Greasemonkey/Tempermonkey script to hide everything but chat on facebook

show-facebook-chat-only.js

'use strict';
var focusMode = localStorage.getItem('____focusMode') === '0' ? false : true;
var ENLARGE_CHATS = true;
var KEEP_DEFAULT_TITLE = 'Facebook';
if (focusMode) {
    var css = 'body {overflow: hidden;} #globalContainer {visibility: hidden} #pagelet_bluebar, #pagelet_canvas_nav_content, #pagelet_ticker, #pagelet_ego_pane {display: none !important}';
    var container = document.head || document.body;
    var style = document.createElement('style');

    if (ENLARGE_CHATS) {
        css += ' .fbDockChatTabFlyout {width: 400px !important;height:642px !important;} .fbNubGroup > .fbNub {width:400px !important;}';
    }
    if (KEEP_DEFAULT_TITLE) {
        setInterval(function() {
            if (document.title !== KEEP_DEFAULT_TITLE) {
                document.title = KEEP_DEFAULT_TITLE;
            }
        }, 200)
    }

    style.appendChild(document.createTextNode(css));
    container.appendChild(style);
}