right click + scroll up/down == left/right

useful for any site with galleries, hold right click and scroll to cycle images

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        right click + scroll up/down == left/right
// @match       https://twitter.com/*
// @version     0.1
// @author      f-carraro
// @description useful for any site with galleries, hold right click and scroll to cycle images
// @namespace https://greasyfork.org/users/699847
// ==/UserScript==

var hold = false;
var didsomething = false;

window.addEventListener("mousedown", ({button}) => {
    if (button === 2) { // right click
        hold = true;
    }
});

window.addEventListener("mouseup", ({button}) => {
    if (button === 2) {
        hold = false;
    }
});

window.addEventListener("wheel", e=>{
    if (hold){
        e.preventDefault;
        if (e.deltaY < 0){
            sendKey(37); 
        } else {
            sendKey(39);  
        }
        didsomething = true;
    }
});

window.addEventListener('contextmenu', e=>{
    if (didsomething){
        e.preventDefault();
    }
    didsomething=false;
});

function sendKey(code){
    const ke = new KeyboardEvent("keydown", {bubbles: true, cancelable: true, keyCode: code});
    document.dispatchEvent(ke);
}