third_party/ot-br-posix/repo/third_party/mdl/repo/src/third_party/rAF.js

   1 // Source: https://github.com/darius/requestAnimationFrame/blob/master/requestAnimationFrame.js
   2 // Adapted from https://gist.github.com/paulirish/1579671 which derived from
   3 // http://paulirish.com/2011/requestanimationframe-for-smart-animating/
   4 // http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating
   5
   6 // requestAnimationFrame polyfill by Erik Möller.
   7 // Fixes from Paul Irish, Tino Zijdel, Andrew Mao, Klemen Slavič, Darius Bacon
   8
   9 // MIT license
  10
  11 (function() {
  12   'use strict';
  13
  14   if (!Date.now) {
  15     /**
  16      * Date.now polyfill.
  17      * @return {number} the current Date
  18      */
  19     Date.now = function() { return new Date().getTime(); };
  20     Date['now'] = Date.now;
  21   }
  22
  23   var vendors = ['webkit', 'moz'];
  24   for (var i = 0; i < vendors.length && !window.requestAnimationFrame; ++i) {
  25     var vp = vendors[i];
  26     window.requestAnimationFrame = window[vp + 'RequestAnimationFrame'];
  27     window.cancelAnimationFrame = (window[vp + 'CancelAnimationFrame'] ||
  28         window[vp + 'CancelRequestAnimationFrame']);
  29     window['requestAnimationFrame'] = window.requestAnimationFrame;
  30     window['cancelAnimationFrame'] = window.cancelAnimationFrame;
  31   }
  32
  33   if (/iP(ad|hone|od).*OS 6/.test(window.navigator.userAgent) || !window.requestAnimationFrame || !window.cancelAnimationFrame) {
  34     var lastTime = 0;
  35     /**
  36      * requestAnimationFrame polyfill.
  37      * @param  {!Function} callback the callback function.
  38      */
  39     window.requestAnimationFrame = function(callback) {
  40       var now = Date.now();
  41       var nextTime = Math.max(lastTime + 16, now);
  42       return setTimeout(function() { callback(lastTime = nextTime); },
  43                         nextTime - now);
  44     };
  45     window.cancelAnimationFrame = clearTimeout;
  46     window['requestAnimationFrame'] = window.requestAnimationFrame;
  47     window['cancelAnimationFrame'] = window.cancelAnimationFrame;
  48   }
  49
  50 })();