// ==UserScript==
// @name             E621 Swimmer
// @description      Navigate e621's pools with arrow keys
// @include          http*://e621.net/posts/*
// @grant            none
// ==/UserScript==

window.onload = function () {
    if (document.getElementsByClassName('pool-category-series')[0]) {
        let poolNavList = Array.prototype.slice.call(document.getElementsByClassName('pool-category-series')[0].childNodes);
        var prev = poolNavList.find(c => c.className === 'prev');
        var next = poolNavList.find(c => c.className === 'next');
        console.log(next.href);
        document.addEventListener('keydown', function (e) {
            if (e.keyCode === 37 && prev.href && e.ctrlKey) {
                window.location = prev.href;
            }
            else if (e.keyCode === 39 && next.href && e.ctrlKey) {
                window.location = next.href;
            }
        }, false);
    }
}()