Tab Media Focus (Smart Filter) のソースコード

Tab Media Focus (Smart Filter)

Pause media in other tabs when playing media in current tab (mobile-like behavior)
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// ==UserScript==
// @name         Tab Media Focus (Smart Filter)
// @namespace    https://greasyfork.org/en/scripts/589569/
// @version      1.2
// @description  Pause media in other tabs when playing media in current tab (mobile-like behavior)
// @author       TechComet
// @match        *://*/*
// @grant        GM_setValue
// @grant        GM_getValue
// @grant        GM_addValueChangeListener
// @run-at       document-idle
// @license      MIT
// ==/UserScript==

// Written using Qwen Ai from the first attempt

(function() {
    'use strict';

    // 1. Generate a unique ID for this tab
    const MY_TAB_ID = 'tab_' + Math.random().toString(36).substr(2, 9);
    const STORAGE_KEY = 'active_media_focus_id';

    // 2. Configuration for Smart Filtering
    const CONFIG = {
        ignoreMuted: true,             // Ignore muted videos (common in previews)
        ignoreShortDuration: true,     // Ignore very short videos (previews)
        minDurationSeconds: 5,         // Minimum duration to be considered "real" media
        previewKeywords: [             // Keywords in class names indicating previews
            'preview', 'thumbnail', 'mini', 'hover', 'feed', 'shorts',
            'ytd-thumbnail', 'video-preview', 'autoplay-preview'
        ]
    };

    console.log(`[MediaFocus] Initialized: ${MY_TAB_ID}`);

    // 3. Check if video is a preview/thumbnail based on multiple criteria
    function isPreviewVideo(media) {
        // A. Check Mute Status (Fastest & Most Reliable)
        if (CONFIG.ignoreMuted && (media.muted || media.volume === 0)) {
            return true;
        }

        // B. Check Class Names (Fast)
        if (media.classList) {
            for (let i = 0; i < media.classList.length; i++) {
                const cls = media.classList[i].toLowerCase();
                for (const keyword of CONFIG.previewKeywords) {
                    if (cls.includes(keyword)) {
                        return true;
                    }
                }
            }
        }

        // C. Check Duration (Reliable if metadata loaded)
        if (CONFIG.ignoreShortDuration && media.duration) {
            if (isFinite(media.duration) && media.duration < CONFIG.minDurationSeconds) {
                return true;
            }
        }

        return false;
    }

    // 4. Pause all media elements in this tab
    function pauseAllMedia() {
        const mediaElements = document.querySelectorAll('video, audio');
        let pausedCount = 0;
        mediaElements.forEach(media => {
            if (!media.paused) {
                media.pause();
                pausedCount++;
            }
        });
        if (pausedCount > 0) console.log(`[MediaFocus] Paused ${pausedCount} media element(s)`);
    }

    // 5. Claim focus when valid media starts playing
    function claimFocus() {
        GM_setValue(STORAGE_KEY, MY_TAB_ID);
    }

    // 6. Listen for 'play' events on the window (Capture Phase)
    // This avoids MutationObserver for better performance
    window.addEventListener('play', (event) => {
        const target = event.target;

        // Ensure it's a valid media element
        if (target instanceof HTMLMediaElement) {
            // Apply smart filters
            if (isPreviewVideo(target)) {
                return; // Ignore preview/thumbnail videos
            }

            // Valid media detected, claim focus
            console.log(`[MediaFocus] Valid media play detected`);
            claimFocus();
        }
    }, true); // 'true' enables capture phase

    // 7. Listen for changes from other tabs via shared storage
    GM_addValueChangeListener(STORAGE_KEY, function(key, oldVal, newVal, remote) {
        // If change came from a remote tab and it's not us, pause local media
        if (remote && newVal && newVal !== MY_TAB_ID) {
            console.log(`[MediaFocus] Tab ${newVal} is playing, pausing local media`);
            pauseAllMedia();
        }
    });

})();