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GitHub Font Preview

A userscript that adds a font file preview

  1. // ==UserScript==
  2. // @name        GitHub Font Preview
  3. // @version     1.0.26
  4. // @description A userscript that adds a font file preview
  5. // @license     MIT
  6. // @author      Rob Garrison
  7. // @namespace   https://github.com/Mottie
  8. // @match       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://greatest.deepsurf.us/scripts/28721-mutations/code/mutations.js?version=1108163
  17. // @require     https://greatest.deepsurf.us/scripts/20469-opentype-js/code/opentypejs.js?version=130870
  18. // @icon        https://github.githubassets.com/pinned-octocat.svg
  19. // @supportURL  https://github.com/Mottie/GitHub-userscripts/issues
  20. // ==/UserScript==
  21.  
  22. /* global opentype */
  23. (() => {
  24. 	"use strict";
  25.  
  26. 	let font;
  27. 	let showUnicode = GM_getValue("gfp-show-unicode", false);
  28. 	let showPoints = GM_getValue("gfp-show-points", true);
  29. 	let showArrows = GM_getValue("gfp-show-arrows", true);
  30. 	let currentIndex = 0;
  31.  
  32. 	// supported font types
  33. 	const fontExt = /\.(otf|ttf|woff)$/i;
  34.  
  35. 	// canvas colors
  36. 	const glyphFillColor = "#808080"; // (big) (mini) fill color
  37. 	const bigGlyphStrokeColor = "#111111"; // (big) stroke color
  38. 	const bigGlyphMarkerColor = "#f00"; // (big) min & max width marker
  39. 	const miniGlyphMarkerColor = "#606060"; // (mini) glyph index (bottom left corner)
  40. 	const glyphRulerColor = "#a0a0a0"; // (mini) min & max width marker & (big) glyph horizontal lines
  41.  
  42. 	function startLoad() {
  43. 		const block = $(".blob-wrapper a[href*='?raw=true']");
  44. 		const body = block && block.closest(".Box-body");
  45. 		if (body) {
  46. 			body.classList.add("ghfp-body");
  47. 			body.innerHTML = "<span class='gfp-loading ghd-invert'></span>";
  48. 		}
  49. 		return block && block.href;
  50. 	}
  51.  
  52. 	function getFont() {
  53. 		const url = startLoad();
  54. 		if (url) {
  55. 			// add loading indicator
  56. 			GM_xmlhttpRequest({
  57. 				method: "GET",
  58. 				url,
  59. 				responseType: "arraybuffer",
  60. 				onload: response => {
  61. 					setupFont(response.response);
  62. 				}
  63. 			});
  64. 		}
  65. 	}
  66.  
  67. 	function setupFont(data) {
  68. 		const block = $(".ghfp-body");
  69. 		const el = $(".final-path");
  70. 		if (block && el) {
  71. 			try {
  72. 				font = opentype.parse(data);
  73. 				addHTML(block, el);
  74. 				showErrorMessage("");
  75. 				onFontLoaded(font);
  76. 			} catch (err) {
  77. 				block.innerHTML = "<h2 class='gfp-message cdel'></h2>";
  78. 				showErrorMessage(err.toString());
  79. 				if (err.stack) {
  80. 					console.error(err.stack);
  81. 				}
  82. 				throw (err);
  83. 			}
  84. 		}
  85. 	}
  86.  
