fix tab-view, segmented-bar, action-bar, all ViewBases (#3340)

apps/.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "typescript.tsdk": "./node_modules/typescript/lib"
+}

apps/app/package.json

@@ -1,4 +1,4 @@
 {
 	"name": "tns-samples-apps",
-	"main": "ui-tests-app/app.js"
+	"main": "cuteness.io/app.js"
 }

tests/app/ui/repeater/repeater-tests.ts

@@ -353,12 +353,12 @@ export var test_RepeaterItemsGestureBindings = function () {
                 hasObservers = gestureObservers ? gestureObservers.length > 0 : false;
             }
             else if (childItem instanceof layoutBaseModule.LayoutBase) {
-                childItem._eachChildView(eachChildCallback);
+                childItem.eachChildView(eachChildCallback);
             }
             return true;
         }
 
-        repeater._eachChildView(eachChildCallback);
+        repeater.eachChildView(eachChildCallback);
 
         TKUnit.assertEqual(hasObservers, true, "Every item should have tap observer!");
     }
@@ -380,12 +380,12 @@ export var test_RepeaterItemsParentBindingsShouldWork = function () {
                 }
             }
             else if (childItem instanceof layoutBaseModule.LayoutBase) {
-                childItem._eachChildView(eachChildCallback);
+                childItem.eachChildView(eachChildCallback);
             }
             return true;
         }
 
-        repeater._eachChildView(eachChildCallback);
+        repeater.eachChildView(eachChildCallback);
 
         TKUnit.assertEqual(testPass, true, "Every item should have text bound to Page binding context!");
     }

tns-core-modules/ui/action-bar/action-bar-common.ts

@@ -141,9 +141,10 @@ export class ActionBarBase extends View implements ActionBarDefinition {
     //     this._actionItems.getItems().forEach((item, i, arr) => { item.bindingContext = newValue; });
     // }
 
-    public _eachChildView(callback: (child: View) => boolean) {
+    public eachChildView(callback: (child: View) => boolean) {
-        if (this.titleView) {
+        const titleView = this.titleView;
-            callback(this.titleView);
+        if (titleView) {
+            callback(titleView);
         }
 
         this.actionItems.getItems().forEach((actionItem) => {
@@ -153,6 +154,22 @@ export class ActionBarBase extends View implements ActionBarDefinition {
         });
     }
 
+    public eachChild(callback: (child: ViewBase) => boolean) {
+        const titleView = this.titleView;
+        if (titleView) {
+            callback(titleView);
+        }
+
+        const navigationButton = this._navigationButton;
+        if (navigationButton) {
+            callback(navigationButton);
+        }
+
+        this.actionItems.getItems().forEach((actionItem) => {
+            callback(actionItem);
+        });
+    }
+
     public _isEmpty(): boolean {
         if (this.title ||
             this.titleView ||

tns-core-modules/ui/content-view/content-view.ts

@@ -60,9 +60,10 @@ export class ContentView extends CustomLayoutView implements ContentViewDefiniti
         }
     }
 
-    public _eachChildView(callback: (child: View) => boolean) {
+    public eachChildView(callback: (child: View) => boolean) {
-        if (this._content) {
+        const content = this._content;
-            callback(this._content);
+        if (content) {
+            callback(content);
         }
     }
 

tns-core-modules/ui/core/view-base.ts

@@ -91,6 +91,8 @@ export function eachDescendant(view: ViewBaseDefinition, callback: (child: ViewB
     view.eachChild(localCallback);
 }
 
+let viewIdCounter = 0;
+
 export class ViewBase extends Observable implements ViewBaseDefinition {
     private _updatingJSPropertiesDict = {};
     private _style: Style;
@@ -106,9 +108,12 @@ export class ViewBase extends Observable implements ViewBaseDefinition {
     public id: string;
     public className: string;
 
+    public _domId: number;
+
     public _cssState: CssState;
     constructor() {
         super();
+        this._domId = viewIdCounter++;
         this._style = new Style(this);
     }
 
@@ -154,17 +159,11 @@ export class ViewBase extends Observable implements ViewBaseDefinition {
         this._emit("loaded");
     }
 
