Youtube Fullscreen Mode

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Verzia zo dňa 18.09.2025. Pozri najnovšiu verziu.

Na nainštalovanie skriptu si budete musieť nainštalovať rozšírenie, ako napríklad Tampermonkey, Greasemonkey alebo Violentmonkey.

Na nainštalovanie skriptu si budete musieť nainštalovať rozšírenie, ako napríklad Tampermonkey, % alebo Violentmonkey.

Na nainštalovanie skriptu si budete musieť nainštalovať rozšírenie, ako napríklad Tampermonkey, % alebo Violentmonkey.

Na nainštalovanie skriptu si budete musieť nainštalovať rozšírenie, ako napríklad Tampermonkey alebo Userscripts.

Na inštaláciu tohto skriptu je potrebné nainštalovať rozšírenie, ako napríklad Tampermonkey.

Na inštaláciu tohto skriptu je potrebné nainštalovať rozšírenie správcu používateľských skriptov.

(Už mám správcu používateľských skriptov, nechajte ma ho nainštalovať!)

Na inštaláciu tohto štýlu je potrebné nainštalovať rozšírenie, ako napríklad Stylus.

Na inštaláciu tohto štýlu je potrebné nainštalovať rozšírenie, ako napríklad Stylus.

Na inštaláciu tohto štýlu je potrebné nainštalovať rozšírenie, ako napríklad Stylus.

Na inštaláciu tohto štýlu je potrebné nainštalovať rozšírenie správcu používateľských štýlov.

Na inštaláciu tohto štýlu je potrebné nainštalovať rozšírenie správcu používateľských štýlov.

Na inštaláciu tohto štýlu je potrebné nainštalovať rozšírenie správcu používateľských štýlov.

(Už mám správcu používateľských štýlov, nechajte ma ho nainštalovať!)

// ==UserScript==
// @name              Youtube Fullscreen Mode
// @name:ko           유튜브 풀스크린
// @description       -
// @description:ko    -
// @version           2025.09.18
// @author            ndaesik
// @icon              https://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Youtube_shorts_icon.svg/193px-Youtube_shorts_icon.svg.png
// @match             *://*.youtube.com/*
// @grant             none
// @namespace https://ndaesik.tistory.com/
// ==/UserScript==

(() => {
  'use strict';
  if (window.top !== window.self) return;

  const suggestBoxToDarkCSS = document.createElement('style');
  suggestBoxToDarkCSS.dataset.tm = 'yt-fullscreen-suggest';
  suggestBoxToDarkCSS.textContent = `
    body{overflow-y:auto;}
  `.replaceAll(';','!important;');

  const fullscreenVideoCSS = document.createElement('style');
  fullscreenVideoCSS.dataset.tm = 'yt-fullscreen-video';
  fullscreenVideoCSS.textContent = `
    ytd-app:not([guide-persistent-and-visible]) [theater] #player video,
    :is(ytd-watch-flexy[theater],ytd-watch-flexy[fullscreen]) #full-bleed-container {
      height:100vh;max-height:100vh;min-height:100vh;
    }
    ytd-watch-flexy[theater]{scrollbar-width:none;}
    ytd-watch-flexy[theater]::-webkit-scrollbar{display:none;}
    ytd-watch-flexy[theater] ~ body{scrollbar-width:none;-ms-overflow-style:none;}
    ytd-watch-flexy[theater] ~ body::-webkit-scrollbar{display:none;}
  `.replaceAll(';','!important;');

  const autoHideTopCSS = document.createElement('style');
  autoHideTopCSS.dataset.tm = 'yt-fullscreen-autohide';
  autoHideTopCSS.className = 'autoHideTopCSS';
  autoHideTopCSS.textContent = `
    #masthead-container.ytd-app:hover,#masthead-container.ytd-app:focus-within{width:100%;}
    #masthead-container.ytd-app,
    #masthead-container.ytd-app:not(:hover):not(:focus-within){width:calc(50% - 150px);}
    #masthead-container.ytd-app:not(:hover):not(:focus-within){transition:width .4s ease-out .4s;}
    ytd-app:not([guide-persistent-and-visible]) :is(#masthead-container ytd-masthead, #masthead-container.ytd-app::after){
      transform:translateY(-56px);transition:transform .1s .3s ease-out;
    }
    ytd-app:not([guide-persistent-and-visible]) :is(#masthead-container:hover ytd-masthead, #masthead-container:hover.ytd-app::after, #masthead-container:focus-within ytd-masthead){
      transform:translateY(0);
    }
    ytd-app:not([guide-persistent-and-visible]) ytd-page-manager{margin-top:0;}
  `.replaceAll(';','!important;');

