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GitHub Code Folding

A userscript that adds code folding to GitHub files

As of 2017-12-15. See the latest version.

  1. // ==UserScript==
  2. // @name        GitHub Code Folding
  3. // @version     1.0.9
  4. // @description A userscript that adds code folding to GitHub files
  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_addStyle
  12. // @require     https://greasemonkey.github.io/gm4-polyfill/gm4-polyfill.js
  13. // @require     https://greatest.deepsurf.us/scripts/28721-mutations/code/mutations.js?version=234970
  14. // @icon        https://assets-cdn.github.com/pinned-octocat.svg
  15. // ==/UserScript==
  16. /**
  17.  * This userscript has been heavily modified from the "github-code-folding"
  18.  * Chrome extension Copyright 2016 by Noam Lustiger; under an MIT license
  19.  * https://github.com/noam3127/github-code-folding
  20.  */
  21. (() => {
  22. 	"use strict";
  23.  
  24. 	GM.addStyle(`
  25. 		td.blob-code.blob-code-inner { padding-left:10px; }
  26. 		.collapser { position:absolute; left:2px; width:22px; opacity:.5;
  27. 			transition:.15s; cursor:pointer; }
  28. 		.collapser:after { content:"\u25bc"; }
  29. 		.collapser:hover { opacity:1; }
  30. 		.sideways { transform:rotate(-90deg); transform-origin:16% 49%; opacity:.8; }
  31. 		.hidden-line { display:none; }
  32. 		.ellipsis { padding:1px 2px; margin-left:2px; cursor:pointer;
  33. 			background:rgba(255,235,59,.4); position:relative; z-index:1; }
  34. 		.ellipsis:hover { background:rgba(255,235,59,.7); }
  35. 	`);
  36.  
  37. 	const pairs = new Map(),
  38. 		ellipsis = document.createElement("span"),
  39. 		triangle = document.createElement("span");
  40.  
  41. 	triangle.className = "collapser";
  42. 	ellipsis.className = "pl-smi ellipsis";
  43. 	ellipsis.innerHTML = "…";
  44.  
  45. 	function countInitialWhiteSpace(arr) {
  46. 		const getWhiteSpaceIndex = i => {
  47. 			if (arr[i] !== " " && arr[i] !== "\t") {
  48. 				return i;
  49. 			}
  50. 			i++;
  51. 			return getWhiteSpaceIndex(i);
  52. 		};
  53. 		return getWhiteSpaceIndex(0);
  54. 	}
  55.  
  56. 	function getPreviousSpaces(map, lineNum) {
  57. 		let prev = map.get(lineNum - 1);
  58. 		return prev === -1 ?
  59. 			getPreviousSpaces(map, lineNum - 1) : {
  60. 				lineNum: lineNum - 1,
  61. 				count: prev
  62. 			};
  63. 	}
  64.  
  65. 	function getLineNumber(el) {
  66. 		let elm = el.closest("td"),
  67. 			index = elm ? elm.id : "";
  68. 		if (index) {
  69. 			return parseInt(index.slice(2), 10);
  70. 		}
  71. 		return "";
  72. 	}
  73.  
  74. 	function toggleCode(action, index, depth) {
  75. 		let els, lineNums;
  76. 		const codeLines = $$(".file table.highlight .blob-code-inner");
  77. 		// depth is a string containing a specific depth number to toggle
  78. 		if (depth) {
  79. 			els = $$(`.collapser[data-depth="${depth}"]`);
  80. 			lineNums = els.map(el => {
  81. 				el.classList.toggle("sideways", action === "hide");
  82. 				return getLineNumber(el);
  83. 			});
  84. 		} else {
  85. 			lineNums = [index];
  86. 		}
  87.  
  88. 		if (action === "hide") {
  89. 			lineNums.forEach(start => {
  90. 				let elm,
  91. 					end = pairs.get(start - 1);
  92. 				codeLines.slice(start, end).forEach(el => {
  93. 					elm = el.closest("tr");
  94. 					if (elm) {
  95. 						elm.classList.add("hidden-line");
  96. 					}
  97. 				});
  98. 				if (!$(".ellipsis", codeLines[start - 1])) {
  99. 					elm = $(".collapser", codeLines[start - 1]);
  100. 					elm.parentNode.insertBefore(
  101. 						ellipsis.cloneNode(true),
  102. 						elm.nextSibling
  103. 					);
  104. 				}
  105. 			});
  106. 		} else if (action === "show") {
  107. 			lineNums.forEach(start => {
  108. 				let end = pairs.get(start - 1);
  109. 				codeLines.slice(start, end).forEach(el => {
  110. 					let elm = el.closest("tr");
  111. 					if (elm) {
  112. 						elm.classList.remove("hidden-line");
  113. 						remove(".ellipsis", elm);
  114. 					}
  115. 					elm = $(".sideways", elm);
