feat: Add methods to get the root view and set a different root view at run time (#5386)

* feat: add option to set a different root view at run time

* feat: expose application getRootView method

* refactor: Introduce ViewEntry interface

* fix: Respect root view rturned from launch event in Android

* refactor: getRootView() code + caching root view per activity.

* refactor: add app-root.xml in apps

* refactor: http test made async

apps/app/ui-tests-app/app-root.xml

@@ -0,0 +1 @@
+<Frame defaultPage="ui-tests-app/main-page" />

apps/app/ui-tests-app/app.ts

@@ -1,13 +1,11 @@
-console.log("####### ------ APP MODULES START ")
+console.log("####### ------ APP MODULES START ");
 
 import * as application from "tns-core-modules/application";
 import * as trace from "tns-core-modules/trace";
+trace.addCategories(trace.categories.NativeLifecycle);
+trace.addCategories(trace.categories.Navigation);
+trace.addCategories(trace.categories.Transition);
 trace.enable();
-trace.setCategories(trace.categories.concat(
-    trace.categories.NativeLifecycle,
-    trace.categories.Navigation,
-    trace.categories.Transition
-    ));
 
 var countResume = 0;
 var countSuspend = 0;
@@ -25,7 +23,7 @@ application.on("uncaughtError", args => {
     }
 });
 
-application.on(application.launchEvent, function (args: application.ApplicationEventData) {
+application.on(application.launchEvent, function(args: application.LaunchEventData) {
     if (args.android) {
         // For Android applications, args.android is an android.content.Intent class.
         console.log("### Launched application with: " + args.android + ".");
@@ -35,7 +33,7 @@ application.on(application.launchEvent, function (args: application.ApplicationE
     }
 });
 
-application.on(application.suspendEvent, function (args: application.ApplicationEventData) {
+application.on(application.suspendEvent, function(args: application.ApplicationEventData) {
     if (args.android) {
         // For Android applications, args.android is an android activity class.
         console.log("#" + ++countSuspend + "# SuspendEvent Activity: " + args.android);
@@ -45,7 +43,7 @@ application.on(application.suspendEvent, function (args: application.Application
     }
 });
 
-application.on(application.resumeEvent, function (args: application.ApplicationEventData) {
+application.on(application.resumeEvent, function(args: application.ApplicationEventData) {
     if (args.android) {
         // For Android applications, args.android is an android activity class.
         console.log("#" + ++countResume + "# ResumeEvent Activity: " + args.android);
@@ -55,7 +53,7 @@ application.on(application.resumeEvent, function (args: application.ApplicationE
     }
 });
 
-application.on(application.exitEvent, function (args: application.ApplicationEventData) {
+application.on(application.exitEvent, function(args: application.ApplicationEventData) {
     if (args.android) {
         // For Android applications, args.android is an android activity class.
         console.log("### ExitEvent Activity: " + args.android);
@@ -65,7 +63,7 @@ application.on(application.exitEvent, function (args: application.ApplicationEve
     }
 });
 
-application.on(application.lowMemoryEvent, function (args: application.ApplicationEventData) {
+application.on(application.lowMemoryEvent, function(args: application.ApplicationEventData) {
     if (args.android) {
         // For Android applications, args.android is an android activity class.
         console.log("### LowMemoryEvent Activity: " + args.android);
@@ -75,12 +73,15 @@ application.on(application.lowMemoryEvent, function (args: application.Applicati
     }
 });
 
-application.on(application.uncaughtErrorEvent, function (args: application.UnhandledErrorEventData) {
-        console.log("### NativeScriptError: " + args.error);
-        console.log("### nativeException: " + (<any>args.error).nativeException);
-        console.log("### stackTace: " + (<any>args.error).stackTrace);
-        console.log("### stack: " + args.error.stack);
+application.on(application.uncaughtErrorEvent, function(args: application.UnhandledErrorEventData) {
+    console.log("### NativeScriptError: " + args.error);
+    console.log("### nativeException: " + (<any>args.error).nativeException);
+    console.log("### stackTrace: " + (<any>args.error).stackTrace);
+    console.log("### stack: " + args.error.stack);
 });
 
 application.setCssFileName("ui-tests-app/app.css");
+
 application.start({ moduleName: "ui-tests-app/main-page" });
+// application.run({ moduleName: "ui-tests-app/app-root" });
+// application.run();

