Merge pull request #4202 from NativeScript/app-displayed-event

App "displayed" event

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

@@ -21,6 +21,7 @@ import { UnhandledErrorEventData, iOSApplication, AndroidApplication, CssChanged
 
 export const launchEvent = "launch";
 export const suspendEvent = "suspend";
+export const displayedEvent = "displayed";
 export const resumeEvent = "resume";
 export const exitEvent = "exit";
 export const lowMemoryEvent = "lowMemory";
@@ -45,6 +46,7 @@ export let ios = undefined;
 export const on: typeof events.on = events.on.bind(events);
 export const off: typeof events.off = events.off.bind(events);
 export const notify: typeof events.notify = events.notify.bind(events);
+export const hasListeners: typeof events.hasListeners = events.hasListeners.bind(events);
 
 let app: iOSApplication | AndroidApplication;
 export function setApplication(instance: iOSApplication | AndroidApplication): void {

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

@@ -4,7 +4,7 @@
 } from ".";
 
 import {
-    notify, lowMemoryEvent, orientationChangedEvent, suspendEvent, resumeEvent,
+    notify, hasListeners, lowMemoryEvent, orientationChangedEvent, suspendEvent, resumeEvent, displayedEvent,
     setApplication, livesync, Observable
 } from "./application-common";
 
@@ -181,7 +181,19 @@ function initLifecycleCallbacks() {
                 androidApp.startActivity = activity;
             }
 
-            androidApp.notify(<AndroidActivityBundleEventData>{ eventName: ActivityCreated, object: androidApp, activity: activity, bundle: savedInstanceState });
+            androidApp.notify(<AndroidActivityBundleEventData>{ eventName: ActivityCreated, object: androidApp, activity, bundle: savedInstanceState });
+
+            if (hasListeners(displayedEvent)) {
+                let rootView = activity.findViewById((<any>android).R.id.content);
+                let onGlobalLayoutListener = new android.view.ViewTreeObserver.OnGlobalLayoutListener({
+                    onGlobalLayout() {
+                        notify({ eventName: displayedEvent, object: androidApp, activity });
+                        let viewTreeObserver = rootView.getViewTreeObserver();
+                        viewTreeObserver.removeOnGlobalLayoutListener(onGlobalLayoutListener);
+                    }
+                });
+                rootView.getViewTreeObserver().addOnGlobalLayoutListener(onGlobalLayoutListener);
+            }
         },
 
         onActivityDestroyed: function (activity: android.app.Activity) {

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

@@ -11,6 +11,11 @@ import { NavigationEntry, View, Observable, EventData } from "../ui/frame";
  */
 export var launchEvent: string;
 
+/**
+ * String value used when hooking to displayed event.
+ */
+export var displayedEvent: string;
+
 /**
  * String value used when hooking to uncaughtError event.
  */
@@ -189,6 +194,13 @@ export function hasListeners(eventName: string): boolean;
  */
 export function on(event: "launch", callback: (args: LaunchEventData) => void, thisArg?: any);
 
+/**
+ * This event is raised after the application has performed most of its startup actions.
+ * Its intent is to be suitable for measuring app startup times.
+ * @experimental
+ */
+export function on(event: "displayed", callback: (args: EventData) => void, thisArg?: any);
+
 /**
  * This event is raised when the Application is suspended.
  */

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

@@ -2,7 +2,7 @@
 
 import {
     notify, launchEvent, resumeEvent, suspendEvent, exitEvent, lowMemoryEvent,
-    orientationChangedEvent, setApplication, livesync
+    orientationChangedEvent, setApplication, livesync, displayedEvent
 } from "./application-common";
 
 // First reexport so that app module is initialized.
@@ -16,6 +16,8 @@ class Responder extends UIResponder {
     //
 }
 
+let displayedOnce = false;
+
 class Window extends UIWindow {
     public content;
 
@@ -138,7 +140,13 @@ class IOSApplication implements IOSApplicationDefinition {
     }
 
     private didBecomeActive(notification: NSNotification) {
-        notify(<ApplicationEventData>{ eventName: resumeEvent, object: this, ios: utils.ios.getter(UIApplication, UIApplication.sharedApplication) });
+        let ios = utils.ios.getter(UIApplication, UIApplication.sharedApplication);
+        let object = this;
+        notify(<ApplicationEventData>{ eventName: resumeEvent, object, ios });
+        if (!displayedOnce) {
+            notify(<ApplicationEventData>{ eventName: displayedEvent, object, ios });
+            displayedOnce = true;
+        }
     }
 
     private didEnterBackground(notification: NSNotification) {