☰

GitHub Font Preview

A userscript that adds a font file preview

目前為 2019-06-07 提交的版本，檢視 最新版本。

  1. // ==UserScript==
  2. // @name        GitHub Font Preview
  3. // @version     1.0.22
  4. // @description A userscript that adds a font file preview
  5. // @license     MIT
  6. // @author      Rob Garrison
  7. // @namespace   https://github.com/Mottie
  8. // @include     https://github.com/*
  9. // @run-at      document-idle
  10. // @grant       GM_addStyle
  11. // @grant       GM_getValue
  12. // @grant       GM_setValue
  13. // @grant       GM_xmlhttpRequest
  14. // @connect     github.com
  15. // @connect     githubusercontent.com
  16. // @require     https://greasyfork.org/scripts/28721-mutations/code/mutations.js?version=666427
  17. // @require     https://greasyfork.org/scripts/20469-opentype-js/code/opentypejs.js?version=130870
  18. // @icon        https://github.githubassets.com/pinned-octocat.svg
  19. // ==/UserScript==
  20. (() => {
  21. 	"use strict";
  22.  
  23. 	let font;
  24. 	let showUnicode = GM_getValue("gfp-show-unicode", false);
  25. 	let showPoints = GM_getValue("gfp-show-points", true);
  26. 	let showArrows = GM_getValue("gfp-show-arrows", true);
  27. 	let currentIndex = 0;
  28.  
  29. 	// supported font types
  30. 	const fontExt = /\.(otf|ttf|woff)$/i;
  31.  
  32. 	// canvas colors
  33. 	const glyphFillColor = "#808080"; // (big) (mini) fill color
  34. 	const bigGlyphStrokeColor = "#111111"; // (big) stroke color
  35. 	const bigGlyphMarkerColor = "#f00"; // (big) min & max width marker
  36. 	const miniGlyphMarkerColor = "#606060"; // (mini) glyph index (bottom left corner)
  37. 	const glyphRulerColor = "#a0a0a0"; // (mini) min & max width marker & (big) glyph horizontal lines
  38.  
  39. 	function startLoad() {
  40. 		const block = $(".blob-wrapper a[href*='?raw=true']");
  41. 		const body = block && block.closest(".Box-body");
  42. 		if (body) {
  43. 			body.classList.add("ghfp-body");
  44. 			body.innerHTML = "<span class='gfp-loading ghd-invert'></span>";
  45. 		}
  46. 		return block && block.href;
  47. 	}
  48.  
  49. 	function getFont() {
  50. 		const url = startLoad();
  51. 		if (url) {
  52. 			// add loading indicator
  53. 			GM_xmlhttpRequest({
  54. 				method: "GET",
  55. 				url,
  56. 				responseType: "arraybuffer",
  57. 				onload: response => {
  58. 					setupFont(response.response);
  59. 				}
  60. 			});
  61. 		}
  62. 	}
  63.  
  64. 	function setupFont(data) {
  65. 		const block = $(".ghfp-body");
  66. 		const el = $(".final-path");
  67. 		if (block && el) {
  68. 			try {
  69. 				font = opentype.parse(data);
  70. 				addHTML(block, el);
  71. 				showErrorMessage("");
  72. 				onFontLoaded(font);
  73. 			} catch (err) {
  74. 				block.innerHTML = "<h2 class='gfp-message cdel'></h2>";
  75. 				showErrorMessage(err.toString());
  76. 				if (err.stack) {
  77. 					console.error(err.stack);
  78. 				}
  79. 				throw (err);
  80. 			}
  81. 		}
  82. 	}
  83.  