tests/app/http/http-tests.ts

@@ -634,20 +634,12 @@ export var test_request_jsonAsContentSentAndReceivedProperly = function (done) {
 };
 
 declare var Worker: any;
-export var test_getString_WorksProperlyInWorker = function () {
-    var ready;
-
-    var worker = new Worker("./http-string-worker");
-
-    worker.onmessage = function (msg) {
-        TKUnit.assert(typeof msg.data === "string", "Result from getString() should be valid string object!");
-        ready = true;
-    }
-
-    worker.onerror = function (e) {
-        ready = true;
-        throw e;
-    }
-
-    TKUnit.waitUntilReady(() => ready);
-}
+export var test_getString_WorksProperlyInWorker = function(done) {
+    let worker = new Worker("./http-string-worker");
+    worker.onmessage = function(msg) {
+        done();
+    };
+    worker.onerror = function(e) {
+        done(e);
+    };
+};

tns-core-modules/application/application-common.ts

@@ -2,6 +2,8 @@
 require("globals");
 
 import { Observable, EventData } from "../data/observable";
+// types
+import { View } from "../ui/core/view";
 import {
     trace as profilingTrace,
     time,

tns-core-modules/application/application.android.ts

@@ -13,7 +13,8 @@ import { profile } from "../profiling";
 // First reexport so that app module is initialized.
 export * from "./application-common";
 
-import { NavigationEntry } from "../ui/frame";
+// types
+import { NavigationEntry, View, AndroidActivityCallbacks } from "../ui/frame";
 
 const ActivityCreated = "activityCreated";
 const ActivityDestroyed = "activityDestroyed";
@@ -53,7 +54,7 @@ export class AndroidApplication extends Observable implements AndroidApplication
         if (this.nativeApp === nativeApp) {
             return;
         }
-        
+
         if (this.nativeApp) {
             throw new Error("application.android already initialized.");
         }
@@ -148,10 +149,35 @@ export function run(entry?: NavigationEntry | string) {
     start(entry);
 }
 
+const CALLBACKS = "_callbacks";
+
+export function _resetRootView(entry?: NavigationEntry | string) {
+    const activity = androidApp.foregroundActivity;
+    if (!activity) {
+        throw new Error("Cannot find android activity.");
+    }
+
+    mainEntry = typeof entry === "string" ? { moduleName: entry } : entry;
+    const callbacks: AndroidActivityCallbacks = activity[CALLBACKS];
+    callbacks.resetActivityContent(activity);
+}
+
 export function getMainEntry() {
     return mainEntry;
 }
 
+export function getRootView() {
+    // Use start activity as a backup when foregroundActivity is still not set
+    // in cases when we are getting the root view before activity.onResumed event is fired
+    const activity = androidApp.foregroundActivity || androidApp.startActivity;
+    if (!activity) {
+        return undefined;
+    }
+    const callbacks: AndroidActivityCallbacks = activity[CALLBACKS];
+
+    return callbacks ? callbacks.getRootView() : undefined;
+}
+
 export function getNativeApplication(): android.app.Application {
     // Try getting it from module - check whether application.android.init has been explicitly called
     let nativeApp = androidApp.nativeApp;
@@ -202,11 +228,11 @@ function initLifecycleCallbacks() {
         }
     });
 
-    const notifyActivityCreated = profile("notifyActivityCreated", function(activity: android.app.Activity, savedInstanceState: android.os.Bundle) {
+    const notifyActivityCreated = profile("notifyActivityCreated", function (activity: android.app.Activity, savedInstanceState: android.os.Bundle) {
         androidApp.notify(<AndroidActivityBundleEventData>{ eventName: ActivityCreated, object: androidApp, activity, bundle: savedInstanceState });
     });
 
-    const subscribeForGlobalLayout = profile("subscribeForGlobalLayout", function(activity: android.app.Activity) {
+    const subscribeForGlobalLayout = profile("subscribeForGlobalLayout", function (activity: android.app.Activity) {
         const rootView = activity.getWindow().getDecorView().getRootView();
         let onGlobalLayoutListener = new android.view.ViewTreeObserver.OnGlobalLayoutListener({
             onGlobalLayout() {

tns-core-modules/application/application.d.ts

@@ -116,6 +116,11 @@ export interface CssChangedEventData extends EventData {
  */
 export function getMainEntry(): NavigationEntry;
 
