fix(android): Ti.App wrongly fires pause/resume events when opening/closing child windows

[jquick-axway]

JIRA:
https://jira.appcelerator.org/browse/TIMOB-26746

Summary:

• Now only fires "pause" and "paused" event when app is backgrounded, like iOS.
• Now only fires "resume" and "resumed event when app is put into the foreground (including app startup), like iOS.
• Updated Ti.App docs to indicate Android supported these events since 7.5.0.
• We can't use Google's ProcessLifecycleOwner Java classes until the Titanium SDK can be built with gradle. This is because we need to use Google's lifecycle compiler JAR to handle its annotations. (Alternatively, we compile with Java 8, but then we could have a potential min Android OS version issue.)

Test:

1. Build and run the below code on Android.
2. Tap the "Open Child" button.
3. Observe log and verify that you do NOT see any pause/resume events.
4. Press the "Home" button to put app in the background.
5. Observe log and verify that you do see "pause" and "paused" events.
6. Resume the app.
7. Observe log and verify that you do see "resume" and "resumed" events.
8. Tap on the "Close Child" button.
9. Observe log and verify that you do NOT see any pause/resume events.

function appEventHandler(e) {
	Ti.API.info("@@@ '" + e.type + "' event received.");
	if (Ti.App.Android || Ti.App.Windows) {
		Ti.UI.createNotification({
			message: e.type,
			duration: Ti.UI.NOTIFICATION_DURATION_SHORT,
		}).show();
	}
}

Ti.App.addEventListener("resume", appEventHandler);
Ti.App.addEventListener("resumed", appEventHandler);
Ti.App.addEventListener("pause", appEventHandler);
Ti.App.addEventListener("paused", appEventHandler);
Ti.App.addEventListener("close", appEventHandler);

var rootWindow = Ti.UI.createWindow({ title: "Parent Window" });
var openButton = Ti.UI.createButton({ title: "Open Child" });
openButton.addEventListener("click", function() {
	var childWindow = Ti.UI.createWindow({ title: "Child Window" });
	var closeButton = Ti.UI.createButton({ title: "Close Child" });
	closeButton.addEventListener("click", function() {
		childWindow.close();
	});
	childWindow.add(closeButton);
	childWindow.open();
});
rootWindow.add(openButton);
rootWindow.open();

[build]

	Messages
📖	💾 Here's the generated SDK zipfile.
📖	✅ All tests are passing Nice one! All 3631 tests are passing.

Generated by 🚫 dangerJS against ec7c4dc

[garymathews]

Should we also put appModule in TiApplicationLifecycle, so we don't have to grab it each time?

[jquick-axway]

I noticed that we add a new "App" module instance every time a new JavaScript runtime gets created (ie: back-out of the app and relaunch).

[garymathews]

CR: PASS

[jquick-axway]

I was verbally told that iOS fires a "pause" event when an alert gets displayed. I'm going to double check. (Not sure if I agree with this behavior, but app devs might be designing around this.)

Edit:
I tested iOS' behavior with alert dialogs and option dialogs. iOS does not fire a pause event when dialogs are displayed. So, this PR is fine and in parity with iOS.

[ssekhri]

The 'resume' and 'resumed' events are fired on app launch, and app foreground. They do not get fired when a window is opened.
The 'pause' and 'paused' events are fired on app background only. They do not get fired on window close.

However there is a slight difference between android and iOS related to events fired during app launch. On iOS only 'resumed' event is fired whereas for android both 'resume' and 'resumed' events are fired.

[jquick-axway]

Update PR so that a "resume" event only gets fired after a "pause" event (like iOS).

You will no longer see a "resume" event on app startup... but you will still see a "resumed" event (with a 'd') on app startup.

[hansemannn]

Can this be merged soon? I see the PR is approved since a while. Thx!

[ssekhri]

FR Passed.
The 'resumed' event is fired on app launch, and 'resume', 'resumed' events are fired on app foreground. They do not get fired when a window is opened.
The 'pause' and 'paused' events are fired on app background only. They do not get fired on window close.
Test Env:
Mac OS 10.14.3
Ti SDK: 8.1.0.v20190320134035
Appc CLI: 7.0.10
Node: 8.12.0
JDK: 9.0.4
Studio: 5.1.2.201903111843
Android Device: Pixel(v9.0), Nexus6 Emulator(v6.0)