Merge pull request #997 from NativeScript/nnikolov/IosFastNavigationIssue

Fixed fast navigation issues in iOS.

ui/frame/frame-common.ts

@@ -194,6 +194,12 @@ export class Frame extends view.CustomLayoutView implements definition.Frame {
             var navigationContext = this._navigationQueue[0];
             this._processNavigationContext(navigationContext);
         }
+
+        this._updateActionBar();
+    }
+
+    public navigationQueueIsEmpty() {
+        return this._navigationQueue.length === 0;
     }
 
     public _isEntryBackstackVisible(entry: definition.BackstackEntry): boolean {

ui/frame/frame.ios.ts

@@ -133,6 +133,9 @@ export class Frame extends frameCommon.Frame {
         var newValue = this._getNavBarVisible(page);
 
         this._ios.showNavigationBar = newValue;
+        if (this._ios.controller.navigationBar) {
+            this._ios.controller.navigationBar.userInteractionEnabled = this.navigationQueueIsEmpty();
+        }
     }
 
     public _getNavBarVisible(page: pages.Page): boolean {
@@ -314,7 +317,7 @@ class UINavigationControllerImpl extends UINavigationController implements UINav
             }
         }
 
-        var isBackNavigation = currentNavigationContext ? currentNavigationContext.isBackNavigation : false;
+        let isBackNavigation = currentNavigationContext ? currentNavigationContext.isBackNavigation : false;
 
         if (isBack) {
             try {

ui/page/page.ios.ts

@@ -151,6 +151,7 @@ export class Page extends pageCommon.Page {
         if (this._enableLoadedEvents) {
             super.onLoaded();
         }
+        this._updateActionBar(false);
     }
 
     public notify<T extends observable.EventData>(data: T) {