+/**
+ * Get current application root view.
+ */
+export function getRootView(): View;
+
 /**
  * Get application level static resources.
  */
@@ -178,6 +183,12 @@ export function start(entry?: NavigationEntry | string);
  */
 export function run(entry?: NavigationEntry | string);
 
+/**
+ * Call this method to change the root view of your application. Important: Your application must already be running.
+ * This method won't create Frame as root view.
+ */
+export function _resetRootView(entry?: NavigationEntry | string);
+
 //@private
 /**
  * Internal method use to check if a root Frame should be automatically created as root view.

tns-core-modules/application/application.ios.ts

@@ -100,6 +100,10 @@ class IOSApplication implements IOSApplicationDefinition {
         }
     }
 
+    get rootView() : View {
+        return this._rootView;
+    }
+
     public addNotificationObserver(notificationName: string, onReceiveCallback: (notification: NSNotification) => void): NotificationObserver {
         const observer = NotificationObserver.initWithCallback(onReceiveCallback);
         utils.ios.getter(NSNotificationCenter, NSNotificationCenter.defaultCenter).addObserverSelectorNameObject(observer, "onReceive", notificationName, null);
@@ -263,6 +267,10 @@ export function getMainEntry() {
     return mainEntry;
 }
 
+export function getRootView() {
+    return iosApp.rootView;
+}
+
 // NOTE: for backwards compatibility. Remove for 4.0.0.
 let createRootFrame = true;
 let started: boolean = false;
@@ -296,6 +304,12 @@ export function run(entry?: string | NavigationEntry) {
     start(entry);
 }
 
+export function _resetRootView(entry?: NavigationEntry | string) {
+    createRootFrame = false;
+    mainEntry = typeof entry === "string" ? { moduleName: entry } : entry;
+    iosApp.setWindowContent();
+}
+
 export function getNativeApplication(): UIApplication {
     return iosApp.nativeApp;
 }

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

@@ -1,7 +1,7 @@
 // Definitions.
 import { LoadOptions } from ".";
 import { View, ViewBase, Template, KeyedTemplate } from "../core/view";
-import { NavigationEntry } from "../frame";
+import { ViewEntry } from "../frame";
 
 // Types.
 import { debug, ScopeError, SourceError, Source } from "../../utils/debug";
@@ -62,7 +62,7 @@ export function loadPage(moduleNamePath: string, fileName: string, context?: any
     return componentModule && componentModule.component;
 }
 
-const loadModule = profile("loadModule", (moduleNamePath: string, entry: NavigationEntry): ModuleExports => {
+const loadModule = profile("loadModule", (moduleNamePath: string, entry: ViewEntry): ModuleExports => {
     // web-pack case where developers register their page JS file manually.
     if (global.moduleExists(entry.moduleName)) {
         return global.loadModule(entry.moduleName);
@@ -94,7 +94,7 @@ const viewFromBuilder = profile("viewFromBuilder", (moduleNamePath: string, modu
     return null;
 })
 
-export const createViewFromEntry = profile("createViewFromEntry", (entry: NavigationEntry): View => {
+export const createViewFromEntry = profile("createViewFromEntry", (entry: ViewEntry): View => {
     if (entry.create) {
         return createView(entry);
     } else if (entry.moduleName) {
@@ -116,7 +116,7 @@ export const createViewFromEntry = profile("createViewFromEntry", (entry: Naviga
     throw new Error("Failed to load page XML file for module: " + entry.moduleName);
 });
 
-const createView = profile("entry.create", (entry: NavigationEntry): View => {
+const createView = profile("entry.create", (entry: ViewEntry): View => {
     const view = entry.create();
     if (!view) {
         throw new Error("Failed to create Page with entry.create() function.");

tns-core-modules/ui/frame/activity.android.ts

@@ -19,7 +19,7 @@ class NativeScriptActivity extends android.app.Activity {
         appModule.android.init(this.getApplication());
         
         // Set isNativeScriptActivity in onCreate.
-        // The JS construcotr might not be called beacuse the activity is created from Andoird.
+        // The JS constructor might not be called because the activity is created from Android.
         this.isNativeScriptActivity = true;
         if (!this._callbacks) {
             setActivityCallbacks(this);

