fix: pr issue

TIUIElements/README.md

@@ -16,7 +16,7 @@ public protocol CollapsibleViewsContainer: class, TableViewHandler {
     var bottomHeaderView: UIView? { get } // tableHeaderView
 
     var fixedTopOffet: CGFloat { get } // status bar + nav bar height
-    var navigationBar: UINavigationBar? { get }
+    var navBar: UINavigationBar? { get }
     
     var tableView: UITableView { get }
 }
@@ -30,6 +30,13 @@ var fixedTopOffet: CGFloat {
 }
 ```
 
+UIViewController have default realization for navBar
+```swift 
+public var navBar: UINavigationBar? {
+    navigationController?.navigationBar
+}
+```
+
 ## Usage if your ViewController don't needs extend UITableViewDelegate
 ```swift 
 let headerTransitionDelegate = HeaderTransitionDelegate(headerViewHandler: self)

TIUIElements/Sources/Helpers/HeaderTransitionDelegate.swift

@@ -16,10 +16,10 @@ open class HeaderTransitionDelegate: NSObject, UIScrollViewDelegate {
     
     private var titleView: UIView? {
         get {
-            headerViewHandler?.navigationBar?.topItem?.titleView
+            headerViewHandler?.navBar?.topItem?.titleView
         }
         set {
-            headerViewHandler?.navigationBar?.topItem?.titleView = newValue
+            headerViewHandler?.navBar?.topItem?.titleView = newValue
         }
     }
     
@@ -103,7 +103,7 @@ open class HeaderTransitionDelegate: NSObject, UIScrollViewDelegate {
     }
     
     private func animate(headerAnimation: HeaderAnimationType, alpha: CGFloat) {
-        
+        debugPrint("titleView = ", headerViewHandler?.navBar)
         switch headerAnimation {
         case .paralaxWithTransition:
             titleView?.transition(to: alpha)

TIUIElements/Sources/Helpers/Protocols/NavigationBarHandler.swift

@@ -0,0 +1,11 @@
+import UIKit
+
+public protocol NavigationBarHandler {
+    var navBar: UINavigationBar? { get }
+}
+
+extension UIViewController: NavigationBarHandler {
+    public var navBar: UINavigationBar? {
+        navigationController?.navigationBar
+    }
+}

TIUIElements/Sources/Helpers/Protocols/NavigationBarСalculated.swift

@@ -1,11 +1,12 @@
 import UIKit
 
-public protocol CollapsibleViewsContainer: class, TableViewHandler {
+public protocol CollapsibleViewsContainer: class,
+                                           TableViewHandler,
+                                           NavigationBarHandler {
+    
     var topHeaderView: UIView? { get } // titleView
     var bottomHeaderView: UIView? { get } // tableHeaderView
-
     var fixedTopOffet: CGFloat { get } // status bar + nav bar height
-    var navigationBar: UINavigationBar? { get }
 }
 
 public extension UIViewController {