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Half page (up/down) scroll

scrolls half a page when pressing page up / down

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.

(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         Half page (up/down) scroll
// @namespace    https://github.com/Alistair1231/my-userscripts/
// @version      0.2.0
// @description  scrolls half a page when pressing page up / down
// @author       Alistair1231
// @match        *://*/*
// @license      MIT
// ==/UserScript==
// https://greasyfork.org/en/scripts/444151-half-page-up-down-scroll/
// https://openuserjs.org/scripts/Alistair1231/Half_page_(updown)_scroll
(function () {
    'use strict';

    document.addEventListener('keydown', function (e) {
        // page down
        if (e.key === "PageDown") {
            e.preventDefault();
            window.scrollBy(0, window.innerHeight*.45);
            console.log("page down");
        }
        // page up
        else if (e.key === "PageUp") {
            e.preventDefault();
            window.scrollBy(0, -window.innerHeight*.45);
            console.log("page up");
        }
    });

})();