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

@@ -25,10 +25,12 @@ import { createViewFromEntry } from "../builder";
 export * from "./frame-common";
 
 const INTENT_EXTRA = "com.tns.activity";
+const ROOT_VIEW_ID_EXTRA = "com.tns.activity.rootViewId";
 const FRAMEID = "_frameId";
 const CALLBACKS = "_callbacks";
 
 const ownerSymbol = Symbol("_owner");
+const activityRootViewsMap = new Map<number, WeakRef<View>>();
 
 let navDepth = -1;
 let fragmentId = -1;
@@ -73,11 +75,12 @@ function getAttachListener(): android.view.View.OnAttachStateChangeListener {
 }
 
 export function reloadPage(): void {
-    const app = application.android;
-    const rootView: View = (<any>app).rootView;
+    const activity = application.android.foregroundActivity;
+    const callbacks: AndroidActivityCallbacks = activity[CALLBACKS];
+    const rootView: View = callbacks.getRootView();
+
     if (!rootView || !rootView._onLivesync()) {
-        // Delete previously cached root view in order to recreate it.
-        resetActivityContent(application.android.foregroundActivity);
+        callbacks.resetActivityContent(activity);
     }
 }
 
@@ -288,7 +291,7 @@ export class Frame extends FrameBase {
         const newFragment = this.createFragment(newEntry, newFragmentTag);
         const transaction = manager.beginTransaction();
         const animated = this._getIsAnimatedNavigation(newEntry.entry);
-        // NOTE: Don't use transition for the initial nagivation (same as on iOS)
+        // NOTE: Don't use transition for the initial navigation (same as on iOS)
         // On API 21+ transition won't be triggered unless there was at least one
         // layout pass so we will wait forever for transitionCompleted handler...
         // https://github.com/NativeScript/NativeScript/issues/4895
@@ -754,7 +757,11 @@ class FragmentCallbacksImplementation implements AndroidFragmentCallbacks {
 }
 
 class ActivityCallbacksImplementation implements AndroidActivityCallbacks {
-    public _rootView: View;
+    private _rootView: View;
+
+    public getRootView(): View {
+        return this._rootView;
+    }
 
     @profile
     public onCreate(activity: android.app.Activity, savedInstanceState: android.os.Bundle, superFunc: Function): void {
@@ -770,18 +777,29 @@ class ActivityCallbacksImplementation implements AndroidActivityCallbacks {
         let isRestart = !!savedInstanceState && moduleLoaded;
         superFunc.call(activity, isRestart ? savedInstanceState : null);
 
-        setActivityContent(activity, savedInstanceState);
+        // Try to get the rootViewId form the saved state in case the activity
+        // was destroyed and we are now recreating it.
+        if (savedInstanceState) {
+            const rootViewId = savedInstanceState.getInt(ROOT_VIEW_ID_EXTRA, -1);
+            if (rootViewId !== -1 && activityRootViewsMap.has(rootViewId)) {
+                this._rootView = activityRootViewsMap.get(rootViewId).get();
+            }
+        }
+
+        this.setActivityContent(activity, savedInstanceState, true);
         moduleLoaded = true;
     }
 
     @profile
     public onSaveInstanceState(activity: android.app.Activity, outState: android.os.Bundle, superFunc: Function): void {
         superFunc.call(activity, outState);
-        const frame = this._rootView;
-        if (frame instanceof Frame) {
-            outState.putInt(INTENT_EXTRA, frame.android.frameId);
-            frame._saveFragmentsState();
+        const rootView = this._rootView;
+        if (rootView instanceof Frame) {
+            outState.putInt(INTENT_EXTRA, rootView.android.frameId);
+            rootView._saveFragmentsState();
         }
+
+        outState.putInt(ROOT_VIEW_ID_EXTRA, rootView._domId);
     }
 
     @profile
@@ -870,7 +888,13 @@ class ActivityCallbacksImplementation implements AndroidActivityCallbacks {
     }
 
     @profile
-    public onRequestPermissionsResult(activity: any, requestCode: number, permissions: Array<String>, grantResults: Array<number>, superFunc: Function): void {
+    public onRequestPermissionsResult(
+        activity: any,
+        requestCode: number,
+        permissions: Array<String>,
+        grantResults: Array<number>,
+        superFunc: Function
+    ): void {
         if (traceEnabled()) {
             traceWrite("NativeScriptActivity.onRequestPermissionsResult;", traceCategories.NativeLifecycle);
         }
@@ -886,7 +910,13 @@ class ActivityCallbacksImplementation implements AndroidActivityCallbacks {
     }
 