-    get _childrenCount(): number {
-        return 0;
-    }
-
     public _loadEachChildView() {
-        if (this._childrenCount > 0) {
+        this.eachChild((child) => {
-            this.eachChild((child) => {
+            child.onLoaded();
-                child.onLoaded();
+            return true;
-                return true;
+        });
-            });
-        }
     }
 
     public onUnloaded() {
@@ -175,15 +174,13 @@ export class ViewBase extends Observable implements ViewBaseDefinition {
     }
 
     private _unloadEachChildView() {
-        if (this._childrenCount > 0) {
+        this.eachChild((child) => {
-            this.eachChild((child) => {
+            if (child.isLoaded) {
-                if (child.isLoaded) {
+                child.onUnloaded();
-                    child.onUnloaded();
+            }
-                }
 
-                return true;
+            return true;
-            });
+        });
-        }
     }
 
     public _applyStyleFromScope() {

tns-core-modules/ui/core/view-common.ts

@@ -66,8 +66,6 @@ export function PseudoClassHandler(...pseudoClasses: string[]): MethodDecorator
     }
 }
 
-let viewIdCounter = 0;
-
 export abstract class ViewCommon extends ViewBase implements ViewDefinition {
     // Dynamic properties.
     left: Length;
@@ -97,9 +95,6 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
     private _cssType: string;
 
     private _updatingInheritedProperties: boolean;
-
-
-    public _domId: number;
     public _isAddedToNativeVisualTree: boolean;
     public _gestureObservers = {};
 
@@ -107,8 +102,6 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 
     constructor() {
         super();
-
-        this._domId = viewIdCounter++;
         this._goToVisualState("normal");
     }
 
@@ -794,13 +787,13 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
     //@endios
 
     public eachChild(callback: (child: ViewBase) => boolean): void {
-        this._eachChildView(<any>callback);
+        this.eachChildView(<any>callback);
     }
 
-    public _eachChildView(callback: (view: ViewDefinition) => boolean) {
+    public eachChildView(callback: (view: ViewDefinition) => boolean) {
         //
     }
-
+ 
     _childIndexToNativeChildIndex(index?: number): number {
         return index;
     }
@@ -857,8 +850,8 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
     //     //     return true;
     //     // });
     // }
-
+    
-    /**
+      /**
      * Method is intended to be overridden by inheritors and used as "protected".
      */
     public _addViewToNativeVisualTree(view: ViewDefinition, atIndex?: number): boolean {

tns-core-modules/ui/core/view.android.ts

@@ -148,23 +148,18 @@ export class View extends ViewCommon {
             traceNotifyEvent(this, "_onAttached");
         }
 
-        if (this._childrenCount > 0) {
+        // Notify each child for the _onAttached event
-            // Notify each child for the _onAttached event
+        this.eachChildView((child) => {
-            let that = this;
+            child._onAttached(context);
-            // TODO: This should be done in a call 
+            if (!child._isAddedToNativeVisualTree) {
-            let eachChild = (child: View): boolean => {
+                // since we have lazy loading of the android widgets, we need to add the native instances at this point.
-                child._onAttached(context);
+                child._isAddedToNativeVisualTree = this._addViewToNativeVisualTree(child);
-                if (!child._isAddedToNativeVisualTree) {
-                    // since we have lazy loading of the android widgets, we need to add the native instances at this point.
-                    child._isAddedToNativeVisualTree = that._addViewToNativeVisualTree(child);
-                }
-
-                // copy all the locally cached values to the native android widget
-                return true;
             }
-            this._eachChildView(eachChild);
-        } 
 
+            return true;
+        });
+
+        // copy all the locally cached values to the native android widget
         applyNativeSetters(this);
     }
 
@@ -173,20 +168,16 @@ export class View extends ViewCommon {
             traceWrite(`${this}._onDetached(force)`, traceCategories.VisualTreeEvents);
         }
 
