☰

SE Preview on hover

Shows preview of the linked questions/answers on hover

目前為 2017-02-14 提交的版本，檢視 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        0.1.0
  5. // @author         wOxxOm
  6. // @namespace      wOxxOm.scripts
  7. // @license        MIT License
  8. // @match          *://*.stackoverflow.com/*
  9. // @match          *://*.superuser.com/*
  10. // @match          *://*.serverfault.com/*
  11. // @match          *://*.askubuntu.com/*
  12. // @match          *://*.stackapps.com/*
  13. // @match          *://*.mathoverflow.net/*
  14. // @match          *://*.stackexchange.com/*
  15. // @require        https://greasyfork.org/scripts/12228/code/setMutationHandler.js
  16. // @grant          GM_addStyle
  17. // @grant          GM_xmlhttpRequest
  18. // @connect        stackoverflow.com
  19. // @connect        superuser.com
  20. // @connect        serverfault.com
  21. // @connect        askubuntu.com
  22. // @connect        stackapps.com
  23. // @connect        mathoverflow.net
  24. // @connect        stackexchange.com
  25. // @connect        cdn.sstatic.net
  26. // @run-at         document-end
  27. // @noframes
  28. // ==/UserScript==
  29.  
  30. /* jshint lastsemic:true, multistr:true, laxbreak:true, -W030, -W041, -W084 */
  31.  
  32. const PREVIEW_DELAY = 100;
  33. const COLORS = {
  34. 	question: {
  35. 		backRGB: '80, 133, 195',
  36. 		foreRGB: '#265184',
  37. 	},
  38. 	answer: {
  39. 		backRGB: '112, 195, 80',
  40. 		foreRGB: '#3f7722',
  41. 		foreInv: 'white',
  42. 	},
  43. };
  44.  
  45. let xhr;
  46. let preview = {
  47. 	frame: null,
  48. 	link: null,
  49. 	hover: {x:0, y:0},
  50. 	timer: 0,
  51. 	CSScache: {},
  52. 	stylesOverride: '',
  53. };
  54.  
  55. const rxPreviewable = getURLregexForMatchedSites();
  56. const thisPageUrls = getPageBaseUrls(location.href);
  57.  
  58. initStyles();
  59. initPolyfills();
  60. setMutationHandler('a', onLinkAdded, {processExisting: true});
  61.  
  62. /**************************************************************/
  63.  
  64. function onLinkAdded(links) {
  65. 	for (let i = 0, link; (link = links[i++]); ) {
  66. 		if (isLinkPreviewable(link)) {
  67. 			link.removeAttribute('title');
  68. 			link.addEventListener('mouseover', onLinkHovered);
  69. 		}
  70. 	}
  71. }
  72.  
  73. function onLinkHovered(e) {
  74. 	if (e.ctrlKey || e.altKey || e.shiftKey || e.metaKey)
  75. 		return;
  76. 	preview.link = this;
  77. 	preview.link.addEventListener('mousemove', onLinkMouseMove);
  78. 	preview.link.addEventListener('mouseout', abortPreview);
  79. 	preview.link.addEventListener('mousedown', abortPreview);
  80. 	restartPreviewTimer();
  81. }
  82.  
  83. function onLinkMouseMove(e) {
  84. 	let stoppedMoving = Math.abs(preview.hover.x - e.clientX) < 2 &&
  85. 				  Math.abs(preview.hover.y - e.clientY) < 2;
  86. 	if (!stoppedMoving)
  87. 		return;
  88. 	preview.hover.x = e.clientX;
  89. 	preview.hover.y = e.clientY;
  90. 	restartPreviewTimer();
  91. }
  92.  
  93. function restartPreviewTimer() {
  94. 	clearTimeout(preview.timer);
  95. 	preview.timer = setTimeout(() => {
  96. 		preview.timer = 0;
  97. 		releaseLinkListeners();
  98. 		if (preview.link.matches(':hover'))
  99. 			downloadPreview(preview.link.href);
  100. 	}, PREVIEW_DELAY);
  101. }
  102.  
  103. function releaseLinkListeners() {
  104. 	preview.link.removeEventListener('mousemove', onLinkMouseMove);
  105. 	preview.link.removeEventListener('mouseout', abortPreview);
  106. 	preview.link.removeEventListener('mousedown', abortPreview);
  107. 	clearTimeout(preview.timer);
  108. }
  109.  
