Merge pull request #975 from NativeScript/nnikolov/Issue926

Fixed issue #926.

apps/tests/ui/page/page-tests-common.ts

@@ -394,6 +394,46 @@ export function test_WhenPageIsLoadedFrameCurrentPageIsTheSameInstance() {
     }
 }
 
+export function test_WhenNavigatingForwardAndBack_IsBackNavigationIsCorrect() {
+    var page1;
+    var page2;
+    var forwardCounter = 0;
+    var backCounter = 0;
+    var loadedEventHandler = function (args: PageModule.NavigatedData) {
+        if (args.isBackNavigation) {
+            backCounter++;
+        }
+        else {
+            forwardCounter++;
+        }
+    }
+
+    var pageFactory1 = function (): PageModule.Page {
+        page1 = new PageModule.Page();
+        page1.on(PageModule.Page.navigatedToEvent, loadedEventHandler);
+        return page1;
+    };
+
+    var pageFactory2 = function (): PageModule.Page {
+        page2 = new PageModule.Page();
+        page2.on(PageModule.Page.navigatedToEvent, loadedEventHandler);
+        return page2;
+    };
+
+    try {
+        helper.navigate(pageFactory1);
+        helper.navigate(pageFactory2);
+        helper.goBack();
+        TKUnit.assertEqual(forwardCounter, 2, "Forward navigation counter should be 1");
+        TKUnit.assertEqual(backCounter, 1, "Backward navigation counter should be 1");
+        page1.off(PageModule.Page.navigatedToEvent, loadedEventHandler);
+        page2.off(PageModule.Page.navigatedToEvent, loadedEventHandler);
+    }
+    finally {
+        helper.goBack();
+    }
+}
+
 //export function test_ModalPage_Layout_is_Correct() {
 //    var testPage: PageModule.Page;
 //    var label: LabelModule.Label;

ui/frame/frame-common.ts

@@ -222,7 +222,7 @@ export class Frame extends view.CustomLayoutView implements definition.Frame {
 
     private performNavigation(navigationContext: NavigationContext) {
         var navContext = navigationContext.entry;
-        this._onNavigatingTo(navContext);
+        this._onNavigatingTo(navContext, navigationContext.isBackNavigation);
 
         if (navigationContext.entry.entry.clearHistory) {
             this._backStack.length = 0;
@@ -237,7 +237,7 @@ export class Frame extends view.CustomLayoutView implements definition.Frame {
 
     private performGoBack(navigationContext: NavigationContext) {
         var navContext = navigationContext.entry;
-        this._onNavigatingTo(navContext);
+        this._onNavigatingTo(navContext, navigationContext.isBackNavigation);
         this._goBackCore(navContext);
         this._onNavigatedTo(navContext, true);
     }
@@ -250,12 +250,12 @@ export class Frame extends view.CustomLayoutView implements definition.Frame {
         //
     }
 
-    public _onNavigatingTo(backstackEntry: definition.BackstackEntry) {
+    public _onNavigatingTo(backstackEntry: definition.BackstackEntry, isBack: boolean) {
         if (this.currentPage) {
-            this.currentPage.onNavigatingFrom();
+            this.currentPage.onNavigatingFrom(isBack);
         }
 
-        backstackEntry.resolvedPage.onNavigatingTo(backstackEntry.entry.context);
+        backstackEntry.resolvedPage.onNavigatingTo(backstackEntry.entry.context, isBack);
     }
 
     public _onNavigatedTo(backstackEntry: definition.BackstackEntry, isBack: boolean) {

ui/frame/frame.android.ts

@@ -159,11 +159,22 @@ function onFragmentShown(fragment: PageFragmentBody) {
     var entry: definition.BackstackEntry = fragment.entry;
     var page: pages.Page = entry.resolvedPage;
 
+    let currentNavigationContext;
+    let navigationQueue = (<any>frame)._navigationQueue;
+    for (let i = 0; i < navigationQueue.length; i++) {
+        if (navigationQueue[i].entry === entry) {
+            currentNavigationContext = navigationQueue[i];
+            break;
+        }
+    }
+
+    var isBack = currentNavigationContext ? currentNavigationContext.isBackNavigation : false;
+
     frame._currentEntry = entry;
 
     // notify the page
     frame._addView(page);
-    page.onNavigatedTo();
+    page.onNavigatedTo(isBack);
     frame._processNavigationQueue(page);
 }
 