  87. 	function addHTML(block, el) {
  88. 		let name = el.textContent || "";
  89. 		block.innerHTML = `
  90. 			<div id="gfp-wrapper">
  91. 				<span class="gfp-info" id="gfp-font-name">${name}</span>
  92. 				<h2 class="gfp-message cdel"></h2>
  93. 				<hr>
  94. 				<div id="gfp-font-data">
  95. 					<div class="gfp-collapsed">Font Header table <a href="https://www.microsoft.com/typography/OTSPEC/head.htm" target="_blank">head</a></div>
  96. 					<dl id="gfp-head-table"><dt>Undefined</dt></dl>
  97. 					<div class="gfp-collapsed">Horizontal Header table <a href="https://www.microsoft.com/typography/OTSPEC/hhea.htm" target="_blank">hhea</a></div>
  98. 					<dl id="gfp-hhea-table"><dt>Undefined</dt></dl>
  99. 					<div class="gfp-collapsed">Maximum Profile table <a href="https://www.microsoft.com/typography/OTSPEC/maxp.htm" target="_blank">maxp</a></div>
  100. 					<dl id="gfp-maxp-table"><dt>Undefined</dt></dl>
  101. 					<div class="gfp-collapsed">Naming table <a href="https://www.microsoft.com/typography/OTSPEC/name.htm" target="_blank">name</a></div>
  102. 					<dl id="gfp-name-table"><dt>Undefined</dt></dl>
  103. 					<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>
  104. 					<dl id="gfp-os2-table"><dt>Undefined</dt></dl>
  105. 					<div class="gfp-collapsed">PostScript table <a href="https://www.microsoft.com/typography/OTSPEC/post.htm" target="_blank">post</a></div>
  106. 					<dl id="gfp-post-table"><dt>Undefined</dt></dl>
  107. 					<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>
  108. 					<dl id="gfp-cmap-table"><dt>Undefined</dt></dl>
  109. 					<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>
  110. 					<dl id="gfp-fvar-table"><dt>Undefined</dt></dl>
  111. 				</div>
  112. 				<hr>
  113. 				<div>
  114. 					<div>Show unicode: <input class="gfp-show-unicode" type="checkbox"${showUnicode ? " checked" : ""}></div>
  115. 					Glyphs <span id="gfp-pagination"></span>
  116. 					<br>
  117. 					<div id="gfp-glyph-list-end"></div>
  118. 				</div>
  119. 				<div style="position: relative">
  120. 					<div id="gfp-glyph-display">
  121. 						<canvas id="gfp-glyph-bg" class="ghd-invert" width="500" height="500"></canvas>
  122. 						<canvas id="gfp-glyph" class="ghd-invert" width="500" height="500"></canvas>
  123. 					</div>
  124. 					<div id="gfp-glyph-data"></div>
  125. 					<div style="clear: both"></div>
  126. 				</div>
  127. 				<span style="font-size:0.8em">Powered by <a href="https://github.com/nodebox/opentype.js">opentype.js</a></span>
  128. 			</div>
  129. 		`;
  130. 		prepareGlyphList();
  131. 		// Add bindings for collapsible font data
  132. 		let tableHeaders = document.getElementById("gfp-font-data").getElementsByTagName("div"),
  133. 			indx = tableHeaders.length;
  134. 		while (indx--) {
  135. 			tableHeaders[indx].addEventListener("click", event => {
  136. 				event.target && event.target.classList.toggle("gfp-collapsed");
  137. 			}, false);
  138. 		}
  139. 		addBindings();
  140. 	}
  141.  
  142. 	function addBindings() {
  143. 		$(".gfp-show-unicode").addEventListener("change", function() {
  144. 			showUnicode = this.checked;
  145. 			GM_setValue("gfp-show-unicode", showUnicode);
  146. 			displayGlyphPage(pageSelected);
  147. 			return false;
  148. 		}, false);
  149.  
  150. 		$("#gfp-glyph-data").addEventListener("change", function() {
  151. 			showPoints = $(".gfp-show-points", this).checked;
  152. 			showArrows = $(".gfp-show-arrows", this).checked;
  153. 			GM_setValue("gfp-show-points", showPoints);
  154. 			GM_setValue("gfp-show-arrows", showArrows);
  155. 			cellSelect();
  156. 			return false;
  157. 		}, false);
  158. 	}
  159.  
  160. 	function $(selector, el) {
  161. 		return (el || document).querySelector(selector);
  162. 	}
  163.  
  164. 	function init() {
  165. 		// get file name from bread crumb
  166. 		let el = $(".final-path");
  167. 		// font extension supported?
  168. 		if (el && fontExt.test(el.textContent || "")) {
  169. 			getFont();
  170. 		}
  171. 	}
  172.  
  173. 	document.addEventListener("ghmo:container", init);
  174. 	init();
  175.  