  110. function abortPreview() {
  111. 	releaseLinkListeners();
  112. 	preview.timer = setTimeout(() => {
  113. 		preview.timer = 0;
  114. 		if (preview.frame && !preview.frame.matches(':hover'))
  115. 			hideAndRemove(preview.frame);
  116. 	}, 1000);
  117. 	if (xhr)
  118. 		xhr.abort();
  119. }
  120.  
  121. function hideAndRemove(element, transition) {
  122. 	if (transition) {
  123. 		element.style.transition = typeof transition == 'number' ? `opacity ${transition}s ease-in-out` : transition;
  124. 		return setTimeout(hideAndRemove, 0, element);
  125. 	}
  126. 	element.style.opacity = 0;
  127. 	element.addEventListener('transitionend', function remove() {
  128. 		element.removeEventListener('transitionend', remove);
  129. 		element.remove();
  130. 	});
  131. }
  132.  
  133. function downloadPreview(url) {
  134. 	xhr = GM_xmlhttpRequest({
  135. 		method: 'GET',
  136. 		url: httpsUrl(url),
  137. 		onload: showPreview,
  138. 	});
  139. }
  140.  
  141. function showPreview(data) {
  142. 	let doc = new DOMParser().parseFromString(data.responseText, 'text/html');
  143. 	if (!doc || !doc.head) {
  144. 		error('empty document received:', data);
  145. 		return;
  146. 	}
  147.  
  148. 	if (!$(doc, 'base'))
  149. 		doc.head.insertAdjacentHTML('afterbegin', `<base href="${data.finalUrl}">`);
  150.  
  151. 	const answerIdMatch = data.finalUrl.match(/questions\/.+?\/(\d+)/);
  152. 	const isQuestion = !answerIdMatch;
  153. 	let postId = answerIdMatch ? '#answer-' + answerIdMatch[1] : '#question';
  154. 	let post = $(doc, postId + ' .post-text');
  155. 	if (!post)
  156. 		return error('No parsable post found', doc);
  157. 	const title = $(doc, 'meta[property="og:title"]').content;
  158. 	let comments = $(doc, `${postId} .comments`);
  159. 	let commentsHidden = +$(comments, 'tbody').dataset.remainingCommentsCount;
  160. 	let commentsShowLink = commentsHidden && $(doc, `${postId} .js-show-link.comments-link`);
  161.  
  162. 	let externalsReady = [preview.stylesOverride];
  163. 	let externalsToGet = new Set();
  164. 	let afterBodyHtml = '';
  165.  
  166. 	fetchExternals();
  167. 	maybeRender();
  168.  
  169. 	function fetchExternals() {
  170. 		let codeBlocks = $$(post, 'pre code');
  171. 		if (codeBlocks.length) {
  172. 			codeBlocks.forEach(e => e.parentElement.classList.add('prettyprint'));
  173. 			externalsReady.push(
  174. 				'<script> StackExchange = {}; </script>',
  175. 				'<script src="https://cdn.sstatic.net/Js/prettify-full.en.js"></script>'
  176. 			);
  177. 			afterBodyHtml += '<script> prettyPrint(); </script>';
  178. 		}
  179.  
  180. 		$$(doc, 'style, link[rel="stylesheet"]').forEach(e => {
  181. 			if (e.localName == 'style')
  182. 				externalsReady.push(e.outerHTML);
  183. 			else if (e.href in preview.CSScache)
  184. 				externalsReady.push(preview.CSScache[e.href]);
  185. 			else {
  186. 				externalsToGet.add(e.href);
  187. 				GM_xmlhttpRequest({
  188. 					method: 'GET',
  189. 					url: e.href,
  190. 					onload: data => {
  191. 						externalsReady.push(preview.CSScache[e.href] = '<style>' + data.responseText + '</style>');
  192. 						externalsToGet.delete(e.href);
  193. 						maybeRender();
  194. 					},
  195. 				});
  196. 			}
  197. 		});
  198.  
  199. 	}
  200.  
