${KBD_COLOR}" stroke-width="3" fill="none"
  1509.               d="M2.5,8.5H15 M9,2L2.5,8.5L9,15"/>
  1510.       </svg>`
  1511.       .replace(/>\s+</g, '><')
  1512.       .replace(/[\r\n]/g, ' ')
  1513.       .replace(/\s\s+/g, ' ')
  1514.       .trim()
  1515.     );
  1516.  
  1517.     const IMPORTANT = '!important;';
  1518.  
  1519.     // language=CSS
  1520.     pv.stylesOverride = [
  1521.       `
  1522.       :host {
  1523.         all: initial;
  1524.         border-color: transparent;
  1525.         display: none;
  1526.         opacity: 0;
  1527.         height: 33%;
  1528.         transition: opacity .25s cubic-bezier(.88,.02,.92,.66),
  1529.                     border-color .25s ease-in-out;
  1530.       }
  1531.       `,
  1532.  
  1533.       `
  1534.       :host {
  1535.         box-sizing: content-box;
  1536.         width: ${WIDTH}px;
  1537.         min-height: ${MIN_HEIGHT}px;
  1538.         position: fixed;
  1539.         right: 0;
  1540.         bottom: 0;
  1541.         padding: 0;
  1542.         margin: 0;
  1543.         background: white;
  1544.         box-shadow: 0 0 100px rgba(0,0,0,0.5);
  1545.         z-index: 999999;
  1546.         border-width: ${TOP_BORDER}px ${BORDER}px ${BORDER}px;
  1547.         border-style: solid;
  1548.       }
  1549.       :host(:not([style*="opacity: 1"])) {
  1550.         pointer-events: none;
  1551.       }
  1552.       :host([\\type$="question"].\\hasAnswerShelf) {
  1553.         border-image: linear-gradient(
  1554.           ${colors.question.back} 66%,
  1555.           ${colors.answer.back}) 1 1;
  1556.       }
  1557.       `.replace(/;/g, IMPORTANT),
  1558.  
  1559.       ...Object.entries(colors).map(([type, colors]) => `
  1560.         :host([\\type$="${type}"]) {
  1561.           border-color: ${colors.back} !important;
  1562.         }
  1563.       `),
  1564.  
  1565.       `
  1566.       #\\body {
  1567.         min-width: unset!important;
  1568.         box-shadow: none!important;
  1569.         padding: 0!important;
  1570.         margin: 0!important;
  1571.         background: ${colors.body.back}!important;
  1572.         color: ${colors.body.fore}!important;
  1573.         display: flex;
  1574.         flex-direction: column;
  1575.         height: 100%;
  1576.       }
  1577.  
  1578.       #\\title {
  1579.         all: unset;
  1580.         display: block;
  1581.         padding: 12px ${PADDING}px;
  1582.         font-weight: bold;
  1583.         font-size: 18px;
  1584.         line-height: 1.2;
  1585.         cursor: pointer;
  1586.       }
  1587.       #\\title:hover {
  1588.         text-decoration: underline;
  1589.         text-decoration-skip: ink;
  1590.       }
  1591.       #\\title:hover + #\\meta {
  1592.         opacity: 1.0;
  1593.       }
  1594.  
  1595.       #\\meta {
  1596.         position: absolute;
  1597.         font: bold 14px/${TOP_BORDER}px sans-serif;
  1598.         height: ${TOP_BORDER}px;
  1599.         top: -${TOP_BORDER}px;
  1600.         left: -${BORDER}px;
  1601.         right: ${BORDER * 2}px;
  1602.         padding: 0 0 0 ${BORDER + PADDING}px;
  1603.         display: flex;
  1604.         align-items: center;
  1605.         cursor: s-resize;
  1606.       }
  1607.       #\\meta b {
  1608.         height: ${TOP_BORDER}px;
  1609.         display: inline-block;
  1610.         padding: 0 6px;
  1611.         margin-left: -6px;
  1612.         margin-right: 3px;
  1613.       }
  1614.  