  84. 	function addHTML(block, el) {
  85. 		let name = el.textContent || "";
  86. 		block.innerHTML = `
  87. 			<div id="gfp-wrapper">
  88. 				<span class="gfp-info" id="gfp-font-name">${name}</span>
  89. 				<h2 class="gfp-message cdel"></h2>
  90. 				<hr>
  91. 				<div id="gfp-font-data">
  92. 					<div class="gfp-collapsed">Font Header table <a href="https://www.microsoft.com/typography/OTSPEC/head.htm" target="_blank">head</a></div>
  93. 					<dl id="gfp-head-table"><dt>Undefined</dt></dl>
  94. 					<div class="gfp-collapsed">Horizontal Header table <a href="https://www.microsoft.com/typography/OTSPEC/hhea.htm" target="_blank">hhea</a></div>
  95. 					<dl id="gfp-hhea-table"><dt>Undefined</dt></dl>
  96. 					<div class="gfp-collapsed">Maximum Profile table <a href="https://www.microsoft.com/typography/OTSPEC/maxp.htm" target="_blank">maxp</a></div>
  97. 					<dl id="gfp-maxp-table"><dt>Undefined</dt></dl>
  98. 					<div class="gfp-collapsed">Naming table <a href="https://www.microsoft.com/typography/OTSPEC/name.htm" target="_blank">name</a></div>
  99. 					<dl id="gfp-name-table"><dt>Undefined</dt></dl>
  100. 					<div class="gfp-collapsed">OS/2 and Windows Metrics table <a href="https://www.microsoft.com/typography/OTSPEC/os2.htm" target="_blank">OS/2</a></div>
  101. 					<dl id="gfp-os2-table"><dt>Undefined</dt></dl>
  102. 					<div class="gfp-collapsed">PostScript table <a href="https://www.microsoft.com/typography/OTSPEC/post.htm" target="_blank">post</a></div>
  103. 					<dl id="gfp-post-table"><dt>Undefined</dt></dl>
  104. 					<div class="gfp-collapsed">Character To Glyph Index Mapping Table <a href="https://www.microsoft.com/typography/OTSPEC/cmap.htm" target="_blank">cmap</a></div>
  105. 					<dl id="gfp-cmap-table"><dt>Undefined</dt></dl>
  106. 					<div class="gfp-collapsed">Font Variations table <a href="https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6fvar.html" target="_blank">fvar</a></div>
  107. 					<dl id="gfp-fvar-table"><dt>Undefined</dt></dl>
  108. 				</div>
  109. 				<hr>
  110. 				<div>
  111. 					<div>Show unicode: <input class="gfp-show-unicode" type="checkbox"${showUnicode ? " checked" : ""}></div>
  112. 					Glyphs <span id="gfp-pagination"></span>
  113. 					<br>
  114. 					<div id="gfp-glyph-list-end"></div>
  115. 				</div>
  116. 				<div style="position: relative">
  117. 					<div id="gfp-glyph-display">
  118. 						<canvas id="gfp-glyph-bg" class="ghd-invert" width="500" height="500"></canvas>
  119. 						<canvas id="gfp-glyph" class="ghd-invert" width="500" height="500"></canvas>
  120. 					</div>
  121. 					<div id="gfp-glyph-data"></div>
  122. 					<div style="clear: both"></div>
  123. 				</div>
  124. 				<span style="font-size:0.8em">Powered by <a href="https://github.com/nodebox/opentype.js">opentype.js</a></span>
  125. 			</div>
  126. 		`;
  127. 		prepareGlyphList();
  128. 		// Add bindings for collapsible font data
  129. 		let tableHeaders = document.getElementById("gfp-font-data").getElementsByTagName("div"),
  130. 			indx = tableHeaders.length;
  131. 		while (indx--) {
  132. 			tableHeaders[indx].addEventListener("click", event => {
  133. 				event.target && event.target.classList.toggle("gfp-collapsed");
  134. 			}, false);
  135. 		}
  136. 		addBindings();
  137. 	}
  138.  
  139. 	function addBindings() {
  140. 		$(".gfp-show-unicode").addEventListener("change", function() {
  141. 			showUnicode = this.checked;
  142. 			GM_setValue("gfp-show-unicode", showUnicode);
  143. 			displayGlyphPage(pageSelected);
  144. 			return false;
  145. 		}, false);
  146.  
  147. 		$("#gfp-glyph-data").addEventListener("change", function() {
  148. 			showPoints = $(".gfp-show-points", this).checked;
  149. 			showArrows = $(".gfp-show-arrows", this).checked;
  150. 			GM_setValue("gfp-show-points", showPoints);
  151. 			GM_setValue("gfp-show-arrows", showArrows);
  152. 			cellSelect();
  153. 			return false;
  154. 		}, false);
  155. 	}
  156.  
