プレゼンタイマー
style.css.timer {
left: 0;
bottom: 0;
position: fixed;
padding: 16px;
background-color: #ffcaca;
font-size: 32px;
font-weight: 800;
margin-right: auto;
margin-left: auto;
z-index: 201;
} script.jslet timerId = null;
let time = 0;
// from https://stackoverflow.com/questions/6312993/javascript-seconds-to-time-string-with-format-hhmmss
const toHHMMSS = function (sec_num) {
var hours = Math.floor(sec_num / 3600);
var minutes = Math.floor((sec_num - (hours * 3600)) / 60);
var seconds = sec_num - (hours * 3600) - (minutes * 60);
if (hours < 10) {hours = "0"+hours;}
if (minutes < 10) {minutes = "0"+minutes;}
if (seconds < 10) {seconds = "0"+seconds;}
return hours+':'+minutes+':'+seconds;
}
const pButton = Array.from(document.querySelectorAll(".dropdown-menu a")).filter(e => e.textContent.match(/Start presentation/))[0];
pButton.addEventListener('click', e => {
const timerDOM = document.createElement('div');
timerDOM.className = 'timer';
document.body.appendChild(timerDOM);
setInterval(e => {
time += 1;
timerDOM.textContent = toHHMMSS(time);
}, 1000);
})