Inject Stylus into shadowRoots

inject styles of stylus-addon in shadowRoot

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

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

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

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

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

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.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name                Inject Stylus into shadowRoots
// @namespace           https://greasyfork.org/users/821661
// @version             2.2
// @description         inject styles of stylus-addon in shadowRoot
// @author              hdyzen
// @run-at              document-start
// @match               https://*/*
// @grant               none
// @license             GPL-3.0-only
// ==/UserScript==

const sheet = new CSSStyleSheet();
const sheetInDoc = new CSSStyleSheet();
const originalShadowRootDescriptor = Object.getOwnPropertyDescriptor(ShadowRoot.prototype, "adoptedStyleSheets");
const originalAttachShadow = Element.prototype.attachShadow;

function syncStyles() {
    const nodes = document.querySelectorAll(
        "html > style:is(.stylus, .stylish-style, .xstyle, [data-source='User JavaScript and CSS'], .amino, [id^='stylebot']), body > style[data-style-created-by='magicss'], head > style[data-custom-css-by-denis]",
    );

    let cssText = "";

    for (const node of nodes) {
        cssText += `${node.textContent}\n`;
    }

    if (sheet.cssRules.length === 0 || sheet.cssRules[0]?.cssText !== cssText) {
        sheet.replaceSync(cssText);
    }
}

Element.prototype.attachShadow = function (init) {
    const shadowRoot = originalAttachShadow.call(this, init);

    shadowRoot.adoptedStyleSheets.push(sheet);
    shadowRoot.adoptedStyleSheets.push(sheetInDoc);

    return shadowRoot;
};

Object.defineProperty(ShadowRoot.prototype, "adoptedStyleSheets", {
    get() {
        return originalShadowRootDescriptor.get.call(this);
    },
    set(newSheets) {
        if (!newSheets.includes(sheet)) {
            newSheets.push(sheet);
        }
        if (!newSheets.includes(sheetInDoc)) {
            newSheets.push(sheetInDoc);
        }

        originalShadowRootDescriptor.set.call(this, newSheets);
    },
    configurable: true,
    enumerable: true,
});

function syncAdoptedStyles() {
    let stylusRules = "";

    for (const s of document.adoptedStyleSheets) {
        if (!s.media.mediaText.includes("stylus-")) continue;

        for (const cssRule of s.cssRules) {
            stylusRules += `${cssRule.cssText}\n`;
        }
    }

    if (sheetInDoc.cssRules.length === 0 || sheetInDoc.cssRules[0]?.cssText !== stylusRules) {
        sheetInDoc.replaceSync(stylusRules);
    }

    // prevent run in inactive tabs
    requestAnimationFrame(() => setTimeout(syncAdoptedStyles, 250));
}

requestAnimationFrame(syncAdoptedStyles);

new MutationObserver(syncStyles).observe(document.documentElement, {
    childList: true,
    subtree: true,
    characterData: true,
});