  157. 	function $(selector, el) {
  158. 		return (el || document).querySelector(selector);
  159. 	}
  160.  
  161. 	function init() {
  162. 		// get file name from bread crumb
  163. 		let el = $(".final-path");
  164. 		// font extension supported?
  165. 		if (el && fontExt.test(el.textContent || "")) {
  166. 			getFont();
  167. 		}
  168. 	}
  169.  
  170. 	document.addEventListener("ghmo:container", init);
  171. 	init();
  172.  
  173. 	/* Code modified from http://opentype.js.org/ demos */
  174. 	GM_addStyle(`
  175. 		#gfp-wrapper { text-align:left; padding:20px; }
  176. 		#gfp-wrapper canvas { background-image:none !important; background-color:transparent !important; }
  177. 		.gfp-message { position:relative; top:-3px; padding:1px 5px; font-weight:bold; border-radius:2px; display:none; clear:both; }
  178. 		#gfp-glyphs { width:950px; }
  179. 		.gfp-info { float:right; font-size:14px; color:#999; }
  180. 		#gfp-wrapper hr { clear:both; border:none; border-bottom:1px solid #ccc; margin:20px 0 20px 0; padding:0; }
  181. 		/* Font Inspector */
  182. 		#gfp-font-data div { font-weight:normal; margin:0; cursor:pointer; }
  183. 		#gfp-font-data div:before { font-size:85%; content:"▼"; display:inline-block; margin-right:6px; transform:unset; }
  184. 		#gfp-font-data .gfp-collapsed:before { transform:rotate(-90deg); }
  185. 		#gfp-font-data div.gfp-collapsed + dl { display:none; }
  186. 		#gfp-font-data dl { margin-top:0; padding-left:2em; color:#777; }
  187. 		#gfp-font-data dt { float:left; }
  188. 		#gfp-font-data dd { margin-left: 12em; word-break:break-all; max-height:100px; overflow-y:auto; }
  189. 		#gfp-font-data .gfp-langtag { font-size:85%; color:#999; white-space:nowrap; }
  190. 		#gfp-font-data .gfp-langname { padding-right:0.5em; }
  191. 		#gfp-font-data .gfp-underline { border-bottom:1px solid #555; }
  192. 		/* Glyph Inspector */
  193. 		#gfp-pagination span { margin:0 0.3em; cursor:pointer; }
  194. 		#gfp-pagination span.gfp-page-selected { font-weight:bold; cursor:default; -webkit-filter:brightness(150%); filter:brightness(150%); }
  195. 		canvas.gfp-item { float:left; border:solid 1px #a0a0a0; margin-right:-1px; margin-bottom:-1px; cursor:pointer; }
  196. 		canvas.gfp-item:hover { opacity:.8; }
  197. 		#gfp-glyph-list-end { clear:both; height:20px; }
  198. 		#gfp-glyph-display { float:left; border:solid 1px #a0a0a0; position:relative; width:500px; height:500px; }
  199. 		#gfp-glyph, #gfp-glyph-bg { position:absolute; top:0; left:0; border:0; }
  200. 		#gfp-glyph-data { float:left; margin-left:2em; }
  201. 		#gfp-glyph-data dl { margin:0; }
  202. 		#gfp-glyph-data dt { float:left; }
  203. 		#gfp-glyph-data dd { margin-left:12em; }
  204. 		#gfp-glyph-data pre { font-size:11px; }
  205. 		pre.gfp-path { margin:0; }
  206. 		pre.gfp-contour { margin:0 0 1em 2em; border-bottom:solid 1px #a0a0a0; }
  207. 		span.gfp-oncurve { color:blue; }
  208. 		span.gfp-offcurve { color:red; }
  209. 		.gfp-loading { display:block; margin:20px auto; border-radius:50%; border-width:2px; border-style:solid; border-color: transparent transparent #000 #000; width:30px; height:30px; animation:gfploading .5s infinite linear; }
  210. 		@keyframes gfploading { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }
  211. 	`);
  212.  
  213. /*eslint-disable */
  214. 	/* Code copied from http://opentype.js.org/font-inspector.html */
  215. 	function escapeHtml(unsafe) {
  216. 		return unsafe
  217. 			.replace(/&/g, '&amp;')
  218. 			.replace(/</g, '&lt;')
  219. 			.replace(/>/g, '&gt;')
  220. 			.replace(/\u0022/g, '&quot;')
  221. 			.replace(/\u0027/g, '&#039;');
  222. 	}
  223.  
