Youtube Fullscreen Mode

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ของเมื่อวันที่ 18-09-2025 ดู เวอร์ชันล่าสุด

คุณจะต้องติดตั้งส่วนขยาย เช่น Tampermonkey, Greasemonkey หรือ Violentmonkey เพื่อติดตั้งสคริปต์นี้

คุณจะต้องติดตั้งส่วนขยาย เช่น Tampermonkey หรือ Violentmonkey เพื่อติดตั้งสคริปต์นี้

คุณจะต้องติดตั้งส่วนขยาย เช่น Tampermonkey หรือ Violentmonkey เพื่อติดตั้งสคริปต์นี้

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 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();
})();