New animation function to auto switch between CSS and JS animation depending on browser support

jquery-animation.js

// Updated: 01/28/2014
// Changes:
//   Removed all non animation specific code
//   Updated to allow passing in of positioning

var cssAnimation = (function($) {
  var speed = 250,
    easing = 'linear',
    cssTransition = 'cubic-bezier(0.39, 0.575, 0.565, 1)',
    done = false,
    animationCompleteCallback = $.noop,
    defaultProperties = {
      top: 0,
      right: 0,
      bottom: 0,
      left: 0
    };

  return {
    setup: function(element) {
      var $element = $(element);

      if(this._isCssAnimation()) {
        $element.addClass('css3-animation')
                .css(this._getVendorPrefix('transition'), this._getVendorPrefix('transform') + ' ' + speed + 'ms ' + cssTransition)
                .css(this._getVendorPrefix('transform'), 'translate3d(0, 0, 0)');
      } 

      $element.data('defaultPosition', $element.css('position'));
    },
    animate: function(element, properties, animationCompleteCallback) {
      properties = $.extend({}, defaultProperties, properties);

      var $element = $(element);

      if (!$element.is(':animated')) {
        if(this._isCssAnimation()) {
          $element.css(this._getVendorPrefix('transition-duration'), speed + 'ms ')
                  .css(this._getVendorPrefix('transform'), 'translate3d(' + properties.left + 'px, ' + properties.top + 'px, 0)');

          //This is the callback event for css animation
          $element.on('webkitTransitionEnd otransitionend oTransitionEnd msTransitionEnd transitionend', function() {
            done = true;
            animationCompleteCallback($element);
            $element.off('webkitTransitionEnd otransitionend oTransitionEnd msTransitionEnd transitionend');
          });
        } else {
          //Animate and call the callback event when complete
          $element.animate(properties, speed, easing, animationCompleteCallback);          
        }
      }
    },
    _isCssAnimation: function() {
      //Mimic modernizr
      return (function() {
        var b = document.body || document.documentElement,
            s = b.style,
            p = 'transition',
            v = ['Moz', 'Webkit', 'Khtml', 'O', 'ms'];

        if(typeof s[p] === 'string') {
          return true;
        }
        p = p.charAt(0).toUpperCase() + p.substr(1);

        for(var i = 0; i < v.length; i++) {
          if(typeof s[v[i] + p] === 'string') {
            return true;
          }
        }
        return false;
      }());
    },
    _getVendorPrefix: function(property, isJavascript) {
    if(!window.getComputedStyle) {
        return property;
      }

      var styles = window.getComputedStyle(document.documentElement, ''),
          pre = (Array.prototype.slice
            .call(styles)
            .join('')
            .match(/-(moz|webkit|ms)-/) || (styles.OLink === '' && ['', 'o'])
          )[1];

      if(isJavascript) {
        return pre + property;
      } else {
        return '-' + pre + '-' + property;  
      }
    }      
  }
}(jQuery));