圆进度条

圆环进度条

<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title>circleProgress using Canvas</title>
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
<style>
tr.label {
font-weight: bold;
text-align: center;
}

tr.circle {
text-align: center;
}

tr.code {
vertical-align: top;
}
</style>
<script type="text/javascript">
(function (window) {
var requestAnimationFrame = (function () {
return window.requestAnimationFrame ||
function (cb) {
return window.setTimeout(cb, 1000 / 60);
};
})();

var cancelAnimationFrame = (function () {
return window.cancelAnimationFrame ||
window.clearTimeout;
})();

var circleProgress = function (options) {
if (options.progress !== 0) {
options.progress = options.progress || 100;
}
if (options.duration !== 0) {
options.duration = options.duration || 1000;
}
options.fps = 60; // requestAnimationFrame / cancelAnimationFrame
options.color = options.color || 'rgb(52, 145, 204)';
options.bgColor = options.bgColor || 'rgb(230, 230, 230)';
options.textColor = options.textColor || 'black';
options.progressWidth = options.progressWidth || 0.25; //r
options.fontScale = options.fontScale || 0.4; //r

options.toFixed = options.toFixed || 0;
var canvas = document.getElementById(options.id);
if (canvas == null || canvas.getContext == null) {
return;
}
options.width = canvas.width;
options.height = canvas.height;
options.context = canvas.getContext('2d');

var step = function () {
if (options.current < options.progress && options.duration > 0) {
drawCircleProgress(options);
options.current += options.progress * (1000 / options.fps) / options.duration;
canvas.setAttribute('data-requestID', requestAnimationFrame(step));
} else {
options.current = options.progress;
drawCircleProgress(options);
canvas.removeAttribute('data-requestID');
}
};

cancelAnimationFrame(canvas.getAttribute('data-requestID'));
options.current = 0;
step();
};

var drawCircleProgress = function (options) {
var ctx = options.context;
var width = options.width;
var height = options.height;
var current = options.current;
var color = options.color;
var bgColor = options.bgColor;
var textColor = options.textColor;
var progressWidth = options.progressWidth;
var fontScale = options.fontScale;

var x = width / 2;
var y = height / 2;
var r1 = Math.floor(Math.min(width, height) / 2);
var r2 = Math.floor(r1 * (1 - progressWidth));
var startAngle = -Math.PI / 2;
var endAngle = startAngle + Math.PI * 2 * current / 100;
var fontSize = Math.floor(r1 * fontScale);

ctx.save();
ctx.clearRect(0, 0, width, height);

ctx.beginPath();
if (current > 0) {
ctx.arc(x, y, r1, startAngle, endAngle, true);
ctx.arc(x, y, r2, endAngle, startAngle, false);
} else {
ctx.arc(x, y, r1, 0, Math.PI * 2, true);
ctx.arc(x, y, r2, Math.PI * 2, 0, false);
}
ctx.closePath();
ctx.fillStyle = bgColor;
ctx.fill();

ctx.beginPath();
ctx.arc(x, y, r1, startAngle, endAngle, false);
ctx.arc(x, y, r2, endAngle, startAngle, true);
ctx.closePath();
ctx.fillStyle = color;
ctx.fill();

ctx.fillStyle = textColor;
ctx.font = '' + fontSize + 'px arial';
ctx.textBaseline = 'middle';
ctx.textAlign = 'center';
ctx.fillText('' + current.toFixed(options.toFixed) + '%', x, y);
ctx.restore();
};

window.circleProgress = circleProgress;

})(this);

</script>
</head>
<body>
<a href="#" onclick="showMe();">Show me!</a>
<table>
<tr class="label">
<td>1. Default options</td>
<td>2. Custom options</td>
</tr>
<tr class="circle">
<td>
<canvas id="circle-progress-default" width="200" height="200"></canvas>
</td>
<td>
<canvas id="circle-progress-custom" width="200" height="200"></canvas>
</td>
</tr>
<tr class="code">
<td>
<pre>
circleProgress({
id: 'circle-progress-default'
});
</pre>
</td>
<td>
<pre>
circleProgress({
id: 'circle-progress-custom',
progress: 70, // default: 100
duration: 2000, // default: 1000
color: 'red', // default: 'rgb(52, 145, 204)'
bgColor: 'green', // default: 'rgb(230, 230, 230)'
textColor: 'blue', // default: 'black'
progressWidth: 0.15, // default: 0.25 (r)
fontScale: 0.5, // default: 0.4 (r)
toFixed: 1 // default: 0
});
</pre>
</td>
</tr>
<tr class="label">
<td>3. Zero progress</td>
<td>4. No animation</td>
</tr>
<tr class="circle">
<td>
<canvas id="circle-progress-zero" width="200" height="200"></canvas>
</td>
<td>
<canvas id="circle-progress-no-animation" width="200" height="200"></canvas>
</td>
</tr>
<tr class="code">
<td>
<pre>
circleProgress({
id: 'circle-progress-zero',
progress: 0 // default: 100
});
</pre>
</td>
<td>
<pre>
circleProgress({
id: 'circle-progress-no-animation',
duration: 0 // default: 1000
});
</pre>
</td>
</tr>
</table>
<script type="text/javascript">
var showMe = function () {
circleProgress({
id: 'circle-progress-default'
});
circleProgress({
id: 'circle-progress-custom',
progress: 70, // default: 100
duration: 2000, // default: 1000
color: 'red', // default: 'rgb(52, 145, 204)'
bgColor: 'green', // default: 'rgb(230, 230, 230)'
textColor: 'blue', // default: 'black'
progressWidth: 0.15, // default: 0.25 (r)
fontScale: 0.5, // default: 0.4 (r)
toFixed: 1 // default: 0
});
circleProgress({
id: 'circle-progress-zero',
progress: 0 // default: 100
});
circleProgress({
id: 'circle-progress-no-animation',
duration: 0 // default: 1000
});
};
showMe();
</script>
</body>
</html>
原文地址:https://www.cnblogs.com/wzzl/p/4603242.html