@@ -351,7 +362,7 @@ export class Frame extends frameCommon.Frame {
         var backstackEntry = this.currentEntry || this._delayedNavigationEntry;
 
         if (isRestart) {
-            this._onNavigatingTo(backstackEntry);
+            this._onNavigatingTo(backstackEntry, false);
             this._onNavigatedTo(backstackEntry, false);
         }
         else {

ui/frame/frame.ios.ts

@@ -304,6 +304,18 @@ class UINavigationControllerImpl extends UINavigationController implements UINav
         // This code check if navigation happened through UI (e.g. back button or swipe gesture).
         // When calling goBack on frame isBack will be false.
         let isBack: boolean = currentEntry && newEntry === currentEntry;
+
+        let currentNavigationContext;
+        let navigationQueue = (<any>frame)._navigationQueue;
+        for (let i = 0; i < navigationQueue.length; i++) {
+            if (navigationQueue[i].entry === newEntry) {
+                currentNavigationContext = navigationQueue[i];
+                break;
+            }
+        }
+
+        var isBackNavigation = currentNavigationContext ? currentNavigationContext.isBackNavigation : false;
+
         if (isBack) {
             try {
                 frame._shouldSkipNativePop = true;
@@ -334,7 +346,7 @@ class UINavigationControllerImpl extends UINavigationController implements UINav
         frame._updateActionBar(newPage);
 
         // notify the page
-        newPage.onNavigatedTo();
+        newPage.onNavigatedTo(isBack || isBackNavigation);
         frame._processNavigationQueue(newPage);
     }
 

ui/page/page-common.ts

@@ -8,11 +8,11 @@ import fs = require("file-system");
 import frameCommon = require("../frame/frame-common");
 import {ActionBar} from "ui/action-bar";
 import {DependencyObservable, PropertyMetadata, PropertyMetadataSettings, PropertyChangeData, Property, ValueSource} from "ui/core/dependency-observable";
-import platform = require("platform");
+
 import proxy = require("ui/core/proxy");
 
 // on Android we explicitly set propertySettings to None because android will invalidate its layout (skip unnecessary native call).
-var AffectsLayout = platform.device.os === platform.platformNames.android ? PropertyMetadataSettings.None : PropertyMetadataSettings.AffectsLayout;
+var AffectsLayout = global.android ? PropertyMetadataSettings.None : PropertyMetadataSettings.AffectsLayout;
 
 var backgroundSpanUnderStatusBarProperty = new Property("backgroundSpanUnderStatusBar", "Page", new proxy.PropertyMetadata(false, AffectsLayout));
 
@@ -163,38 +163,30 @@ export class Page extends ContentView implements dts.Page {
         return <frame.Frame>this.parent;
     }
 
-    public onNavigatingTo(context: any) {
+    private createNavigatedData(eventName: string, isBackNavigation: boolean): dts.NavigatedData {
+        return {
+            eventName: eventName,
+            object: this,
+            context: this.navigationContext,
+            isBackNavigation: isBackNavigation
+        };
+    }
+
+    public onNavigatingTo(context: any, isBackNavigation: boolean) {
         this._navigationContext = context;
-
+        this.notify(this.createNavigatedData(Page.navigatingToEvent, isBackNavigation));
-        this.notify({
-            eventName: Page.navigatingToEvent,
-            object: this,
-            context: this.navigationContext
-        });
     }
 
-    public onNavigatedTo() {
+    public onNavigatedTo(isBackNavigation: boolean) {
-        this.notify({
+        this.notify(this.createNavigatedData(Page.navigatedToEvent, isBackNavigation));
-            eventName: Page.navigatedToEvent,
-            object: this,
-            context: this.navigationContext
-        });
     }
 
-    public onNavigatingFrom() {
+    public onNavigatingFrom(isBackNavigation: boolean) {
-        this.notify({
+        this.notify(this.createNavigatedData(Page.navigatingFromEvent, isBackNavigation));
-            eventName: Page.navigatingFromEvent,
-            object: this,
-            context: this.navigationContext
-        });
     }
 
     public onNavigatedFrom(isBackNavigation: boolean) {
-        this.notify({
+        this.notify(this.createNavigatedData(Page.navigatedFromEvent, isBackNavigation));
-            eventName: Page.navigatedFromEvent,
-            object: this,
-            context: this.navigationContext
-        });
 
         this._navigationContext = undefined;
     }

ui/page/page.d.ts

@@ -21,6 +21,11 @@ declare module "ui/page" {
          * The navigation context (optional, may be undefined) passed to the page navigation events method.
          */
         context: any;
+
+        /**
+         * Represents if a navigation is forward or backward.
+         */
+        isBackNavigation: boolean;
     }
 
     /**
@@ -187,18 +192,21 @@ declare module "ui/page" {
         /**
          * A method called before navigating to the page.
          * @param context - The data passed to the page through the NavigationEntry.context property.
+         * @param isBackNavigation - True if the Page is being navigated from using the Frame.goBack() method, false otherwise.
          */
-        onNavigatingTo(context: any): void;
+        onNavigatingTo(context: any, isBackNavigation: boolean): void;
 
         /**
          * A method called after navigated to the page.
+         * @param isBackNavigation - True if the Page is being navigated from using the Frame.goBack() method, false otherwise.
          */
-        onNavigatedTo(): void;
+        onNavigatedTo(isBackNavigation: boolean): void;
 
         /**
          * A method called before navigating from the page.
+         * @param isBackNavigation - True if the Page is being navigated from using the Frame.goBack() method, false otherwise.
          */
-        onNavigatingFrom(): void;
+        onNavigatingFrom(isBackNavigation: boolean): void;
 
         /**
          * A method called after navigated from the page.