A userscript that adds code folding to GitHub files
// ==UserScript==
// @name GitHub Code Folding
// @version 1.0.12
// @description A userscript that adds code folding to GitHub files
// @license MIT
// @author Rob Garrison
// @namespace https://github.com/Mottie
// @include https://github.com/*
// @run-at document-idle
// @grant GM.addStyle
// @grant GM_addStyle
// @require https://greasemonkey.github.io/gm4-polyfill/gm4-polyfill.js?updated=20180103
// @require https://greasyfork.org/scripts/28721-mutations/code/mutations.js?version=264157
// @icon https://assets-cdn.github.com/pinned-octocat.svg
// ==/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 { position:relative; padding-left:10px; }
.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); position:relative; z-index:1; }
.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 = el.closest("td"),
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="${depth}"]`);
lineNums = els.map(el => {
el.classList.toggle("sideways", action === "hide");
return getLineNumber(el);
});
} else {
lineNums = [index];
}
if (action === "hide") {
lineNums.forEach(start => {
let elm,
end = pairs.get(start - 1);
codeLines.slice(start, end).forEach(el => {
elm = el.closest("tr");
if (elm) {
elm.classList.add("hidden-line");
}
});
if (!$(".ellipsis", codeLines[start - 1])) {
elm = $(".collapser", codeLines[start - 1]);
elm.parentNode.insertBefore(
ellipsis.cloneNode(true),
elm.nextSibling
);
}
});
} else if (action === "show") {
lineNums.forEach(start => {
let end = pairs.get(start - 1);
codeLines.slice(start, end).forEach(el => {
let elm = el.closest("tr");
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 = $$(".file table.highlight .blob-code-inner"),
spaceMap = new Map(),
stack = [];
codeLines.forEach((el, lineNum) => {
let prevSpaces,
line = el.textContent,
count = line.trim().length ?
countInitialWhiteSpace(line.split("")) :
-1;
spaceMap.set(lineNum, count);
function tryPair() {
let el,
top = stack[stack.length - 1];
if (count !== -1 && count <= spaceMap.get(top)) {
pairs.set(top, lineNum);
// prepend triangle
el = triangle.cloneNode();
el.setAttribute("data-depth", count + 1);
codeLines[top].appendChild(el, codeLines[top].childNodes[0]);
stack.pop();
return tryPair();
}
}
tryPair();
prevSpaces = getPreviousSpaces(spaceMap, lineNum);
if (count > prevSpaces.count) {
stack.push(prevSpaces.lineNum);
}
});
}
}
function $(selector, el) {
return (el || document).querySelector(selector);
}
function $$(selector, el) {
return Array.from((el || document).querySelectorAll(selector));
}
function 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();
})();