-        if (this._childrenCount > 0) {
+        // Detach children first
-            // Detach children first
+        this.eachChildView((child: View) => {
-            let that = this;
+            if (child._isAddedToNativeVisualTree) {
-            let eachChild = function (child: View): boolean {
+                this._removeViewFromNativeVisualTree(child);
-                if (child._isAddedToNativeVisualTree) {
-                    that._removeViewFromNativeVisualTree(child);
-                }
-                if (child._context) {
-                    child._onDetached(force);
-                }
-                return true;
             }
-            this._eachChildView(eachChild);
+            if (child._context) {
-        }
+                child._onDetached(force);
+            }
+            return true;
+        });
 
         this._clearAndroidReference();
         this._context = undefined;
@@ -215,6 +206,7 @@ export class View extends ViewCommon {
         if (traceEnabled) {
             traceWrite(`${this}._onContextChanged`, traceCategories.VisualTreeEvents);
         }
+
         this._createUI();
         // Ensure layout params
         if (this._nativeView && !this._nativeView.getLayoutParams()) {
@@ -432,7 +424,7 @@ export class View extends ViewCommon {
                 return Visibility.HIDDEN;
             case android.view.View.GONE:
                 return Visibility.COLLAPSE;
-            default: 
+            default:
                 throw new Error(`Unsupported android.view.View visibility: ${nativeVisibility}. Currently supported values are android.view.View.VISIBLE, android.view.View.INVISIBLE, android.view.View.GONE.`);
         }
     }
@@ -447,7 +439,7 @@ export class View extends ViewCommon {
             case Visibility.COLLAPSE:
                 this.nativeView.setVisibility(android.view.View.GONE);
                 break;
-            default: 
+            default:
                 throw new Error(`Invalid visibility value: ${value}. Valid values are: "${Visibility.VISIBLE}", "${Visibility.HIDDEN}", "${Visibility.COLLAPSE}".`);
         }
     }

tns-core-modules/ui/core/view.d.ts

@@ -562,32 +562,27 @@ declare module "ui/core/view" {
         _removeFromSuperview();
 
         public _applyXmlAttribute(attribute: string, value: any): boolean;
+        public eachChildView(callback: (view: View) => boolean): void;
+
 
         //@private
         /**
          * A property has changed on the native side directly - e.g. the user types in a TextField.
          */
         public nativePropertyChanged(property: Property<any, any>, newValue: any): void;
-        public bind(options: BindingOptions, source?: any): void;
+        
-        public unbind(property: string): void;
-
-        isCollapsed: boolean;
         isLayoutRequired: boolean;
-
         _gestureObservers: any;
         // _isInheritedChange(): boolean;
-        _domId: number;
 
         _isAddedToNativeVisualTree: boolean;
 
         /**
          * Performs the core logic of adding a child view to the native visual tree. Returns true if the view's native representation has been successfully added, false otherwise.
          */
-        _addViewToNativeVisualTree(view: View, atIndex?: number): boolean;
+        _addViewToNativeVisualTree(view: ViewBase, atIndex?: number): boolean;
-        _removeViewFromNativeVisualTree(view: View): void;
+        _removeViewFromNativeVisualTree(view: ViewBase): void;
 
-        _eachChildView(callback: (child: View) => boolean);
-        _childrenCount: number;
 
         _onAttached(context: any /* android.content.Context */): void;
         _onContextChanged(): void;

tns-core-modules/ui/definitions.d.ts

@@ -103,7 +103,7 @@ declare module "ui/core/view-base" {
         public _removeView(view: ViewBase): void;
         public _parentChanged(oldParent: ViewBase): void;
 
-        _childrenCount: number;
+        _domId: number;
 
         _cssState: any /* "ui/styling/style-scope" */;
         _setCssState(next: any /* "ui/styling/style-scope" */);

tns-core-modules/ui/frame/frame-common.ts

@@ -396,7 +396,7 @@ export class FrameBase extends CustomLayoutView implements FrameDefinition {
         return 0;
     }
 
-    public _eachChildView(callback: (child: View) => boolean) {
+    public eachChildView(callback: (child: View) => boolean) {
         if (this.currentPage) {
             callback(this.currentPage);
         }

tns-core-modules/ui/layouts/layout-base-common.ts

@@ -90,7 +90,7 @@ export class LayoutBaseCommon extends CustomLayoutView implements LayoutBaseDefi
         return result;
     }
 
