YouTube Theater Mode Fix

Tries to revert some changes to the youtube theater / fullscreen mode to be like the old UI

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         YouTube Theater Mode Fix
// @version      2.2
// @description  Tries to revert some changes to the youtube theater / fullscreen mode to be like the old UI
// @author       Torkelicious
// @icon         https://www.youtube.com/favicon.ico
// @license      GPL-3.0-or-later
// @match        https://www.youtube.com/*
// @run-at       document-start
// @namespace    https://greasyfork.org/users/1403155
// @grant        GM_getValue
// @grant        GM_setValue
// @grant        GM_registerMenuCommand
// ==/UserScript==

(function () {
  'use strict';

  // avoid loading more than once !!!
  if (window.ytTheaterFixLoaded) return;
  window.ytTheaterFixLoaded = true;

  const DEFAULTS = { mastheadBehavior: 'relative' };
  const COSMETIC = [
    '.ytp-fullscreen-grid-hover-overlay',
    '.ytp-fullscreen-grid-hover-overlay-chevron',
    '.ytp-fullscreen-grid-stills-container'
  ];
  const STYLE_ID = 'yt-theater-fix-styles';

  const STYLE_TEXT = `
    ytd-app { overflow: auto !important; }
    ytd-app[scrolling] {
      position: absolute !important;
      top: 0 !important; left: 0 !important;
      right: calc((var(--ytd-app-fullerscreen-scrollbar-width) + 1px)*-1) !important;
      bottom: 0 !important;
      overflow-x: auto !important;
    }
    ytd-watch-flexy[full-bleed-player] #single-column-container.ytd-watch-flexy,
    ytd-watch-flexy[full-bleed-player] #columns.ytd-watch-flexy {
      display: flex !important;
    }

    /* Keep controls visible and hide the new fullscreen grid UI variants */
    .ytp-fullscreen-grid-peeking.ytp-full-bleed-player:not(.ytp-autohide) .ytp-chrome-bottom {
      bottom: 0 !important; opacity: 1 !important;
    }
    #movie_player:not(.ytp-grid-ended-state) .ytp-fullscreen-grid {
      display: none !important; top: 100% !important; opacity: 0 !important;
    }
    ${COSMETIC.map(sel => `${sel} { display: none !important; }`).join('\n')}

    .html5-video-player.ytp-fullscreen:is(.ytp-fullscreen-grid-peeking,.ytp-fullscreen-grid-active) .ytp-fullscreen-grid {
      display: none !important;
    }
    .html5-video-player.ytp-fullscreen:is(.ytp-fullscreen-grid-peeking,.ytp-fullscreen-grid-active) .ytp-gradient-bottom {
      display: none !important;
    }
    /* Generic fallbacks for renamed classes */
    .html5-video-player.ytp-fullscreen [class*="fullscreen-grid"] { display: none !important; }
    .html5-video-player.ytp-fullscreen [class*="gradient-bottom"] { display: none !important; }

    .html5-video-player.ytp-fullscreen:is(.ytp-fullscreen-grid-peeking,.ytp-fullscreen-grid-active) .ytp-chrome-bottom {
      bottom: 0px !important;
    }
    .html5-video-player.ytp-fullscreen:is(.ytp-fullscreen-grid-peeking,.ytp-fullscreen-grid-active):not(:is(.ytp-autohide,.ytp-autohide-active)) .ytp-chrome-bottom {
      opacity: unset !important;
    }
    .html5-video-player.ytp-fullscreen:is(.ytp-fullscreen-grid-peeking,.ytp-fullscreen-grid-active) .ytp-overlays-container {
      bottom: calc(var(--yt-delhi-bottom-controls-height, 72px) + 30px) !important;
    }
    .html5-video-player.ytp-fullscreen:is(.ytp-fullscreen-grid-peeking,.ytp-fullscreen-grid-active):not(:is(.ytp-autohide,.ytp-autohide-active)) .ytp-overlays-container {
      opacity: unset !important;
    }
    div.html5-video-player {
      --ytp-grid-scroll-percentage: 0 !important;
    }
    div.html5-video-player.ytp-fullscreen-grid-active .ytp-chrome-bottom {
      display: block !important;
    }
  `;