  201. 	function maybeRender() {
  202. 		if (externalsToGet.size)
  203. 			return;
  204. 		if (!preview.frame) {
  205. 			preview.frame = document.createElement('iframe');
  206. 			preview.frame.id = 'SEpreview';
  207. 		}
  208. 		preview.frame.classList.toggle('SEpreviewIsAnswer', !!answerIdMatch);
  209. 		document.body.appendChild(preview.frame);
  210.  
  211. 		const answers = $$(doc, '.answer');
  212. 		const answersShown = answers.length > (isQuestion ? 0 : 1);
  213. 		if (answersShown) {
  214. 			afterBodyHtml += '<div id="SEpreviewAnswers">Answers: ' +
  215. 				answers.map((e, index) =>
  216. 					`<a href="${$(e, '.short-link').href}"
  217. 						title="${$text(e, '.user-details a') + ' (' +
  218. 								 $text(e, '.reputation-score') + ') ' +
  219. 								 $text(e, '.user-action-time')}"
  220. 						class="${e.matches(postId) ? 'SEpreviewed' : ''}"
  221. 					>${index + 1}</a>`
  222. 				).join('') + '</div>';
  223. 		}
  224.  
  225. 		$$remove(doc, 'script, .post-menu');
  226.  
  227. 		let html = `<head>${externalsReady.join('')}</head>
  228. 			<body${answerIdMatch ? ' class="SEpreviewIsAnswer"' : ''}>
  229. 				<a id="SEpreviewTitle" href="${
  230. 					isQuestion ? data.finalUrl : data.finalUrl.replace(/\/\d+[^\/]*$/, '')
  231. 				}">${title}</a>
  232. 				<div id="SEpreviewBody">${
  233. 					[post.parentElement, comments, commentsShowLink]
  234. 						.map(e => e ? e.outerHTML : '').join('')
  235. 				}</div>
  236. 				${afterBodyHtml}
  237. 			</body>`;
  238.  
  239. 		try {
  240. 			let pvDoc = preview.frame.contentDocument;
  241. 			pvDoc.open();
  242. 			pvDoc.write(html);
  243. 			pvDoc.close();
  244. 		} catch(e) {
  245. 			preview.frame.srcdoc = `<html>${html}</html>`;
  246. 		}
  247.  
  248. 		preview.frame.onload = () => {
  249. 			preview.frame.onload = null;
  250. 			preview.frame.style.opacity = 1;
  251. 			let pvDoc = preview.frame.contentDocument;
  252. 			pvDoc.addEventListener('mouseover', retainMainScrollPos);
  253. 			pvDoc.addEventListener('click', interceptLinks);
  254. 		};
  255. 	}
  256.  
  257. 	function interceptLinks(e) {
  258. 		const link = e.target;
  259. 		if (link.localName != 'a')
  260. 			return;
  261. 		if (link.matches('.js-show-link.comments-link')) {
  262. 			hideAndRemove(link, 0.5);
  263. 			downloadComments();
  264. 		}
  265. 		else if (e.button || e.ctrlKey || e.altKey || e.shiftKey || e.metaKey ||
  266. 				 !isLinkPreviewable(link))
  267. 			return link.target = '_blank';
  268. 		else if (!link.matches('.SEpreviewed'))
  269. 			downloadPreview(link.href);
  270. 		e.preventDefault();
  271. 	}
  272.  
  273. 	function downloadComments() {
  274. 		GM_xmlhttpRequest({
  275. 			method: 'GET',
  276. 			url: new URL(data.finalUrl).origin + '/posts/' + comments.id.match(/\d+/)[0] + '/comments',
  277. 			onload: r => showComments(r.responseText),
  278. 		});
  279. 	}
  280.  
  281. 	function showComments(html) {
  282. 		let tbody = $(preview.frame.contentDocument, `#${comments.id} tbody`);
  283. 		let oldIds = new Set([...tbody.rows].map(e => e.id));
  284. 		tbody.innerHTML = html;
  285. 		for (let tr of tbody.rows)
  286. 			if (!oldIds.has(tr.id))
  287. 				tr.classList.add('new-comment-highlight');
  288. 	}
  289. }
  290.  
  291. function retainMainScrollPos(e) {
  292. 	let scrollPos = {x:scrollX, y:scrollY};
  293. 	document.addEventListener('scroll', preventScroll);
  294. 	document.addEventListener('mouseover', releaseScrollLock);
  295.  