-    public _eachChildView(callback: (child: View) => boolean): void {
+    public eachChildView(callback: (child: View) => boolean): void {
         for (let i = 0, length = this._subViews.length; i < length; i++) {
             const retVal = callback(this._subViews[i]);
             if (retVal === false) {
@@ -98,11 +98,11 @@ export class LayoutBaseCommon extends CustomLayoutView implements LayoutBaseDefi
             }
         }
     }
-
+    
     public eachLayoutChild(callback: (child: View, isLast: boolean) => void): void {
         var lastChild: View = null;
         
-        this._eachChildView((cv) => {
+        this.eachChildView((cv) => {
             cv._eachLayoutView((lv) => {
                 if (lastChild && !lastChild.isCollapsed) {
                     callback(lastChild, false);

tns-core-modules/ui/list-view/list-view.android.ts

@@ -90,7 +90,7 @@ export class ListView extends ListViewBase {
         return this._realizedItems.size;
     }
 
-    public _eachChildView(callback: (child: View) => boolean): void {
+    public eachChildView(callback: (child: View) => boolean): void {
         this._realizedItems.forEach((view, nativeView, map) => {
             if (view.parent instanceof ListView) {
                 callback(view);

tns-core-modules/ui/list-view/list-view.ios.ts

@@ -227,7 +227,7 @@ export class ListView extends ListViewBase {
         return this._map.size;
     }
 
-    public _eachChildView(callback: (child: View) => boolean): void {
+    public eachChildView(callback: (child: View) => boolean): void {
         this._map.forEach((view, key) => {
             callback(view);
         });

tns-core-modules/ui/page/page-common.ts

@@ -252,8 +252,8 @@ export class PageBase extends ContentView implements PageDefinition {
         return this._styleScope;
     }
 
-    public _eachChildView(callback: (child: View) => boolean) {
+    public eachChildView(callback: (child: View) => boolean) {
-        super._eachChildView(callback);
+        super.eachChildView(callback);
         callback(this.actionBar);
     }
 

tns-core-modules/ui/proxy-view-container/proxy-view-container.ts

@@ -38,7 +38,7 @@ export class ProxyViewContainer extends LayoutBase implements ProxyViewContainer
 
     public _getNativeViewsCount(): number {
         let result = 0;
-        this._eachChildView((cv) => {
+        this.eachChildView((cv) => {
             result += cv._getNativeViewsCount();
             return true;
         });
@@ -47,7 +47,7 @@ export class ProxyViewContainer extends LayoutBase implements ProxyViewContainer
     }
 
     public _eachLayoutView(callback: (View) => void): void {
-        this._eachChildView((cv) => {
+        this.eachChildView((cv) => {
             if (!cv.isCollapsed) {
                 cv._eachLayoutView(callback);
             }
@@ -99,7 +99,7 @@ export class ProxyViewContainer extends LayoutBase implements ProxyViewContainer
 
     public _addToSuperview(superview: any, atIndex?: number): boolean {
         let index = 0;
-        this._eachChildView((cv) => {
+        this.eachChildView((cv) => {
             if (!cv._isAddedToNativeVisualTree) {
                 cv._isAddedToNativeVisualTree = this._addViewToNativeVisualTree(cv, index++);
             }
@@ -110,7 +110,7 @@ export class ProxyViewContainer extends LayoutBase implements ProxyViewContainer
     }
 
     public _removeFromSuperview() {
-        this._eachChildView((cv) => {
+        this.eachChildView((cv) => {
             if (cv._isAddedToNativeVisualTree) {
                 this._removeViewFromNativeVisualTree(cv);
             }
@@ -147,12 +147,12 @@ export class ProxyViewContainer extends LayoutBase implements ProxyViewContainer
         const oldLayout = <LayoutBase>oldParent;
 
         if (addingToParent && newLayout instanceof LayoutBase) {
-            this._eachChildView((child) => {
+            this.eachChildView((child) => {
                 newLayout._registerLayoutChild(child);
                 return true;
             });
         } else if (oldLayout instanceof LayoutBase) {
-            this._eachChildView((child) => {
+            this.eachChildView((child) => {
                 oldLayout._unregisterLayoutChild(child);
                 return true;
             });

tns-core-modules/ui/repeater/repeater.ts

@@ -92,7 +92,7 @@ export class Repeater extends CustomLayoutView implements RepeaterDefinition {
         return count;
     }
 
