Spacebar scroll marker

Fading marker line when you hit space to scroll.

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 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.

(Tôi đã có Trình quản lý tập lệnh người dùng, hãy cài đặt nó!)

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         Spacebar scroll marker
// @namespace    None
// @version      0.1
// @description  Fading marker line when you hit space to scroll.
// @match        *://*/*
// @exclude      *://*.reddit.com/*
// @grant        none
// @license MIT
// ==/UserScript==

(function() {
    'use strict';

    let i, elements=document.querySelectorAll('body *');
    for (i=0;i < elements.length;i++) {
        if (getComputedStyle(elements[i]).position === 'fixed' || getComputedStyle(elements[i]).position === 'sticky') {
            elements[i].parentNode.removeChild(elements[i]);
        }
    }
    let elem=Array.from(document.getElementsByTagName("body"))[0].appendChild(document.createElement('div'));
    elem.style.width="100%";
    elem.style.borderTop="1px solid red";
    elem.style.position="absolute";
    elem.style.top="0px";
    elem.style.opacity="0";
    elem.style.transition="opacity 1500ms";
    window.addEventListener('keydown', e => {
        if(e.code === "Space"){
            elem.style.transition="";
            elem.style.top=(window.innerHeight + window.scrollY) + "px";
            elem.style.opacity="1";
            setTimeout(function(){
                elem.style.transition="opacity 1500ms";
                elem.style.opacity="0";
            }, 200);
        }
    }
);
}())();