material-design-lite/src/third_party/rAF.js

51 lines
1.9 KiB
JavaScript

// Source: https://github.com/darius/requestAnimationFrame/blob/master/requestAnimationFrame.js
// Adapted from https://gist.github.com/paulirish/1579671 which derived from
// http://paulirish.com/2011/requestanimationframe-for-smart-animating/
// http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating
// requestAnimationFrame polyfill by Erik Möller.
// Fixes from Paul Irish, Tino Zijdel, Andrew Mao, Klemen Slavič, Darius Bacon
// MIT license
(function() {
'use strict';
if (!Date.now) {
/**
* Date.now polyfill.
* @return {number} the current Date
*/
Date.now = function() { return new Date().getTime(); };
Date['now'] = Date.now;
}
var vendors = ['webkit', 'moz'];
for (var i = 0; i < vendors.length && !window.requestAnimationFrame; ++i) {
var vp = vendors[i];
window.requestAnimationFrame = window[vp + 'RequestAnimationFrame'];
window.cancelAnimationFrame = (window[vp + 'CancelAnimationFrame'] ||
window[vp + 'CancelRequestAnimationFrame']);
window['requestAnimationFrame'] = window.requestAnimationFrame;
window['cancelAnimationFrame'] = window.cancelAnimationFrame;
}
if (/iP(ad|hone|od).*OS 6/.test(window.navigator.userAgent) || !window.requestAnimationFrame || !window.cancelAnimationFrame) {
var lastTime = 0;
/**
* requestAnimationFrame polyfill.
* @param {!Function} callback the callback function.
*/
window.requestAnimationFrame = function(callback) {
var now = Date.now();
var nextTime = Math.max(lastTime + 16, now);
return setTimeout(function() { callback(lastTime = nextTime); },
nextTime - now);
};
window.cancelAnimationFrame = clearTimeout;
window['requestAnimationFrame'] = window.requestAnimationFrame;
window['cancelAnimationFrame'] = window.cancelAnimationFrame;
}
})();