  1615.       #\\close {
  1616.         position: absolute;
  1617.         top: -${TOP_BORDER}px;
  1618.         right: -${BORDER}px;
  1619.         width: ${BORDER * 3}px;
  1620.         flex: none;
  1621.         cursor: pointer;
  1622.         padding: .5ex 1ex;
  1623.         font: normal 15px/1.0 sans-serif;
  1624.         color: #fff8;
  1625.       }
  1626.       #\\close:after {
  1627.         content: "x";
  1628.       }
  1629.       #\\close:active {
  1630.         background-color: rgba(0,0,0,.2);
  1631.       }
  1632.       #\\close:hover {
  1633.         background-color: rgba(0,0,0,.1);
  1634.       }
  1635.  
  1636.       #\\parts {
  1637.         position: relative;
  1638.         overflow-y: overlay; /* will replace with scrollbar-gutter once it's implemented */
  1639.         overflow-x: hidden;
  1640.         flex-grow: 2;
  1641.         outline: none;
  1642.         margin: 0;
  1643.       }
  1644.       [\\type^="question"] #\\parts {
  1645.         padding: ${(WIDTH - QUESTION_WIDTH) / 2}px !important;
  1646.       }
  1647.       [\\type^="answer"] #\\parts {
  1648.         padding: ${(WIDTH - ANSWER_WIDTH) / 2}px !important;
  1649.       }
  1650.       #\\parts > .question-status {
  1651.         margin: -${PADDING}px -${PADDING}px ${PADDING}px;
  1652.         padding-left: ${PADDING}px;
  1653.       }
  1654.       #\\parts .question-originals-of-duplicate {
  1655.         margin: -${PADDING}px -${PADDING}px ${PADDING}px;
  1656.         padding: ${PADDING / 2 >> 0}px ${PADDING}px;
  1657.       }
  1658.       #\\parts > .question-status h2 {
  1659.         font-weight: normal;
  1660.       }
  1661.       #\\parts a.SEpreviewable {
  1662.         text-decoration: underline !important;
  1663.         text-decoration-skip: ink;
  1664.       }
  1665.  
  1666.       #\\parts .comment-actions {
  1667.         width: 20px !important;
  1668.       }
  1669.       #\\parts .comment-edit,
  1670.       #\\parts .delete-tag,
  1671.       #\\parts .comment-actions > :not(.comment-score) {
  1672.         display: none;
  1673.       }
  1674.       #\\parts .comments {
  1675.         border-top: none;
  1676.       }
  1677.       #\\parts .comments .comment:last-child .comment-text {
  1678.         border-bottom: none;
  1679.       }
  1680.       #\\parts .comments .new-comment-highlight .comment-text {
  1681.         -webkit-animation: highlight 9s cubic-bezier(0,.8,.37,.88);
  1682.         -moz-animation: highlight 9s cubic-bezier(0,.8,.37,.88);
  1683.         animation: highlight 9s cubic-bezier(0,.8,.37,.88);
  1684.       }
  1685.       #\\parts .post-menu > span {
  1686.         opacity: .35;
  1687.       }
  1688.  
  1689.       #\\parts #user-menu {
  1690.         position: absolute;
  1691.       }
  1692.       .\\userCard {
  1693.         position: absolute;
  1694.         display: none;
  1695.         transition: opacity .25s cubic-bezier(.88,.02,.92,.66) .5s;
  1696.         margin-top: -3rem;
  1697.       }
  1698.       #\\parts .wmd-preview a:not(.post-tag),
  1699.       #\\parts .postcell a:not(.post-tag),
  1700.       #\\parts .comment-copy a:not(.post-tag) {
  1701.         border-bottom: none;
  1702.       }
  1703.  
  1704.       #\\answers-title {
  1705.         margin: .5ex 1ex 0 0;
  1706.         font-size: 18px;
  1707.         line-height: 1.0;
  1708.         float: left;
  1709.       }
  1710.       #\\answers-title p {
  1711.         font-size: 11px;
  1712.         font-weight: normal;
  1713.         max-width: 8em;
  1714.         line-height: 1.0;
  1715.         margin: 1ex 0 0 0;
  1716.         padding: 0;
  1717.       }
  1718.       #\\answers-title b,
  1719.       #\\answers-title label {
  1720.         background: linear-gradient(#fff8 30%, #fff);
  1721.         width: 10px;
  1722.         height: 10px;
  1723.         padding: 2px;
  1724.         margin-right: 2px;
  1725.         box-shadow: 0 1px 3px #0008;
  1726.         border-radius: 3px;
  1727.         font-weight: normal;
  1728.         display: inline-block;
  1729.         vertical-align: middle;
  1730.       }
  1731.       #\\answers-title b::after {
  1732.         content: "";
  1733.         display: block;
  1734.         width: 100%;
  1735.         height: 100%;
  1736.         background: url('data:image/svg+xml;base64,${SVG_ARROW}') no-repeat center;
  1737.       }
  1738.       #\\answers-title b[mirrored]::after {
  1739.         transform: scaleX(-1);
  1740.       }
  1741.       #\\answers-title label {
  1742.         width: auto;
  1743.         color: ${KBD_COLOR};
  1744.       }
  1745.  
