animation.js

'use strict';

var $$AnimationProvider = ['$animateProvider', function($animateProvider) {
  var NG_ANIMATE_REF_ATTR = 'ng-animate-ref';

  var drivers = this.drivers = [];

  var RUNNER_STORAGE_KEY = '$$animationRunner';

  function setRunner(element, runner) {
    element.data(RUNNER_STORAGE_KEY, runner);
  }

  function removeRunner(element) {
    element.removeData(RUNNER_STORAGE_KEY);
  }

  function getRunner(element) {
    return element.data(RUNNER_STORAGE_KEY);
  }

  this.$get = ['$$jqLite', '$rootScope', '$injector', '$$AnimateRunner', '$$rAFScheduler',
       function($$jqLite,   $rootScope,   $injector,   $$AnimateRunner,   $$rAFScheduler) {

    var animationQueue = [];
    var applyAnimationClasses = applyAnimationClassesFactory($$jqLite);

    var totalPendingClassBasedAnimations = 0;
    var totalActiveClassBasedAnimations = 0;
    var classBasedAnimationsQueue = [];

    // TODO(matsko): document the signature in a better way
    return function(element, event, options) {
      options = prepareAnimationOptions(options);
      var isStructural = ['enter', 'move', 'leave'].indexOf(event) >= 0;

      // there is no animation at the current moment, however
      // these runner methods will get later updated with the
      // methods leading into the driver's end/cancel methods
      // for now they just stop the animation from starting
      var runner = new $$AnimateRunner({
        end: function() { close(); },
        cancel: function() { close(true); }
      });

      if (!drivers.length) {
        close();
        return runner;
      }

      setRunner(element, runner);

      var classes = mergeClasses(element.attr('class'), mergeClasses(options.addClass, options.removeClass));
      var tempClasses = options.tempClasses;
      if (tempClasses) {
        classes += ' ' + tempClasses;
        options.tempClasses = null;
      }

      var classBasedIndex;
      if (!isStructural) {
        classBasedIndex = totalPendingClassBasedAnimations;
        totalPendingClassBasedAnimations += 1;
      }

      animationQueue.push({
        // this data is used by the postDigest code and passed into
        // the driver step function
        element: element,
        classes: classes,
        event: event,
        classBasedIndex: classBasedIndex,
        structural: isStructural,
        options: options,
        beforeStart: beforeStart,
        close: close
      });

      element.on('$destroy', handleDestroyedElement);

      // we only want there to be one function called within the post digest
      // block. This way we can group animations for all the animations that
      // were apart of the same postDigest flush call.
      if (animationQueue.length > 1) return runner;

      $rootScope.$$postDigest(function() {
        totalActiveClassBasedAnimations = totalPendingClassBasedAnimations;
        totalPendingClassBasedAnimations = 0;
        classBasedAnimationsQueue.length = 0;

        var animations = [];
        forEach(animationQueue, function(entry) {
          // the element was destroyed early on which removed the runner
          // form its storage. This means we can't animate this element
          // at all and it already has been closed due to destruction.
          if (getRunner(entry.element)) {
            animations.push(entry);
          }
        });

        // now any future animations will be in another postDigest
        animationQueue.length = 0;

        forEach(groupAnimations(animations), function(animationEntry) {
          if (animationEntry.structural) {
            triggerAnimationStart();
          } else {
            classBasedAnimationsQueue.push({
              node: getDomNode(animationEntry.element),
              fn: triggerAnimationStart
            });

            if (animationEntry.classBasedIndex === totalActiveClassBasedAnimations - 1) {
              // we need to sort each of the animations in order of parent to child
              // relationships. This ensures that the child classes are applied at the
              // right time.
              classBasedAnimationsQueue = classBasedAnimationsQueue.sort(function(a,b) {
                return b.node.contains(a.node);
              }).map(function(entry) {
                return entry.fn;
              });

              $$rAFScheduler(classBasedAnimationsQueue);
            }
          }

          function triggerAnimationStart() {
            // it's important that we apply the `ng-animate` CSS class and the
            // temporary classes before we do any driver invoking since these
            // CSS classes may be required for proper CSS detection.
            animationEntry.beforeStart();

            var startAnimationFn, closeFn = animationEntry.close;

            // in the event that the element was removed before the digest runs or
            // during the RAF sequencing then we should not trigger the animation.
            var targetElement = animationEntry.anchors
                ? (animationEntry.from.element || animationEntry.to.element)
                : animationEntry.element;

            if (getRunner(targetElement) && getDomNode(targetElement).parentNode) {
              var operation = invokeFirstDriver(animationEntry);
              if (operation) {
                startAnimationFn = operation.start;
              }
            }

            if (!startAnimationFn) {
              closeFn();
            } else {
              var animationRunner = startAnimationFn();
              animationRunner.done(function(status) {
                closeFn(!status);
              });
              updateAnimationRunners(animationEntry, animationRunner);
            }
          }
        });
      });

      return runner;