  224. 	function displayNames(names) {
  225. 		let indx, property, translations, langs, lang, langIndx, langLen, esclang,
  226. 			html = '',
  227. 			properties = Object.keys(names),
  228. 			len = properties.length;
  229. 		for (indx = 0; indx < len; indx++) {
  230. 			property = properties[indx];
  231. 			html += '<dt>' + escapeHtml(property) + '</dt><dd>';
  232. 			translations = names[property];
  233. 			langs = Object.keys(translations);
  234. 			langLen = langs.length;
  235. 			for (langIndx = 0; langIndx < langLen; langIndx++) {
  236. 				lang = langs[langIndx];
  237. 				esclang = escapeHtml(lang);
  238. 				html += '<span class="gfp-langtag">' + esclang +
  239. 					'</span> <span class="gfp-langname" lang=' + esclang + '>' +
  240. 					escapeHtml(translations[lang]) + '</span> ';
  241. 			}
  242. 			html += '</dd>';
  243. 		}
  244. 		document.getElementById('gfp-name-table').innerHTML = html;
  245. 	}
  246.  
  247. 	function displayFontData() {
  248. 		let html, tablename, table, property, value, element;
  249. 		for (tablename in font.tables) {
  250. 			if (font.tables.hasOwnProperty(tablename)) {
  251. 				table = font.tables[tablename];
  252. 				if (tablename === 'name') {
  253. 					displayNames(table);
  254. 					continue;
  255. 				}
  256. 				html = '';
  257. 				for (property in table) {
  258. 					if (table.hasOwnProperty(property)) {
  259. 						value = table[property];
  260. 						html += '<dt>' + property + '</dt><dd>';
  261. 						if (Array.isArray(value) && typeof value[0] === 'object') {
  262. 							html += value.map(item => {
  263. 								return JSON.stringify(item);
  264. 							}).join('<br>');
  265. 						} else if (typeof value === 'object') {
  266. 							html += JSON.stringify(value);
  267. 						} else {
  268. 							html += value;
  269. 						}
  270. 						html += '</dd>';
  271. 					}
  272. 				}
  273. 				element = document.getElementById('gfp-' + tablename + '-table');
  274. 				if (element) {
  275. 					element.innerHTML = html;
  276. 				}
  277. 			}
  278. 		}
  279. 	}
  280.  
  281. 	/* Code copied from http://opentype.js.org/glyph-inspector.html */
  282. 	const cellCount = 100,
  283. 		cellWidth = 62,
  284. 		cellHeight = 60,
  285. 		cellMarginTop = 1,
  286. 		cellMarginBottom = 8,
  287. 		cellMarginLeftRight = 1,
  288. 		glyphMargin = 5,
  289. 		pixelRatio = window.devicePixelRatio || 1,
  290. 		arrowLength = 10,
  291. 		arrowAperture = 4;
  292.  
  293. 	let pageSelected, fontScale, fontSize, fontBaseline, glyphScale, glyphSize, glyphBaseline;
  294.  
  295. 	function enableHighDPICanvas(canvas) {
  296. 		let pixelRatio, oldWidth, oldHeight;
  297. 		if (typeof canvas === 'string') {
  298. 			canvas = document.getElementById(canvas);
  299. 		}
  300. 		pixelRatio = window.devicePixelRatio || 1;
  301. 		if (pixelRatio === 1) {
  302. 			return;
  303. 		}
  304. 		oldWidth = canvas.width;
  305. 		oldHeight = canvas.height;
  306. 		canvas.width = oldWidth * pixelRatio;
  307. 		canvas.height = oldHeight * pixelRatio;
  308. 		canvas.style.width = oldWidth + 'px';
  309. 		canvas.style.height = oldHeight + 'px';
  310. 		canvas.getContext('2d').scale(pixelRatio, pixelRatio);
  311. 	}
  312.  
  313. 	function showErrorMessage(message) {
  314. 		let el = $('.gfp-message');
  315. 		el.style.display = (!message || message.trim().length === 0) ? 'none' : 'block';
  316. 		el.innerHTML = message;
  317. 	}
  318.  