  176. 	/* Code modified from http://opentype.js.org/ demos */
  177. 	GM_addStyle(`
  178. 		#gfp-wrapper { text-align:left; padding:20px; }
  179. 		#gfp-wrapper canvas { background-image:none !important; background-color:transparent !important; }
  180. 		.gfp-message { position:relative; top:-3px; padding:1px 5px; font-weight:bold; border-radius:2px; display:none; clear:both; }
  181. 		#gfp-glyphs { width:950px; }
  182. 		.gfp-info { float:right; font-size:14px; color:#999; }
  183. 		#gfp-wrapper hr { clear:both; border:none; border-bottom:1px solid #ccc; margin:20px 0 20px 0; padding:0; }
  184. 		/* Font Inspector */
  185. 		#gfp-font-data div { font-weight:normal; margin:0; cursor:pointer; }
  186. 		#gfp-font-data div:before { font-size:85%; content:"▼"; display:inline-block; margin-right:6px; transform:unset; }
  187. 		#gfp-font-data .gfp-collapsed:before { transform:rotate(-90deg); }
  188. 		#gfp-font-data div.gfp-collapsed + dl { display:none; }
  189. 		#gfp-font-data dl { margin-top:0; padding-left:2em; color:#777; }
  190. 		#gfp-font-data dt { float:left; }
  191. 		#gfp-font-data dd { margin-left: 12em; word-break:break-all; max-height:100px; overflow-y:auto; }
  192. 		#gfp-font-data .gfp-langtag { font-size:85%; color:#999; white-space:nowrap; }
  193. 		#gfp-font-data .gfp-langname { padding-right:0.5em; }
  194. 		#gfp-font-data .gfp-underline { border-bottom:1px solid #555; }
  195. 		/* Glyph Inspector */
  196. 		#gfp-pagination a { margin:0 0.3em; cursor:pointer; }
  197. 		#gfp-pagination .gfp-page-selected { font-weight:bold; cursor:default; -webkit-filter:brightness(150%); filter:brightness(150%); }
  198. 		canvas.gfp-item { float:left; border:solid 1px #a0a0a0; margin-right:-1px; margin-bottom:-1px; cursor:pointer; }
  199. 		canvas.gfp-item:hover { opacity:.8; }
  200. 		#gfp-glyph-list-end { clear:both; height:20px; }
  201. 		#gfp-glyph-display { float:left; border:solid 1px #a0a0a0; position:relative; width:500px; height:500px; }
  202. 		#gfp-glyph, #gfp-glyph-bg { position:absolute; top:0; left:0; border:0; }
  203. 		#gfp-glyph-data { float:left; margin-left:2em; }
  204. 		#gfp-glyph-data dl { margin:0; }
  205. 		#gfp-glyph-data dt { float:left; }
  206. 		#gfp-glyph-data dd { margin-left:12em; }
  207. 		#gfp-glyph-data pre { font-size:11px; }
  208. 		pre.gfp-path { margin:0; }
  209. 		pre.gfp-contour { margin:0 0 1em 2em; border-bottom:solid 1px #a0a0a0; }
  210. 		span.gfp-oncurve { color:var(--color-scale-blue-6); }
  211. 		span.gfp-offcurve { color:var(--color-scale-red-6); }
  212. 		.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; }
  213. 		@keyframes gfploading { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }
  214. 	`);
  215.  
  216. /*eslint-disable */
  217. 	/* Code copied from http://opentype.js.org/font-inspector.html */
  218. 	function escapeHtml(unsafe) {
  219. 		return unsafe
  220. 			.replace(/&/g, '&amp;')
  221. 			.replace(/</g, '&lt;')
  222. 			.replace(/>/g, '&gt;')
  223. 			.replace(/\u0022/g, '&quot;')
  224. 			.replace(/\u0027/g, '&#039;');
  225. 	}
  226.  
