fix(android): Ti.App wrongly fires pause/resume events when opening/c…

…losing child windows (#10658)

- Fixed bug where Ti.App wrongly fires pause/resume events when opening/closing child windows
- Updated Ti.App docs to indicate Android supported these events since 7.5.0
- Modified to only fire a "resume" event after a "pause" like iOS
- Changed "TiApplicationLifecycle" class' static variables to instance member variables. They don't need to be static.

Fixes TIMOB-26746

android/titanium/src/java/org/appcelerator/titanium/TiApplicationLifecycle.java

@@ -13,35 +13,82 @@
 import com.appcelerator.aps.APSAnalytics;
 
 import org.appcelerator.kroll.common.Log;
+import org.appcelerator.kroll.KrollModule;
 
 public class TiApplicationLifecycle implements Application.ActivityLifecycleCallbacks
 {
 	private static final String TAG = "TiApplicationLifecycle";
 
 	private TiApplication tiApp = TiApplication.getInstance();
-	private static int activityCount = 0;
+	private int existingActivityCount;
+	private int visibleActivityCount;
+	private boolean wasPaused;
 
 	@Override
 	public void onActivityCreated(Activity activity, Bundle savedInstanceState)
 	{
+		// Reset "wasPaused" state when creating the 1st activity in a UI task.
+		// Needed to detect if the app is resuming after being paused.
+		if (this.existingActivityCount <= 0) {
+			this.wasPaused = false;
+		}
+
+		// Increment count of all known activities.
+		this.existingActivityCount++;
 	}
 
 	@Override
 	public void onActivityStarted(Activity activity)
 	{
-		if (activityCount == 0 && tiApp != null && tiApp.isAnalyticsEnabled()) {
-			APSAnalytics.getInstance().sendAppForegroundEvent();
+		// If no activities have been started, then app is going to be put into the foreground.
+		if (this.visibleActivityCount == 0) {
+			// Fire Ti.App resume events.
+			// Note: The "resume" event should only be fired after a "pause" event and never on app startup.
+			KrollModule appModule = this.tiApp.getModuleByName("App");
+			if (appModule != null) {
+				if (this.wasPaused) {
+					appModule.fireEvent(TiC.EVENT_RESUME, null);
+				}
+				appModule.fireEvent(TiC.EVENT_RESUMED, null);
+			}
+
+			// Post analytics for this event, if enabled.
+			if (this.tiApp.isAnalyticsEnabled()) {
+				APSAnalytics.getInstance().sendAppForegroundEvent();
+			}
 		}
-		activityCount++;
+
+		// Increment number of "started" activities. These are activities that are currently in the foreground.
+		// Note: Should never be more than 1, unless some of these activities are fragments.
+		this.visibleActivityCount++;
 	}
 
 	@Override
 	public void onActivityStopped(Activity activity)
 	{
-		if (activityCount == 1 && tiApp != null && tiApp.isAnalyticsEnabled()) {
-			APSAnalytics.getInstance().sendAppBackgroundEvent();
+		// If this is the last activity being stopped, then the app is going to be put into the background.
+		if (this.visibleActivityCount == 1) {
+			// Flag that we've been paused at least once for this UI task.
+			this.wasPaused = true;
+
+			// Fire Ti.App pause events.
+			KrollModule appModule = this.tiApp.getModuleByName("App");
+			if (appModule != null) {
+				appModule.fireEvent(TiC.EVENT_PAUSE, null);
+				appModule.fireEvent(TiC.EVENT_PAUSED, null);
+			}
+
+			// Post analytics for this event, if enabled.
+			if (this.tiApp.isAnalyticsEnabled()) {
+				APSAnalytics.getInstance().sendAppBackgroundEvent();
+			}
+		}
+
+		// Decrement count of started/visible activities.
+		this.visibleActivityCount--;
+		if (this.visibleActivityCount < 0) {
+			this.visibleActivityCount = 0;
 		}
-		activityCount--;
 	}
 
 	@Override
@@ -62,5 +109,10 @@ public void onActivitySaveInstanceState(Activity activity, Bundle outState)
 	@Override
 	public void onActivityDestroyed(Activity activity)
 	{
+		// Decrement total activity count.
+		this.existingActivityCount--;
+		if (this.existingActivityCount < 0) {
+			this.existingActivityCount = 0;
+		}
 	}
 }

android/titanium/src/java/org/appcelerator/titanium/TiBaseActivity.java

@@ -1375,11 +1375,6 @@ protected void onPause()
 		if (activityProxy != null) {
 			activityProxy.fireEvent(TiC.EVENT_PAUSE, null);
 		}
-		KrollModule appModule = tiApp.getModuleByName("App");
-		if (appModule != null) {
-			appModule.fireEvent(TiC.EVENT_PAUSE, null);
-			appModule.fireEvent(TiC.EVENT_PAUSED, null);
-		}
 
 		synchronized (lifecycleListeners.synchronizedList())
 		{
@@ -1421,11 +1416,6 @@ protected void onResume()
 		if (activityProxy != null) {
 			activityProxy.fireEvent(TiC.EVENT_RESUME, null);
 		}
-		KrollModule appModule = tiApp.getModuleByName("App");
-		if (appModule != null) {
-			appModule.fireEvent(TiC.EVENT_RESUME, null);
-			appModule.fireEvent(TiC.EVENT_RESUMED, null);
-		}
 
