From 46f7c46b1aedb45d53421781e87ade0e59749a90 Mon Sep 17 00:00:00 2001
From: Michael Chen <mingyuan.chen@verizonwireless.com>
Date: Tue, 5 Jun 2018 13:30:30 -0400
Subject: [PATCH] add delegate function for interactiveTransitionGetCanceled

---
 .../PresentationHandling/MVMCoreNavigationOperation.m    | 9 +++++++--
 .../MVMCorePresentationDelegateProtocol.h                | 4 ++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/MVMCore/MVMCore/PresentationHandling/MVMCoreNavigationOperation.m b/MVMCore/MVMCore/PresentationHandling/MVMCoreNavigationOperation.m
index 95f78cd..c037aa4 100644
--- a/MVMCore/MVMCore/PresentationHandling/MVMCoreNavigationOperation.m
+++ b/MVMCore/MVMCore/PresentationHandling/MVMCoreNavigationOperation.m
@@ -250,8 +250,7 @@
 
 - (nullable id <UIViewControllerInteractiveTransitioning>)navigationController:(UINavigationController *)navigationController interactionControllerForAnimationController:(id<UIViewControllerAnimatedTransitioning>)animationController {
     if (self.delegate && [self.delegate respondsToSelector:@selector(navigationController:interactionControllerForAnimationController:)]) {
-        id interactiveTransitioning = [self.delegate navigationController:navigationController interactionControllerForAnimationController:animationController];
-        return interactiveTransitioning;
+        return [self.delegate navigationController:navigationController interactionControllerForAnimationController:animationController];
     } else {
         return nil;
     }
@@ -259,12 +258,18 @@
 
 - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context {
     if ([keyPath isEqualToString:@"interactiveTransitionCanceled"]) {
+        [object removeObserver:self forKeyPath:@"interactiveTransitionCanceled"];
         BOOL transitionCanceled = ((NSNumber*)change[NSKeyValueChangeNewKey]).boolValue;
         if (transitionCanceled) {
             //When interactive transition canceled, the destination viewController should be removed from navigationController
             [self.navigationObject.viewController removeFromParentViewController];
             [self markAsFinished];
+            if (self.delegate && [self.delegate respondsToSelector:@selector(navigationController:interactiveTransitionGetCanceled:)]) {
+                [self.delegate navigationController:self.navigationObject.navigationController interactiveTransitionGetCanceled: true];
+            }
         }
+    } else {
+        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
     }
 }
 
diff --git a/MVMCore/MVMCore/PresentationHandling/MVMCorePresentationDelegateProtocol.h b/MVMCore/MVMCore/PresentationHandling/MVMCorePresentationDelegateProtocol.h
index b4c29c4..c57afab 100644
--- a/MVMCore/MVMCore/PresentationHandling/MVMCorePresentationDelegateProtocol.h
+++ b/MVMCore/MVMCore/PresentationHandling/MVMCorePresentationDelegateProtocol.h
@@ -19,6 +19,10 @@
 // Called when a view controller has been displayed on a navigation controller
 - (void)navigationController:(nonnull UINavigationController *)navigationController displayedViewController:(nonnull UIViewController *)viewController;
 
+// Called when interactive transition get canceled
+- (void)navigationController:(nonnull UINavigationController *)navigationController interactiveTransitionGetCanceled:(BOOL)canceled;
+
+
 - (nullable id <UIViewControllerAnimatedTransitioning>)navigationController:(nonnull UINavigationController *)navigationController
                                             animationControllerForOperation:(UINavigationControllerOperation)operation
                                                          fromViewController:(nonnull UIViewController *)fromVC