PDF Background Color Controller

This script can change the backgroud color for the pdf files opened by your brower. It is applicable for Chrome build-in PDF viewer, pdf.js, overleaf's pdf reviewer and your local files (Please allow the Tampermonkey to access file urls in browser's setting by going to chrome://extensions/, and set Allow access to file URLs.).

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 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         PDF Background Color Controller
// @namespace    http://tampermonkey.net/
// @version      0.7
// @description  This script can change the backgroud color for the pdf files opened by your brower. It is applicable for Chrome build-in PDF viewer, pdf.js, overleaf's pdf reviewer and your local files (Please allow the Tampermonkey to access file urls in browser's setting by going to chrome://extensions/, and set Allow access to file URLs.).
// @author       Maple
// @match        *://*/*
// @icon         https://icon-icons.com/downloadimage.php?id=130274&root=2107/ICO/64/&file=file_type_pdf_icon_130274.ico
// @grant        none
// @license MIT
// ==/UserScript==

function get_cover() {
    let css = `
        position: absolute;
        pointer-events: none;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: #FDF6E3;
        mix-blend-mode: multiply;
        z-index: 100000;
    `;
    var cover = document.createElement("div");
    cover.setAttribute("style", css);
    return cover;
}

function renderPage(url, panelSelector) {
    if (window.location.href.includes(url)) {
        var cover = get_cover();
        var scope = document.querySelector(panelSelector);
        //console.log(scope);
        if (scope === null) {
            setTimeout(() => renderPage(url, panelSelector), 1000); // Retry after 1 second
        } else {
            scope.appendChild(cover);
        }
    }
}

(function() {
    'use strict';

    renderPage("https://www.overleaf.com/project/", "div.ide-react-panel[data-panel-id='panel-pdf']"); // Call renderPage for possible Overleaf pages
    renderPage("https://docs.google.com/", "div.kix-scrollareadocumentplugin.docs-ui-hit-region-surface"); // Call renderPage for possible Overleaf pages

    var embed = document.querySelector("embed");
    if ((embed !== null && embed.type == "application/pdf") || (typeof pdfjsLib !== "undefined") || (window.location.href.includes(".pdf"))) {
        var cover = get_cover();
        document.body.appendChild(cover);
    }
})();