  296. 	function preventScroll(e) {
  297. 		scrollTo(scrollPos.x, scrollPos.y);
  298. 		log('prevented main page scroll');
  299. 	}
  300. 	function releaseScrollLock(e) {
  301. 		document.removeEventListener('mouseout', releaseScrollLock);
  302. 		document.removeEventListener('scroll', preventScroll);
  303. 	}
  304. }
  305.  
  306. function getURLregexForMatchedSites() {
  307. 	return new RegExp('https?://(\\w*\\.)*(' + GM_info.script.matches.map(m =>
  308. 		m.match(/^.*?\/\/\W*(\w.*?)\//)[1].replace(/\./g, '\\.')
  309. 	).join('|') + ')/(questions|q|a)/\\d+');
  310. }
  311.  
  312. function getPageBaseUrls(url) {
  313. 	let base = httpsUrl((url.match(rxPreviewable) || [])[0]);
  314. 	return base ? {
  315. 		base,
  316. 		short: base.replace('/questions/', '/q/'),
  317. 	} : {};
  318. }
  319.  
  320. function isLinkPreviewable(link) {
  321. 	const inPreview = link.ownerDocument != document;
  322. 	if (inPreview && link.matches('#SEpreviewAnswers a, a#SEpreviewTitle'))
  323. 		return true;
  324. 	if (!rxPreviewable.test(link.href) || link.matches('.short-link'))
  325. 		return false;
  326. 	const pageUrls = inPreview ? getPageBaseUrls(preview.link.href) : thisPageUrls;
  327. 	const url = httpsUrl(link.href);
  328. 	return !url.startsWith(pageUrls.base) &&
  329. 		   !url.startsWith(pageUrls.short);
  330. }
  331.  
  332. function httpsUrl(url) {
  333. 	return (url || '').replace(/^http:/, 'https:');
  334. }
  335.  
  336. function $(node__optional, selector) {
  337. 	return (node__optional || document).querySelector(selector || node__optional);
  338. }
  339.  
  340. function $$(node__optional, selector) {
  341. 	return (node__optional || document).querySelectorAll(selector || node__optional);
  342. }
  343.  
  344. function $text(node__optional, selector) {
  345. 	let e = $(node__optional, selector);
  346. 	return e ? e.textContent.trim() : '';
  347. }
  348.  
  349. function $$remove(node__optional, selector) {
  350. 	(node__optional || document).querySelectorAll(selector || node__optional)
  351. 		.forEach(e => e.remove());
  352. }
  353.  
  354. function log(...args) {
  355. 	console.log(GM_info.script.name, ...args);
  356. }
  357.  
  358. function error(...args) {
  359. 	console.error(GM_info.script.name, ...args);
  360. }
  361.  
  362. function initPolyfills() {
  363. 	NodeList.prototype.forEach = NodeList.prototype.forEach || Array.prototype.forEach;
  364. 	NodeList.prototype.map = NodeList.prototype.map || Array.prototype.map;
  365. }
  366.  
  367. function initStyles() {
  368. 	GM_addStyle(`
  369. 		#SEpreview {
  370. 			all: unset;
  371. 			box-sizing: content-box;
  372. 			width: 720px; /* 660px + 30px + 30px */
  373. 			height: 33%;
  374. 			min-height: 200px;
  375. 			position: fixed;
  376. 			opacity: 0;
  377. 			transition: opacity .5s cubic-bezier(.88,.02,.92,.66);
  378. 			right: 0;
  379. 			bottom: 0;
  380. 			padding: 0;
  381. 			margin: 0;
  382. 			background: white;
  383. 			box-shadow: 0 0 100px rgba(0,0,0,0.5);
  384. 			z-index: 999999;
  385. 			border: 8px solid rgb(${COLORS.question.backRGB});
  386. 		}
  387. 		#SEpreview.SEpreviewIsAnswer {
  388. 			border-color: rgb(${COLORS.answer.backRGB});
  389. 		}
  390. 	`);
  391.  
