fix(ngAnimate): properly cancel-out previously running class-based animations

Prior to this fix the addition and removal of a CSS class via
ngAnimate would cause flicker effects because $animate was unable
to keep track of the CSS classes once they were applied to the
element. This fix ensures that ngAnimate always keeps a reference
to the classes in the currently running animation so that cancelling
works accordingly.

Closes angular#10156

Author: matsko

src/ngAnimate/.jshintrc

@@ -49,7 +49,7 @@
     "assertArg": false,
     "isPromiseLike": false,
     "mergeClasses": false,
-    "mergeAnimationOptions": false,
+    "mergeAnimationDetails": false,
     "prepareAnimationOptions": false,
     "applyAnimationStyles": false,
     "applyAnimationFromStyles": false,

src/ngAnimate/animateQueue.js

@@ -42,22 +42,21 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
     });
   }
 
-  function hasAnimationClasses(options, and) {
-    options = options || {};
-    var a = (options.addClass || '').length > 0;
-    var b = (options.removeClass || '').length > 0;
+  function hasAnimationClasses(animation, and) {
+    var a = (animation.addClass || '').length > 0;
+    var b = (animation.removeClass || '').length > 0;
     return and ? a && b : a || b;
   }
 
   rules.join.push(function(element, newAnimation, currentAnimation) {
     // if the new animation is class-based then we can just tack that on
-    return !newAnimation.structural && hasAnimationClasses(newAnimation.options);
+    return !newAnimation.structural && hasAnimationClasses(newAnimation);
   });
 
   rules.skip.push(function(element, newAnimation, currentAnimation) {
     // there is no need to animate anything if no classes are being added and
     // there is no structural animation that will be triggered
-    return !newAnimation.structural && !hasAnimationClasses(newAnimation.options);
+    return !newAnimation.structural && !hasAnimationClasses(newAnimation);
   });
 
   rules.skip.push(function(element, newAnimation, currentAnimation) {
@@ -83,19 +82,17 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
   });
 
   rules.cancel.push(function(element, newAnimation, currentAnimation) {
-
-
-    var nA = newAnimation.options.addClass;
-    var nR = newAnimation.options.removeClass;
-    var cA = currentAnimation.options.addClass;
-    var cR = currentAnimation.options.removeClass;
+    var nA = newAnimation.addClass;
+    var nR = newAnimation.removeClass;
+    var cA = currentAnimation.addClass;
+    var cR = currentAnimation.removeClass;
 
     // early detection to save the global CPU shortage :)
     if ((isUndefined(nA) && isUndefined(nR)) || (isUndefined(cA) && isUndefined(cR))) {
       return false;
     }
 
-    return (hasMatchingClasses(nA, cR)) || (hasMatchingClasses(nR, cA));
+    return hasMatchingClasses(nA, cR) || hasMatchingClasses(nR, cA);
   });
 
   this.$get = ['$$rAF', '$rootScope', '$rootElement', '$document', '$$HashMap',
@@ -167,8 +164,8 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
 
     var applyAnimationClasses = applyAnimationClassesFactory($$jqLite);
 
-    function normalizeAnimationOptions(element, options) {
-      return mergeAnimationOptions(element, options, {});
+    function normalizeAnimationDetails(element, animation) {
+      return mergeAnimationDetails(element, animation, {});
     }
 
     // IE9-11 has no method "contains" in SVG element and in Node.prototype. Bug #10259.
@@ -362,19 +359,27 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
         structural: isStructural,
         element: element,
         event: event,
+        addClass: options.addClass,
+        removeClass: options.removeClass,
         close: close,
         options: options,
         runner: runner
       };
 
+      if (!hasExistingAnimation) {
+        // normalization in this case means that it removes redundant CSS classes that
+        // already exist (addClass) or do not exist (removeClass) on the element
+        normalizeAnimationDetails(element, newAnimation);
+      }
+
       if (hasExistingAnimation) {
         var skipAnimationFlag = isAllowed('skip', element, newAnimation, existingAnimation);
         if (skipAnimationFlag) {
           if (existingAnimation.state === RUNNING_STATE) {
             close();
             return runner;
           } else {
-            mergeAnimationOptions(element, existingAnimation.options, options);
+            mergeAnimationDetails(element, existingAnimation.options, options);
             return existingAnimation.runner;
           }
         }
@@ -393,7 +398,8 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
             existingAnimation.close();
           } else {
             // this will merge the new animation options into existing animation options
-            mergeAnimationOptions(element, existingAnimation.options, newAnimation.options);
+            mergeAnimationDetails(element, existingAnimation, newAnimation);
+
             return existingAnimation.runner;
           }
         } else {
@@ -403,23 +409,19 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
           var joinAnimationFlag = isAllowed('join', element, newAnimation, existingAnimation);
           if (joinAnimationFlag) {
             if (existingAnimation.state === RUNNING_STATE) {
-              normalizeAnimationOptions(element, options);
+              normalizeAnimationDetails(element, newAnimation);
             } else {
               applyGeneratedPreparationClasses(element, isStructural ? event : null, options);
 
               event = newAnimation.event = existingAnimation.event;
-              options = mergeAnimationOptions(element, existingAnimation.options, newAnimation.options);
+              options = mergeAnimationDetails(element, existingAnimation, newAnimation);
 
               //we return the same runner since only the option values of this animation will
               //be fed into the `existingAnimation`.
               return existingAnimation.runner;
             }
           }
         }
-      } else {
-        // normalization in this case means that it removes redundant CSS classes that
-        // already exist (addClass) or do not exist (removeClass) on the element
-        normalizeAnimationOptions(element, options);
       }
 
