YouTube Permanent ProgressBar

Keeps YouTube progressbar visible all the time.
当前为 2021-05-10 提交的版本，查看最新版本。
换行
// ==UserScript==
// @name         YouTube Permanent ProgressBar
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Keeps YouTube progressbar visible all the time.
// @author       Can Kurt
// @match        *://www.youtube.com/*
// @license      MIT
// ==/UserScript==


var permanentProgressBar = {

    setup : function(){
        // keep progressBar visible with css
        document.querySelector(".ytp-chrome-bottom").style.cssText = "opacity: 1 !important;";
    },

    prettifyVideoTime : function(video){
        let seconds = "" + Math.floor(video.currentTime%60);
        let minutes = "" + Math.floor((video.currentTime%3600)/60);
        let hours = "" + Math.floor(video.currentTime/3600);
        if(video.currentTime/60 > 60){
            return `${hours}:${minutes.padStart(2, '0')}:${seconds.padStart(2, '0')}`;
        }
        else{
            return `${minutes}:${seconds.padStart(2, '0')}`;
        }
    },

    getDuration : function(video, type){
        if(type === "PROGRESSBAR"){
            return video.currentTime;
        }
        else if(type === "BUFFERBAR"){
            return video.buffered.end(video.buffered.length-1);
        }
    },

    updateCurrentTimeField : function(player){
        const video = player.querySelector("video");
        const currentTime = player.querySelector(".ytp-time-current");
        if (!video || !currentTime) {
            return;
        }

        currentTime.innerText = permanentProgressBar.prettifyVideoTime(video);
    },

    updateProgressBar : function(player){
        // works only on chapterless (old) videos
        const video = player.querySelector("video");
        const progressBar = player.querySelector(".ytp-play-progress");
        const bufferBar = player.querySelector(".ytp-load-progress");
        if (!video || !progressBar || !bufferBar) {
            return;
        }

        progressBar.style.transform = `scaleX(${video.currentTime/video.duration})`;
        bufferBar.style.transform = `scaleX(${video.buffered.end(video.buffered.length-1)/video.duration})`;
    },

    updateProgressBarWithChapters : function(player, type){
        // YouTube api does not provides current time in chapters
        // this function finds current time in the chapter by finding the ratio between total video duration and total width of the chapters div

        const video = player.querySelector("video");

        // there can be multiple chapters
        const progressBarWidthsCollection = player.getElementsByClassName("ytp-progress-bar-padding");

        // select progress or bufferBar
        let progressBarChaptersCollection;
        if(type === "PROGRESSBAR"){
            progressBarChaptersCollection = player.getElementsByClassName("ytp-play-progress");
        }
        if(type === "BUFFERBAR"){
            progressBarChaptersCollection = player.getElementsByClassName("ytp-load-progress");
        }

        // quit if elements does not exists
        if (!video || !progressBarWidthsCollection || !progressBarChaptersCollection) {
            return;
        }

        // find the ratio between total video duration and total width of the chapters div
        let totalProgressBarWidth = 0;
        for (let i = 0; i < progressBarWidthsCollection.length; i++) {
            totalProgressBarWidth += progressBarWidthsCollection[i].offsetWidth;
        }
        const durationWidthRatio = video.duration/totalProgressBarWidth;

        // loop inside chapters
        let chaptersPixelWidthUntilCurrentChapter = 0;
        for (let i = 0; i < progressBarWidthsCollection.length; i++) {

            // if current time is bigger than durationWidthRatio * (chapters pixel width including current one) scale the current chapter to 1 because we passed it
            if(permanentProgressBar.getDuration(video, type) > durationWidthRatio*(chaptersPixelWidthUntilCurrentChapter + progressBarWidthsCollection[i].offsetWidth)){
                progressBarChaptersCollection[i].style.transform = "scaleX(1)";

                // increase the current chapters location by adding last watched chapter
                chaptersPixelWidthUntilCurrentChapter += progressBarWidthsCollection[i].offsetWidth;
            }

            // If not, it means that we are on this chapter.
            // Find the appropriate size for the chapter and scale it
            else{
                // current time
                let currentTimeInChapterInSeconds = permanentProgressBar.getDuration(video, type) - (durationWidthRatio*chaptersPixelWidthUntilCurrentChapter);

                // total chapter time
                let currentChapterLengthInSeconds = durationWidthRatio*progressBarWidthsCollection[i].offsetWidth;

                let currentChapterTimeRatio = currentTimeInChapterInSeconds / currentChapterLengthInSeconds

                progressBarChaptersCollection[i].style.transform = `scaleX(${currentChapterTimeRatio})`;

                break;
            }

        }

    },

    update : function(){
        const player = document.querySelector(".html5-video-player");
        if (!player) {
            return;
        }

        // update video timer
        permanentProgressBar.updateCurrentTimeField(player);

        // update progressBars
        permanentProgressBar.updateProgressBarWithChapters(player, "PROGRESSBAR");

        permanentProgressBar.updateProgressBarWithChapters(player, "BUFFERBAR");

    },

    start : function(){
        permanentProgressBar.setup();
        setInterval(permanentProgressBar.update, 500);
    }

}


permanentProgressBar.start();