SE Preview on hover

Shows preview of the linked questions/answers on hover while Ctrl key is held

Verze ze dne 13. 02. 2017. Zobrazit nejnovější verzi.

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name           SE Preview on hover
// @description    Shows preview of the linked questions/answers on hover while Ctrl key is held
// @version        0.0.4
// @author         wOxxOm
// @namespace      wOxxOm.scripts
// @license        MIT License
// @match          *://*.stackoverflow.com/*
// @match          *://*.superuser.com/*
// @match          *://*.serverfault.com/*
// @match          *://*.askubuntu.com/*
// @match          *://*.stackapps.com/*
// @match          *://*.mathoverflow.net/*
// @match          *://*.stackexchange.com/*
// @require        https://greasyfork.org/scripts/12228/code/setMutationHandler.js
// @grant          GM_addStyle
// @grant          GM_xmlhttpRequest
// @connect        stackoverflow.com
// @connect        superuser.com
// @connect        serverfault.com
// @connect        askubuntu.com
// @connect        stackapps.com
// @connect        mathoverflow.net
// @connect        stackexchange.com
// @connect        cdn.sstatic.net
// @run-at         document-end
// @noframes
// ==/UserScript==

/* jshint lastsemic:true, multistr:true, laxbreak:true, -W030, -W041, -W084 */

const PREVIEW_DELAY = 100;
const COLORS = {
	question: {
		back: '80, 133, 195',
		fore: '#265184',
	},
	answer: {
		back: '112, 195, 80',
		fore: '#3f7722',
	},
};

let xhr;
let preview;
let previewLink;
let previewTimer;
let previewCSScache = {};
let hovering = {stoppedAt: {x:0, y:0}};

const rx = getURLregexForMatchedSites();
const thisPageBaseUrl = (location.href.match(rx) || [])[0];
const thisPageBaseUrlShort = thisPageBaseUrl ? thisPageBaseUrl.replace('/questions/', '/q/') : undefined;

const stylesOverride = `<style>
	body, html {
		min-width: unset!important;
		box-shadow: none!important;
	}
	html, body {
		background: unset!important;;
	}
	body {
		display: flex;
		flex-direction: column;
		height: 100%;
	}
	#SEpreviewTitle {
	    all: unset;
	    display: block;
	    padding: 20px 30px;
	    font-weight: bold;
	    font-size: 20px;
	    line-height: 1.3;
	    background-color: rgba(${COLORS.question.back}, 0.37);
	    color: ${COLORS.question.fore};
	}
	#SEpreviewTitle:hover {
	    text-decoration: underline;
	}
	#SEpreviewBody {
		padding: 30px!important;
		overflow: auto;
	}
	#SEpreviewBody::-webkit-scrollbar {
		background-color: rgba(${COLORS.question.back}, 0.1);
	}
	#SEpreviewBody::-webkit-scrollbar-thumb {
		background-color: rgba(${COLORS.question.back}, 0.2);
	}
	#SEpreviewBody::-webkit-scrollbar-thumb:hover {
		background-color: rgba(${COLORS.question.back}, 0.3);
	}
	#SEpreviewBody::-webkit-scrollbar-thumb:active {
		background-color: rgba(${COLORS.question.back}, 0.75);
	}

	body.SEpreviewIsAnswer #SEpreviewTitle {
	    background-color: rgba(${COLORS.answer.back}, 0.37);
	    color: ${COLORS.answer.fore};
	}
	body.SEpreviewIsAnswer #SEpreviewBody::-webkit-scrollbar {
		background-color: rgba(${COLORS.answer.back}, 0.1);
	}
	body.SEpreviewIsAnswer #SEpreviewBody::-webkit-scrollbar-thumb {
		background-color: rgba(${COLORS.answer.back}, 0.2);
	}
	body.SEpreviewIsAnswer #SEpreviewBody::-webkit-scrollbar-thumb:hover {
		background-color: rgba(${COLORS.answer.back}, 0.3);
	}
	body.SEpreviewIsAnswer #SEpreviewBody::-webkit-scrollbar-thumb:active {
		background-color: rgba(${COLORS.answer.back}, 0.75);
	}

	#SEpreviewAnswers {
		all: unset;
		display: block;
		padding: 10px 30px;
		font-weight: bold;
		font-size: 20px;
		line-height: 1.3;
		border-top: 4px solid rgba(${COLORS.answer.back}, 0.37);
		background-color: rgba(${COLORS.answer.back}, 0.37);
		color: ${COLORS.answer.fore};
	}

