read-when-copy.user.js

// ==UserScript==
// @name         google sheet read.
// @namespace    https://houkanshan.com
// @version      0.1
// @description  try to take over the world!
// @author       Houkanshan
// @match        https://docs.google.com/spreadsheets/*
// @grant        none
// ==/UserScript==

var utterances = []; // Chrome Bug: https://stackoverflow.com/a/35935851
var currMsg = null;

function read(text) {
    return new Promise((resolve, reject) => {
        window.speechSynthesis.cancel();
        var msg = new SpeechSynthesisUtterance(text);
        utterances.push(msg);
        msg.addEventListener('end', () => {

            if (msg._stop) { return reject(); }

            var msgSlow = new SpeechSynthesisUtterance(text);
            utterances.push(msg);
            msgSlow.rate = 0.5;
            msgSlow.addEventListener('end', () => {
                if (msg._stop) { return reject(); }
                currMsg = null;
                resolve();
            });
            currMsg = msgSlow;
            window.speechSynthesis.speak(msgSlow);
        });
        currMsg = msg;
        window.speechSynthesis.speak(msg);
    });
}

(function() {
    'use strict';
    document.addEventListener('copy', function(e) {
        if (currMsg) {
            currMsg._stop = true;
            currMsg = null;
        }
        utterances = [];
        var text = e.clipboardData.getData('Text');
        text.split(/\n+/).reduce((acc, word) => {
            return acc.then(() => read(word));
        }, Promise.resolve()).then(() => utterances = [], () => {});
    });

})();