     @profile
-    public onActivityResult(activity: any, requestCode: number, resultCode: number, data: android.content.Intent, superFunc: Function): void {
+    public onActivityResult(
+        activity: any,
+        requestCode: number,
+        resultCode: number,
+        data: android.content.Intent,
+        superFunc: Function
+    ): void {
         superFunc.call(activity, requestCode, resultCode, data);
         if (traceEnabled()) {
             traceWrite(`NativeScriptActivity.onActivityResult(${requestCode}, ${resultCode}, ${data})`, traceCategories.NativeLifecycle);
@@ -901,78 +931,98 @@ class ActivityCallbacksImplementation implements AndroidActivityCallbacks {
             intent: data
         });
     }
-}
 
-function resetActivityContent(activity: android.app.Activity): void {
-    const callbacks: ActivityCallbacksImplementation = activity[CALLBACKS];
-    const app = application.android;
+    public resetActivityContent(activity: android.app.Activity): void {
+        // Delete previously cached root view in order to recreate it.
+        this._rootView = null;
+        this.setActivityContent(activity, null, false);
+        this._rootView.callLoaded();
+    }
 
-    // Delete previously cached root view in order to recreate it.
-    callbacks._rootView = (<any>app).rootView = null;
-    setActivityContent(activity, null);
-    callbacks._rootView.callLoaded();
-}
+    // Paths that go trough this method:
+    // 1. Application initial start - there is no rootView in callbacks.
+    // 2. Application revived after Activity is destroyed. this._rootView should have been restored by id in onCreate. 
+    // 3. Livesync if rootView has no custom _onLivesync. this._rootView should have been cleared upfront. Launch event should not fired
+    // 4. _resetRootView method. this._rootView should have been cleared upfront. Launch event should not fired
+    private setActivityContent(
+        activity: android.app.Activity,
+        savedInstanceState: android.os.Bundle,
+        fireLaunchEvent: boolean
+    ): void {
+        const shouldCreateRootFrame = application.shouldCreateRootFrame();
+        let rootView = this._rootView;
 
-function setActivityContent(activity: android.app.Activity, savedInstanceState: android.os.Bundle): void {
-    const callbacks: ActivityCallbacksImplementation = activity[CALLBACKS];
-
-    const shouldCreateRootFrame = application.shouldCreateRootFrame();
-    const app = application.android;
-
-    // TODO: this won't work if we open more than one activity!!!
-    let rootView = callbacks._rootView = (<any>app).rootView;
-    if (!rootView) {
-        const mainEntry = application.getMainEntry();
-        const intent = activity.getIntent();
-        rootView = notifyLaunch(intent, savedInstanceState);
-        if (shouldCreateRootFrame) {
-            const extras = intent.getExtras();
-            let frameId = -1;
-
-            // We have extras when we call - new Frame().navigate();
-            // savedInstanceState is used when activity is recreated.
-            // NOTE: On API 23+ we get extras on first run.
-            // Check changed - first try to get frameId from Extras if not from saveInstanceState.
-            if (extras) {
-                frameId = extras.getInt(INTENT_EXTRA, -1);
-            }
-
-            if (savedInstanceState && frameId < 0) {
-                frameId = savedInstanceState.getInt(INTENT_EXTRA, -1);
-            }
-
-            if (!rootView) {
-                // If we have frameId from extras - we are starting a new activity from navigation (e.g. new Frame().navigate()))
-                // Then we check if we have frameId from savedInstanceState - this happens when Activity is destroyed but app was not (e.g. suspend)
-                rootView = getFrameById(frameId) || new Frame();
-            }
-
-            if (rootView instanceof Frame) {
-                rootView.navigate(mainEntry);
-            } else {
-                throw new Error("A Frame must be used to navigate to a Page.");
-            }
-        } else {
-            rootView = createViewFromEntry(mainEntry);
+        if (traceEnabled()) {
+            traceWrite(
+                `Frame.setActivityContent rootView: ${rootView} shouldCreateRootFrame: ${shouldCreateRootFrame} fireLaunchEvent: ${fireLaunchEvent}`,
+                traceCategories.NativeLifecycle
+            );
         }
 
-        callbacks._rootView = (<any>app).rootView = rootView;
-    }
+        if (!rootView) {
+            const mainEntry = application.getMainEntry();
+            const intent = activity.getIntent();
 