  392. 	preview.stylesOverride = `<style>
  393. 		body, html {
  394. 			min-width: unset!important;
  395. 			box-shadow: none!important;
  396. 		}
  397. 		html, body {
  398. 			background: unset!important;;
  399. 		}
  400. 		body {
  401. 			display: flex;
  402. 			flex-direction: column;
  403. 			height: 100vh;
  404. 		}
  405. 		#SEpreviewTitle {
  406. 			all: unset;
  407. 			display: block;
  408. 			padding: 20px 30px;
  409. 			font-weight: bold;
  410. 			font-size: 20px;
  411. 			line-height: 1.3;
  412. 			background-color: rgba(${COLORS.question.backRGB}, 0.37);
  413. 			color: ${COLORS.question.foreRGB};
  414. 			cursor: pointer;
  415. 		}
  416. 		#SEpreviewTitle:hover {
  417. 			text-decoration: underline;
  418. 		}
  419. 		#SEpreviewBody {
  420. 			padding: 30px!important;
  421. 			overflow: auto;
  422. 			flex-grow: 2;
  423. 		}
  424. 		#SEpreviewBody::-webkit-scrollbar {
  425. 			background-color: rgba(${COLORS.question.backRGB}, 0.1);
  426. 		}
  427. 		#SEpreviewBody::-webkit-scrollbar-thumb {
  428. 			background-color: rgba(${COLORS.question.backRGB}, 0.2);
  429. 		}
  430. 		#SEpreviewBody::-webkit-scrollbar-thumb:hover {
  431. 			background-color: rgba(${COLORS.question.backRGB}, 0.3);
  432. 		}
  433. 		#SEpreviewBody::-webkit-scrollbar-thumb:active {
  434. 			background-color: rgba(${COLORS.question.backRGB}, 0.75);
  435. 		}
  436.  
  437. 		body.SEpreviewIsAnswer #SEpreviewTitle {
  438. 			background-color: rgba(${COLORS.answer.backRGB}, 0.37);
  439. 			color: ${COLORS.answer.foreRGB};
  440. 		}
  441. 		body.SEpreviewIsAnswer #SEpreviewBody::-webkit-scrollbar {
  442. 			background-color: rgba(${COLORS.answer.backRGB}, 0.1);
  443. 		}
  444. 		body.SEpreviewIsAnswer #SEpreviewBody::-webkit-scrollbar-thumb {
  445. 			background-color: rgba(${COLORS.answer.backRGB}, 0.2);
  446. 		}
  447. 		body.SEpreviewIsAnswer #SEpreviewBody::-webkit-scrollbar-thumb:hover {
  448. 			background-color: rgba(${COLORS.answer.backRGB}, 0.3);
  449. 		}
  450. 		body.SEpreviewIsAnswer #SEpreviewBody::-webkit-scrollbar-thumb:active {
  451. 			background-color: rgba(${COLORS.answer.backRGB}, 0.75);
  452. 		}
  453.  
  454. 		#SEpreviewAnswers {
  455. 			all: unset;
  456. 			display: block;
  457. 			padding: 10px 30px;
  458. 			font-weight: bold;
  459. 			font-size: 20px;
  460. 			line-height: 1.3;
  461. 			border-top: 4px solid rgba(${COLORS.answer.backRGB}, 0.37);
  462. 			background-color: rgba(${COLORS.answer.backRGB}, 0.37);
  463. 			color: ${COLORS.answer.foreRGB};
  464. 		}
  465. 		#SEpreviewAnswers a {
  466. 			color: ${COLORS.answer.foreRGB};
  467. 			padding: .25ex .75ex;
  468. 			text-decoration: none;
  469. 		}
  470. 		#SEpreviewAnswers a:hover:not(.SEpreviewed) {
  471. 			text-decoration: underline;
  472. 		}
  473. 		#SEpreviewAnswers a.SEpreviewed {
  474. 			background-color: ${COLORS.answer.foreRGB};
  475. 			color: ${COLORS.answer.foreInv};
  476. 		}
  477.  
  478. 		.comments .new-comment-highlight {
  479. 			-webkit-animation: highlight 9s cubic-bezier(0,.8,.37,.88);
  480. 			-moz-animation: highlight 9s cubic-bezier(0,.8,.37,.88);
  481. 			animation: highlight 9s cubic-bezier(0,.8,.37,.88);
  482. 		}
  483.  
  484. 		@-webkit-keyframes highlight {
  485. 			from {background-color: #ffcf78}
  486. 			to   {background-color: none}
  487. 		}
  488. 	</style>`;
  489. }