-    public _eachChildView(callback: (child: View) => boolean) {
+    public eachChildView(callback: (child: View) => boolean) {
         if (this.itemsLayout) {
             callback(this.itemsLayout);
         }

tns-core-modules/ui/segmented-bar/segmented-bar-common.ts

@@ -12,7 +12,6 @@ export module knownCollections {
 
 export abstract class SegmentedBarItemBase extends ViewBase implements SegmentedBarItemDefinition {
     private _title: string = "";
-    public _parent: SegmentedBarBase;
 
     get title(): string {
         return this._title;
@@ -64,8 +63,8 @@ export abstract class SegmentedBarBase extends View implements SegmentedBarDefin
     }
 
     // TODO: Make _addView to keep its children so this method is not needed!
-    public _eachChildView(callback: (child: ViewBase) => boolean): void {
+    public eachChild(callback: (child: ViewBase) => boolean): void {
-        let items = this.items;
+        const items = this.items;
         if (items) {
             items.forEach((item, i) => {
                 callback(item);

tns-core-modules/ui/segmented-bar/segmented-bar.ios.ts

@@ -9,11 +9,12 @@ export * from "./segmented-bar-common";
 
 export class SegmentedBarItem extends SegmentedBarItemBase {
     public _update() {
-        if (this._parent) {
+        const parent = <SegmentedBar>this.parent;
-            let tabIndex = this._parent.items.indexOf(this);
+        if (parent) {
+            let tabIndex = parent.items.indexOf(this);
             let title = this.title;
             title = (title === null || title === undefined) ? "" : title;
-            this._parent.ios.setTitleForSegmentAtIndex(title, tabIndex);
+            parent.ios.setTitleForSegmentAtIndex(title, tabIndex);
         }
     }
 }

tns-core-modules/ui/tab-view/tab-view-common.ts

@@ -87,37 +87,6 @@ export class TabViewBase extends View implements TabViewDefinition, AddChildFrom
         }
     }
 
-    public _removeTabs(oldItems: Array<TabViewItemDefinition>) {
-        for (let i = 0, length = oldItems.length; i < length; i++) {
-            let oldItem = oldItems[i];
-
-            if (!oldItem) {
-                throw new Error("TabViewItem at index " + i + " is undefined.");
-            }
-
-            if (!oldItem.view) {
-                throw new Error("TabViewItem at index " + i + " does not have a view.");
-            }
-            this._removeView(oldItem);
-        }
-    }
-
-    public _addTabs(newItems: Array<TabViewItemDefinition>) {
-        // Validate that all items are ok before the native _addTabs code runs.
-        for (let i = 0, length = newItems.length; i < length; i++) {
-            let newItem = newItems[i];
-
-            if (!newItem) {
-                throw new Error(`TabViewItem at index ${i} is undefined.`);
-            }
-
-            if (!newItem.view) {
-                throw new Error(`TabViewItem at index ${i} does not have a view.`);
-            }
-            this._addView(newItem);
-        }
-    }
-
     get _selectedView(): View {
         let selectedIndex = this.selectedIndex;
         return selectedIndex > -1 ? this.items[selectedIndex].view : null;
@@ -131,17 +100,21 @@ export class TabViewBase extends View implements TabViewDefinition, AddChildFrom
         return 0;
     }
 
-    public _eachChildView(callback: (child: ViewBase) => boolean) {
+    public eachChild(callback: (child: ViewBase) => boolean) {
         const items = this.items;
-        if (!items) {
+        if (items) {
-            return;
+            items.forEach((item, i) => {
-        }
-
-        for (let i = 0, length = items.length; i < length; i++) {
-            let item = items[i];
-            if (item) {
                 callback(item);
-            }
+            });
+        }
+    }
+
+    public eachChildView(callback: (child: View) => boolean) {
+        const items = this.items;
+        if (items) {
+            items.forEach((item, i) => {
+                callback(item.view);
+            });
         }
     }
 

tns-core-modules/ui/tab-view/tab-view.android.ts

@@ -16,11 +16,11 @@ const PRIMARY_COLOR = "colorPrimary";
 const DEFAULT_ELEVATION = 4;
 
