fixed GitHub issue 149 - When Keyboard is visible, swipe back gesture causes UI to run infinite loop of layout updates. App becomes unresponsible. Issue appears ONLY when keyboard is VISIBLE. Disabling interactive pop gesture recogniser of navigation controller solves this problem.

Author: pro100andrey

QMChatViewController/QMChatViewController.m

@@ -93,21 +93,20 @@ - (void)viewDidLoad {
     self.systemInputToolbar.frame = CGRectMake(0, 0, 0, kQMSystemInputToolbarDebugHeight);
     self.systemInputToolbar.hostViewFrameChangeBlock = ^(UIView *view, BOOL animated) {
 
-       CGFloat pos = weakSelf.view.frame.size.height - [view.superview convertPoint:view.frame.origin toView:weakSelf.view].y;
-
+        CGFloat pos = weakSelf.view.frame.size.height - [weakSelf.view.superview convertPoint:view.frame.origin toView:weakSelf.view].y;
+        
         if (weakSelf.inputToolbar.contentView.textView.isFirstResponder) {
-            
-            if (view.superview.frame.origin.y > 0 && pos == 0) {
+            if (view.superview.frame.origin.y > 0 && pos <= 0) {
                 return;
             }
         }
-
+        
         const CGFloat v = [weakSelf inputToolBarStartPos];
-
+        
         if (pos < v || !view) {
             pos = v;
         }
-
+        
         [weakSelf setToolbarBottomConstraintValue:pos animated:animated];
     };
 
@@ -254,18 +253,18 @@ - (void)changeDataSource:(QMChatDataSource *)dataSource
         }
 
         switch (updateType) {
-            
+                
             case QMDataSourceActionTypeAdd:
-            [self.collectionView insertItemsAtIndexPaths:indexPaths];
-            break;
-            
+                [self.collectionView insertItemsAtIndexPaths:indexPaths];
+                break;
+                
             case QMDataSourceActionTypeUpdate:
-            [self.collectionView reloadItemsAtIndexPaths:indexPaths];
-            break;
-            
+                [self.collectionView reloadItemsAtIndexPaths:indexPaths];
+                break;
+                
             case QMDataSourceActionTypeRemove:
-            [self.collectionView deleteItemsAtIndexPaths:indexPaths];
-            break;
+                [self.collectionView deleteItemsAtIndexPaths:indexPaths];
+                break;
         }
     };
 
@@ -282,7 +281,7 @@ - (void)chatDataSource:(QMChatDataSource *)chatDataSource willBeChangedWithMessa
 #pragma mark - View lifecycle
 
 - (NSUInteger)inputToolBarStartPos {
-
+    
     return 0;
 }
 
@@ -794,12 +793,6 @@ - (void)setToolbarBottomConstraintValue:(CGFloat)constraintValue animated:(BOOL)
     self.toolbarBottomLayoutGuide.constant = constraintValue;
 
     if (animated) {
-        self.navigationController.interactivePopGestureRecognizer.enabled = NO;
-        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
-            
-            self.navigationController.interactivePopGestureRecognizer.enabled = YES;
-        });
-        
         [self.view layoutIfNeeded];
     }
 }
@@ -950,10 +943,10 @@ - (void)checkAuthorizationStatusWithCompletion:(void (^)(BOOL granted))completio
         switch (status)
         {
             case PHAuthorizationStatusAuthorized:
-            if (completion) {
-                completion(YES);
-            }
-            break;
+                if (completion) {
+                    completion(YES);
+                }
+                break;
             case PHAuthorizationStatusNotDetermined:
             {
                 [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus authorizationStatus)
@@ -967,10 +960,10 @@ - (void)checkAuthorizationStatusWithCompletion:(void (^)(BOOL granted))completio
                 break;
             }
             default:
-            if (completion) {
-                completion(NO);
-            }
-            break;
+                if (completion) {
+                    completion(NO);
+                }
+                break;
         }
     }
 }