RequestAnimationFrame在Safari中不可用 - 如何进行流体动画？

Question

这个网站在Safari的每个浏览器中都运行顺畅,因为它没有"RequestAnimationFrame".请注意,元素是使用JavaScript定位的,如果没有它,可能无法完成.在Safari上,我必须使用window.onscroll刷新元素的位置,这不会产生流畅的结果.

我怎么解决这个问题？

Answer 1

Safari 6 具有rAF的前缀支持.

对于跨浏览器兼容性,有一个使用计时器的polyfill.在使用rAF之前,只需删除此代码即可.

// 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 and Tino Zijdel
// MIT license
(function () {
  var lastTime = 0;
  var vendors = ['ms', 'moz', 'webkit', 'o'];
  for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
    window.requestAnimationFrame = window[vendors[x] + 'RequestAnimationFrame'];
    window.cancelAnimationFrame = window[vendors[x] + 'CancelAnimationFrame'] || window[vendors[x] + 'CancelRequestAnimationFrame'];
  }
  if(!window.requestAnimationFrame)
    window.requestAnimationFrame = function (callback, element) {
      var currTime = new Date().getTime();
      var timeToCall = Math.max(0, 16 - (currTime - lastTime));
      var id = window.setTimeout(function () {
        callback(currTime + timeToCall);
      },
      timeToCall);
      lastTime = currTime + timeToCall;
      return id;
  };
  if(!window.cancelAnimationFrame)
    window.cancelAnimationFrame = function (id) {
      clearTimeout(id);
  };
}());