       // when the options are merged and cleaned up we may end up not having to do
@@ -429,7 +431,7 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
       if (!isValidAnimation) {
         // animate (from/to) can be quickly checked first, otherwise we check if any classes are present
         isValidAnimation = (newAnimation.event === 'animate' && Object.keys(newAnimation.options.to || {}).length > 0)
-                            || hasAnimationClasses(newAnimation.options);
+                            || hasAnimationClasses(newAnimation);
       }
 
       if (!isValidAnimation) {
@@ -459,7 +461,7 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
         var isValidAnimation = parentElement.length > 0
                                 && (animationDetails.event === 'animate'
                                     || animationDetails.structural
-                                    || hasAnimationClasses(animationDetails.options));
+                                    || hasAnimationClasses(animationDetails));
 
         // this means that the previous animation was cancelled
         // even if the follow-up animation is the same event
@@ -491,7 +493,7 @@ var $$AnimateQueueProvider = ['$animateProvider', function($animateProvider) {
 
         // this combined multiple class to addClass / removeClass into a setClass event
         // so long as a structural event did not take over the animation
-        event = !animationDetails.structural && hasAnimationClasses(animationDetails.options, true)
+        event = !animationDetails.structural && hasAnimationClasses(animationDetails, true)
             ? 'setClass'
             : animationDetails.event;
 

src/ngAnimate/shared.js

@@ -218,7 +218,10 @@ function applyAnimationToStyles(element, options) {
   }
 }
 
-function mergeAnimationOptions(element, target, newOptions) {
+function mergeAnimationDetails(element, oldAnimation, newAnimation) {
+  var target = oldAnimation.options || {};
+  var newOptions = newAnimation.options || {};
+
   var toAdd = (target.addClass || '') + ' ' + (newOptions.addClass || '');
   var toRemove = (target.removeClass || '') + ' ' + (newOptions.removeClass || '');
   var classes = resolveElementClasses(element.attr('class'), toAdd, toRemove);
@@ -250,6 +253,9 @@ function mergeAnimationOptions(element, target, newOptions) {
     target.removeClass = null;
   }
 
+  oldAnimation.addClass = target.addClass;
+  oldAnimation.removeClass = target.removeClass;
+
   return target;
 }
 

test/ngAnimate/.jshintrc

@@ -3,7 +3,7 @@
   "browser": true,
   "newcap": false,
   "globals": {
-    "mergeAnimationOptions": false,
+    "mergeAnimationDetails": false,
     "prepareAnimationOptions": false,
     "applyAnimationStyles": false,
     "applyAnimationFromStyles": false,

test/ngAnimate/animateSpec.js

@@ -6,11 +6,18 @@ describe("animations", function() {
   beforeEach(module('ngAnimateMock'));
 
   var element, applyAnimationClasses;
+
+  beforeEach(module(function() {
+    return function($$jqLite) {
+      applyAnimationClasses = applyAnimationClassesFactory($$jqLite);
+    };
+  }));
+
   afterEach(inject(function($$jqLite) {
-    applyAnimationClasses = applyAnimationClassesFactory($$jqLite);
     dealoc(element);
   }));
 
+
   it('should allow animations if the application is bootstrapped on the document node', function() {
     var capturedAnimation;
 
@@ -1081,7 +1088,7 @@ describe("animations", function() {
         expect(enterDone).toHaveBeenCalled();
       }));
 
-      it('should cancel the previously running addClass animation if a follow-up removeClass animation is using the same class value',
+      it('should finish off the previously running addClass animation if a follow-up removeClass animation is using the same class value',
         inject(function($animate, $rootScope) {
 
         parent.append(element);
@@ -1099,7 +1106,7 @@ describe("animations", function() {
         expect(doneHandler).toHaveBeenCalled();
       }));
 
-      it('should cancel the previously running removeClass animation if a follow-up addClass animation is using the same class value',
+      it('should finish off the previously running removeClass animation if a follow-up addClass animation is using the same class value',
         inject(function($animate, $rootScope) {
 
         element.addClass('active-class');
@@ -1118,6 +1125,25 @@ describe("animations", function() {
         expect(doneHandler).toHaveBeenCalled();
       }));
 
+      it('should cancel the former class-based animation when the same CSS class is added/removed right after',
+        inject(function($animate, $rootScope, $$AnimateRunner) {
+
+        parent.append(element);
+
+        overriddenAnimationRunner = new $$AnimateRunner();
+        var endSpy = spyOn(overriddenAnimationRunner, 'end');
+
+        $animate.addClass(element, 'active-class');
+        $rootScope.$digest();
+
+        expect(endSpy).not.toHaveBeenCalled();
+
+        $animate.removeClass(element, 'active-class');
+        $rootScope.$digest();
+
+        expect(endSpy).toHaveBeenCalled();
+      }));
+
       it('should immediately skip the class-based animation if there is an active structural animation',
         inject(function($animate, $rootScope) {
 

test/ngAnimate/animationHelperFunctionsSpec.js

@@ -110,7 +110,7 @@ describe("animation option helper functions", function() {
     }));
   });
 
-  describe('mergeAnimationOptions', function() {
+  describe('mergeAnimationDetails', function() {
     it('should merge in new options', inject(function() {
       element.attr('class', 'blue');
       var options = prepareAnimationOptions({
@@ -120,11 +120,16 @@ describe("animation option helper functions", function() {
         removeClass: 'blue gold'
       });
 
-      mergeAnimationOptions(element, options, {
-        age: 29,
-        addClass: 'gold brown',
-        removeClass: 'orange'
-      });
+      var animation1 = { options: options };
+      var animation2 = {
+        options: {
+          age: 29,
+          addClass: 'gold brown',
+          removeClass: 'orange'
+        }
+      };
+
+      mergeAnimationDetails(element, animation1, animation2);
 
       expect(options.name).toBe('matias');
       expect(options.age).toBe(29);