Function prepareFromToAnchorAnimation

test/angular/1.6/angular-animate.js:1704–1755

(from, to, classes, anchors)

    }

    function prepareFromToAnchorAnimation(from, to, classes, anchors) {
      var fromAnimation = prepareRegularAnimation(from, noop);
      var toAnimation = prepareRegularAnimation(to, noop);

      var anchorAnimations = [];
      forEach(anchors, function(anchor) {
        var outElement = anchor['out'];
        var inElement = anchor['in'];
        var animator = prepareAnchoredAnimation(classes, outElement, inElement);
        if (animator) {
          anchorAnimations.push(animator);
        }
      });

      // no point in doing anything when there are no elements to animate
      if (!fromAnimation && !toAnimation && anchorAnimations.length === 0) return;

      return {
        start: function() {
          var animationRunners = [];

          if (fromAnimation) {
            animationRunners.push(fromAnimation.start());
          }

          if (toAnimation) {
            animationRunners.push(toAnimation.start());
          }

          forEach(anchorAnimations, function(animation) {
            animationRunners.push(animation.start());
          });

          var runner = new $$AnimateRunner({
            end: endFn,
            cancel: endFn // CSS-driven animations cannot be cancelled, only ended
          });

          $$AnimateRunner.all(animationRunners, function(status) {
            runner.complete(status);
          });

          return runner;

          function endFn() {
            forEach(animationRunners, function(runner) {
              runner.end();
            });
          }
        }
      };
    }

    function prepareRegularAnimation(animationDetails) {
      var element = animationDetails.element;