  const $ = {
    els: { ytdApp: null, player: null, chatFrame: null },
    update() {
      this.els.ytdApp = document.querySelector('ytd-app');
      this.els.player = document.querySelector('#ytd-player');
      this.els.chatFrame = document.querySelector('ytd-live-chat-frame');
    }
  };

  let scrollTimer = null, isContentHidden = false;
  let observerForTheater = null;
  let listenersAttached = false;
  let listenerAbort = null;

  const isWatchPage = () => location.pathname === '/watch';
  const inTheater = () => {
    $.update();
    const { ytdApp, player, chatFrame } = $.els;
    return ytdApp && player && isWatchPage() &&
      (window.innerWidth - ytdApp.offsetWidth + player.offsetWidth +
       (chatFrame && !chatFrame.attributes.collapsed ? chatFrame.offsetWidth : 0)) === window.innerWidth;
  };

  const rafUntil = (pred, timeout = 5000) => new Promise(resolve => {
    const t0 = performance.now();
    const tick = () => {
      if (pred()) return resolve(true);
      if (performance.now() - t0 > timeout) return resolve(false);
      requestAnimationFrame(tick);
    };
    tick();
  });

  const isProgressHidden = () => {
    const p = document.querySelector('yt-page-navigation-progress');
    if (!p) return true;
    if (p.hasAttribute('hidden')) return true;
    const s = getComputedStyle(p);
    return s.display === 'none' || s.visibility === 'hidden' || s.opacity === '0';
  };

  const isPlayerReady = () => {
    const v = document.querySelector('#ytd-player video, #movie_player video, ytd-player video');
    return !!(v && v.readyState >= 1);
  };

  const resetScrollTopSmart = async () => {
    try { if ('scrollRestoration' in history) history.scrollRestoration = 'manual'; } catch(_) {}
    window.scrollTo(0,0);
    await new Promise(r => requestAnimationFrame(() => { window.scrollTo(0,0); r(); }));
    await new Promise(r => requestAnimationFrame(() => { window.scrollTo(0,0); r(); }));
    await rafUntil(() => (document.readyState === 'complete' || isProgressHidden()) && isPlayerReady());
    window.scrollTo(0,0);
  };

  let autoHideOn = false;

  const shouldShowAutoHideCSS = () => {
    const scrollPosition = window.scrollY;
    const viewportHeight = window.innerHeight + 56;
    return isWatchPage() && inTheater() && scrollPosition <= viewportHeight;
  };

  const updateAutoHideCSS = () => {
    const need = shouldShowAutoHideCSS();
    if (need === autoHideOn) return;
    autoHideOn = need;
    if (need) {
      if (!document.head.querySelector('style[data-tm="yt-fullscreen-autohide"]')) {
        document.head.appendChild(autoHideTopCSS);
      }
    } else {
      autoHideTopCSS.remove();
    }
  };

  const checkConditions = () => {
    if (!isWatchPage()) return;
    const watchFlexy = document.querySelector('ytd-watch-flexy');
    const primaryContent = document.querySelector('#primary');
    const secondaryContent = document.querySelector('#secondary');
    const isTheater = watchFlexy?.hasAttribute('theater');
    const isScrollTop = window.scrollY === 0;
    if (!primaryContent || !secondaryContent || !isTheater) return;
    if (isScrollTop && !isContentHidden) {
      if (scrollTimer) clearTimeout(scrollTimer);
      scrollTimer = setTimeout(() => {
        primaryContent.style.display = 'none';
        secondaryContent.style.display = 'none';
        isContentHidden = true;
      }, 2000);
    } else if (!isScrollTop && scrollTimer) {
      clearTimeout(scrollTimer);
      scrollTimer = null;
      if (isContentHidden) {
        primaryContent.style.display = '';
        secondaryContent.style.display = '';
        isContentHidden = false;
      }
    }
  };