  1746.       #\\answers {
  1747.         all: unset;
  1748.         display: block;
  1749.         padding: 10px 10px 10px ${PADDING}px;
  1750.         font-weight: bold;
  1751.         line-height: 1.0;
  1752.         border-top: 4px solid ${colors.answer.back}5e;
  1753.         background-color: ${colors.answer.back}5e;
  1754.         color: ${colors.answer.fore};
  1755.         word-break: break-word;
  1756.       }
  1757.       #\\answers a {
  1758.         color: ${colors.answer.fore};
  1759.         text-decoration: none;
  1760.         font-size: 11px;
  1761.         font-family: monospace;
  1762.         width: 32px !important;
  1763.         display: inline-block;
  1764.         position: relative;
  1765.         vertical-align: top;
  1766.         margin: 0 1ex 1ex 0;
  1767.         padding: 0 0 1.1ex 0;
  1768.       }
  1769.       [\\type*="deleted"] #\\answers a {
  1770.         color: ${colors.deleted.fore};
  1771.       }
  1772.       #\\answers img {
  1773.         width: 32px;
  1774.         height: 32px;
  1775.       }
  1776.       #\\answers a.deleted-answer {
  1777.         color: ${colors.deleted.fore};
  1778.         background: transparent;
  1779.         opacity: 0.25;
  1780.       }
  1781.       #\\answers a.deleted-answer:hover {
  1782.         opacity: 1.0;
  1783.       }
  1784.       #\\answers a:hover:not(.SEpreviewed) {
  1785.         text-decoration: underline;
  1786.         text-decoration-skip: ink;
  1787.       }
  1788.       #\\answers a.SEpreviewed {
  1789.         background-color: ${colors.answer.fore};
  1790.         color: ${colors.answer.foreInv};
  1791.         outline: 4px solid ${colors.answer.fore};
  1792.       }
  1793.       #\\answers a::after {
  1794.         white-space: nowrap;
  1795.         overflow: hidden;
  1796.         text-overflow: ellipsis;
  1797.         max-width: 40px;
  1798.         position: absolute;
  1799.         content: attr(title);
  1800.         top: 44px;
  1801.         left: 0;
  1802.         font: normal .75rem/1.0 sans-serif;
  1803.         opacity: .7;
  1804.       }
  1805.       #\\answers a:only-child::after {
  1806.         max-width: calc(${WIDTH}px - 10em);
  1807.       }
  1808.       #\\answers a:hover::after {
  1809.         opacity: 1;
  1810.       }
  1811.       .\\accepted::before {
  1812.         content: "✔";
  1813.         position: absolute;
  1814.         display: block;
  1815.         top: 1.3ex;
  1816.         right: -0.7ex;
  1817.         font-size: 32px;
  1818.         color: #4bff2c;
  1819.         text-shadow: 1px 2px 2px rgba(0,0,0,0.5);
  1820.       }
  1821.  
  1822.       @-webkit-keyframes highlight {
  1823.         from {background: #ffcf78}
  1824.         to   {background: none}
  1825.       }
  1826.       `,
  1827.  