-    // Initialize native visual tree;
-    if (shouldCreateRootFrame) {
-        // Don't setup as styleScopeHost
-        rootView._setupUI(activity);
-    } else {
-        // setup view as styleScopeHost
-        rootView._setupAsRootView(activity);
-    }
+            if (fireLaunchEvent) {
+                rootView = notifyLaunch(intent, savedInstanceState);
+            }
 
-    activity.setContentView(rootView.nativeViewProtected, new org.nativescript.widgets.CommonLayoutParams());
+            if (shouldCreateRootFrame) {
+                const extras = intent.getExtras();
+                let frameId = -1;
+
+                // We have extras when we call - new Frame().navigate();
+                // savedInstanceState is used when activity is recreated.
+                // NOTE: On API 23+ we get extras on first run.
+                // Check changed - first try to get frameId from Extras if not from saveInstanceState.
+                if (extras) {
+                    frameId = extras.getInt(INTENT_EXTRA, -1);
+                }
+
+                if (savedInstanceState && frameId < 0) {
+                    frameId = savedInstanceState.getInt(INTENT_EXTRA, -1);
+                }
+
+                if (!rootView) {
+                    // If we have frameId from extras - we are starting a new activity from navigation (e.g. new Frame().navigate()))
+                    // Then we check if we have frameId from savedInstanceState - this happens when Activity is destroyed but app was not (e.g. suspend)
+                    rootView = getFrameById(frameId) || new Frame();
+                }
+
+                if (rootView instanceof Frame) {
+                    rootView.navigate(mainEntry);
+                } else {
+                    throw new Error("A Frame must be used to navigate to a Page.");
+                }
+            } else {
+                // Create the root view if the notifyLaunch didn't return it
+                rootView = rootView || createViewFromEntry(mainEntry);
+            }
+
+            this._rootView = rootView;
+            activityRootViewsMap.set(rootView._domId, new WeakRef(rootView));
+        }
+
+        // Initialize native visual tree;
+        if (shouldCreateRootFrame) {
+            // Don't setup as styleScopeHost
+            rootView._setupUI(activity);
+        } else {
+            // setup view as styleScopeHost
+            rootView._setupAsRootView(activity);
+        }
+
+        activity.setContentView(rootView.nativeViewProtected, new org.nativescript.widgets.CommonLayoutParams());
+    }
 }
 
 const notifyLaunch = profile("notifyLaunch", function notifyLaunch(intent: android.content.Intent, savedInstanceState: android.os.Bundle): View {
-    const launchArgs: application.LaunchEventData = { eventName: application.launchEvent, object: application.android, android: intent, savedInstanceState };
+    const launchArgs: application.LaunchEventData = {
+        eventName: application.launchEvent, 
+        object: application.android, 
+        android: intent, savedInstanceState 
+    };
+    
     application.notify(launchArgs);
     application.notify(<application.LoadAppCSSEventData>{ eventName: "loadAppCss", object: <any>this, cssFile: application.getCssFileName() });
     return launchArgs.root;

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

@@ -187,19 +187,23 @@ export function goBack();
 export function stack(): Array<Frame>;
 
 /**
- * Represents an entry in passed to navigate method.
+ * Represents an entry to be used to create a view or load it form file
  */
-export interface NavigationEntry {
+export interface ViewEntry {
     /**
-     * The name of the module containing the Page instance to load. Optional.
+     * The name of the module containing the View instance to load. Optional.
      */
     moduleName?: string;
 
     /**
-     * A function used to create the Page instance. Optional.
+     * A function used to create the View instance. Optional.
      */
-    create?: () => Page;
-
+    create?: () => View;
+}
+/**
+ * Represents an entry in passed to navigate method.
+ */
+export interface NavigationEntry extends ViewEntry {
     /**
      * An object passed to the onNavigatedTo callback of the Page. Typically this is used to pass some data among pages. Optional.
      */
@@ -377,6 +381,9 @@ export interface AndroidFrame extends Observable {
 }
 
 export interface AndroidActivityCallbacks {
+    getRootView(): View;
+    resetActivityContent(activity: any): void;
+    
     onCreate(activity: any, savedInstanceState: any, superFunc: Function): void;
     onSaveInstanceState(activity: any, outState: any, superFunc: Function): void;
     onStart(activity: any, superFunc: Function): void;