如果您不打算使用该input[type=range]
元素,则可以将代码更改为:
(function (window) {
'use strict';
var document = window.document,
ring = document.getElementsByTagName('path')[0],
range = 0,
text = document.getElementsByTagName('text')[0],
Math = window.Math,
toRadians = Math.PI / 180,
r = 100;
function draw() {
// Update the wheel giving to it a value in degrees, getted from the percentage of the input value a.k.a. (value * 360) / 100
var degrees = range * 3.5999,
// Convert the degrees value to radians
rad = degrees * toRadians,
// Determine X and cut to 2 decimals
x = (Math.sin(rad) * r).toFixed(2),
// Determine Y and cut to 2 decimals
y = -(Math.cos(rad) * r).toFixed(2),
// The another half ring. Same as (deg > 180) ? 1 : 0
lenghty = window.Number(degrees > 180),
// Moveto + Arcto
descriptions = ['M', 0, 0, 'v', -r, 'A', r, r, 1, lenghty, 1, x, y, 'z'];
// Apply changes to the path
ring.setAttribute('d', descriptions.join(' '));
// Update the numeric display
text.textContent = range;
range++;
if(range > 100) {
clearInterval(timer);
}
}
// Translate the center axis to a half of total size
ring.setAttribute('transform', 'translate(' + r + ', ' + r + ')');
var timer = setInterval(draw,100);
}(this));
基本上改变range
为一个从 0 开始的简单变量,每次draw()
调用都会增加它的值。在这种情况下,创建一个间隔(名为timer
)以每 0.1 秒运行一次(当然这取决于您),并在适当的时候清除该间隔draw()
......
JSFiddle Demo