spoken chat

spoken.user.js

// ==UserScript==
// @name          Spoken Chat
// @author        Robert Lemon
// @version       0.42
// @namespace     
// @description   Speaks the chat.
// @include       http://chat.stackoverflow.com/rooms/*
// ==/UserScript==
function exec(fn) {
    var script = document.createElement('script');
    script.setAttribute('type', 'application/javascript');
    script.textContent = '(' + fn + ')();';
    document.body.appendChild(script); // run the script
}
exec(function() {
    var reading = true;
    var toggle = document.createElement('input');
    toggle.checked = true;
    toggle.type = 'checkbox';
    toggle.onchange = function(e) {
        console.log(this.checked);
        reading = this.checked;
    };
    document.getElementById('chat-buttons').appendChild(toggle);
    var speechUtteranceChunker = function(utt, settings, callback) {
        settings = settings || {};
        var chunkLength = settings && settings.chunkLength || 160;
        var pattRegex = new RegExp('^.{' + Math.floor(chunkLength / 2) + ',' + chunkLength + '}[\.\!\?\,]{1}|^.{1,' + chunkLength + '}$|^.{1,' + chunkLength + '} ');
        var txt = (settings && settings.offset !== undefined ? utt.text.substring(settings.offset) : utt.text);
        var chunkArr = txt.match(pattRegex);
        if (chunkArr[0] !== undefined && chunkArr[0].length > 2) {
            var chunk = chunkArr[0];
            var newUtt = new SpeechSynthesisUtterance(chunk);
            for (x in utt) {
                if (utt.hasOwnProperty(x) && x !== 'text') {
                    newUtt[x] = utt[x];
                }
            }
            newUtt.onend = function() {
                settings.offset = settings.offset || 0;
                settings.offset += chunk.length - 1;
                speechUtteranceChunker(utt, settings, callback);
            }
            console.log(newUtt); //IMPORTANT!! Do not remove: Logging the object out fixes some onend firing issues.
            //placing the speak invocation inside a callback fixes ordering and onend issues.
            if (reading) {
                setTimeout(function() {
                    speechSynthesis.speak(newUtt);
                }, 0);
            }
        }
    };
    new MutationObserver(function(records) {
        records.forEach(function(record) {
            [].forEach.call(record.addedNodes, function(node) {
                if (node.classList && node.classList.contains('message') && !node.classList.contains('pending')) {
                    var anchor = node.parentNode.parentNode.firstChild,
                        user = anchor.querySelector('.username').textContent,
                        utterance = new SpeechSynthesisUtterance(user + ' said: ' + node.textContent),
                        voices = speechSynthesis.getVoices();
                    utterance.voice = voices[2];
                    speechUtteranceChunker(utterance, {
                        chunkLength: 120
                    });
                }
            });
        });
    }).observe(document.getElementById('chat'), {
        childList: true,
        subtree: true
    });
});

Very cool!