  // defensive GM wrappers (in case manager doesn't expose GM_* exactly)
  const hasGMGet = typeof GM_getValue === 'function';
  const hasGMSet = typeof GM_setValue === 'function';
  const gmGet = (k) => (hasGMGet ? GM_getValue(k) : undefined) ?? DEFAULTS[k];
  const gmSet = (k, v) => { if (hasGMSet) GM_setValue(k, v); };

  const setImp = (el, prop, val) => el?.style?.setProperty(prop, val, 'important');
  const removeImp = (el, prop) => el?.style?.removeProperty(prop);

  function injectStylesEarly() {
    if (document.getElementById(STYLE_ID)) return;
    const st = document.createElement('style');
    st.id = STYLE_ID;
    st.textContent = STYLE_TEXT;
    (document.head || document.documentElement).appendChild(st);
  }

  function applyWatchFixes() {
    const watch = document.querySelector('ytd-watch-flexy');
    const masthead = document.querySelector('#masthead-container');
    const app = document.querySelector('ytd-app');
    const pm = document.getElementById('page-manager');
    if (!watch || !app) return;

    const player = document.getElementById('movie_player') || document.querySelector('.html5-video-player');
    const behavior = gmGet('mastheadBehavior');

    // mode detection
    const isTheater = watch.hasAttribute('theater');
    const isFullscreen =
      watch.hasAttribute('fullscreen') ||
      !!document.fullscreenElement ||
      player?.classList.contains('ytp-fullscreen');

    const hasMini = document.querySelector('ytd-miniplayer')?.hasAttribute('active');

    if (isTheater || isFullscreen) {
      if (!hasMini && masthead) {
        if (isFullscreen || behavior === 'hide') {
          setImp(masthead, 'display', 'none');
        } else if (behavior === 'relative') {
          removeImp(masthead, 'display');
          setImp(masthead, 'position', 'relative');
          setImp(masthead, 'z-index', '2020');
        } else {
          removeImp(masthead, 'display');
          removeImp(masthead, 'position');
          removeImp(masthead, 'z-index');
        }
      }

      if (!hasMini) {
        setImp(app, 'overflow', 'auto');
        if (app.hasAttribute('scrolling')) {
          setImp(app, 'position', 'absolute');
          setImp(app, 'top', '0');
          setImp(app, 'left', '0');
          setImp(app, 'right', 'calc((var(--ytd-app-fullerscreen-scrollbar-width) + 1px)*-1)');
          setImp(app, 'bottom', '0');
          setImp(app, 'overflow-x', 'auto');
        }
      }

      const sc =
        document.querySelector('#single-column-container.ytd-watch-flexy') ||
        document.getElementById('single-column-container');
      const cols =
        document.querySelector('#columns.ytd-watch-flexy') ||
        document.getElementById('columns');
      if (sc) setImp(sc, 'display', 'flex');
      if (cols) setImp(cols, 'display', 'flex');

      if (behavior === 'relative' && !isFullscreen && pm) setImp(pm, 'margin-top', '0');
    } else {
      if (masthead) {
        removeImp(masthead, 'display');
        removeImp(masthead, 'position');
        removeImp(masthead, 'z-index');
      }
      if (pm) removeImp(pm, 'margin-top');
    }
  }

  let debounceTimer = null;
  function scheduleRun(delay = 100) {
    clearTimeout(debounceTimer);
    debounceTimer = setTimeout(() => {
      applyWatchFixes();
      // Retry once if watch page not loaded yet
      if (!document.querySelector('ytd-watch-flexy') && location.pathname.includes('/watch')) {
        setTimeout(applyWatchFixes, 500);
      }
    }, delay);
  }