  319. 	function pathCommandToString(cmd) {
  320. 		let str = '<strong>' + cmd.type + '</strong> ' +
  321. 			((cmd.x !== undefined) ? 'x=' + cmd.x + ' y=' + cmd.y + ' ' : '') +
  322. 			((cmd.x1 !== undefined) ? 'x1=' + cmd.x1 + ' y1=' + cmd.y1 + ' ' : '') +
  323. 			((cmd.x2 !== undefined) ? 'x2=' + cmd.x2 + ' y2=' + cmd.y2 : '');
  324. 		return str;
  325. 	}
  326.  
  327. 	function contourToString(contour) {
  328. 		return '<pre class="gfp-contour">' + contour.map(point => {
  329. 			// ".text-blue" class modified by GitHub Dark style
  330. 			// ".cdel" class modified by GitHub Dark style - more readable red
  331. 			return '<span class="gfp-' + (point.onCurve ? 'oncurve text-blue' : 'offcurve cdel') +
  332. 				'">x=' + point.x + ' y=' + point.y + '</span>';
  333. 		}).join('\n') + '</pre>';
  334. 	}
  335.  
  336. 	function formatUnicode(unicode) {
  337. 		unicode = unicode.toString(16);
  338. 		if (unicode.length > 4) {
  339. 			return ('000000' + unicode.toUpperCase()).substr(-6);
  340. 		} else {
  341. 			return ('0000' + unicode.toUpperCase()).substr(-4);
  342. 		}
  343. 	}
  344.  
  345. 	function displayGlyphData(glyphIndex) {
  346. 		let glyph, contours, html,
  347. 			container = document.getElementById('gfp-glyph-data'),
  348. 			addItem = name => {
  349. 				return glyph[name] ? `<dt>${name}</dt><dd>${glyph[name]}</dd>` : '';
  350. 			};
  351. 		if (glyphIndex < 0) {
  352. 			container.innerHTML = '';
  353. 			return;
  354. 		}
  355. 		glyph = font.glyphs.get(glyphIndex);
  356. 		html = `<dl>
  357. 			<dt>Show points</dt>
  358. 			<dd><input class="gfp-show-points" type="checkbox"${showPoints ? ' checked' : ''}></dd>
  359. 			<dt>Show arrows</dt>
  360. 			<dd><input class="gfp-show-arrows" type="checkbox"${showArrows ? ' checked' : ''}></dd>
  361. 			<dt>name</dt><dd>${glyph.name}</dd>`;
  362.  
  363. 		if (glyph.unicode) {
  364. 			html += '<dt>unicode</dt><dd>' + glyph.unicodes.map(formatUnicode).join(', ') + '</dd>';
  365. 		}
  366. 		html += addItem('index') +
  367. 			addItem('xMin') +
  368. 			addItem('xMax') +
  369. 			addItem('yMin') +
  370. 			addItem('yMax') +
  371. 			addItem('advanceWidth') +
  372. 			addItem('leftSideBearing') +
  373. 			'</dl>';
  374.  
  375. 		if (glyph.numberOfContours > 0) {
  376. 			contours = glyph.getContours();
  377. 			html += 'contours:<br>' + contours.map(contourToString).join('\n');
  378. 		} else if (glyph.isComposite) {
  379. 			html += '<br>This composite glyph is a combination of :<ul><li>' +
  380. 				glyph.components.map(component => {
  381. 					return 'glyph ' + component.glyphIndex + ' at dx=' + component.dx +
  382. 						', dy=' + component.dy;
  383. 				}).join('</li><li>') + '</li></ul>';
  384. 		} else if (glyph.path) {
  385. 			html += 'path:<br><pre class="gfp-path">  ' +
  386. 				glyph.path.commands.map(pathCommandToString).join('\n  ') + '\n</pre>';
  387. 		}
  388. 		container.innerHTML = html;
  389. 	}
  390.  