 		synchronized (lifecycleListeners.synchronizedList())
 		{

apidoc/Titanium/App/App.yml

@@ -200,7 +200,8 @@ events:
         Note that calls to functions that modify the UI during this event may be partially executed,
         **up to** the UI call before the suspension. See [paused](Titanium.App.paused) event. If this happens, the remainder of the code will
         be executed after the application is resumed, but before the `resume` event is triggered.
-    platforms: [iphone, ipad]
+    platforms: [android, iphone, ipad]
+    since: {android: "7.5.0", iphone: "0.8", ipad: "0.8"}
 
   - name: paused
     summary: Fired when the application transitions to the background on a multitasked system.
@@ -214,8 +215,8 @@ events:
         [Monitoring Application State Changes](https://developer.apple.com/documentation/uikit/uiapplicationdelegate/1622997-applicationdidenterbackground?language=objc)
         for the exact behavior that triggers this event.
 
-    platforms: [iphone, ipad]
-    since: '2.1.0'
+    platforms: [android, iphone, ipad]
+    since: {android: "7.5.0", iphone: "2.1.0", ipad: "2.1.0"}
 
   - name: proximity
     summary: Fired when the proximity sensor changes state.
@@ -280,7 +281,8 @@ events:
         See the `applicationWillEnterForeground` section of the official Apple documentation about
         [Monitoring Application State Changes](https://developer.apple.com/documentation/uikit/uiapplicationdelegate/1623076-applicationwillenterforeground)
         for the exact behavior that triggers this event.
-    platforms: [iphone, ipad]
+    platforms: [android, iphone, ipad]
+    since: {android: "7.5.0", iphone: "0.8", ipad: "0.8"}
 
   - name: resumed
     summary: Fired when the application returns to the foreground.
@@ -296,7 +298,8 @@ events:
         Note: This event will not be fired for URL's in iOS 10+ that are handled by the <Modules.SafariDialog>
         or <Titanium.UI.WebView>, because Apple does not call the `applicationDidBecomeActive` for
         URL-handling anymore. Instead, use the `handleurl` event in <Titanium.App.iOS>.
-    platforms: [iphone, ipad]
+    platforms: [android, iphone, ipad]
+    since: {android: "7.5.0", iphone: "0.8", ipad: "0.8"}
 
   - name: started
     summary: Fired after the "app.js" or "alloy.js" gets executed during application startup.

tests/Resources/ti.app.addontest.js

@@ -0,0 +1,54 @@
+/*
+ * Appcelerator Titanium Mobile
+ * Copyright (c) 2011-Present by Appcelerator, Inc. All Rights Reserved.
+ * Licensed under the terms of the Apache Public License
+ * Please see the LICENSE included with this distribution for details.
+ */
+/* eslint-env mocha */
+/* global Ti */
+/* eslint no-unused-expressions: "off" */
+'use strict';
+var should = require('./utilities/assertions');
+
+describe('Titanium.App', function () {
+	it.android('pause/resume events', function (finish) {
+		this.timeout(5000);
+		let wasPauseEventReceived = false;
+		let wasResumeEventReceived = false;
+
+		// Handle Ti.App pause/resume events. They happen when app is sent to background/foreground.
+		// - "pause" event must be received before "paused" event.
+		// - "resume" event must be received before "resumed" event.
+		Ti.App.addEventListener('pause', function pauseEventHandler(e) {
+			Ti.API.info('Received event: ' + e.type);
+			Ti.App.removeEventListener(e.type, pauseEventHandler);
+			wasPauseEventReceived = true;
+		});
+		Ti.App.addEventListener('paused', function pausedEventHandler(e) {
+			Ti.API.info('Received event: ' + e.type);
+			Ti.App.removeEventListener(e.type, pausedEventHandler);
+			should(wasPauseEventReceived).be.true;
+			Ti.Android.currentActivity.startActivity(Ti.App.Android.launchIntent); // Resume this app.
+		});
+		Ti.App.addEventListener('resume', function resumeEventHandler(e) {
+			Ti.API.info('Received event: ' + e.type);
+			Ti.App.removeEventListener(e.type, resumeEventHandler);
+			wasResumeEventReceived = true;
+		});
+		Ti.App.addEventListener('resumed', function resumedEventHandler(e) {
+			Ti.API.info('Received event: ' + e.type);
+			Ti.App.removeEventListener(e.type, resumedEventHandler);
+			should(wasResumeEventReceived).be.true;
+			finish();
+		});
+
+		// Navigate to the device's home screen. Equivalent to pressing the "home" button.
+		// This should fire this app's "pause" and "paused" events.
+		const homeIntent = Ti.Android.createIntent({
+			action: Ti.Android.ACTION_MAIN,
+		});
+		homeIntent.addCategory(Ti.Android.CATEGORY_HOME);
+		homeIntent.setFlags(Ti.Android.FLAG_ACTIVITY_NEW_TASK);
+		Ti.Android.currentActivity.startActivity(homeIntent);
+	});
+});