Disable website keyboard hooks

Stop websites from hijacking keyboard shortcuts.

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

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.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name           Disable website keyboard hooks
// @description    Stop websites from hijacking keyboard shortcuts.
// @author         Isaac Levy, Jonas Singe
// @run-at         document-start
// @include        *
// @grant          none
// @version        0.0.2
// @namespace      https://github.com/isaacl/keycodeScript
// ==/UserScript==

// Disable these keys when no keyboard modifier is pressed
var std_keycodes = new Set([
    // Add keycodes as desired
    37, 38, 39, 40 // Arrow Keys.
]);

// Disable these keys when Meta key is pressed.
var meta_keycodes = new Set([
    // Add keycodes as desired
    70 // Ctrl + F
]);

// Disable these keys when Alt key is pressed.
var alt_keycodes = new Set([
    // Add keycodes as desired
    83 // Alt + S
]);


// Don't change below this line.

var isMac = navigator.platform.indexOf('Mac') >= 0;


document.addEventListener('keydown', function(e) {
    var keycode_set;
    if (isMac ? e.metaKey : e.ctrlKey) {
        keycode_set = meta_keycodes;
    } else if (e.altKey) {
        keycode_set = alt_keycodes;
    } else {
        keycode_set = std_keycodes;
    }

    if (keycode_set.has(e.keyCode)) {
        e.stopImmediatePropagation();
    }
    return false;
});