  391. 	function drawArrow(ctx, x1, y1, x2, y2) {
  392. 		let dx = x2 - x1,
  393. 			dy = y2 - y1,
  394. 			segmentLength = Math.sqrt(dx * dx + dy * dy),
  395. 			unitx = dx / segmentLength,
  396. 			unity = dy / segmentLength,
  397. 			basex = x2 - arrowLength * unitx,
  398. 			basey = y2 - arrowLength * unity,
  399. 			normalx = arrowAperture * unity,
  400. 			normaly = -arrowAperture * unitx;
  401. 		ctx.beginPath();
  402. 		ctx.moveTo(x2, y2);
  403. 		ctx.lineTo(basex + normalx, basey + normaly);
  404. 		ctx.lineTo(basex - normalx, basey - normaly);
  405. 		ctx.lineTo(x2, y2);
  406. 		ctx.closePath();
  407. 		ctx.fill();
  408. 	}
  409.  
  410. 	/**
  411. 	 * This function is Path.prototype.draw with an arrow
  412. 	 * at the end of each contour.
  413. 	 */
  414. 	function drawPathWithArrows(ctx, path) {
  415. 		let indx, cmd, x1, y1, x2, y2,
  416. 			arrows = [],
  417. 			len = path.commands.length;
  418. 		ctx.beginPath();
  419. 		for (indx = 0; indx < len; indx++) {
  420. 			cmd = path.commands[indx];
  421. 			if (cmd.type === 'M') {
  422. 				if (x1 !== undefined) {
  423. 					arrows.push([ctx, x1, y1, x2, y2]);
  424. 				}
  425. 				ctx.moveTo(cmd.x, cmd.y);
  426. 			} else if (cmd.type === 'L') {
  427. 				ctx.lineTo(cmd.x, cmd.y);
  428. 				x1 = x2;
  429. 				y1 = y2;
  430. 			} else if (cmd.type === 'C') {
  431. 				ctx.bezierCurveTo(cmd.x1, cmd.y1, cmd.x2, cmd.y2, cmd.x, cmd.y);
  432. 				x1 = cmd.x2;
  433. 				y1 = cmd.y2;
  434. 			} else if (cmd.type === 'Q') {
  435. 				ctx.quadraticCurveTo(cmd.x1, cmd.y1, cmd.x, cmd.y);
  436. 				x1 = cmd.x1;
  437. 				y1 = cmd.y1;
  438. 			} else if (cmd.type === 'Z') {
  439. 				arrows.push([ctx, x1, y1, x2, y2]);
  440. 				ctx.closePath();
  441. 			}
  442. 			x2 = cmd.x;
  443. 			y2 = cmd.y;
  444. 		}
  445. 		if (path.fill) {
  446. 			ctx.fillStyle = path.fill;
  447. 			ctx.fill();
  448. 		}
  449. 		if (path.stroke) {
  450. 			ctx.strokeStyle = path.stroke;
  451. 			ctx.lineWidth = path.strokeWidth;
  452. 			ctx.stroke();
  453. 		}
  454. 		ctx.fillStyle = bigGlyphStrokeColor;
  455. 		if (showArrows) {
  456. 			arrows.forEach(arrow => {
  457. 				drawArrow.apply(null, arrow);
  458. 			});
  459. 		}
  460. 	}
  461.  
  462. 	function displayGlyph(glyphIndex) {
  463. 		let glyph, glyphWidth, xmin, xmax, x0, markSize, path,
  464. 			canvas = document.getElementById('gfp-glyph'),
  465. 			ctx = canvas.getContext('2d'),
  466. 			width = canvas.width / pixelRatio,
  467. 			height = canvas.height / pixelRatio;
  468. 		ctx.clearRect(0, 0, width, height);
  469. 		if (glyphIndex < 0) {
  470. 			return;
  471. 		}
  472. 		glyph = font.glyphs.get(glyphIndex);
  473. 		glyphWidth = glyph.advanceWidth * glyphScale;
  474. 		xmin = (width - glyphWidth) / 2;
  475. 		xmax = (width + glyphWidth) / 2;
  476. 		x0 = xmin;
  477. 		markSize = 10;
  478.  
