GitHub Code Folding

A userscript that adds code folding to GitHub files

Från och med 2017-04-24. Se den senaste versionen.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

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

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

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

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

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

(I already have a user script manager, let me install it!)

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.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name        GitHub Code Folding
// @version     1.0.4
// @description A userscript that adds code folding to GitHub files
// @license     https://opensource.org/licenses/MIT
// @author      Rob Garrison
// @namespace   https://github.com/Mottie
// @include     https://github.com/*
// @run-at      document-idle
// @grant       GM_addStyle
// @require     https://greasyfork.org/scripts/28721-mutations/code/mutations.js?version=189706
// @icon        https://github.com/fluidicon.png
// ==/UserScript==
/**
 * This userscript has been heavily modified from the "github-code-folding"
 * Chrome extension Copyright 2016 by Noam Lustiger; under an MIT license
 * https://github.com/noam3127/github-code-folding
 */
(() => {
	"use strict";

	GM_addStyle(`
		td.blob-code.blob-code-inner { padding-left:13px; }
		.collapser { position:absolute; left:2px; width:22px; opacity:.5;
			transition:.15s; cursor:pointer; }
		.collapser:after { content:"\u25bc"; }
		.collapser:hover { opacity:1; }
		.sideways { transform:rotate(-90deg); transform-origin:16% 49%; opacity:.8; }
		.hidden-line { display:none; }
		.ellipsis { padding:1px 2px; margin-left:2px; cursor:pointer;
			background:rgba(255,235,59,.4); }
		.ellipsis:hover { background:rgba(255,235,59,.7); }
	`);

	const pairs = new Map(),
		ellipsis = document.createElement("span"),
		triangle = document.createElement("span");

	triangle.className = "collapser";
	ellipsis.className = "pl-smi ellipsis";
	ellipsis.innerHTML = "…";

	function countInitialWhiteSpace(arr) {
		const getWhiteSpaceIndex = i => {
			if (arr[i] !== " " && arr[i] !== "\t") {
				return i;
			}
			i++;
			return getWhiteSpaceIndex(i);
		};
		return getWhiteSpaceIndex(0);
	}

	function getPreviousSpaces(map, lineNum) {
		let prev = map.get(lineNum - 1);
		return prev === -1 ?
			getPreviousSpaces(map, lineNum - 1) : {
				lineNum: lineNum - 1,
				count: prev
			};
	}

	function getLineNumber(el) {
		let elm = closest("td", el),
			index = elm ? elm.id : "";
		if (index) {
			return parseInt(index.slice(2), 10);
		}
		return "";
	}

	function toggleCode(action, index, depth) {
		let els, lineNums;
		const codeLines = $$(".file table.highlight .blob-code-inner");
		// depth is a string containing a specific depth number to toggle
		if (depth) {
			els = $$(`.collapser[data-depth="${depth}"]`);
			lineNums = els.map(el => {
				el.classList.toggle("sideways", action === "hide");
				return getLineNumber(el);
			});
		} else {
			lineNums = [index];
		}

		if (action === "hide") {
			lineNums.forEach(start => {
				let end = pairs.get(start - 1);
				codeLines.slice(start, end).forEach(el => {
					let elm = closest("tr", el);
					if (elm) {
						elm.classList.add("hidden-line");
					}
				});
				if (!$(".ellipsis", codeLines[start - 1])) {
					codeLines[start - 1].appendChild(ellipsis.cloneNode(true));
				}
			});
		} else if (action === "show") {
			lineNums.forEach(start => {
				let end = pairs.get(start - 1);
				codeLines.slice(start, end).forEach(el => {
					let elm = closest("tr", el);
					if (elm) {
						elm.classList.remove("hidden-line");
						remove(".ellipsis", elm);
					}
					elm = $(".sideways", elm);
					if (elm) {
						elm.classList.remove("sideways");
					}
				});
				remove(".ellipsis", codeLines[start - 1]);
			});
		}
		// shift ends up selecting text on the page, so clear it
		if (lineNums.length > 1) {
			removeSelection();
		}
	}

	function addBindings() {
		document.addEventListener("click", event => {
			let index, elm, isCollapsed;
			const el = event.target;

			// click on collapser
			if (el && el.classList.contains("collapser")) {
				isCollapsed = el.classList.contains("sideways");
				index = getLineNumber(el);
				// Shift + click to toggle them all
				if (index && event.getModifierState("Shift")) {
					return toggleCode(
						isCollapsed ? "show" : "hide",
						index,
						el.getAttribute("data-depth")
					);
				}
				if (index) {
					if (isCollapsed) {
						el.classList.remove("sideways");
						toggleCode("show", index);
					} else {
						el.classList.add("sideways");
						toggleCode("hide", index);
					}
				}
				return;
			}

			// click on ellipsis
			if (el && el.classList.contains("ellipsis")) {
				elm = $(".sideways", el.parentNode);
				if (elm) {
					elm.classList.remove("sideways");
				}
				index = getLineNumber(el);
				if (index) {
					toggleCode("show", index);
				}
			}
		});
	}

	function addCodeFolding() {
		if ($(".file table.highlight")) {
			// In case this script has already been run and modified the DOM on a
			// previous page in github, make sure to reset it.
			remove("span.collapser");
			pairs.clear();

			const codeLines = $$(".file table.highlight .blob-code-inner"),
				spaceMap = new Map(),
				stack = [];

			codeLines.forEach((el, lineNum) => {
				let prevSpaces,
					line = el.textContent,
					count = line.trim().length ?
						countInitialWhiteSpace(line.split("")) :
						-1;
				spaceMap.set(lineNum, count);

				function tryPair() {
					let el,
						top = stack[stack.length - 1];
					if (count !== -1 && count <= spaceMap.get(top)) {
						pairs.set(top, lineNum);
						// prepend triangle
						el = triangle.cloneNode();
						el.setAttribute("data-depth", count + 1);
						codeLines[top].insertBefore(el, codeLines[top].childNodes[0]);
						stack.pop();
						return tryPair();
					}
				}
				tryPair();

				prevSpaces = getPreviousSpaces(spaceMap, lineNum);
				if (count > prevSpaces.count) {
					stack.push(prevSpaces.lineNum);
				}
			});
		}
	}

	function $(selector, el) {
		return (el || document).querySelector(selector);
	}

	function $$(selector, el) {
		return Array.from((el || document).querySelectorAll(selector));
	}

	function closest(selector, el) {
		while (el && el.nodeType === 1) {
			if (el.matches(selector)) {
				return el;
			}
			el = el.parentNode;
		}
		return null;
	}

	function remove(selector, el) {
		let els = $$(selector, el),
			index = els.length;
		while (index--) {
			els[index].parentNode.removeChild(els[index]);
		}
	}

	function removeSelection() {
		// remove text selection - https://stackoverflow.com/a/3171348/145346
		const sel = window.getSelection ?
			window.getSelection() :
			document.selection;
		if (sel) {
			if (sel.removeAllRanges) {
				sel.removeAllRanges();
			} else if (sel.empty) {
				sel.empty();
			}
		}
	}

	document.addEventListener("ghmo:container", addCodeFolding);
	addCodeFolding();
	addBindings();

})();