From cf96e7252cdf66230cc03ddec907168e47d1f250 Mon Sep 17 00:00:00 2001
From: Martin Guillon <martin.guillon@akylas.fr>
Date: Fri, 13 Nov 2020 05:51:03 +0100
Subject: [PATCH] feat(frame): add navigatingTo and navigatedTo events (#9025)

---
 packages/core/ui/frame/frame-common.ts | 13 +++++++++++++
 packages/core/ui/frame/index.d.ts      | 18 +++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/packages/core/ui/frame/frame-common.ts b/packages/core/ui/frame/frame-common.ts
index af20f2b90..709b5c211 100644
--- a/packages/core/ui/frame/frame-common.ts
+++ b/packages/core/ui/frame/frame-common.ts
@@ -249,6 +249,12 @@ export class FrameBase extends CustomLayoutView {
 		}
 
 		newPage.onNavigatedTo(isBack);
+		this.notify({
+			eventName: Page.navigatedToEvent,
+			object: this,
+			isBack,
+			entry,
+		});
 
 		// Reset executing context after NavigatedTo is raised;
 		// we do not want to execute two navigations in parallel in case
@@ -417,6 +423,13 @@ export class FrameBase extends CustomLayoutView {
 		}
 
 		backstackEntry.resolvedPage.onNavigatingTo(backstackEntry.entry.context, isBack, backstackEntry.entry.bindingContext);
+		this.notify({
+			eventName: Page.navigatingToEvent,
+			object: this,
+			isBack,
+			entry: backstackEntry.entry,
+			fromEntry:this.currentEntry
+		});
 	}
 
 	public get animated(): boolean {
diff --git a/packages/core/ui/frame/index.d.ts b/packages/core/ui/frame/index.d.ts
index 55ebe53eb..dabdcda93 100644
--- a/packages/core/ui/frame/index.d.ts
+++ b/packages/core/ui/frame/index.d.ts
@@ -1,11 +1,17 @@
 import { NavigationType, FrameBase } from './frame-common';
-import { Page } from '../page';
+import { NavigatedData, Page } from '../page';
 import { Observable, EventData } from '../../data/observable';
 import { View } from '../core/view';
 import { Transition } from '../transition';
 
 export * from './frame-interfaces';
 
+export interface NavigationData extends EventData  {
+	entry?: NavigationEntry;
+	fromEntry?: NavigationEntry;
+	isBack?: boolean;
+}
+
 /**
  * Represents the logical View unit that is responsible for navigation within an application.
  * Nested frames are supported, enabling hierarchical navigation scenarios.
@@ -210,6 +216,16 @@ export class Frame extends FrameBase {
 	 * @param thisArg - An optional parameter which will be used as `this` context for callback execution.
 	 */
 	on(eventNames: string, callback: (args: EventData) => void, thisArg?: any);
+
+	/**
+	 * Raised when navigation to the page has started.
+	 */
+	public on(event: 'navigatingTo', callback: (args: NavigationData) => void, thisArg?: any);
+
+	/**
+	 * Raised when navigation to the page has finished.
+	 */
+	public on(event: 'navigatedTo', callback: (args: NavigationData) => void, thisArg?: any);
 }
 
 /**