A userscript that adds a color swatch next to the code color definition
// ==UserScript==
// @name GitHub Code Colors
// @version 1.1.3
// @description A userscript that adds a color swatch next to the code color definition
// @license https://creativecommons.org/licenses/by-sa/4.0/
// @namespace https://github.com/Mottie
// @include https://github.com/*
// @grant GM_addStyle
// @run-at document-idle
// @author Rob Garrison
// ==/UserScript==
(() => {
"use strict";
GM_addStyle(`
.ghcc-block { width:12px; height:12px; display:inline-block;
vertical-align:middle; margin-right:4px; border:1px solid #555; }
`);
const namedColors = [
"aliceblue", "antiquewhite", "aqua", "aquamarine", "azure", "beige",
"bisque", "black", "blanchedalmond", "blue", "blueviolet", "brown",
"burlywood", "cadetblue", "chartreuse", "chocolate", "coral",
"cornflowerblue", "cornsilk", "crimson", "cyan", "darkblue", "darkcyan",
"darkgoldenrod", "darkgray", "darkgrey", "darkgreen", "darkkhaki",
"darkmagenta", "darkolivegreen", "darkorange", "darkorchid", "darkred",
"darksalmon", "darkseagreen", "darkslateblue", "darkslategray",
"darkslategrey", "darkturquoise", "darkviolet", "deeppink", "deepskyblue",
"dimgray", "dimgrey", "dodgerblue", "firebrick", "floralwhite",
"forestgreen", "fuchsia", "gainsboro", "ghostwhite", "gold", "goldenrod",
"gray", "grey", "green", "greenyellow", "honeydew", "hotpink",
"indianred", "indigo", "ivory", "khaki", "lavender", "lavenderblush",
"lawngreen", "lemonchiffon", "lightblue", "lightcoral", "lightcyan",
"lightgoldenrodyellow", "lightgray", "lightgrey", "lightgreen",
"lightpink", "lightsalmon", "lightseagreen", "lightskyblue",
"lightslategray", "lightslategrey", "lightsteelblue", "lightyellow",
"lime", "limegreen", "linen", "magenta", "maroon", "mediumaquamarine",
"mediumblue", "mediumorchid", "mediumpurple", "mediumseagreen",
"mediumslateblue", "mediumspringgreen", "mediumturquoise",
"mediumvioletred", "midnightblue", "mintcream", "mistyrose", "moccasin",
"navajowhite", "navy", "oldlace", "olive", "olivedrab", "orange",
"orangered", "orchid", "palegoldenrod", "palegreen", "paleturquoise",
"palevioletred", "papayawhip", "peachpuff", "peru", "pink", "plum",
"powderblue", "purple", "rebeccapurple", "red", "rosybrown", "royalblue",
"saddlebrown", "salmon", "sandybrown", "seagreen", "seashell", "sienna",
"silver", "skyblue", "slateblue", "slategray", "slategrey", "snow",
"springgreen", "steelblue", "tan", "teal", "thistle", "tomato",
"turquoise", "violet", "wheat", "white", "whitesmoke", "yellow",
"yellowgreen"
].join("|"),
// don't use a div, because GitHub-Dark adds a :hover background
// color definition on divs
block = document.createElement("span");
block.className = "ghcc-block";
function addNode(el, val) {
const node = block.cloneNode();
node.style.backgroundColor = val;
// don't add node if color is invalid
if (node.style.backgroundColor !== "") {
el.insertBefore(node, el.childNodes[0]);
}
}
function addColors() {
if (document.querySelector(".highlight")) {
let indx = 0;
const regexNamed = new RegExp("^(" + namedColors + ")$", "i"),
// #123, #123456 or 0x123456 (unix style colors, used by three.js)
regexHex = /^(#|0x)([0-9A-F]{6,8}|[0-9A-F]{3,4})$/i,
// rgb(0,0,0) or rgba(0,0,0,0.2)
regexRGB = /^rgba?(\([^\)]+\))?/i,
regexRGBA = /rgba/i,
// hsl(0,0%,0%) or hsla(0,0%,0%,0.2);
regexHSL = /^hsla?(\([^\)]+\))?/i,
// misc regex
regexQuotes = /['"]/g,
regexUnix = /^0x/,
regexPercent = /%%/g,
// .pl-c1 targets css hex colors, "rgb" and "hsl"
els = document.querySelectorAll(".pl-c1, .pl-s"),
len = els.length;
// loop with delay to allow user interaction
const loop = () => {
let el, txt, tmp, indx2,
// max number of DOM insertions per loop
max = 0;
while (max < 20 && indx < len) {
if (indx >= len) {
return;
}
el = els[indx];
txt = el.textContent;
if (el.classList.contains("pl-s")) {
txt = txt.replace(regexQuotes, "");
}
if (regexHex.test(txt) || regexNamed.test(txt)) {
if (!el.querySelector(".ghcc-block")) {
addNode(el, txt.replace(regexUnix, "#"));
max++;
}
} else if (regexRGB.test(txt)) {
if (!el.querySelector(".ghcc-block")) {
// color in a string contains everything
if (el.classList.contains("pl-s")) {
txt = txt.match(regexRGB)[0];
} else {
// rgb(a) colors contained in multiple "pl-c1" spans
indx2 = regexRGBA.test(txt) ? 4 : 3;
tmp = [];
while (indx2) {
tmp.push(els[++indx].textContent);
indx2--;
}
txt += "(" + tmp.join(",") + ")";
}
addNode(el, txt);
max++;
}
} else if (regexHSL.test(txt)) {
if (!el.querySelector(".ghcc-block")) {
tmp = /a$/i.test(txt);
txt = el.classList.contains("pl-s") ?
// color in a string contains everything
txt.match(regexHSL)[0] :
// traverse this HTML... & els only contains the pl-c1 nodes
// <span class="pl-c1">hsl</span>(<span class="pl-c1">1</span>,
// <span class="pl-c1">1</span><span class="pl-k">%</span>,
// <span class="pl-c1">1</span><span class="pl-k">%</span>);
txt + "(" + els[++indx].textContent + "," +
els[++indx].textContent + "%," +
// hsla needs one more parameter
els[++indx].textContent + "%" +
(tmp ? "," + els[++indx].textContent : "") + ")";
// sometimes (previews only?) the .pl-k span is nested inside
// the .pl-c1 span, so we end up with "%%"
addNode(el, txt.replace(regexPercent, "%"));
max++;
}
}
indx++;
}
if (indx < len) {
setTimeout(() => {
loop();
}, 200);
}
};
loop();
}
}
document.addEventListener("pjax:end", addColors);
// "preview:render" only fires when using the hotkey :(
// "preview:setup" fires on hover & click of comment preview tab
document.addEventListener("preview:setup", () => {
setTimeout(() => {
// must include some rendering time...
// 200 ms seems to be enough for a 1100+ line markdown file
addColors();
}, 500);
});
addColors();
})();