myScripts.js

// ==UserScript==
// @name	BlackenPage
// @version	1.0.3
// @match	http://*/*
// @match	https://*/*
// @grant	GM_xmlhttpRequest
// @run-at document-start
// ==/UserScript==


(function () {
    'use strict';
    window.addEventListener('load', () => {
        addButton('blacken', selectReadFn);
    });
    function addButton(text, onclick) {
        let button = document.createElement('button');
        let btnStyle = button.style;
        document.body.appendChild(button);
        button.innerHTML = text;
        button.onclick = onclick;
        btnStyle.position = 'absolute';
        btnStyle.top = '10px';
        btnStyle.zIndex = '999';
        return button;
    }
    async function aaaa() {
        function RGBtoHSL(RGBColor) {
            const R = RGBColor[0];
            const G = RGBColor[1];
            const B = RGBColor[2];
            let H, S;
            const cMax = Math.max(Math.max(R, G), B);
            const cMin = Math.min(Math.min(R, G), B);
            const sum = cMax + cMin;
            const diff = cMax - cMin;
            const L = sum >> 1;
            if (cMax === cMin) {
                S = 0;
                H = 0;
            }
            else {
                if (L <= 0.5) {
                    S = diff / sum;
                }
                else {
                    S = diff / (2 - sum);
                }
                const Rdelta = R / 6 / diff;
                const Gdelta = G / 6 / diff;
                const Bdelta = B / 6 / diff;
                if (R === cMax) {
                    H = Gdelta - Bdelta;
                }
                else if (G === cMax) {
                    H = (1 / 3) + Bdelta - Rdelta;
                }
                else {
                    H = (2 / 3) + Rdelta - Gdelta;
                }
                if (H < 0) {
                    H += 1;
                }
                if (H > 1) {
                    H -= 1;
                }
            }
            return [H, S, L];
        }
        function getRGBColor(node, prop) {
            const rgb = getComputedStyle(node, null).getPropertyValue(prop);
            if (/rgb\((\d+),\s(\d+),\s(\d+)\)/.exec(rgb)) {
                const r = parseInt(RegExp.$1, 10);
                const g = parseInt(RegExp.$2, 10);
                const b = parseInt(RegExp.$3, 10);
                return [r / 255, g / 255, b / 255];
            }
            return rgb;
        }
        function hslToCSS(hsl) {
            const [hue, saturation, lightness] = hsl;
            return `hsl(${Math.round(hue * 360)}, ${Math.round(saturation * 100)}%, ${Math.round(lightness * 100)}%)`;
        }
        const props = ["color", "background-color", "border-left-color", "border-right-color", "border-top-color", "border-bottom-color"];
        const props2 = ["color", "backgroundColor", "borderLeftColor", "borderRightColor", "borderTopColor", "borderBottomColor"];
        if (typeof getRGBColor(document.documentElement, "background-color") == "string") {
            document.documentElement.style.backgroundColor = "white";
        }
        revl(document.documentElement);
        function revl(n) {
            let i, x;
            if (n.nodeType == Node.ELEMENT_NODE) {
                for (i = 0; x = n.childNodes[i]; ++i) {
                    revl(x);
                }
                for (i = 0; x = props[i]; ++i) {
                    const color = getRGBColor(n, x);
                    if (typeof (color) != "string") {
                        const hsl = RGBtoHSL(color);
                        let lightness = hsl[2];
                        lightness = 1 - lightness;
                        n.style[props2[i]] = hslToCSS(hsl);
                    }
                }
            }
        }
    }
    function selectReadFn() {
        const promise = aaaa();
    }
})();