  1828.       ...Object.keys(colors).map(s => `
  1829.         #\\title {
  1830.           background-color: ${colors[s].back}5e;
  1831.           color: ${colors[s].fore};
  1832.         }
  1833.         #\\meta {
  1834.           color: ${colors[s].fore};
  1835.         }
  1836.         #\\meta b {
  1837.           color: ${colors[s].foreInv};
  1838.           background: ${colors[s].fore};
  1839.         }
  1840.         #\\close {
  1841.           color: ${colors[s].fore};
  1842.         }
  1843.         #\\parts::-webkit-scrollbar {
  1844.           background-color: ${colors[s].back}19;
  1845.         }
  1846.         #\\parts::-webkit-scrollbar-thumb {
  1847.           background-color: ${colors[s].back}32;
  1848.         }
  1849.         #\\parts::-webkit-scrollbar-thumb:hover {
  1850.           background-color: ${colors[s].back}4b;
  1851.         }
  1852.         #\\parts::-webkit-scrollbar-thumb:active {
  1853.           background-color: ${colors[s].back}c0;
  1854.         }
  1855.       `
  1856.       // language=JS
  1857.         .replace(/#\\/g, `[\\type$="${s}"] $&`)
  1858.       ),
  1859.  
  1860.       ...['deleted', 'closed'].map(s => /* language=CSS */ `
  1861.         #\\answers {
  1862.           border-top-color: ${colors[s].back}5e;
  1863.           background-color: ${colors[s].back}5e;
  1864.           color: ${colors[s].fore};
  1865.         }
  1866.         #\\answers a.SEpreviewed {
  1867.           background-color: ${colors[s].fore};
  1868.           color: ${colors[s].foreInv};
  1869.         }
  1870.         #\\answers a.SEpreviewed:after {
  1871.           border-color: ${colors[s].fore};
  1872.         }
  1873.       `
  1874.       // language=JS
  1875.         .replace(/#\\/g, `[\\type$="${s}"] $&`)
  1876.       ),
  1877.  
  1878.       GM_getResourceText(`HL-style${isDark ? '-dark' : ''}`),
  1879.     ].join('\n').replace(/\\/g, `${ID}-`);
  1880.   }
  1881.  
  1882.   static applyRemScale(id, css) {
  1883.     const el = pv.styles.get(id);
  1884.     if (pv.remScale && pv.remScale !== 1 && !pv.stylesScaled.has(id)) {
  1885.       css = (css || el.textContent).replace(/([:\s])((?:\d*\.?)?\d+)(?=rem([;}\s]|\/\*))/gi,
  1886.         (_, prev, size) => prev + (pv.remScale * size));
  1887.       pv.stylesScaled.add(id);
  1888.     }
  1889.     el.textContent = css;
  1890.   }
  1891. }
  1892.  
  1893. function $(selector, node = pv.shadow) {
  1894.   return node && node.querySelector(selector);
  1895. }
  1896.  
  1897. Object.assign($, {
  1898.  
  1899.   all(selector, node = pv.shadow) {
  1900.     return node ? [...node.querySelectorAll(selector)] : [];
  1901.   },
  1902.  
  1903.   on(eventName, node, fn, options) {
  1904.     return node.addEventListener(eventName, fn, options);
  1905.   },
  1906.  
  1907.   off(eventName, node, fn, options) {
  1908.     return node.removeEventListener(eventName, fn, options);
  1909.   },
  1910.  
  1911.   remove(selector, node = pv.shadow) {
  1912.     for (const el of node.querySelectorAll(selector))
  1913.       el.remove();
  1914.   },
  1915.  
  1916.   text(selector, node = pv.shadow) {
  1917.     const el = typeof selector === 'string' ?
  1918.       node && node.querySelector(selector) :
  1919.       selector;
  1920.     return el ? el.textContent.trim() : '';
  1921.   },
  1922.  