 export class TabViewItem extends TabViewItemBase {
-    public _parent: TabView;
 
     public _update() {
-        if (this._parent) {
+        const parent = <TabView>this.parent;
-            this._parent._updateTabForItem(this);
+        if (parent) {
+            parent._updateTabForItem(this);
         }
     }
 }
@@ -62,9 +62,9 @@ function ensurePagerAdapterClass() {
             }
 
             let item = this.items[index];
-            if (item.view.parent !== this.owner) {
+            // if (item.view.parent !== this.owner) {
-                this.owner._addView(item.view);
+            //     this.owner._addView(item.view);
-            }
+            // }
 
             if (this[VIEWS_STATES]) {
                 if (traceEnabled) {
@@ -92,9 +92,9 @@ function ensurePagerAdapterClass() {
 
             // Note: this.owner._removeView will clear item.view._nativeView.
             // So call this after the native instance is removed form the container. 
-            if (item.view.parent === this.owner) {
+            // if (item.view.parent === this.owner) {
-                this.owner._removeView(item.view);
+            //     this.owner._removeView(item.view);
-            }
+            // }
         }
 
         isViewFromObject(view: android.view.View, _object: any) {
@@ -122,7 +122,8 @@ function ensurePagerAdapterClass() {
                 }
                 return true;
             }
-            owner._eachChildView(childCallback);
+            
+            owner.eachChildView(childCallback);
 
             let bundle = new android.os.Bundle();
             bundle.putSparseParcelableArray(VIEWS_STATES, viewStates);
@@ -191,12 +192,12 @@ export class TabView extends TabViewBase {
 
         this.setElevation();
 
-        let accentColor = ad.resources.getPalleteColor(ACCENT_COLOR, this._context);
+        const accentColor = ad.resources.getPalleteColor(ACCENT_COLOR, this._context);
         if (accentColor) {
             this._tabLayout.setSelectedIndicatorColors([accentColor]);
         }
 
-        let primaryColor = ad.resources.getPalleteColor(PRIMARY_COLOR, this._context);
+        const primaryColor = ad.resources.getPalleteColor(PRIMARY_COLOR, this._context);
         if (primaryColor) {
             this._tabLayout.setBackgroundColor(primaryColor);
         }
@@ -207,7 +208,7 @@ export class TabView extends TabViewBase {
 
         this._viewPager = new android.support.v4.view.ViewPager(this._context);
         this._viewPager.setId(this._androidViewId);
-        let lp = new org.nativescript.widgets.CommonLayoutParams();
+        const lp = new org.nativescript.widgets.CommonLayoutParams();
         lp.row = 1;
         this._viewPager.setLayoutParams(lp);
         this._grid.addView(this._viewPager);
@@ -218,7 +219,7 @@ export class TabView extends TabViewBase {
     }
 
     private setElevation() {
-        let compat = <any>android.support.v4.view.ViewCompat;
+        const compat = <any>android.support.v4.view.ViewCompat;
         if (compat.setElevation) {
             let val = DEFAULT_ELEVATION * layout.getDisplayDensity();
             compat.setElevation(this._grid, val);
@@ -226,48 +227,31 @@ export class TabView extends TabViewBase {
         }
     }
 
-    public _onItemsPropertyChangedSetNativeValue() {
+    private setAdapter(items: Array<TabViewItem>) {
-        throw new Error("Compilation error: Can't find this.previousItems");
+        const length = items ? items.length : 0;
-        // let oldItems = <TabViewItem[]>this.previousItems;
+        if (length === 0) {
-        // if (oldItems) {
+            this._viewPager.setAdapter(null);
-        //     oldItems.forEach((oldItem) => {
+            this._pagerAdapter = null;
-        //         // _removeView is called within destroyItem method 
+            this._tabLayout.setItems(null, null);
-        //         oldItem._parent = null;
+            return;
-        //     });
+        }
 
-        //     this._viewPager.setAdapter(null);
+        const tabItems = new Array<org.nativescript.widgets.TabItemSpec>();
-        //     this._pagerAdapter = null;
+        items.forEach((item, idx, arr) => {
-        //     this._tabLayout.setItems(null, null);
+            tabItems.push(this.createTabItem(item));
-        // }
+        });
 
