Google Auto Translate

Automatically triggers Google Translate when the page language is different from the user-selected language.
当前为 2025-03-10 提交的版本，查看最新版本。
换行
// ==UserScript==
// @name         Google Auto Translate
// @namespace    https://greasyfork.org/en/users/1030895-universedev
// @author       UniverseDev
// @license      GPL-3.0-or-later
// @version      1.4
// @description  Automatically triggers Google Translate when the page language is different from the user-selected language.
// @match        *://*/*
// @grant        unsafeWindow
// ==/UserScript==

(function () {
    "use strict";

    const STORAGE_KEY = "userTranslateLang";
    const DEFAULT_LANG = "en";

    const getUserLanguage = () => localStorage.getItem(STORAGE_KEY) || DEFAULT_LANG;
    const setUserLanguage = (lang) => {
        localStorage.setItem(STORAGE_KEY, lang);
        location.reload();
    };

    const detectPageLanguage = () =>
        document.documentElement.lang || document.querySelector("html")?.getAttribute("lang") || null;

    const isAlreadyTranslated = () => {
        return document.querySelector("body").classList.contains("translated-ltr") ||
            document.querySelector("body").classList.contains("translated-rtl");
    };

    const canEmbedIframe = (url) => {
        const iframe = document.createElement("iframe");
        iframe.style.display = "none";
        iframe.src = url;

        return new Promise((resolve, reject) => {
            iframe.onload = () => resolve(true);
            iframe.onerror = () => reject(false);
            document.body.appendChild(iframe);
            setTimeout(() => {
                document.body.removeChild(iframe);
            }, 2000);
        });
    };

    const createTranslateOverlay = async (targetLang) => {
        const pageLang = detectPageLanguage();
        if (pageLang && pageLang.toLowerCase() === targetLang.toLowerCase()) {
            return;
        }

        const translateUrl = `https://translate.google.com/translate?hl=${targetLang}&sl=auto&tl=${targetLang}&u=${encodeURIComponent(location.href)}`;

        const canEmbed = await canEmbedIframe(translateUrl);
        if (!canEmbed) {
            console.log("Iframe embedding is not allowed on this page.");
            return;
        }

        if (document.getElementById("googleTranslateIframe")) return;
        const iframe = document.createElement("iframe");
        iframe.id = "googleTranslateIframe";
        iframe.src = translateUrl;
        Object.assign(iframe.style, {
            position: "fixed",
            top: 0,
            left: 0,
            width: "100vw",
            height: "100vh",
            border: "none",
            zIndex: 99999,
            backgroundColor: "#fff",
        });
        document.body.appendChild(iframe);
    };

    const insertGoogleTranslateWidget = () => {
        if (document.querySelector("script[src*='translate_a/element.js']")) {
            return;
        }

        const translateDiv = document.createElement("div");
        translateDiv.id = "google_translate_element";
        Object.assign(translateDiv.style, {
            position: "fixed",
            bottom: "10px",
            right: "10px",
            zIndex: 100000,
        });
        document.body.appendChild(translateDiv);

        const script = document.createElement("script");
        script.src = "//translate.google.com/translate_a/element.js?cb=googleTranslateInit";
        document.body.appendChild(script);
    };

    unsafeWindow.googleTranslateInit = () => {
        new google.translate.TranslateElement(
            { pageLanguage: "auto", includedLanguages: getUserLanguage(), autoDisplay: true, multilanguagePage: true },
            "google_translate_element"
        );
    };

    const autoTranslateIfNeeded = async () => {
        const targetLang = getUserLanguage();
        const pageLang = detectPageLanguage();

        if (!pageLang || pageLang.toLowerCase() !== targetLang.toLowerCase()) {
            await createTranslateOverlay(targetLang);
        }
    };

    window.addEventListener("load", autoTranslateIfNeeded);
})();