Animierter Countdown-Zähler

<html>
<head>

<style type="text/css">
.base-timer {width: 15%; height: 15%; top: 0; display: flex; align-items: center; justify-content: center;}
.base-timer__svg {transform: scaleX(-1);}
.base-timer__circle {fill: none; stroke: none;}
.base-timer__path-elapsed {stroke-width: 7px; stroke: blue;}
.base-timer__path-remaining {stroke-width: 7px; stroke-linecap: round; transform: rotate(90deg); transform-origin: center; transition: 1s linear all; fill-rule: nonzero; stroke: currentColor;}
.base-timer__path-remaining.green {color: rgb(65, 184, 131);}
.base-timer__path-remaining.orange {color: orange;}
.base-timer__path-remaining.red {color: red;}
.base-timer__label {width: 50%; height: 50%; top: 0; display: flex; align-items: center; justify-content: center; font-size: 48px;}
</style>
<head>

<body >
<div id="app"></div></center>
<script>
const FULL_DASH_ARRAY = 283;
const WARNING_THRESHOLD = 10;
const ALERT_THRESHOLD = 5;
const COLOR_CODES = {
info: {
color: "green"
},
warning: {
color: "orange",
threshold: WARNING_THRESHOLD
},
alert: {
color: "red",
threshold: ALERT_THRESHOLD
}
};
const TIME_LIMIT = 10;
let timePassed = 0;
let timeLeft = TIME_LIMIT;
let timerInterval = null;
let remainingPathColor = COLOR_CODES.info.color;
document.getElementById("app").innerHTML = `
<div class="base-timer">
<svg class="base-timer__svg" viewBox="0 0 100 100" xmlns="">
<g class="base-timer__circle">
<circle class="base-timer__path-elapsed" cx="50" cy="50" r="45"></circle>
<path
id="base-timer-path-remaining"
stroke-dasharray="283"
class="base-timer__path-remaining ${remainingPathColor}"
d="
M 50, 50
m -45, 0
a 45,45 0 1,0 90,0
a 45,45 0 1,0 -90,0
"
></path>
</g>
</svg>
<span id="base-timer-label" class="base-timer__label">${formatTime(
timeLeft
)}</span>
</div>
`;
startTimer();
function onTimesUp() {
clearInterval(timerInterval);
}
function startTimer() {
timerInterval = setInterval(() => {
timePassed = timePassed += 1;
timeLeft = TIME_LIMIT - timePassed;
document.getElementById("base-timer-label").innerHTML = formatTime(
timeLeft
);
setCircleDasharray();
setRemainingPathColor(timeLeft);

if (timeLeft === 0) {
onTimesUp();
}
}, 1000);
}
function formatTime(time) {
const minutes = Math.floor(time / 60);
let seconds = time % 60;
if (seconds < 10) {
seconds = `0${seconds}`;
}
return `${minutes}:${seconds}`;
}
function setRemainingPathColor(timeLeft) {
const { alert, warning, info } = COLOR_CODES;
if (timeLeft <= alert.threshold) {
document
.getElementById("base-timer-path-remaining")
.classList.remove(warning.color);
document
.getElementById("base-timer-path-remaining")
.classList.add(alert.color);
} else if (timeLeft <= warning.threshold) {
document
.getElementById("base-timer-path-remaining")
.classList.remove(info.color);
document
.getElementById("base-timer-path-remaining")
.classList.add(warning.color);
}
}
function calculateTimeFraction() {
const rawTimeFraction = timeLeft / TIME_LIMIT;
return rawTimeFraction - (1 / TIME_LIMIT) * (1 - rawTimeFraction);
}
function setCircleDasharray() {
const circleDasharray = `${(
calculateTimeFraction() * FULL_DASH_ARRAY
).toFixed(0)} 283`;
document
.getElementById("base-timer-path-remaining")
.setAttribute("stroke-dasharray", circleDasharray);
}
</script>
</body>

</html>