hotfix/fix-child-appearance-methods

Call appearance methods for visible screen (at current index).

Sources/ContainerLifeCycleController.swift

@@ -67,6 +67,22 @@ class ContainerLifeCycleController {
     func update(currentIndex index: Int) {
         state = .changing(toIndex: index)
     }
+
+    func startAppearanceForCurrentIndex() {
+        startAppearance(for: menuDataSource.currentIndex)
+    }
+
+    func endAppearanceForCurrentIndex() {
+        endAppearance(for: menuDataSource.currentIndex)
+    }
+
+    func startDisappearanceForCurrentIndex() {
+        startDisappearance(for: menuDataSource.currentIndex)
+    }
+
+    func endDisappearanceForCurrentIndex() {
+        endDisappearance(for: menuDataSource.currentIndex)
+    }
     
     // MARK: Private functionality
     

Sources/HorizontalMenuViewController.swift

@@ -148,11 +148,30 @@ public class HorizontalMenuViewController: UIViewController, MenuDataSource, Pag
         initializeSubviews()
         initializeControllers()
     }
+
+    public override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+
+        containerLifeCycleController.startAppearanceForCurrentIndex()
+    }
     
     public override func viewDidAppear(_ animated: Bool) {
         super.viewDidAppear(animated)
         
         selectionController.selectItem(at: paginationController.currentIndex)
+        containerLifeCycleController.endAppearanceForCurrentIndex()
+    }
+
+    public override func viewWillDisappear(_ animated: Bool) {
+        super.viewWillDisappear(animated)
+
+        containerLifeCycleController.startDisappearanceForCurrentIndex()
+    }
+
+    public override func viewDidDisappear(_ animated: Bool) {
+        super.viewDidDisappear(animated)
+
+        containerLifeCycleController.endDisappearanceForCurrentIndex()
     }
     
     public override func viewDidLayoutSubviews() {

Sources/MenuDataSource.swift

@@ -28,6 +28,9 @@ public protocol MenuDataSource: class {
     /// Boolean to configure if the intermediate screens on menu item selection should be loaded
     var preloadIntermediateScreensOnSelection: Bool { get }
 
+    /// The current index of pagination.
+    var currentIndex: Int { get }
+
     /// The number of elements is the same for items and screen.
     /// However the items.count might be 0 because they are optional.
     var numberOfElements: Int { get }