-        // let items = <TabViewItem[]>this.items;
+        ensurePagerAdapterClass();
-        // if (items) {
+        // TODO: optimize by reusing the adapter and calling setAdapter(null) then the same adapter.
-        //     let tabItems = new Array<org.nativescript.widgets.TabItemSpec>();
+        this._pagerAdapter = new PagerAdapterClass(this, items);
-        //     items.forEach((item, idx, arr) => {
+        this._viewPager.setAdapter(this._pagerAdapter);
-        //         if (!item.view) {
-        //             throw new Error("View of TabViewItem at index " + idx + " is " + item.view);
-        //         }
 
-        //         item._parent = this;
+        this._tabLayout.setItems(tabItems, this._viewPager);
-        //         if (item.view.parent !== this) {
-        //             this._addView(item.view, idx);
-        //         }
-        //         tabItems.push(this.createTabItem(item));
-        //     });
 
-        //     ensurePagerAdapterClass();
+        let selectedIndex = this.selectedIndex;
-        //     // TODO: optimize by reusing the adapter and calling setAdapter(null) then the same adapter.
+        if (selectedIndex < 0) {
-        //     this._pagerAdapter = new PagerAdapterClass(this, items);
+            this.selectedIndex = this._viewPager.getCurrentItem();
-        //     this._viewPager.setAdapter(this._pagerAdapter);
+        }
-
-        //     this._tabLayout.setItems(tabItems, this._viewPager);
-        // }
-
-        // let nativeSelectedIndex = this._viewPager.getCurrentItem();
-        // let selectedIndex = this.selectedIndex;
-        // if (selectedIndex < 0) {
-        //     this.selectedIndex = nativeSelectedIndex;
-        // }
     }
 
     public _updateTabForItem(item: TabViewItem) {
@@ -320,7 +304,7 @@ export class TabView extends TabViewBase {
         return null;
     }
     set [itemsProperty.native](value: TabViewItemBase[]) {
-        this._onItemsPropertyChangedSetNativeValue();
+        this.setAdapter(value);
     }
 
     get [tabTextColorProperty.native](): number {

tns-core-modules/ui/tab-view/tab-view.ios.ts

@@ -121,23 +121,24 @@ function updateItemTitlePosition(tabBarItem: UITabBarItem): void {
 }
 
 export class TabViewItem extends TabViewItemBase {
-    public _controller: UIViewController;
-    public _parent: TabView;
 
     public _update() {
-        if (this._parent && this._controller) {
+        const parent = <TabView>this.parent;
-            const icon = this._parent._getIcon(this.iconSource);
+        let controller = <UIViewController>this.nativeView;
-            const tabBarItem = UITabBarItem.alloc().initWithTitleImageTag((this.title), icon, this._parent.items.indexOf(this));
+        if (parent && controller) {
+            const icon = parent._getIcon(this.iconSource);
+            const index = parent.items.indexOf(this);
+            const tabBarItem = UITabBarItem.alloc().initWithTitleImageTag(this.title, icon, index);
             if (!icon) {
                 updateItemTitlePosition(tabBarItem);
             }
 
             // TODO: Repeating code. Make TabViewItemBase - ViewBase and move the colorProperty on tabViewItem.
             // Delete the repeating code.
-            const states = getTitleAttributesForStates(this._parent);
+            const states = getTitleAttributesForStates(parent);
             tabBarItem.setTitleTextAttributesForState(states.normalState, UIControlState.Normal);
             tabBarItem.setTitleTextAttributesForState(states.selectedState, UIControlState.Selected);
-            this._controller.tabBarItem = tabBarItem;
+            controller.tabBarItem = tabBarItem;
         }
     }
 }
@@ -226,47 +227,30 @@ export class TabView extends TabViewBase {
         }
     }
 
-    public _removeTabs(oldItems: Array<TabViewItem>) {
+    private setViewControllers(items: Array<TabViewItem>) {
-        if (traceEnabled) {
+        const length = items ? items.length : 0;
-            traceWrite("TabView._removeTabs(" + oldItems + ");", traceCategories.Debug);
+        if (length === 0) {
-        }
+            this._ios.viewControllers = null;
-        super._removeTabs(oldItems);
+            return;
-
-        for (let i = 0, length = oldItems.length; i < length; i++) {
-            let oldItem = oldItems[i];
-            oldItem._parent = null;
-            oldItem._controller = null;
         }
 