  227. 	function displayNames(names) {
  228. 		let indx, property, translations, langs, lang, langIndx, langLen, esclang,
  229. 			html = '',
  230. 			properties = Object.keys(names),
  231. 			len = properties.length;
  232. 		for (indx = 0; indx < len; indx++) {
  233. 			property = properties[indx];
  234. 			html += '<dt>' + escapeHtml(property) + '</dt><dd>';
  235. 			translations = names[property];
  236. 			langs = Object.keys(translations);
  237. 			langLen = langs.length;
  238. 			for (langIndx = 0; langIndx < langLen; langIndx++) {
  239. 				lang = langs[langIndx];
  240. 				esclang = escapeHtml(lang);
  241. 				html += '<span class="gfp-langtag">' + esclang +
  242. 					'</span> <span class="gfp-langname" lang=' + esclang + '>' +
  243. 					escapeHtml(translations[lang]) + '</span> ';
  244. 			}
  245. 			html += '</dd>';
  246. 		}
  247. 		document.getElementById('gfp-name-table').innerHTML = html;
  248. 	}
  249.  
  250. 	function displayFontData() {
  251. 		let html, tablename, table, property, value, element;
  252. 		for (tablename in font.tables) {
  253. 			if (font.tables.hasOwnProperty(tablename)) {
  254. 				table = font.tables[tablename];
  255. 				if (tablename === 'name') {
  256. 					displayNames(table);
  257. 					continue;
  258. 				}
  259. 				html = '';
  260. 				for (property in table) {
  261. 					if (table.hasOwnProperty(property)) {
  262. 						value = table[property];
  263. 						html += '<dt>' + property + '</dt><dd>';
  264. 						if (Array.isArray(value) && typeof value[0] === 'object') {
  265. 							html += value.map(item => {
  266. 								return JSON.stringify(item);
  267. 							}).join('<br>');
  268. 						} else if (typeof value === 'object') {
  269. 							html += JSON.stringify(value);
  270. 						} else {
  271. 							html += value;
  272. 						}
  273. 						html += '</dd>';
  274. 					}
  275. 				}
  276. 				element = document.getElementById('gfp-' + tablename + '-table');
  277. 				if (element) {
  278. 					element.innerHTML = html;
  279. 				}
  280. 			}
  281. 		}
  282. 	}
  283.  
  284. 	/* Code copied from http://opentype.js.org/glyph-inspector.html */
  285. 	const cellCount = 100,
  286. 		cellWidth = 62,
  287. 		cellHeight = 60,
  288. 		cellMarginTop = 1,
  289. 		cellMarginBottom = 8,
  290. 		cellMarginLeftRight = 1,
  291. 		glyphMargin = 5,
  292. 		pixelRatio = window.devicePixelRatio || 1,
  293. 		arrowLength = 10,
  294. 		arrowAperture = 4;
  295.  
  296. 	let pageSelected, fontScale, fontSize, fontBaseline, glyphScale, glyphSize, glyphBaseline;
  297.  
  298. 	function enableHighDPICanvas(canvas) {
  299. 		let pixelRatio, oldWidth, oldHeight;
  300. 		if (typeof canvas === 'string') {
  301. 			canvas = document.getElementById(canvas);
  302. 		}
  303. 		pixelRatio = window.devicePixelRatio || 1;
  304. 		if (pixelRatio === 1) {
  305. 			return;
  306. 		}
  307. 		oldWidth = canvas.width;
  308. 		oldHeight = canvas.height;
  309. 		canvas.width = oldWidth * pixelRatio;
  310. 		canvas.height = oldHeight * pixelRatio;
  311. 		canvas.style.width = oldWidth + 'px';
  312. 		canvas.style.height = oldHeight + 'px';
  313. 		canvas.getContext('2d').scale(pixelRatio, pixelRatio);
  314. 	}
  315.  
  316. 	function showErrorMessage(message) {
  317. 		let el = $('.gfp-message');
  318. 		el.style.display = (!message || message.trim().length === 0) ? 'none' : 'block';
  319. 		el.innerHTML = message;
  320. 	}
  321.  
