feat(transition): emulateTransitionEnd implementation (BLOCKS #934)

src/transition/test/transition.spec.js

@@ -54,6 +54,23 @@ describe('$transition', function() {
     expect(triggerFunction).toHaveBeenCalledWith(element);
   });
 
+  // transitionend emulation
+  describe('emulateTransitionEnd', function() {
+    it('should emit transition end-event after the specified duration', function() {
+      var element = angular.element('<div></div>');
+      var transitionEndHandler = jasmine.createSpy('transitionEndHandler');
+
+      // There is no transition property, so transitionend could not be fired 
+      // on its own.
+      var promise = $transition(element, {height: '100px'});
+      promise.then(transitionEndHandler);
+      promise.emulateTransitionEnd(1);
+
+      $timeout.flush();
+      expect(transitionEndHandler).toHaveBeenCalledWith(element);
+    });
+  });
+
   // Versions of Internet Explorer before version 10 do not have CSS transitions
   if ( !ie  || ie > 9 ) {
     describe('transitionEnd event', function() {

src/transition/transition.js

@@ -52,6 +52,31 @@ angular.module('ui.bootstrap.transition', [])
       deferred.reject('Transition cancelled');
     };
 
+    // Emulate transitionend event, useful when support is assumed to be
+    // available, but may not actually be used due to a transition property
+    // not being used in CSS (for example, in versions of firefox prior to 16,
+    // only -moz-transition is supported -- and is not used in Bootstrap3's CSS
+    // -- As such, no transitionend event would be fired due to no transition
+    // ever taking place. This method allows a fallback for such browsers.)
+    deferred.promise.emulateTransitionEnd = function(duration) {
+      var called = false;
+      deferred.promise.then(
+        function() { called = true; },
+        function() { called = true; }
+      );
+
+      var callback = function() {
+        if ( !called ) {
+          // If we got here, we probably aren't going to get a real 
+          // transitionend event. Emit a dummy to the handler.
+          element.triggerHandler(endEventName);
+        }        
+      };
+
+      $timeout(callback, duration);
+      return deferred.promise;
+    };
+
     return deferred.promise;
   };