Control YouTube video volume by mouse wheel.
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// ==UserScript==
// @name YouTube Volume Mouse Controller
// @namespace wddd
// @version 1.5.0
// @author wddd
// @license MIT
// @description Control YouTube video volume by mouse wheel.
// @homepage https://github.com/wdwind/YouTubeVolumeMouseController
// @match *://www.youtube.com/*
// ==/UserScript==
function getVideo() {
return document.getElementsByTagName("video")[0];
}
function getPlayer() {
var ytd_player = document.getElementsByTagName("ytd-player")[0];
for (var player of ytd_player) {
if (player.getPlayer()) {
return player.getPlayer();
}
}
}
function run() {
var player = getPlayer();
var timer = 0;
// detect available wheel event
var support = "onwheel" in document.createElement("div") ? "wheel" : // Modern browsers support "wheel"
document.onmousewheel !== undefined ? "mousewheel" : // Webkit and IE support at least "mousewheel"
"DOMMouseScroll"; // let"s assume that remaining browsers are older Firefox
getVideo().addEventListener(support, function (event) {
var volume = player.getVolume();
var volumeDelta = 5;
var deltaY = support == "mousewheel" ? event.wheelDelta : (event.deltaY || event.detail);
// Optimize volume change for touchpad
if (Math.abs(deltaY) < 5) {
volumeDelta = Math.max(Math.floor(Math.abs(deltaY)), 1);
}
volume += (deltaY > 0 ? -volumeDelta : volumeDelta);
// Limit the volume between 0 and 100
volume = Math.max(0, Math.min(100, volume));
if (volume > 0) {
player.unMute(true);
}
player.setVolume(volume, true);
timer = showSlider(timer, volume);
// Prevent the page to scroll
event.preventDefault();
event.stopImmediatePropagation();
return false;
});
}
function showSlider(timer, volume) {
if (timer) {
clearTimeout(timer);
}
var sliderBar = appendSlideBar();
sliderBar.style.display = "block";
timer = setTimeout(function () {
sliderBar.style.display = "none";
}, 1000);
sliderBar.innerText = "Volume: " + volume;
return timer;
}
function appendSlideBar() {
var sliderBar = document.getElementById("sliderBar");
if (!sliderBar) {
var sliderBarElement = document.createElement("div");
sliderBarElement.id = "sliderBar";
document.getElementsByClassName("html5-video-container")[0].appendChild(sliderBarElement);
sliderBar = document.getElementById("sliderBar");
addCss(sliderBar, {
"width": "100%",
"height": "20px",
"position": "relative",
"z-index": "9999",
"text-align": "center",
"color": "#fff",
"font-size": "initial",
"opacity": "0.9",
"background-color": "rgba(0,0,0,0.2)",
});
}
addCss(sliderBar, {"top": getSliderBarTopProp() + "px"});
return sliderBar;
}
function addCss(element, css) {
for (var cssAttr in css) {
element.style[cssAttr] = css[cssAttr];
}
}
function getSliderBarTopProp() {
var fullScreenTitleHeight = 0;
var fullScreenTitle = document.getElementsByClassName("ytp-title")[0];
if (fullScreenTitle && fullScreenTitle.offsetParent) {
fullScreenTitleHeight = fullScreenTitle.offsetHeight;
}
var videoTop = getVideo().getBoundingClientRect().top;
var headerBoundingBox =
(document.getElementById("masthead-positioner") || document.getElementById("masthead-container")).getBoundingClientRect();
var headerTop = headerBoundingBox.top;
var headerHeight = headerBoundingBox.height;
var overlap = (headerHeight + headerTop > 0) ? Math.max(0, headerHeight - videoTop) : 0;
return Math.max(fullScreenTitleHeight, overlap);
}
/**
* YouTube use Javascript to navigate between pages. So the script will not work:
* 1. If the script only includes/matches the sub pages (like the video page www.youtube.com/watch?v=...)
* 2. And the user navigates to the sub page from a page which is not included/matched by the script
*
* In the above scenario, the script will not be executed.
*
* To run the script in all cases,
* 1. Include/match the whole YouTube host
* 2. Detect Javascript events, and run the script appropriately
*
* Details:
* * https://stackoverflow.com/questions/32275387/recall-tampermonkey-script-when-page-location-changes/32277150#32277150
* * https://stackoverflow.com/questions/34077641/how-to-detect-page-navigation-on-youtube-and-modify-html-before-page-is-rendered
* * https://github.com/1c7/Youtube-Auto-Subtitle-Download/blob/master/Youtube-Subtitle-Downloader/Tampermonkey.js#L122-L152
*/
// trigger when navigating to new material design page
window.addEventListener("yt-navigate-finish", function () {
if (window.location.href.includes("/watch?v=")) {
run();
}
});
// trigger when navigating to the old page
window.addEventListener("spfdone", function () {
if (window.location.href.includes("/watch?v=")) {
run();
}
});
// trigger when directly loading the page
window.addEventListener("DOMContentLoaded", function () {
if (window.location.href.includes("/watch?v=")) {
run();
}
});
/**
* Use MutationObserver to cover all edge cases.
* https://stackoverflow.com/a/39803618
*
* This is to handle the use case where navigation happens but <video> has not been loaded yet.
* (In YouTube the contents are loaded asynchronously.)
*/
var observer = new MutationObserver(function() {
if (getVideo() && getPlayer()) {
observer.disconnect();
run();
}
});
observer.observe(document.body, /* config */ {childList: true, subtree: true});