  const observer = new MutationObserver((mutations) => {
    for (const m of mutations) {
      if (
        (m.type === 'childList' && [...m.addedNodes].some(n => n.matches?.('ytd-watch-flexy, ytd-miniplayer, #movie_player, .html5-video-player'))) ||
        (m.type === 'attributes' && (
          m.target.matches?.('ytd-watch-flexy, ytd-miniplayer') ||
          m.target.id === 'movie_player' ||
          m.target.matches?.('.html5-video-player')
        ))
      ) {
        scheduleRun(50);
        break;
      }
    }
  });

  function startObserver() {
    const target = document.querySelector('ytd-app') || document.documentElement;
    observer.observe(target, {
      childList: true,
      subtree: true,
      attributes: true,
      attributeFilter: ['theater', 'fullscreen', 'active', 'class']
    });
  }

  //  settings dialog using DOM methods to avoid TrustedTypes TrustedHTML errors
  function showSettings() {
    if (document.getElementById('yt-theater-fix-settings')) return;
    const current = gmGet('mastheadBehavior');

    const overlay = document.createElement('div');
    overlay.id = 'yt-theater-fix-settings';
    overlay.style.cssText = 'position:fixed;inset:0;display:flex;align-items:center;justify-content:center;z-index:99999;background-color:rgba(0,0,0,0.6)';

    const dialog = document.createElement('div');
    dialog.style.cssText = 'background:#222;color:#fff;padding:18px;border-radius:8px;min-width:320px;font-family:Arial,Helvetica,sans-serif;box-shadow:0 4px 12px rgba(0,0,0,0.5);';

    const title = document.createElement('h3');
    title.textContent = 'Theater Mode Settings';
    title.style.cssText = 'margin:0 0 12px 0;font-size:16px';

    const options = document.createElement('div');
    options.style.cssText = 'display:flex;flex-direction:column;gap:8px';

    function mkOption(val, text) {
      const label = document.createElement('label');
      const input = document.createElement('input');
      input.type = 'radio';
      input.name = 'mf';
      input.value = val;
      if (current === val) input.checked = true;
      label.appendChild(input);
      label.appendChild(document.createTextNode(' ' + text));
      return label;
    }

    options.appendChild(mkOption('relative', 'Show masthead (scrollable)'));
    options.appendChild(mkOption('hide', 'Hide masthead'));
    options.appendChild(mkOption('fixed', 'Show masthead (fixed)'));

    const controls = document.createElement('div');
    controls.style.cssText = 'display:flex;gap:8px;justify-content:flex-end;margin-top:12px';

    const btnCancel = document.createElement('button');
    btnCancel.id = 'yt-m-cancel';
    btnCancel.textContent = 'Cancel';

    const btnSave = document.createElement('button');
    btnSave.id = 'yt-m-save';
    btnSave.textContent = 'Save & Reload';

    controls.appendChild(btnCancel);
    controls.appendChild(btnSave);

    dialog.appendChild(title);
    dialog.appendChild(options);
    dialog.appendChild(controls);
    overlay.appendChild(dialog);

    (document.documentElement || document.body || document).appendChild(overlay);

    const close = () => overlay.remove();
    overlay.addEventListener('click', (e) => { if (e.target === overlay) close(); });
    btnCancel.onclick = close;
    btnSave.onclick = () => {
      const v = document.querySelector('input[name="mf"]:checked')?.value || DEFAULTS.mastheadBehavior;
      gmSet('mastheadBehavior', v);
      close();
      location.reload();
    };
  }

  // register menu command fail silently
  try {
    if (typeof GM_registerMenuCommand === 'function') GM_registerMenuCommand('Theater Mode Settings', showSettings);
  } catch (e) { /* ignore */ }

  // Re run on SPA navigations and fullscreen toggles
  window.addEventListener('yt-navigate-finish', () => scheduleRun(50), { passive: true });
  document.addEventListener('fullscreenchange', () => scheduleRun(20), { passive: true });

  // Init
  injectStylesEarly();
  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', () => {
      scheduleRun(50);
      startObserver();
    });
  } else {
    scheduleRun(50);
    startObserver();
  }
})();