  322. 	function pathCommandToString(cmd) {
  323. 		let str = '<strong>' + cmd.type + '</strong> ' +
  324. 			((cmd.x !== undefined) ? 'x=' + cmd.x + ' y=' + cmd.y + ' ' : '') +
  325. 			((cmd.x1 !== undefined) ? 'x1=' + cmd.x1 + ' y1=' + cmd.y1 + ' ' : '') +
  326. 			((cmd.x2 !== undefined) ? 'x2=' + cmd.x2 + ' y2=' + cmd.y2 : '');
  327. 		return str;
  328. 	}
  329.  
  330. 	function contourToString(contour) {
  331. 		return '<pre class="gfp-contour">' + contour.map(point => {
  332. 			return '<span class="gfp-' + (point.onCurve ? 'oncurve' : 'offcurve') +
  333. 				'">x=' + point.x + ' y=' + point.y + '</span>';
  334. 		}).join('\n') + '</pre>';
  335. 	}
  336.  
  337. 	function formatUnicode(unicode) {
  338. 		unicode = unicode.toString(16);
  339. 		if (unicode.length > 4) {
  340. 			return ('000000' + unicode.toUpperCase()).substr(-6);
  341. 		} else {
  342. 			return ('0000' + unicode.toUpperCase()).substr(-4);
  343. 		}
  344. 	}
  345.  
  346. 	function displayGlyphData(glyphIndex) {
  347. 		let glyph, contours, html,
  348. 			container = document.getElementById('gfp-glyph-data'),
  349. 			addItem = name => {
  350. 				return glyph[name] ? `<dt>${name}</dt><dd>${glyph[name]}</dd>` : '';
  351. 			};
  352. 		if (glyphIndex < 0) {
  353. 			container.innerHTML = '';
  354. 			return;
  355. 		}
  356. 		glyph = font.glyphs.get(glyphIndex);
  357. 		html = `<dl>
  358. 			<dt>Show points</dt>
  359. 			<dd><input class="gfp-show-points" type="checkbox"${showPoints ? ' checked' : ''}></dd>
  360. 			<dt>Show arrows</dt>
  361. 			<dd><input class="gfp-show-arrows" type="checkbox"${showArrows ? ' checked' : ''}></dd>
  362. 			<dt>name</dt><dd>${glyph.name}</dd>`;
  363.  
  364. 		if (glyph.unicode) {
  365. 			html += '<dt>unicode</dt><dd>' + glyph.unicodes.map(formatUnicode).join(', ') + '</dd>';
  366. 		}
  367. 		html += addItem('index') +
  368. 			addItem('xMin') +
  369. 			addItem('xMax') +
  370. 			addItem('yMin') +
  371. 			addItem('yMax') +
  372. 			addItem('advanceWidth') +
  373. 			addItem('leftSideBearing') +
  374. 			'</dl>';
  375.  
  376. 		if (glyph.numberOfContours > 0) {
  377. 			contours = glyph.getContours();
  378. 			html += 'contours:<br>' + contours.map(contourToString).join('\n');
  379. 		} else if (glyph.isComposite) {
  380. 			html += '<br>This composite glyph is a combination of :<ul><li>' +
  381. 				glyph.components.map(component => {
  382. 					return 'glyph ' + component.glyphIndex + ' at dx=' + component.dx +
  383. 						', dy=' + component.dy;
  384. 				}).join('</li><li>') + '</li></ul>';
  385. 		} else if (glyph.path) {
  386. 			html += 'path:<br><pre class="gfp-path">  ' +
  387. 				glyph.path.commands.map(pathCommandToString).join('\n  ') + '\n</pre>';
  388. 		}
  389. 		container.innerHTML = html;
  390. 	}
  391.  
  392. 	function drawArrow(ctx, x1, y1, x2, y2) {
  393. 		let dx = x2 - x1,
  394. 			dy = y2 - y1,
  395. 			segmentLength = Math.sqrt(dx * dx + dy * dy),
  396. 			unitx = dx / segmentLength,
  397. 			unity = dy / segmentLength,
  398. 			basex = x2 - arrowLength * unitx,
  399. 			basey = y2 - arrowLength * unity,
  400. 			normalx = arrowAperture * unity,
  401. 			normaly = -arrowAperture * unitx;
  402. 		ctx.beginPath();
  403. 		ctx.moveTo(x2, y2);
  404. 		ctx.lineTo(basex + normalx, basey + normaly);
  405. 		ctx.lineTo(basex - normalx, basey - normaly);
  406. 		ctx.lineTo(x2, y2);
  407. 		ctx.closePath();
  408. 		ctx.fill();
  409. 	}
  410.  