      // TODO(matsko): change to reference nodes
      function getAnchorNodes(node) {
        var SELECTOR = '[' + NG_ANIMATE_REF_ATTR + ']';
        var items = node.hasAttribute(NG_ANIMATE_REF_ATTR)
              ? [node]
              : node.querySelectorAll(SELECTOR);
        var anchors = [];
        forEach(items, function(node) {
          var attr = node.getAttribute(NG_ANIMATE_REF_ATTR);
          if (attr && attr.length) {
            anchors.push(node);
          }
        });
        return anchors;
      }

      function groupAnimations(animations) {
        var preparedAnimations = [];
        var refLookup = {};
        forEach(animations, function(animation, index) {
          var element = animation.element;
          var node = getDomNode(element);
          var event = animation.event;
          var enterOrMove = ['enter', 'move'].indexOf(event) >= 0;
          var anchorNodes = animation.structural ? getAnchorNodes(node) : [];

          if (anchorNodes.length) {
            var direction = enterOrMove ? 'to' : 'from';

            forEach(anchorNodes, function(anchor) {
              var key = anchor.getAttribute(NG_ANIMATE_REF_ATTR);
              refLookup[key] = refLookup[key] || {};
              refLookup[key][direction] = {
                animationID: index,
                element: jqLite(anchor)
              };
            });
          } else {
            preparedAnimations.push(animation);
          }
        });

        var usedIndicesLookup = {};
        var anchorGroups = {};
        forEach(refLookup, function(operations, key) {
          var from = operations.from;
          var to = operations.to;

          if (!from || !to) {
            // only one of these is set therefore we can't have an
            // anchor animation since all three pieces are required
            var index = from ? from.animationID : to.animationID;
            var indexKey = index.toString();
            if (!usedIndicesLookup[indexKey]) {
              usedIndicesLookup[indexKey] = true;
              preparedAnimations.push(animations[index]);
            }
            return;
          }

          var fromAnimation = animations[from.animationID];
          var toAnimation = animations[to.animationID];
          var lookupKey = from.animationID.toString();
          if (!anchorGroups[lookupKey]) {
            var group = anchorGroups[lookupKey] = {
              structural: true,
              beforeStart: function() {
                fromAnimation.beforeStart();
                toAnimation.beforeStart();
              },
              close: function() {
                fromAnimation.close();
                toAnimation.close();
              },
              classes: cssClassesIntersection(fromAnimation.classes, toAnimation.classes),
              from: fromAnimation,
              to: toAnimation,
              anchors: [] // TODO(matsko): change to reference nodes
            };

            // the anchor animations require that the from and to elements both have at least
            // one shared CSS class which effictively marries the two elements together to use
            // the same animation driver and to properly sequence the anchor animation.
            if (group.classes.length) {
              preparedAnimations.push(group);
            } else {
              preparedAnimations.push(fromAnimation);
              preparedAnimations.push(toAnimation);
            }
          }

          anchorGroups[lookupKey].anchors.push({
            'out': from.element, 'in': to.element
          });
        });

        return preparedAnimations;
      }

      function cssClassesIntersection(a,b) {
        a = a.split(' ');
        b = b.split(' ');
        var matches = [];

        for (var i = 0; i < a.length; i++) {
          var aa = a[i];
          if (aa.substring(0,3) === 'ng-') continue;

          for (var j = 0; j < b.length; j++) {
            if (aa === b[j]) {
              matches.push(aa);
              break;
            }
          }
        }

        return matches.join(' ');
      }

      function invokeFirstDriver(animationDetails) {
        // we loop in reverse order since the more general drivers (like CSS and JS)
        // may attempt more elements, but custom drivers are more particular
        for (var i = drivers.length - 1; i >= 0; i--) {
          var driverName = drivers[i];
          if (!$injector.has(driverName)) continue; // TODO(matsko): remove this check

          var factory = $injector.get(driverName);
          var driver = factory(animationDetails);
          if (driver) {
            return driver;
          }
        }
      }

      function beforeStart() {
        element.addClass(NG_ANIMATE_CLASSNAME);
        if (tempClasses) {
          $$jqLite.addClass(element, tempClasses);
        }
      }

      function updateAnimationRunners(animation, newRunner) {
        if (animation.from && animation.to) {
          update(animation.from.element);
          update(animation.to.element);
        } else {
          update(animation.element);
        }

        function update(element) {
          getRunner(element).setHost(newRunner);
        }
      }

      function handleDestroyedElement() {
        var runner = getRunner(element);
        if (runner && (event !== 'leave' || !options.$$domOperationFired)) {
          runner.end();
        }
      }

      function close(rejected) { // jshint ignore:line
        element.off('$destroy', handleDestroyedElement);
        removeRunner(element);

        applyAnimationClasses(element, options);
        applyAnimationStyles(element, options);
        options.domOperation();

        if (tempClasses) {
          $$jqLite.removeClass(element, tempClasses);
        }

        element.removeClass(NG_ANIMATE_CLASSNAME);
        runner.complete(!rejected);
      }
    };
  }];
}];