-        this._ios.viewControllers = null;
+        const controllers = NSMutableArray.alloc<UIViewController>().initWithCapacity(length);
-    }
-
-    public _addTabs(newItems: Array<TabViewItem>) {
-        if (traceEnabled) {
-            traceWrite("TabView._addTabs(" + newItems + ");", traceCategories.Debug);
-        }
-        super._addTabs(newItems);
-
-        const length = newItems.length;
-        const newControllers: NSMutableArray<any> = NSMutableArray.alloc().initWithCapacity(length);
         const states = getTitleAttributesForStates(this);
 
         for (let i = 0; i < length; i++) {
-            const item = <TabViewItem>newItems[i];
+            const item = items[i];
             let newController: UIViewController;
 
             if (item.view.ios instanceof UIViewController) {
-                newController = <UIViewController>item.view.ios;
+                newController = item.view.ios;
             } else {
                 newController = UIViewController.new();
                 newController.view.addSubview(item.view.ios);
             }
 
-            item._parent = this;
+            item.nativeView = newController;
-            item._controller = newController;
 
             const icon = this._getIcon(item.iconSource);
-
             const tabBarItem = UITabBarItem.alloc().initWithTitleImageTag((item.title || ""), icon, i);
             if (!icon) {
                 updateItemTitlePosition(tabBarItem);
@@ -275,17 +259,17 @@ export class TabView extends TabViewBase {
             tabBarItem.setTitleTextAttributesForState(states.selectedState, UIControlState.Selected);
 
             newController.tabBarItem = tabBarItem;
-            newControllers.addObject(newController);
+            controllers.addObject(newController);
         }
 
-        this._ios.viewControllers = newControllers;
+        this._ios.viewControllers = controllers;
         this._ios.customizableViewControllers = null;
 
         // When we set this._ios.viewControllers, someone is clearing the moreNavigationController.delegate, so we have to reassign it each time here.
         this._ios.moreNavigationController.delegate = this._moreNavigationControllerDelegate;
 
-        if (this._ios.selectedIndex !== this.selectedIndex) {
+        if (this.selectedIndex < 0) {
-            this._ios.selectedIndex = this.selectedIndex;
+            this.selectedIndex = this._ios.selectedIndex;
         }
     }
 
@@ -399,19 +383,6 @@ export class TabView extends TabViewBase {
         }
     }
 
-    private _onItemsPropertyChangedSetNativeValue() {
-        throw new Error("Compilation error: Can't find this.previousItems");
-        // let oldValue = <TabViewItem[]>this.previousItems;
-        // if (oldValue) {
-        //     this._removeTabs(oldValue);
-        // }
-
-        // let newValue = <TabViewItem[]>this.items;
-        // if (newValue) {
-        //     this._addTabs(newValue);
-        // }
-    }
-
     get [selectedIndexProperty.native](): number {
         return -1;
     }
@@ -429,7 +400,7 @@ export class TabView extends TabViewBase {
         return null;
     }
     set [itemsProperty.native](value: TabViewItemBase[]) {
-        this._onItemsPropertyChangedSetNativeValue();
+        this.setViewControllers(value);
     }
 
     get [tabTextColorProperty.native](): UIColor {
@@ -479,7 +450,7 @@ export class TabView extends TabViewBase {
         let items = this.items;
         if (items && items.length) {
             for (let i = 0, length = items.length; i < length; i++) {
-                const item = items[i]; 
+                const item = items[i];
                 if (items[i].iconSource) {
                     (<TabViewItem>items[i])._update();
                 }
@@ -495,7 +466,7 @@ function getTitleAttributesForStates(tabView: TabView): { normalState: any, sele
     }
 
     const selectedState = {};
-    let tabItemTextColor = tabView.style.tabTextColor; 
+    let tabItemTextColor = tabView.style.tabTextColor;
     if (tabItemTextColor instanceof Color) {
         selectedState[UITextAttributeTextColor] = tabItemTextColor.ios;
     }