  411. 	/**
  412. 	 * This function is Path.prototype.draw with an arrow
  413. 	 * at the end of each contour.
  414. 	 */
  415. 	function drawPathWithArrows(ctx, path) {
  416. 		let indx, cmd, x1, y1, x2, y2,
  417. 			arrows = [],
  418. 			len = path.commands.length;
  419. 		ctx.beginPath();
  420. 		for (indx = 0; indx < len; indx++) {
  421. 			cmd = path.commands[indx];
  422. 			if (cmd.type === 'M') {
  423. 				if (x1 !== undefined) {
  424. 					arrows.push([ctx, x1, y1, x2, y2]);
  425. 				}
  426. 				ctx.moveTo(cmd.x, cmd.y);
  427. 			} else if (cmd.type === 'L') {
  428. 				ctx.lineTo(cmd.x, cmd.y);
  429. 				x1 = x2;
  430. 				y1 = y2;
  431. 			} else if (cmd.type === 'C') {
  432. 				ctx.bezierCurveTo(cmd.x1, cmd.y1, cmd.x2, cmd.y2, cmd.x, cmd.y);
  433. 				x1 = cmd.x2;
  434. 				y1 = cmd.y2;
  435. 			} else if (cmd.type === 'Q') {
  436. 				ctx.quadraticCurveTo(cmd.x1, cmd.y1, cmd.x, cmd.y);
  437. 				x1 = cmd.x1;
  438. 				y1 = cmd.y1;
  439. 			} else if (cmd.type === 'Z') {
  440. 				arrows.push([ctx, x1, y1, x2, y2]);
  441. 				ctx.closePath();
  442. 			}
  443. 			x2 = cmd.x;
  444. 			y2 = cmd.y;
  445. 		}
  446. 		if (path.fill) {
  447. 			ctx.fillStyle = path.fill;
  448. 			ctx.fill();
  449. 		}
  450. 		if (path.stroke) {
  451. 			ctx.strokeStyle = path.stroke;
  452. 			ctx.lineWidth = path.strokeWidth;
  453. 			ctx.stroke();
  454. 		}
  455. 		ctx.fillStyle = bigGlyphStrokeColor;
  456. 		if (showArrows) {
  457. 			arrows.forEach(arrow => {
  458. 				drawArrow.apply(null, arrow);
  459. 			});
  460. 		}
  461. 	}
  462.  
  463. 	function displayGlyph(glyphIndex) {
  464. 		let glyph, glyphWidth, xmin, xmax, x0, markSize, path,
  465. 			canvas = document.getElementById('gfp-glyph'),
  466. 			ctx = canvas.getContext('2d'),
  467. 			width = canvas.width / pixelRatio,
  468. 			height = canvas.height / pixelRatio;
  469. 		ctx.clearRect(0, 0, width, height);
  470. 		if (glyphIndex < 0) {
  471. 			return;
  472. 		}
  473. 		glyph = font.glyphs.get(glyphIndex);
  474. 		glyphWidth = glyph.advanceWidth * glyphScale;
  475. 		xmin = (width - glyphWidth) / 2;
  476. 		xmax = (width + glyphWidth) / 2;
  477. 		x0 = xmin;
  478. 		markSize = 10;
  479.  
  480. 		ctx.fillStyle = bigGlyphMarkerColor;
  481. 		ctx.fillRect(xmin - markSize + 1, glyphBaseline, markSize, 1);
  482. 		ctx.fillRect(xmin, glyphBaseline, 1, markSize);
  483. 		ctx.fillRect(xmax, glyphBaseline, markSize, 1);
  484. 		ctx.fillRect(xmax, glyphBaseline, 1, markSize);
  485. 		ctx.textAlign = 'center';
  486. 		ctx.fillText('0', xmin, glyphBaseline + markSize + 10);
  487. 		ctx.fillText(glyph.advanceWidth, xmax, glyphBaseline + markSize + 10);
  488.  
