Loop exercise videos

Exercise videos will loop, press space to start playing, press F for full screen.

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         Loop exercise videos
// @namespace    Itsnotlupus Industries
// @version      1.0
// @description  Exercise videos will loop, press space to start playing, press F for full screen.
// @author       itsnotlupus
// @license      MIT
// @match        https://www.muscleandstrength.com/exercises/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=muscleandstrength.com
// @grant        none
// ==/UserScript==
/* global Vimeo, YT */
/* jshint esversion: 11 */

// Videos seen so far are one of
// 1. adhoc flowplayer with <video> tags
// 2. embedded Vimeo players
// 3. embedded Youtube players
// Each type needs its own handling to loop and control playback.

document.head.append(Object.assign(document.createElement('script'), { src: "https://www.youtube.com/iframe_api" }));
document.head.append(Object.assign(document.createElement('script'), { src: "https://player.vimeo.com/api/player.js" }));

function onYouTubeIframeAPIReady() {
  console.log("YOUTUBE IFRAME API READY!");
}

function init() {
  const video = document.querySelector('video');
  const iframe = document.querySelector('iframe');
  if (!video && !iframe) return setTimeout(init, 1000);
  if (!window.YT) return setTimeout(init, 1000);
  if (!window.Vimeo) return setTimeout(init, 1000);
  let player; // youtube or vimeo player API.
  if (video) {
    console.log('found old video, adding loop attribute');
    video.loop = true;
  } else if (iframe) {
    const url = new URL(iframe.src);
    if (url.host.includes('youtube')) {
      console.log('found youtube video, adding loop and loading player object');
      const id = url.pathname.split('/').at(-1);
      iframe.src += '&enablejsapi=1&mute=1&loop=1&playlist=' + id;
      iframe.id = iframe.id || 'YoutubeVideoWidget';
      player = new YT.Player(iframe.id);
    } else if (url.host.includes('vimeo')) {
      console.log('found vimeo video, adding loop and loading player object');
      iframe.src += '&loop=1';
      player = new Vimeo.Player(iframe);
    } else {
      return setTimeout(init, 1000);
    }
  }
  // full screen toggling by pressing "F"
  const fullscreen = (e=document.documentElement, d=e.ownerDocument) => d.fullscreenElement ? d.exitFullscreen() : e.requestFullscreen();
  addEventListener('keypress', async e=> {
    if (document.activeElement != document.body) return; // don't mess with text fields.
    if (e.key == 'f') {
      e.preventDefault();
      fullscreen(video?.parentElement?.parentElement ?? iframe);
    }
    if (e.key == ' ') {
      e.preventDefault();
      if (video) document.querySelector('.fp-ui').click();
      if (iframe) {
        const url = new URL(iframe.src);
        if (url.host.includes('youtube')) {
          if (player.getPlayerState() == 1) {
            player.pauseVideo();
          } else {
            player.playVideo();
          }
        } else {
          // vimeo, probably
          const paused = await player.getPaused();
          if (paused) {
            player.play();
          } else {
            player.pause();
          }
        }
      }
    }
  });
}

init();