  1923.   create(
  1924.     selector,
  1925.     opts = {},
  1926.     children = opts.children ||
  1927.                (typeof opts !== 'object' || Util.isIterable(opts)) && opts
  1928.   ) {
  1929.     const EOL = selector.length;
  1930.     const idStart = (selector.indexOf('#') + 1 || EOL + 1) - 1;
  1931.     const clsStart = (selector.indexOf('.', idStart < EOL ? idStart : 0) + 1 || EOL + 1) - 1;
  1932.     const tagEnd = Math.min(idStart, clsStart);
  1933.     const tag = (tagEnd < EOL ? selector.slice(0, tagEnd) : selector) || opts.tag || 'div';
  1934.     const id = idStart < EOL && selector.slice(idStart + 1, clsStart) || opts.id || '';
  1935.     const cls = clsStart < EOL && selector.slice(clsStart + 1).replace(/\./g, ' ') ||
  1936.                 opts.className ||
  1937.                 '';
  1938.     const el = id && pv.shadow && pv.shadow.getElementById(id) ||
  1939.                document.createElement(tag);
  1940.     if (el.id !== id)
  1941.       el.id = id;
  1942.     if (el.className !== cls)
  1943.       el.className = cls;
  1944.     const hasOwnProperty = Object.hasOwnProperty;
  1945.     for (const key in opts) {
  1946.       if (!hasOwnProperty.call(opts, key))
  1947.         continue;
  1948.       const value = opts[key];
  1949.       switch (key) {
  1950.         case 'tag':
  1951.         case 'id':
  1952.         case 'className':
  1953.         case 'children':
  1954.           break;
  1955.         case 'dataset': {
  1956.           const dataset = el.dataset;
  1957.           for (const k in value) {
  1958.             if (hasOwnProperty.call(value, k)) {
  1959.               const v = value[k];
  1960.               if (dataset[k] !== v)
  1961.                 dataset[k] = v;
  1962.             }
  1963.           }
  1964.           break;
  1965.         }
  1966.         case 'attributes': {
  1967.           for (const k in value) {
  1968.             if (hasOwnProperty.call(value, k)) {
  1969.               const v = value[k];
  1970.               if (el.getAttribute(k) !== v)
  1971.                 el.setAttribute(k, v);
  1972.             }
  1973.           }
  1974.           break;
  1975.         }
  1976.         default:
  1977.           if (el[key] !== value)
  1978.             el[key] = value;
  1979.       }
  1980.     }
  1981.     if (children) {
  1982.       if (!hasOwnProperty.call(opts, 'textContent'))
  1983.         el.textContent = '';
  1984.       $.appendChildren(el, children);
  1985.     }
  1986.     let before, after, parent;
  1987.     if ((before = opts.before) && before !== el.nextSibling && before !== el)
  1988.       before.insertAdjacentElement('beforebegin', el);
  1989.     else if ((after = opts.after) && after !== el.previousSibling && after !== el)
  1990.       after.insertAdjacentElement('afterend', el);
  1991.     else if ((parent = opts.parent) && parent !== el.parentNode)
  1992.       parent.appendChild(el);
  1993.     return el;
  1994.   },
  1995.  
  1996.   appendChild(parent, child, shouldClone = true) {
  1997.     if (!child)
  1998.       return;
  1999.     if (child.nodeType)
  2000.       return parent.appendChild(shouldClone ? document.importNode(child, true) : child);
  2001.     if (Util.isIterable(child))
  2002.       return $.appendChildren(parent, child, shouldClone);
  2003.     else
  2004.       return parent.appendChild(document.createTextNode(child));
  2005.   },
  2006.  
  2007.   appendChildren(newParent, children) {
  2008.     if (!Util.isIterable(children))
  2009.       return $.appendChild(newParent, children);
  2010.     const fragment = document.createDocumentFragment();
  2011.     for (const el of children)
  2012.       $.appendChild(fragment, el);
  2013.     return newParent.appendChild(fragment);
  2014.   },
  2015.  
  2016.   setStyle(el, ...props) {
  2017.     const style = el.style;
  2018.     const s0 = style.cssText;
  2019.     let s = s0;
  2020.  
  2021.     for (const p of props) {
  2022.       if (!p)
  2023.         continue;
  2024.  
  2025.       const [name, value, important = true] = p;
  2026.       const rValue = value + (important && value ? ' !important' : '');
  2027.       const rx = new RegExp(`(^|[\\s;])${name}(\\s*:\\s*)([^;]*?)(\\s*(?:;|$))`, 'i');
  2028.       const m = rx.exec(s);
  2029.  
  2030.       if (!m && value) {
  2031.         const rule = name + ': ' + rValue;
  2032.         s += !s || s.endsWith(';') ? rule : '; ' + rule;
  2033.         continue;
  2034.       }
  2035.  
  2036.       if (!m && !value)
  2037.         continue;
  2038.  
  2039.       const [, sep1, sep2, oldValue, sep3] = m;
  2040.       if (value !== oldValue) {
  2041.         s = s.slice(0, m.index) +
  2042.             sep1 + (rValue ? name + sep2 + rValue + sep3 : '') +
  2043.             s.slice(m.index + m[0].length);
  2044.       }
  2045.     }
  2046.  
  2047.     if (s !== s0)
  2048.       style.cssText = s;
  2049.   },
  2050. });