  489. 		ctx.fillStyle = bigGlyphStrokeColor;
  490. 		path = glyph.getPath(x0, glyphBaseline, glyphSize);
  491. 		path.fill = glyphFillColor;
  492. 		path.stroke = bigGlyphStrokeColor;
  493. 		path.strokeWidth = 1.5;
  494. 		drawPathWithArrows(ctx, path);
  495. 		if (showPoints) {
  496. 			glyph.drawPoints(ctx, x0, glyphBaseline, glyphSize);
  497. 		}
  498. 	}
  499.  
  500. 	function renderGlyphItem(canvas, glyphIndex) {
  501. 		const cellMarkSize = 4,
  502. 			ctx = canvas.getContext('2d');
  503. 		ctx.clearRect(0, 0, cellWidth, cellHeight);
  504. 		if (glyphIndex >= font.numGlyphs) {
  505. 			return;
  506. 		}
  507.  
  508. 		ctx.fillStyle = miniGlyphMarkerColor;
  509. 		ctx.font = '10px sans-serif';
  510. 		let glyph = font.glyphs.get(glyphIndex),
  511. 			glyphWidth = glyph.advanceWidth * fontScale,
  512. 			xmin = (cellWidth - glyphWidth) / 2,
  513. 			xmax = (cellWidth + glyphWidth) / 2,
  514. 			x0 = xmin;
  515.  
  516. 		ctx.fillText(showUnicode ? glyph.unicodes.map(formatUnicode).join(', ') : glyphIndex, 1, cellHeight - 1);
  517.  
  518. 		ctx.fillStyle = glyphRulerColor;
  519. 		ctx.fillRect(xmin - cellMarkSize + 1, fontBaseline, cellMarkSize, 1);
  520. 		ctx.fillRect(xmin, fontBaseline, 1, cellMarkSize);
  521. 		ctx.fillRect(xmax, fontBaseline, cellMarkSize, 1);
  522. 		ctx.fillRect(xmax, fontBaseline, 1, cellMarkSize);
  523.  
  524. 		ctx.fillStyle = '#000000';
  525. 		let path = glyph.getPath(x0, fontBaseline, fontSize);
  526. 		path.fill = glyphFillColor;
  527. 		path.draw(ctx);
  528. 	}
  529.  
  530. 	function displayGlyphPage(pageNum) {
  531. 		pageSelected = pageNum;
  532.     const last = $('.gfp-page-selected');
  533.     if (last) last.className = '';
  534. 		document.getElementById('gfp-p' + pageNum).className = 'gfp-page-selected';
  535. 		let indx,
  536. 			firstGlyph = pageNum * cellCount;
  537. 		for (indx = 0; indx < cellCount; indx++) {
  538. 			renderGlyphItem(document.getElementById('gfp-g' + indx), firstGlyph + indx);
  539. 		}
  540. 	}
  541.  
  542. 	function pageSelect(event) {
  543. 		displayGlyphPage((event.target.id || '').replace('gfp-p', ''));
  544. 	}
  545.  
  546. 	function initGlyphDisplay() {
  547. 		let glyphBgCanvas = document.getElementById('gfp-glyph-bg'),
  548. 			w = glyphBgCanvas.width / pixelRatio,
  549. 			h = glyphBgCanvas.height / pixelRatio,
  550. 			glyphW = w - glyphMargin * 2,
  551. 			glyphH = h - glyphMargin * 2,
  552. 			head = font.tables.head,
  553. 			maxHeight = head.yMax - head.yMin,
  554. 			ctx = glyphBgCanvas.getContext('2d');
  555.  
  556. 		glyphScale = Math.min(glyphW / (head.xMax - head.xMin), glyphH / maxHeight);
  557. 		glyphSize = glyphScale * font.unitsPerEm;
  558. 		glyphBaseline = glyphMargin + glyphH * head.yMax / maxHeight;
  559.  
