A userscript that collapses markdown headers
// ==UserScript==
// @name GitHub Collapse Markdown
// @version 1.2.3
// @description A userscript that collapses markdown headers
// @license MIT
// @author Rob Garrison
// @namespace https://github.com/Mottie
// @match https://github.com/*
// @match https://gist.github.com/*
// @match https://help.github.com/*
// @run-at document-idle
// @grant GM_addStyle
// @grant GM_getValue
// @grant GM_setValue
// @grant GM_registerMenuCommand
// @require https://greatest.deepsurf.us/scripts/28721-mutations/code/mutations.js?version=1108163
// @icon https://github.githubassets.com/pinned-octocat.svg
// @supportURL https://github.com/Mottie/GitHub-userscripts/issues
// ==/UserScript==
(() => {
"use strict";
const defaultColors = [
// palette generated by http://tools.medialab.sciences-po.fr/iwanthue/
// (colorblind friendly, soft)
"#6778d0", "#ac9c3d", "#b94a73", "#56ae6c", "#9750a1", "#ba543d"
],
blocks = [
".markdown-body",
".markdown-format",
"" // leave empty string at the end
],
headers = "H1 H2 H3 H4 H5 H6".split(" "),
collapsed = "ghcm-collapsed",
arrowColors = document.createElement("style");
let startCollapsed = GM_getValue("ghcm-collapsed", false),
colors = GM_getValue("ghcm-colors", defaultColors);
// .markdown-body h1:after, .markdown-format h1:after, ... {}
GM_addStyle(`
${blocks.join(" h1,")} ${blocks.join(" h2,")}
${blocks.join(" h3,")} ${blocks.join(" h4,")}
${blocks.join(" h5,")} ${blocks.join(" h6,").slice(0, -1)} {
position:relative;
padding-right:.8em;
cursor:pointer;
}
${blocks.join(" h1:after,")} ${blocks.join(" h2:after,")}
${blocks.join(" h3:after,")} ${blocks.join(" h4:after,")}
${blocks.join(" h5:after,")} ${blocks.join(" h6:after,").slice(0, -1)} {
display:inline-block;
position:absolute;
right:0;
top:calc(50% - .5em);
font-size:.8em;
content:"\u25bc";
}
${blocks.join(" ." + collapsed + ":after,").slice(0, -1)} {
transform: rotate(90deg);
}
/* clicking on header link won't pass svg as the event.target */
.octicon-link, .octicon-link > * {
pointer-events:none;
}
.ghcm-hidden, .ghcm-no-content:after {
display:none !important;
}
`);
function addColors() {
let sel,
styles = "";
headers.forEach((header, indx) => {
sel = `${blocks.join(" " + header + ":after,").slice(0, -1)}`;
styles += `${sel} { color:${colors[indx]} }`;
});
arrowColors.textContent = styles;
}
function toggle(el, shifted) {
if (el && !el.classList.contains("ghcm-no-content")) {
el.classList.toggle(collapsed);
let els;
const name = el.nodeName || "",
// convert H# to #
level = parseInt(name.replace(/[^\d]/, ""), 10),
isCollapsed = el.classList.contains(collapsed);
if (shifted) {
// collapse all same level anchors
els = $$(`${blocks.join(" " + name + ",").slice(0, -1)}`);
for (el of els) {
nextHeader(el, level, isCollapsed);
}
} else {
nextHeader(el, level, isCollapsed);
}
removeSelection();
}
}
function nextHeader(el, level, isCollapsed) {
el.classList.toggle(collapsed, isCollapsed);
const selector = headers.slice(0, level).join(","),
name = [collapsed, "ghcm-hidden"],
els = [];
el = el.nextElementSibling;
while (el && !el.matches(selector)) {
els[els.length] = el;
el = el.nextElementSibling;
}
if (els.length) {
if (isCollapsed) {
els.forEach(el => {
el.classList.add("ghcm-hidden");
});
} else {
els.forEach(el => {
el.classList.remove(...name);
});
}
}
}
// show siblings of hash target
function siblings(target) {
let el = target.nextElementSibling,
els = [target];
const level = parseInt((target.nodeName || "").replace(/[^\d]/, ""), 10),
selector = headers.slice(0, level - 1).join(",");
while (el && !el.matches(selector)) {
els[els.length] = el;
el = el.nextElementSibling;
}
el = target.previousElementSibling;
while (el && !el.matches(selector)) {
