Discord - Custom Background Image

You can set custom background image of Discord;

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

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

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

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

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

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

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.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Discord - Custom Background Image
// @namespace    http://tampermonkey.net/
// @version      0.7
// @description  You can set custom background image of Discord;
// @author       You
// @match        https://discord.com/channels/*
// @match        https://discord.com/channels/*/*
// @icon         https://www.google.com/s2/favicons?domain=discord.com
// @grant        GM.xmlHttpRequest
// @grant        GM.registerMenuCommand
// @grant        GM.getValue
// @grant        GM.setValue
// @grant        GM.addElement
// @connect      i.imgur.com
// @license      MIT
// ==/UserScript==

(async window => {
    'use strict';
    let intervalTime = 30 * 1000;
    let urls = [
        'https://i.imgur.com/cHKbKQT.jpeg',
        'https://i.imgur.com/sqmqy20.png',
        'https://i.imgur.com/cCL6TPk.jpeg',
        'https://i.imgur.com/Z6GYpxh.jpeg',
        'https://i.imgur.com/FNJdY5h.jpeg',
        'https://i.imgur.com/uKVG1XM.jpeg'
    ];
    let g_elm = null;
    const del = () => {
        if(g_elm) {
            g_elm.remove();
            g_elm = null;
            return true;
        }
        else return false;
    };
    const addInput = async value => {
        if(del()) return;
        g_elm = await GM.addElement(document.body, 'div', {});
        Object.assign(g_elm.style, {
            'position': 'fixed',
            'width': '100vw',
            'height': '100vh',
            'display': 'flex',
            'flex-wrap': 'wrap',
            'justify-content': 'center',
            'align-items': 'center',
            'z-index': Infinity
        });
        const input = await GM.addElement(g_elm, 'textarea', {
            textContent: value
        });
        Object.assign(input.style, {
            'width': '50vw',
            'height': '30vh',
            'font-size': '24px',
            'font-weight': 'bold'
        });
        const btnSave = await GM.addElement(g_elm, 'button', {
            textContent: 'save'
        });
        await GM.addElement(g_elm, 'div', {
            textContent: ' '
        });
        const btnCancel = await GM.addElement(g_elm, 'button', {
            textContent: 'cancel'
        });
        for(const v of [btnSave, btnCancel]) Object.assign(v.style, {
            'color': 'white',
            'backgroundColor': 'red'
        });
        return new Promise((resolve, reject) => {
            btnSave.addEventListener('click', () => del() && resolve(input.value));
            btnCancel.addEventListener('click', () => del() && reject());
        });
    };
    const key1 = 'intervalTime';
    GM.registerMenuCommand('config interval time', async () => {
        const res = await addInput(await GM.getValue(key1, intervalTime));
        if(!res) return;
        const m = res.match(/[0-9]+/);
        if(!m) return;
        const n = Number(m[0]);
        intervalTime = n;
        GM.setValue(key1, n);
    });
    intervalTime = await GM.getValue(key1, intervalTime);
    const key2 = 'URL';
    GM.registerMenuCommand('config URL', async () => {
        const res = await addInput(await GM.getValue(key2, urls.join('\n')));
        if(!res) return;
        const a = findURL(res);
        if(!a.length) return;
        urls = a;
        GM.setValue(key2, a.join('\n'));
    });
    urls = (await GM.getValue(key2, urls.join('\n'))).split('\n');
    const findURL = str => {
        const m = str.match(/(https?|ftp)(:\/\/[-_.!~*\'()a-zA-Z0-9;\/?:\@&=+\$,%#]+)/g);
        return m ? m : [];
    };
    const memo = new Map;
    const get = async url => {
        if(memo.has(url)) return memo.get(url);
        const res = await GM.xmlHttpRequest({
            method: 'GET',
            url: url,
            withCredentials: true,
            responseType: 'arraybuffer',
        });
        const _url = URL.createObjectURL(new Blob([res.response], {type: 'application/octet-binary'}));
        memo.set(url, _url);
        return _url;
    };
    let g_url = await get(urls[0]);
    const wait = resolve => {
        if(document.querySelector('[class^="chatContent"]')) return resolve();
        setTimeout(() => wait(resolve), 500);
    };
    await new Promise(resolve => wait(resolve));
    const setURL = () => {
        Object.assign(document.body.children[0].style, {
            'background-image': 'url("' + g_url + '")',
            'background-attachment': 'fixed',
            'background-position': 'center center',
            'background-size': 'cover',
            'background-repeat': 'no-repeat',
            'transition-duration': '1.5s'
        });
    };
    setURL();
    const setOther = () => {
        for(const v of document.querySelectorAll('*')) v.style.backgroundColor = 'rgba(0, 0, 0, 0)';
        document.body.children[0].children[3].style.backgroundColor = 'rgba(0, 0, 0, 0.7)';
    };
    setOther();
    let _url = location.href,
        _time = 0,
        index = 0;
    const update = async () => {
        const time = performance.now();
        if(time - _time > intervalTime) {
            g_url = await get(urls[(++index) % urls.length]);
            _time = performance.now();
            setURL();
        }
        else {
            const url = location.href;
            if(url !== _url) {
                _url = url;
                setOther();
            }
        }
        requestAnimationFrame(update);
    };
    update();
})(window.unsafeWindow || window);