	.comments .new-comment-highlight {
		-webkit-animation: highlight 9s cubic-bezier(0,.8,.37,.88);
		-moz-animation: highlight 9s cubic-bezier(0,.8,.37,.88);
		animation: highlight 9s cubic-bezier(0,.8,.37,.88);
	}

	@-webkit-keyframes highlight {
		from {background-color: #ffcf78}
		to   {background-color: none}
	}
</style>`;

GM_addStyle(`
	#SEpreview {
	    all: unset;
	    box-sizing: content-box;
	    width: 720px; /* 660px + 30px + 30px */
	    height: 33%;
	    min-height: 200px;
	    position: fixed;
	    transition: opacity .25s ease-in-out;
	    right: 0;
	    bottom: 0;
	    padding: 0;
	    margin: 0;
	    background: white;
	    box-shadow: 0 0 100px rgba(0,0,0,0.5);
	    z-index: 999999;
	    border: 8px solid rgb(${COLORS.question.back});
	}
	#SEpreview.SEpreviewIsAnswer {
	    border-color: rgb(${COLORS.answer.back});
	}
`);

processExistingAndSetMutationHandler('a', onLinkAdded);

/**************************************************************/

function onLinkAdded(links) {
	for (let i = 0, link; (link = links[i++]); ) {
		if (rx.test(link.href) &&
			!link.matches('.short-link') &&
			!link.href.startsWith(thisPageBaseUrl) &&
			!link.href.startsWith(thisPageBaseUrlShort)
		) {
			link.removeAttribute('title');
			link.addEventListener('mouseover', onLinkHovered);
		}
	}
}

function onLinkHovered(e) {
	if (e.ctrlKey || e.altKey || e.shiftKey || e.metaKey)
		return;
	previewLink = this;
	previewLink.addEventListener('mousemove', onLinkMouseMove);
	previewLink.addEventListener('mouseout', abortPreview);
	previewLink.addEventListener('mousedown', abortPreview);
	restartPreviewTimer();
}

function onLinkMouseMove(e) {
	if (Math.abs(hovering.stoppedAt.x - e.clientX) < 2 && Math.abs(hovering.stoppedAt.y - e.clientY) < 2)
		return;
	hovering.stoppedAt.x = e.clientX;
	hovering.stoppedAt.y = e.clientY;
	restartPreviewTimer();
}

function restartPreviewTimer() {
	clearTimeout(previewTimer);
	previewTimer = setTimeout(() => {
		previewTimer = 0;
		if (!previewLink.matches(':hover'))
			return;
		downloadPage();
	}, PREVIEW_DELAY);
}

function abortPreview() {
	previewLink.removeEventListener('mousemove', onLinkMouseMove);
	previewLink.removeEventListener('mouseout', abortPreview);
	previewLink.removeEventListener('mousedown', abortPreview);
	clearTimeout(previewTimer);
	previewTimer = setTimeout(() => {
		previewTimer = 0;
		if (preview && !preview.matches(':hover'))
			hidePreview();
	}, 500);
	if (xhr)
		xhr.abort();
}

function downloadPage() {
	xhr = GM_xmlhttpRequest({
		method: 'GET',
		url: previewLink.href,
		onload: showPreview,
	});
}

function showPreview(data) {
	let doc = new DOMParser().parseFromString(data.responseText, 'text/html');
	if (!doc || !doc.head) {
		console.error(GM_info.script.name, 'empty document received:', data);
		return;
	}

	if (!$(doc, 'base'))
		doc.head.insertAdjacentHTML('afterbegin', `<base href="${data.finalUrl}">`);

	let answerIdMatch = data.finalUrl.match(/questions\/.+?\/(\d+)/);
	let postId = answerIdMatch ? '#answer-' + answerIdMatch[1] : '#question';
	let post = $(doc, postId + ' .post-text');
	if (!post)
		return;
	let title = $(doc, 'meta[property="og:title"]').content;
	let comments = $(doc, `${postId} .comments`);
	let commentsMore = $(doc, `${postId} .js-show-link.comments-link`);
	let answers; // = answerIdMatch ? null : $$(doc, '.answer');

	$$remove(doc, 'script, .post-menu');

	let externalsReady = [stylesOverride];
	let stylesToGet = new Set();
	let afterBodyHtml = '';

	fetchExternals();
	maybeRender();