  560. 		function hline(text, yunits) {
  561. 			let ypx = glyphBaseline - yunits * glyphScale;
  562. 			ctx.fillText(text, 2, ypx + 3);
  563. 			ctx.fillRect(80, ypx, w, 1);
  564. 		}
  565.  
  566. 		ctx.clearRect(0, 0, w, h);
  567. 		ctx.fillStyle = glyphRulerColor;
  568. 		hline('Baseline', 0);
  569. 		hline('yMax', font.tables.head.yMax);
  570. 		hline('yMin', font.tables.head.yMin);
  571. 		hline('Ascender', font.tables.hhea.ascender);
  572. 		hline('Descender', font.tables.hhea.descender);
  573. 		hline('Typo Ascender', font.tables.os2.sTypoAscender);
  574. 		hline('Typo Descender', font.tables.os2.sTypoDescender);
  575. 	}
  576.  
  577. 	function onFontLoaded(font) {
  578. 		let indx, link, lastIndex,
  579. 			w = cellWidth - cellMarginLeftRight * 2,
  580. 			h = cellHeight - cellMarginTop - cellMarginBottom,
  581. 			head = font.tables.head,
  582. 			maxHeight = head.yMax - head.yMin,
  583. 			pagination = document.getElementById('gfp-pagination'),
  584. 			fragment = document.createDocumentFragment(),
  585. 			numPages = Math.ceil(font.numGlyphs / cellCount);
  586.  
  587. 		fontScale = Math.min(w / (head.xMax - head.xMin), h / maxHeight);
  588. 		fontSize = fontScale * font.unitsPerEm;
  589. 		fontBaseline = cellMarginTop + h * head.yMax / maxHeight;
  590. 		pagination.innerHTML = '';
  591.  
  592. 		for (indx = 0; indx < numPages; indx++) {
  593. 			link = document.createElement('a');
  594. 			lastIndex = Math.min(font.numGlyphs - 1, (indx + 1) * cellCount - 1);
  595. 			link.textContent = indx * cellCount + '-' + lastIndex;
  596. 			link.id = 'gfp-p' + indx;
  597. 			link.addEventListener('click', pageSelect, false);
  598. 			fragment.appendChild(link);
  599. 			// A white space allows to break very long lines into multiple lines.
  600. 			// This is needed for fonts with thousands of glyphs.
  601. 			fragment.appendChild(document.createTextNode(' '));
  602. 		}
  603. 		pagination.appendChild(fragment);
  604.  
  605. 		displayFontData();
  606. 		initGlyphDisplay();
  607. 		displayGlyphPage(0);
  608. 		displayGlyph(-1);
  609. 		displayGlyphData(-1);
  610. 	}
  611.  
  612. 	function cellSelect(event) {
  613. 		if (!font) {
  614. 			return;
  615. 		}
  616. 		let firstGlyphIndex = pageSelected * cellCount,
  617. 			cellIndex = event ? +event.target.id.replace('gfp-g', '') : currentIndex,
  618. 			glyphIndex = firstGlyphIndex + cellIndex;
  619. 		currentIndex = cellIndex;
  620. 		if (glyphIndex < font.numGlyphs) {
  621. 			displayGlyph(glyphIndex);
  622. 			displayGlyphData(glyphIndex);
  623. 		}
  624. 	}
  625.  
  626. 	function prepareGlyphList() {
  627. 		let indx, canvas,
  628. 			marker = document.getElementById('gfp-glyph-list-end'),
  629. 			parent = marker.parentElement;
  630. 		for (indx = 0; indx < cellCount; indx++) {
  631. 			canvas = document.createElement('canvas');
  632. 			canvas.width = cellWidth;
  633. 			canvas.height = cellHeight;
  634. 			canvas.className = 'gfp-item ghd-invert';
  635. 			canvas.id = 'gfp-g' + indx;
  636. 			canvas.addEventListener('click', cellSelect, false);
  637. 			enableHighDPICanvas(canvas);
  638. 			parent.insertBefore(canvas, marker);
  639. 		}
  640. 	}
  641. 	/* eslint-enable */
  642.  
  643. })();