els[els.length] = el;
el = el.previousElementSibling;
}
if (els.length) {
els = els.filter(el => {
return el.nodeName === target.nodeName;
});
for (el of els) {
el.classList.remove("glcm-hidden");
}
}
nextHeader(target, level, false);
}
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();
}
}
}
function addBinding() {
document.addEventListener("click", event => {
let target = event.target;
const name = (target && (target.nodeName || "")).toLowerCase();
if (name === "path") {
target = target.closest("svg");
}
if (!target || target.classList.contains("anchor") ||
name === "a" || name === "img" ||
// add support for "pointer-events:none" applied to "anchor" in
// https://github.com/StylishThemes/GitHub-FixedHeader
target.classList.contains("octicon-link")) {
return;
}
// check if element is inside a header
target = event.target.closest(headers.join(","));
if (target && headers.indexOf(target.nodeName || "") > -1) {
// make sure the header is inside of markdown
if (target.closest(blocks.slice(0, -1).join(","))) {
toggle(target, event.shiftKey);
}
}
});
document.addEventListener("ghmo:container", () => {
// init after a short delay to allow rendering of file list
setTimeout(() => {
ignoreEmptyHeaders();
}, 200);
});
}
function checkHash() {
let el, els, md;
const mds = $$(blocks.slice(0, -1).join(",")),
id = (window.location.hash || "").replace(/#/, "");
for (md of mds) {
els = $$(headers.join(","), md);
if (els.length > 1) {
for (el of els) {
if (el && !el.classList.contains(collapsed)) {
toggle(el, true);
}
}
}
}
if (id) {
openHash(id);
}
}
// open header matching hash
function openHash(id) {
const els = $(`#user-content-${id}`);
if (els && els.classList.contains("anchor")) {
let el = els.parentNode;
if (el.matches(headers.join(","))) {
siblings(el);
document.documentElement.scrollTop = el.offsetTop;
// set scrollTop a second time, in case of browser lag
setTimeout(() => {
document.documentElement.scrollTop = el.offsetTop;
}, 500);
}
}
}
function checkColors() {
if (!colors || colors.length !== 6) {
colors = [].concat(defaultColors);
}
}
function ignoreEmptyHeaders() {
$$("a.anchor").forEach(el => {
const parent = el.parentNode;
if (parent && parent.matches(headers.join(",")) && !parent.nextElementSibling) {
parent.classList.add("ghcm-no-content");
}
});
}
function init() {
document.querySelector("head").appendChild(arrowColors);
checkColors();
addColors();
addBinding();
ignoreEmptyHeaders();
if (startCollapsed) {
checkHash();
}
}
function $(selector, el) {
return (el || document).querySelector(selector);
}
function $$(selectors, el) {
return [...(el || document).querySelectorAll(selectors)];
}
// Add GM options
GM_registerMenuCommand("Set collapse markdown state", () => {
const val = prompt(
"Set initial state to (c)ollapsed or (e)xpanded (first letter necessary):",
startCollapsed ? "collapsed" : "expanded"
);
if (val !== null) {
startCollapsed = /^c/i.test(val);
GM_setValue("ghcm-collapsed", startCollapsed);
console.log(
`GitHub Collapse Markdown: Headers will ${startCollapsed ? "be" : "not be"} initially collapsed`
);
}
});
GM_registerMenuCommand("Set collapse markdown colors", () => {
let val = prompt("Set header arrow colors:", JSON.stringify(colors));
if (val !== null) {
// allow pasting in a JSON format
try {
val = JSON.parse(val);
if (val && val.length === 6) {
colors = val;
GM_setValue("ghcm-colors", colors);
console.log("GitHub Collapse Markdown: colors set to", colors);
addColors();
return;
}
console.error(
"GitHub Collapse Markdown: invalid color definition (6 colors)",
val
);
// reset colors to default (in case colors variable is corrupted)
checkColors();
} catch (err) {
console.error("GitHub Collapse Markdown: invalid JSON");
}
}
});
init();
})();