YouTube Channel Hover Popup

Display a hover popup with channel info on YouTube after dynamic content load, with immediate loading indicator

您需要先安裝使用者腳本管理器擴展,如 TampermonkeyGreasemonkeyViolentmonkey 之後才能安裝該腳本。

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyViolentmonkey 後才能安裝該腳本。

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyViolentmonkey 後才能安裝該腳本。

您需要先安裝使用者腳本管理器擴充功能,如 TampermonkeyUserscripts 後才能安裝該腳本。

你需要先安裝一款使用者腳本管理器擴展,比如 Tampermonkey,才能安裝此腳本

您需要先安裝使用者腳本管理器擴充功能後才能安裝該腳本。

(我已經安裝了使用者腳本管理器,讓我安裝!)

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展,比如 Stylus,才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

你需要先安裝一款使用者樣式管理器擴展後才能安裝此樣式

(我已經安裝了使用者樣式管理器,讓我安裝!)

// ==UserScript==
// @name         YouTube Channel Hover Popup
// @namespace    http://tampermonkey.net/
// @version      1.1
// @description  Display a hover popup with channel info on YouTube after dynamic content load, with immediate loading indicator
// @author       @dmtri
// @match        https://www.youtube.com/*
// @grant        none
// @license MIT
// ==/UserScript==

(function() {
    'use strict';
    let policy = null

    const createPopup = () => {
        const popup = document.createElement('div');
        popup.style.position = 'fixed';
        popup.style.zIndex = '1000';
        popup.style.width = '300px';
        popup.style.background = 'white';
        popup.style.border = '1px solid black';
        popup.style.borderRadius = '8px';
        popup.style.padding = '16px';
        popup.style.boxShadow = '0 4px 6px rgba(0,0,0,0.1)';
        popup.style.display = 'none';
        popup.style.fontSize = '16px';
        document.body.appendChild(popup);
        return popup;
    };

    const popup = createPopup();

    const showLoadingPopup = (popup, x, y) => {
        policy = trustedTypes.createPolicy('default2', {
            createHTML: (string) => string, // Allow all HTML strings
        });

        popup.innerHTML = policy.createHTML('<strong>Loading...</strong>');
        popup.style.left = `${x}px`;
        popup.style.top = `${y}px`;
        popup.style.display = 'block';
    };

    const updatePopupContent = (popup, content) => {
        popup.innerHTML = policy.createHTML(content);
        const closeButton = document.createElement('button');
        closeButton.textContent = 'X';
        closeButton.style.position = 'absolute';
        closeButton.style.top = '5px';
        closeButton.style.right = '10px';
        closeButton.style.border = 'none';
        closeButton.style.background = 'none';
        closeButton.style.cursor = 'pointer';
        closeButton.style.color = '#333';
        closeButton.style.fontSize = '16px';
        closeButton.style.fontWeight = 'bold';
        closeButton.onclick = () => popup.style.display = 'none';
        popup.appendChild(closeButton);
    };

    const fetchChannelInfo = async (url) => {
        try {
            const response = await fetch(url);
            const html = await response.text();
            const parser = new DOMParser();
            const doc = parser.parseFromString(policy.createHTML(html), 'text/html');
            const meta = doc.querySelector('meta[property="og:description"]');
            const description = meta ? meta.getAttribute('content') : 'No description available.';
            return `<strong>Description:</strong> ${description}<br>`;
        } catch (error) {
            return 'Failed to load description.';
        }
    };

    const throttle = (func, limit) => {
        let lastFunc;
        let lastRan;
        return function() {
            const context = this;
            const args = arguments;
            if (!lastRan) {
                func.apply(context, args);
                lastRan = Date.now();
            } else {
                clearTimeout(lastFunc);
                lastFunc = setTimeout(function() {
                    if ((Date.now() - lastRan) >= limit) {
                        func.apply(context, args);
                        lastRan = Date.now();
                    }
                }, limit - (Date.now() - lastRan));
            }
        };
    };

    const observeDOM = () => {
        const observer = new MutationObserver((mutations, obs) => {
            setTimeout(() => {
                const channelElements = document.querySelectorAll('.ytd-channel-name#text-container');
                if (channelElements.length) {
                    init(channelElements);
                    obs.disconnect(); // Stop observing after successful initialization
                }
            }, 1000);
        });
        observer.observe(document.body, {
            childList: true,
            subtree: true
        });
        console.log('[YouTube Channel Hover Popup] - observeDOM')
    };

    const init = (channelElements) => {
        console.log('YouTube Channel Hover Popup - init', { channelElements } )
        channelElements.forEach(channelElement => {
            let popupTimeout;

            channelElement.addEventListener('mouseenter', async (e) => {
                clearTimeout(popupTimeout);
                popupTimeout = setTimeout(async () => {
                    const url = channelElement.querySelector('a').href;
                    showLoadingPopup(popup, e.clientX, e.clientY + 20);
                    const content = await fetchChannelInfo(url);
                    updatePopupContent(popup, content);
                }, 500);
            });

            channelElement.addEventListener('mouseleave', () => {
                clearTimeout(popupTimeout);
                popup.style.display = 'none';
            });

            const throttledMouseMove = throttle((e) => {
                if (popup.style.display !== 'none') {
                    popup.style.left = `${e.clientX}px`;
                    popup.style.top = `${e.clientY + 20}px`;
                }
            }, 100); // Update popup position at most every 100ms

            channelElement.addEventListener('mousemove', throttledMouseMove);
        });
    };

    setTimeout(() => {
        const channelElements = document.querySelectorAll('.ytd-channel-name#text-container');
        init(channelElements)
    }, 5000); // Start observing DOM for changes
        setTimeout(() => {
        observeDom()
    }, 15000); // Start observing DOM for changes
})();