  479. 		ctx.fillStyle = bigGlyphMarkerColor;
  480. 		ctx.fillRect(xmin - markSize + 1, glyphBaseline, markSize, 1);
  481. 		ctx.fillRect(xmin, glyphBaseline, 1, markSize);
  482. 		ctx.fillRect(xmax, glyphBaseline, markSize, 1);
  483. 		ctx.fillRect(xmax, glyphBaseline, 1, markSize);
  484. 		ctx.textAlign = 'center';
  485. 		ctx.fillText('0', xmin, glyphBaseline + markSize + 10);
  486. 		ctx.fillText(glyph.advanceWidth, xmax, glyphBaseline + markSize + 10);
  487.  
  488. 		ctx.fillStyle = bigGlyphStrokeColor;
  489. 		path = glyph.getPath(x0, glyphBaseline, glyphSize);
  490. 		path.fill = glyphFillColor;
  491. 		path.stroke = bigGlyphStrokeColor;
  492. 		path.strokeWidth = 1.5;
  493. 		drawPathWithArrows(ctx, path);
  494. 		if (showPoints) {
  495. 			glyph.drawPoints(ctx, x0, glyphBaseline, glyphSize);
  496. 		}
  497. 	}
  498.  
  499. 	function renderGlyphItem(canvas, glyphIndex) {
  500. 		const cellMarkSize = 4,
  501. 			ctx = canvas.getContext('2d');
  502. 		ctx.clearRect(0, 0, cellWidth, cellHeight);
  503. 		if (glyphIndex >= font.numGlyphs) {
  504. 			return;
  505. 		}
  506.  
  507. 		ctx.fillStyle = miniGlyphMarkerColor;
  508. 		ctx.font = '10px sans-serif';
  509. 		let glyph = font.glyphs.get(glyphIndex),
  510. 			glyphWidth = glyph.advanceWidth * fontScale,
  511. 			xmin = (cellWidth - glyphWidth) / 2,
  512. 			xmax = (cellWidth + glyphWidth) / 2,
  513. 			x0 = xmin;
  514.  
  515. 		ctx.fillText(showUnicode ? glyph.unicodes.map(formatUnicode).join(', ') : glyphIndex, 1, cellHeight - 1);
  516.  
  517. 		ctx.fillStyle = glyphRulerColor;
  518. 		ctx.fillRect(xmin - cellMarkSize + 1, fontBaseline, cellMarkSize, 1);
  519. 		ctx.fillRect(xmin, fontBaseline, 1, cellMarkSize);
  520. 		ctx.fillRect(xmax, fontBaseline, cellMarkSize, 1);
  521. 		ctx.fillRect(xmax, fontBaseline, 1, cellMarkSize);
  522.  
  523. 		ctx.fillStyle = '#000000';
  524. 		let path = glyph.getPath(x0, fontBaseline, fontSize);
  525. 		path.fill = glyphFillColor;
  526. 		path.draw(ctx);
  527. 	}
  528.  
  529. 	function displayGlyphPage(pageNum) {
  530. 		pageSelected = pageNum;
  531. 		document.getElementById('gfp-p' + pageNum).className = 'gfp-page-selected';
  532. 		let indx,
  533. 			firstGlyph = pageNum * cellCount;
  534. 		for (indx = 0; indx < cellCount; indx++) {
  535. 			renderGlyphItem(document.getElementById('gfp-g' + indx), firstGlyph + indx);
  536. 		}
  537. 	}
  538.  
  539. 	function pageSelect(event) {
  540. 		document.getElementsByClassName('gfp-page-selected')[0].className = 'text-blue';
  541. 		displayGlyphPage((event.target.id || '').replace('gfp-p', ''));
  542. 	}
  543.  
  544. 	function initGlyphDisplay() {
  545. 		let glyphBgCanvas = document.getElementById('gfp-glyph-bg'),
  546. 			w = glyphBgCanvas.width / pixelRatio,
  547. 			h = glyphBgCanvas.height / pixelRatio,
  548. 			glyphW = w - glyphMargin * 2,
  549. 			glyphH = h - glyphMargin * 2,
  550. 			head = font.tables.head,
  551. 			maxHeight = head.yMax - head.yMin,
  552. 			ctx = glyphBgCanvas.getContext('2d');
  553.  
  554. 		glyphScale = Math.min(glyphW / (head.xMax - head.xMin), glyphH / maxHeight);
  555. 		glyphSize = glyphScale * font.unitsPerEm;
  556. 		glyphBaseline = glyphMargin + glyphH * head.yMax / maxHeight;
  557.  
