Function animateSetup

test/angular/1.2/angular-animate.js:1308–1372

(animationEvent, element, className, calculationDecorator)

      }

      function animateSetup(animationEvent, element, className, calculationDecorator) {
        var cacheKey = getCacheKey(element);
        var eventCacheKey = cacheKey + ' ' + className;
        var itemIndex = lookupCache[eventCacheKey] ? ++lookupCache[eventCacheKey].total : 0;

        var stagger = {};
        if(itemIndex > 0) {
          var staggerClassName = className + '-stagger';
          var staggerCacheKey = cacheKey + ' ' + staggerClassName;
          var applyClasses = !lookupCache[staggerCacheKey];

          applyClasses && element.addClass(staggerClassName);

          stagger = getElementAnimationDetails(element, staggerCacheKey);

          applyClasses && element.removeClass(staggerClassName);
        }

        /* the animation itself may need to add/remove special CSS classes
         * before calculating the anmation styles */
        calculationDecorator = calculationDecorator ||
                               function(fn) { return fn(); };

        element.addClass(className);

        var formerData = element.data(NG_ANIMATE_CSS_DATA_KEY) || {};

        var timings = calculationDecorator(function() {
          return getElementAnimationDetails(element, eventCacheKey);
        });

        var transitionDuration = timings.transitionDuration;
        var animationDuration = timings.animationDuration;
        if(transitionDuration === 0 && animationDuration === 0) {
          element.removeClass(className);
          return false;
        }

        element.data(NG_ANIMATE_CSS_DATA_KEY, {
          running : formerData.running || 0,
          itemIndex : itemIndex,
          stagger : stagger,
          timings : timings,
          closeAnimationFn : noop
        });

        //temporarily disable the transition so that the enter styles
        //don't animate twice (this is here to avoid a bug in Chrome/FF).
        var isCurrentlyAnimating = formerData.running > 0 || animationEvent == 'setClass';
        if(transitionDuration > 0) {
          blockTransitions(element, className, isCurrentlyAnimating);
        }

        //staggering keyframe animations work by adjusting the `animation-delay` CSS property
        //on the given element, however, the delay value can only calculated after the reflow
        //since by that time $animate knows how many elements are being animated. Therefore,
        //until the reflow occurs the element needs to be blocked (where the keyframe animation
        //is set to `none 0s`). This blocking mechanism should only be set for when a stagger