Prevent Spacebar Doing Page Down

When the Spacebar key is received outside a text entry area, discard it

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        Prevent Spacebar Doing Page Down
// @author      Jefferson "jscher2000" Scher
// @namespace   JeffersonScher
// @description When the Spacebar key is received outside a text entry area, discard it
// @include     *
// @version     1.0
// @grant       none
// @copyright   Copyright 2018 Jefferson Scher
// @license     BSD 3-clause
// ==/UserScript==

function PSDPD_KeyCheck(key){
  // Don't modify text editing
  if (key.target.nodeName == "INPUT" || key.target.nodeName == "TEXTAREA" || key.target.nodeName == "SELECT") return;
  if (key.target.hasAttribute("contenteditable") && key.target.getAttribute("contenteditable") == "true") return;
  // Don't modify certain combinations
  if (key.ctrlKey || key.altKey || key.metaKey) return;
  // If it's a space character, kill the event
  if (key.key == ' '){
    key.stopPropagation();
    key.preventDefault();
    return false;
  }
}
// Monitor the keydown event
document.addEventListener('keydown', PSDPD_KeyCheck);