  558. 		function hline(text, yunits) {
  559. 			let ypx = glyphBaseline - yunits * glyphScale;
  560. 			ctx.fillText(text, 2, ypx + 3);
  561. 			ctx.fillRect(80, ypx, w, 1);
  562. 		}
  563.  
  564. 		ctx.clearRect(0, 0, w, h);
  565. 		ctx.fillStyle = glyphRulerColor;
  566. 		hline('Baseline', 0);
  567. 		hline('yMax', font.tables.head.yMax);
  568. 		hline('yMin', font.tables.head.yMin);
  569. 		hline('Ascender', font.tables.hhea.ascender);
  570. 		hline('Descender', font.tables.hhea.descender);
  571. 		hline('Typo Ascender', font.tables.os2.sTypoAscender);
  572. 		hline('Typo Descender', font.tables.os2.sTypoDescender);
  573. 	}
  574.  
  575. 	function onFontLoaded(font) {
  576. 		let indx, link, lastIndex,
  577. 			w = cellWidth - cellMarginLeftRight * 2,
  578. 			h = cellHeight - cellMarginTop - cellMarginBottom,
  579. 			head = font.tables.head,
  580. 			maxHeight = head.yMax - head.yMin,
  581. 			pagination = document.getElementById('gfp-pagination'),
  582. 			fragment = document.createDocumentFragment(),
  583. 			numPages = Math.ceil(font.numGlyphs / cellCount);
  584.  
  585. 		fontScale = Math.min(w / (head.xMax - head.xMin), h / maxHeight);
  586. 		fontSize = fontScale * font.unitsPerEm;
  587. 		fontBaseline = cellMarginTop + h * head.yMax / maxHeight;
  588. 		pagination.innerHTML = '';
  589.  
  590. 		for (indx = 0; indx < numPages; indx++) {
  591. 			link = document.createElement('span');
  592. 			lastIndex = Math.min(font.numGlyphs - 1, (indx + 1) * cellCount - 1);
  593. 			link.textContent = indx * cellCount + '-' + lastIndex;
  594. 			link.id = 'gfp-p' + indx;
  595. 			link.className = 'text-blue';
  596. 			link.addEventListener('click', pageSelect, false);
  597. 			fragment.appendChild(link);
  598. 			// A white space allows to break very long lines into multiple lines.
  599. 			// This is needed for fonts with thousands of glyphs.
  600. 			fragment.appendChild(document.createTextNode(' '));
  601. 		}
  602. 		pagination.appendChild(fragment);
  603.  
  604. 		displayFontData();
  605. 		initGlyphDisplay();
  606. 		displayGlyphPage(0);
  607. 		displayGlyph(-1);
  608. 		displayGlyphData(-1);
  609. 	}
  610.  
  611. 	function cellSelect(event) {
  612. 		if (!font) {
  613. 			return;
  614. 		}
  615. 		let firstGlyphIndex = pageSelected * cellCount,
  616. 			cellIndex = event ? +event.target.id.replace('gfp-g', '') : currentIndex,
  617. 			glyphIndex = firstGlyphIndex + cellIndex;
  618. 		currentIndex = cellIndex;
  619. 		if (glyphIndex < font.numGlyphs) {
  620. 			displayGlyph(glyphIndex);
  621. 			displayGlyphData(glyphIndex);
  622. 		}
  623. 	}
  624.  
  625. 	function prepareGlyphList() {
  626. 		let indx, canvas,
  627. 			marker = document.getElementById('gfp-glyph-list-end'),
  628. 			parent = marker.parentElement;
  629. 		for (indx = 0; indx < cellCount; indx++) {
  630. 			canvas = document.createElement('canvas');
  631. 			canvas.width = cellWidth;
  632. 			canvas.height = cellHeight;
  633. 			canvas.className = 'gfp-item ghd-invert';
  634. 			canvas.id = 'gfp-g' + indx;
  635. 			canvas.addEventListener('click', cellSelect, false);
  636. 			enableHighDPICanvas(canvas);
  637. 			parent.insertBefore(canvas, marker);
  638. 		}
  639. 	}
  640. 	/* eslint-enable */
  641.  
  642. })();