	function fetchExternals() {
		let codeBlocks = $$(post, 'pre code');
		if (codeBlocks.length) {
			codeBlocks.forEach(e => e.parentElement.classList.add('prettyprint'));
			externalsReady.push(
				'<script> StackExchange = {}; </script>',
				'<script src="https://cdn.sstatic.net/Js/prettify-full.en.js"></script>'
			);
			afterBodyHtml = '<script> prettyPrint(); </script>';
		}

		$$(doc, 'style, link[rel="stylesheet"]').forEach(e => {
			if (e.localName == 'style')
				externalsReady.push(e.outerHTML);
			else if (e.href in previewCSScache)
				externalsReady.push(previewCSScache[e.href]);
			else {
				stylesToGet.add(e.href);
				GM_xmlhttpRequest({
					method: 'GET',
					url: e.href,
					onload: data => {
						externalsReady.push(previewCSScache[e.href] = '<style>' + data.responseText + '</style>');
						stylesToGet.delete(e.href);
						maybeRender();
					},
				});
			}
		});

	}

	function maybeRender() {
		if (stylesToGet.size)
			return;
		if (!preview) {
			preview = document.createElement('iframe');
			preview.id = 'SEpreview';
			preview.sandbox = 'allow-same-origin allow-scripts';
		}
		preview.classList.toggle('SEpreviewIsAnswer', !!answerIdMatch);
		document.body.appendChild(preview);

		let headHtml = externalsReady.join('');
		let bodyHtml = [post.parentElement, comments, commentsMore].map(e => e ? e.outerHTML : '').join('');
		let pvDoc = preview.contentDocument;
		pvDoc.open();
		pvDoc.write(`
			<head>${headHtml}</head>
			<body${answerIdMatch ? ' class="SEpreviewIsAnswer"' : ''}>
				<a id="SEpreviewTitle" href="${data.finalUrl}">${title}</a>
				<div id="SEpreviewBody">${bodyHtml}</div>
				${!answers ? '' : '<div id="SEpreviewAnswers">' + answers.length + ' answer' + (answers.length > 1 ? 's' : '') + '</div>'}
				${afterBodyHtml}
			</body>`);
		pvDoc.close();

		pvDoc.addEventListener('mouseover', retainMainScrollPos);
		if (commentsMore)
			$(pvDoc, '.js-show-link.comments-link').addEventListener('click', downloadComments);
		if (answers)
			$(pvDoc, '#SEpreviewAnswers').addEventListener('click', revealAnswers);
	}

	function downloadComments() {
		this.remove();
		GM_xmlhttpRequest({
			method: 'GET',
			url: new URL(data.finalUrl).origin + '/posts/' + comments.id.match(/\d+/)[0] + '/comments',
			onload: r => showComments(r.responseText),
		});
	}

	function showComments(html) {
		let tbody = $(preview.contentDocument, `#${comments.id} tbody`);
		let oldIds = new Set([...tbody.rows].map(e => e.id));
		tbody.innerHTML = html;
		for (let tr of tbody.rows)
			if (!oldIds.has(tr.id))
				tr.classList.add('new-comment-highlight');
	}
}

function retainMainScrollPos(e) {
	let scrollPos = {x:scrollX, y:scrollY};
	document.addEventListener('scroll', preventScroll);
	document.addEventListener('mouseover', releaseScrollLock);

	function preventScroll(e) {
		scrollTo(scrollPos.x, scrollPos.y);
	}
	function releaseScrollLock(e) {
		document.removeEventListener('mouseout', releaseScrollLock);
		document.removeEventListener('scroll', preventScroll);
	}
}

function hidePreview() {
	preview.remove();
}

function getURLregexForMatchedSites() {
	return new RegExp('https?://(\\w*\\.)*(' + GM_info.script.matches.map(m =>
		m.match(/^.*?\/\/\W*(\w.*?)\//)[1].replace(/\./g, '\\.')
	).join('|') + ')/(questions|q|a)/\\d+');
}

function $(node__optional, selector) {
// or    $(selector) {
	return (node__optional || document).querySelector(selector || node__optional);
}

function $$(node__optional, selector) {
// or    $$(selector) {
	return (node__optional || document).querySelectorAll(selector || node__optional);
}

function $$remove(node__optional, selector) {
// or    $$remove(selector) {
	(node__optional || document).querySelectorAll(selector || node__optional)
		.forEach(e => e.remove());
}