  const showContent = () => {
    const primaryContent = document.querySelector('#primary');
    const secondaryContent = document.querySelector('#secondary');
    if (isContentHidden && primaryContent && secondaryContent) {
      primaryContent.style.display = '';
      secondaryContent.style.display = '';
      isContentHidden = false;
      if (scrollTimer) { clearTimeout(scrollTimer); scrollTimer = null; }
      setTimeout(checkConditions, 1000);
    }
  };

  const attachCSS = () => {
    if (!document.head.querySelector('style[data-tm="yt-fullscreen-suggest"]')) {
      document.head.appendChild(suggestBoxToDarkCSS);
    }
    if (!document.head.querySelector('style[data-tm="yt-fullscreen-video"]')) {
      document.head.appendChild(fullscreenVideoCSS);
    }
    updateAutoHideCSS();
  };

  const detachCSS = () => {
    suggestBoxToDarkCSS.remove();
    fullscreenVideoCSS.remove();
    autoHideTopCSS.remove();
    observerForTheater?.disconnect();
    observerForTheater = null;
    if (listenerAbort) { listenerAbort.abort(); listenerAbort = null; }
    listenersAttached = false;
    if (isContentHidden) {
      const primaryContent = document.querySelector('#primary');
      const secondaryContent = document.querySelector('#secondary');
      if (primaryContent) primaryContent.style.display = '';
      if (secondaryContent) secondaryContent.style.display = '';
      isContentHidden = false;
    }
    if (scrollTimer) { clearTimeout(scrollTimer); scrollTimer = null; }
    autoHideOn = false;
  };

  const setupEventListeners = () => {
    if (listenersAttached) return;
    listenersAttached = true;
    listenerAbort = new AbortController();
    const sig = listenerAbort.signal;

    window.addEventListener('scroll', () => requestAnimationFrame(() => {
      updateAutoHideCSS();
      checkConditions();
    }), { passive: true, signal: sig });

    window.addEventListener('click', () => {
      setTimeout(updateAutoHideCSS, 100);
      requestAnimationFrame(showContent);
    }, { passive: true, signal: sig });

    window.addEventListener('wheel', () => requestAnimationFrame(showContent), { passive: true, signal: sig });

    const watchFlexyInit = () => {
      const watchFlexy = document.querySelector('ytd-watch-flexy');
      if (!watchFlexy) return;
      observerForTheater?.disconnect();
      observerForTheater = new MutationObserver(() => requestAnimationFrame(checkConditions));
      observerForTheater.observe(watchFlexy, { attributes: true, attributeFilter: ['theater'] });
    };
    new MutationObserver(watchFlexyInit).observe(document.documentElement, { childList: true, subtree: true });
    watchFlexyInit();

    window.addEventListener('yt-navigate-finish', () => { resetScrollTopSmart(); }, { passive: true, signal: sig });
  };

  const URL_EVENT = 'tm-url-change';
  const fireUrlEvent = () => window.dispatchEvent(new Event(URL_EVENT));

  const _pushState = history.pushState;
  const _replaceState = history.replaceState;
  history.pushState = function(...args) { const r = _pushState.apply(this, args); fireUrlEvent(); return r; };
  history.replaceState = function(...args) { const r = _replaceState.apply(this, args); fireUrlEvent(); return r; };

  window.addEventListener('popstate', fireUrlEvent);
  window.addEventListener('hashchange', fireUrlEvent);
  window.addEventListener('yt-navigate-finish', fireUrlEvent);
  window.addEventListener('yt-navigate-start', fireUrlEvent);

  let lastPath = location.pathname + location.search;

  const onRoute = () => {
    const now = location.pathname + location.search;
    if (now === lastPath) return;
    lastPath = now;
    if (isWatchPage()) {
      attachCSS();
      setupEventListeners();
      resetScrollTopSmart();
      requestAnimationFrame(() => {
        updateAutoHideCSS();
        checkConditions();
      });
    } else {
      detachCSS();
    }
  };

  const boot = () => {
    if (isWatchPage()) {
      attachCSS();
      setupEventListeners();
      resetScrollTopSmart();
      requestAnimationFrame(() => {
        updateAutoHideCSS();
        checkConditions();
      });
    } else {
      detachCSS();
    }
  };

  window.addEventListener(URL_EVENT, onRoute);
  boot();
})();