From 97a2af27f94b01fab7b1252a4f5d7a2b5025c623 Mon Sep 17 00:00:00 2001
From: Alexander Djenkov <a.djenkov90@gmail.com>
Date: Wed, 3 Jul 2019 22:32:16 +0300
Subject: [PATCH] fix(tabs): current TabContentItem index not set (#7441)

---
 e2e/nested-frame-navigation/e2e/screen.ts            |  8 ++++----
 .../tab-content-item/tab-content-item.android.ts     |  8 +++++++-
 tns-core-modules/ui/tabs/tabs.android.ts             | 12 +++++++++---
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/e2e/nested-frame-navigation/e2e/screen.ts b/e2e/nested-frame-navigation/e2e/screen.ts
index 3a1bcbe4e..f847b3273 100644
--- a/e2e/nested-frame-navigation/e2e/screen.ts
+++ b/e2e/nested-frame-navigation/e2e/screen.ts
@@ -6,10 +6,10 @@ const layoutWithMultiFrame = "Layout w/ multi frame";
 const pageWithFrame = "Page w/ frame";
 const pageWithFrameNonDefaultTransition = "Frame to NestedFrame (non-default transition)";
 const pageWithMultiFrame = "Page w/ multi frame";
-const pageTabTopWithFrames = "Page w/ tabs (top)";
-const pageTabBottomWithFrames = "Page w/ tabs (bottom)";
-const tabTopRootWithFrames = "Root tabs (top)";
-const tabBottomRootWithFrames = "Root tabs (bottom)";
+const pageTabTopWithFrames = "Page w/ tabview (top)";
+const pageTabBottomWithFrames = "Page w/ tabview (bottom)";
+const tabTopRootWithFrames = "Root tabview (top)";
+const tabBottomRootWithFrames = "Root tabview (bottom)";
 const layoutHome = "layout home page";
 const layoutHomeSecondary = "layout home secondary page";
 const frameHome = "frame home page";
diff --git a/tns-core-modules/ui/tab-navigation-base/tab-content-item/tab-content-item.android.ts b/tns-core-modules/ui/tab-navigation-base/tab-content-item/tab-content-item.android.ts
index 50ad820f3..697325b5b 100644
--- a/tns-core-modules/ui/tab-navigation-base/tab-content-item/tab-content-item.android.ts
+++ b/tns-core-modules/ui/tab-navigation-base/tab-content-item/tab-content-item.android.ts
@@ -3,7 +3,8 @@ import { TabContentItem as TabContentItemDefinition } from ".";
 import { TabNavigationBase } from "../tab-navigation-base";
 
 // Requires
-import { TabContentItemBase } from "./tab-content-item-common";
+import { TabContentItemBase, traceCategory } from "./tab-content-item-common";
+import { traceEnabled, traceWrite, traceMessageType } from "../../core/view";
 
 export * from "./tab-content-item-common";
 
@@ -49,6 +50,11 @@ export class TabContentItem extends TabContentItemBase {
         const tabView = <TabNavigationBase>this.parent;
         let tabFragment = null;
         const fragmentManager = tabView._getFragmentManager();
+
+        if (typeof this.index === "undefined") {
+            traceWrite(`Current TabContentItem index is not set`, traceCategory, traceMessageType.error);
+        }
+
         for (let fragment of (<Array<any>>fragmentManager.getFragments().toArray())) {
             if (fragment.index === this.index) {
                 tabFragment = fragment;
diff --git a/tns-core-modules/ui/tabs/tabs.android.ts b/tns-core-modules/ui/tabs/tabs.android.ts
index d521b0b47..215acf070 100644
--- a/tns-core-modules/ui/tabs/tabs.android.ts
+++ b/tns-core-modules/ui/tabs/tabs.android.ts
@@ -229,7 +229,7 @@ function initializeNativeClasses() {
             }
         }
     }
-    
+
     PagerAdapter = FragmentPagerAdapter;
 }
 
@@ -451,7 +451,7 @@ export class Tabs extends TabsBase {
 
     public _onRootViewReset(): void {
         super._onRootViewReset();
-        
+
         // call this AFTER the super call to ensure descendants apply their rootview-reset logic first
         // i.e. in a scenario with tab frames let the frames cleanup their fragments first, and then
         // cleanup the tab fragments to avoid
@@ -508,6 +508,13 @@ export class Tabs extends TabsBase {
     private setItems(items: Array<TabContentItem>) {
         if (this.shouldUpdateAdapter(items)) {
             (<any>this._pagerAdapter).items = items;
+
+            if (items && items.length) {
+                items.forEach((item: TabContentItem, i) => {
+                    (<any>item).index = i;
+                });
+            }
+
             this._pagerAdapter.notifyDataSetChanged();
         }
     }
@@ -523,7 +530,6 @@ export class Tabs extends TabsBase {
         const tabItems = new Array<org.nativescript.widgets.TabItemSpec>();
         items.forEach((item: TabStripItem, i, arr) => {
             const tabItemSpec = createTabItemSpec(item);
-            (<any>item).index = i;
             (<any>item).tabItemSpec = tabItemSpec;
             tabItems.push(tabItemSpec);
         });