  116. 					if (elm) {
  117. 						elm.classList.remove("sideways");
  118. 					}
  119. 				});
  120. 				remove(".ellipsis", codeLines[start - 1]);
  121. 			});
  122. 		}
  123. 		// shift ends up selecting text on the page, so clear it
  124. 		if (lineNums.length > 1) {
  125. 			removeSelection();
  126. 		}
  127. 	}
  128.  
  129. 	function addBindings() {
  130. 		document.addEventListener("click", event => {
  131. 			let index, elm, isCollapsed;
  132. 			const el = event.target;
  133.  
  134. 			// click on collapser
  135. 			if (el && el.classList.contains("collapser")) {
  136. 				isCollapsed = el.classList.contains("sideways");
  137. 				index = getLineNumber(el);
  138. 				// Shift + click to toggle them all
  139. 				if (index && event.getModifierState("Shift")) {
  140. 					return toggleCode(
  141. 						isCollapsed ? "show" : "hide",
  142. 						index,
  143. 						el.getAttribute("data-depth")
  144. 					);
  145. 				}
  146. 				if (index) {
  147. 					if (isCollapsed) {
  148. 						el.classList.remove("sideways");
  149. 						toggleCode("show", index);
  150. 					} else {
  151. 						el.classList.add("sideways");
  152. 						toggleCode("hide", index);
  153. 					}
  154. 				}
  155. 				return;
  156. 			}
  157.  
  158. 			// click on ellipsis
  159. 			if (el && el.classList.contains("ellipsis")) {
  160. 				elm = $(".sideways", el.parentNode);
  161. 				if (elm) {
  162. 					elm.classList.remove("sideways");
  163. 				}
  164. 				index = getLineNumber(el);
  165. 				if (index) {
  166. 					toggleCode("show", index);
  167. 				}
  168. 			}
  169. 		});
  170. 	}
  171.  
  172. 	function addCodeFolding() {
  173. 		if ($(".file table.highlight")) {
  174. 			// In case this script has already been run and modified the DOM on a
  175. 			// previous page in github, make sure to reset it.
  176. 			remove("span.collapser");
  177. 			pairs.clear();
  178.  
  179. 			const codeLines = $$(".file table.highlight .blob-code-inner"),
  180. 				spaceMap = new Map(),
  181. 				stack = [];
  182.  
  183. 			codeLines.forEach((el, lineNum) => {
  184. 				let prevSpaces,
  185. 					line = el.textContent,
  186. 					count = line.trim().length ?
  187. 						countInitialWhiteSpace(line.split("")) :
  188. 						-1;
  189. 				spaceMap.set(lineNum, count);
  190.  
  191. 				function tryPair() {
  192. 					let el,
  193. 						top = stack[stack.length - 1];
  194. 					if (count !== -1 && count <= spaceMap.get(top)) {
  195. 						pairs.set(top, lineNum);
  196. 						// prepend triangle
  197. 						el = triangle.cloneNode();
  198. 						el.setAttribute("data-depth", count + 1);
  199. 						codeLines[top].appendChild(el, codeLines[top].childNodes[0]);
  200. 						stack.pop();
  201. 						return tryPair();
  202. 					}
  203. 				}
  204. 				tryPair();
  205.  
  206. 				prevSpaces = getPreviousSpaces(spaceMap, lineNum);
  207. 				if (count > prevSpaces.count) {
  208. 					stack.push(prevSpaces.lineNum);
  209. 				}
  210. 			});
  211. 		}
  212. 	}
  213.  
  214. 	function $(selector, el) {
  215. 		return (el || document).querySelector(selector);
  216. 	}
  217.  
  218. 	function $$(selector, el) {
  219. 		return Array.from((el || document).querySelectorAll(selector));
  220. 	}
  221.  
  222. 	function remove(selector, el) {
  223. 		let els = $$(selector, el),
  224. 			index = els.length;
  225. 		while (index--) {
  226. 			els[index].parentNode.removeChild(els[index]);
  227. 		}
  228. 	}
  229.  
  230. 	function removeSelection() {
  231. 		// remove text selection - https://stackoverflow.com/a/3171348/145346
  232. 		const sel = window.getSelection ?
  233. 			window.getSelection() :
  234. 			document.selection;
  235. 		if (sel) {
  236. 			if (sel.removeAllRanges) {
  237. 				sel.removeAllRanges();
  238. 			} else if (sel.empty) {
  239. 				sel.empty();
  240. 			}
  241. 		}
  242. 	}
  243.  
  244. 	document.addEventListener("ghmo:container", addCodeFolding);
  245. 	addCodeFolding();
  246. 	addBindings();
  247.  
  248. })();