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Is there possibility to "Auto-start" application when users become inactive?

I have to create an app, which detects user inactivity, and then start activity which displays some videos with WebView, and then when displaying with WebView is finished, it has to play videos from SDCard. I've already handled part with WebView and SDCard (with JavaScriptInterface etc.)
This application has to work with API 19 all the way to the newest one.
The question is - Is there a possibility to detect if user is inactive and start my application, or keep the app running in background, and then start activity in the foreground after the user becomes inactive for certain time?
I'm not trying to play ads, when user is not looking at his screen. Application is for my client, who have stores with all kind of electrical equipments, including smartphones. The goal is to play video presentations with hardware details specific for each smartphone (informations about processor, ram, camera, screen etc.).
In short: I have to make an app which is similar to "Demo Apps" created for example by Samsung (playing some kind of presentations on screen).
So far I've read and tested things like:
1) BroadcastReceiver with combination of ACTION_SCREEN_OFF / ACTION_SCREEN_ON events.
Receiver works properly, I can detect this event and then start activity, but... The screen is already off so i can't see the displayed activity - it's visible running in the foreground after unlocking the phone. Is there a way to unlock the phone when the event is received?
That's my code so far.
EventReceiver Class:
class EventReceiver: BroadcastReceiver() {
override fun onReceive(context: Context, intent: Intent) {
StringBuilder().apply {
append("Action: ${intent.action}\n")
append("URI: ${intent.toUri(Intent.URI_INTENT_SCHEME)}\n")
toString().also { log ->
Log.d(TAG, log)
Toast.makeText(context, log, Toast.LENGTH_LONG).show()
}
}
if (intent.action == Intent.ACTION_SCREEN_OFF) {
val i = Intent(context, MainActivity::class.java)
context.startActivity(i)
}
}
}
MainActivity Class:
val br : BroadcastReceiver = EventReceiver()
val filter = IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION).apply {
addAction(Intent.ACTION_SCREEN_OFF)
addAction(Intent.ACTION_SCREEN_ON)
addAction(Intent.ACTION_BOOT_COMPLETED)
}
2) Foreground Services - I read that this is a great way to make some asyc stuff in the background and show notifications to user. Is there a way to start the activity with it?
3) Job Scheduler
4) Daydream / Dream Service - it actually works great with almost every API and manufacturer, but.. there's no way to set the app as Screen Saver on Huawei/Honor smartphones, at least from phone settings, I've read that this is possible with ADB etc. but this is not an option that I can use here.
It seems that none of these fullfill my expectations.

Android Studio - Using Service to call final() vs. FLAG_ACTIVITY_NEW_TASK

I have been scouting around for a while, but cannot locate any information for calling final() using started services... or rather, when not using bound services. There is tons of info for bound services, but I already have two pretty large "started services" without binding, so I didn't want to modify the existing services more than absolutely necessary.
My app works by reading bluetooth data every 10 seconds, and depending on the data read, the Service will change to a new activity. However, I cannot call final() from my services, so I fear that I might be endlessly stacking activities while the application/services are running.
To change activities, I had to add Intent.FLAG_ACTIVITY_NEW_TASK. Considering the below image/definition from the developer's page, this flag looks like it might already handle my stacking issue? I do NOT allow for users to use the back button on their phones as everything is handled via confirm/cancel buttons and the services. My app MUST be this way for a few reasons. Thus, keeping the stack order isn't important to my application.
Key Points -
I want to ensure i'm not stacking up activities endlessly when starting new activities
Flagging "new task" when starting activities via my services
Stack order is not important to my app
Below is a very small cut of my code with comments to explain what i'm trying to do. Please make sure to look to the onDestroy() method of this service.
public class AlertService extends Service {
final class Threader implements Runnable{
// Scans bluetooth advertisement packets every 10 seconds
// Thread Runs until interrupted
// Stops service via service ID
stopSelf(this.serviceID);
}
#Override
public void onCreate(){
super.onCreate();
}
// Runs a thread until alert is found.
// Alert calls thread.interrupt()
#Override
public int onStartCommand(Intent intent, int flags, int startID){
enableBluetooth();
// Start Thread
thread = new Thread(new Threader(startID));
thread.start();
return START_STICKY;
}
#Override
public void onDestroy(){
thread.interrupt();
Intent alertActivity = new Intent(this, AlertActivity.class)
alertActivity.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(alertActivity);
}
// Unused Method - We will not be binding
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
EDIT via recommendation to use android:taskAffinity -
Using android:taskAffinity won't help me in this situation. By default, all activities in an application have the same affinity. When I create a new task by setting Intent.FLAG_ACTIVITY_NEW_TASK in the intent flags, the new activity will STILL be started in the same task if the activity has the same taskAffinity of the root activity in the task. Since I am just using the default affinity, everything should have the normal stack flow. I just cannot call finish(), which means that I am stacking up tons of activities.

To answer my own question, each new activity called via Intent.FLAG_ACTIVITY_NEW_TASK, was creating a new instance of each activity and putting it on the stack. This is true. However, each activity is NOT making a new Task, which was one of my fears as well.
When I create a new task by setting Intent.FLAG_ACTIVITY_NEW_TASK in the intent flags, the new activity will STILL be started in the same task (not in a new task) if the new activity has the same taskAffinity of the root activity in the task. Since I am just using the default affinity, every activity I create is being put into the same task. This means that nothing is acting any differently than the normal flow of creating activities and such.
Though, since I have disable the back button for my application, these activities created by flagging a new task are not finished, destroyed, or removed from the stack. To solve this, I will use FLAG_ACTIVITY_CLEAR_TOP, which finds a running instance of an activity in the stack (if there is one) and closes all of the activities above it.
Since my application always starts with the home screen, then ends with the home screen, flagging "clear top" will always close all activities above my home screen. So, upon return to the home screen, the only item on the stack will be the home screen.
I will have to test this, but it seems that I will not call finish() from my home activity to achieve this result - Otherwise, upon returning to the home activity, not all of the stack will be cleared.

How do I process broadcasts that were sent while my activity was stopped?

My activity starts a service which runs a CountDownTimer. The timer sends broadcasts back to the activity as it counts down. The activity processes the broadcasts in the onReceive method of a BroadcastReceiver. All of this works fine.
My problem comes when the following events happen in this order:
App is stopped (via onPause())
Timer finishes
App is resumed (via onResume())
When the app is resumed the service is no longer sending broadcasts, so the activity does not know how much time is left on the timer or if it's finished. This prevents the activity from updating the UI.
I've tried a dozen ways of dealing with this, and read through many Stack Overflow questions and answers, but I've yet to find a solution. I would think that there's a way to pick up a broadcast that was sent while the activity was not active, but I've yet to find a way.
For the record, here is my relevant Activity and Service code:
activity.java
// Start service
timerIntent.putExtra("totalLength", totalLength);
this.startService(timerIntent);
// ...
// BroadcastReceiver
private BroadcastReceiver br = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getExtras() != null && inSession) {
session.setRemaining(intent.getExtras().getLong("millisUntilFinished"));
updateProgress();
}
}
};
// ...
// onResume
#Override
public void onResume() {
super.onResume();
registerReceiver(br, new IntentFilter(TimerService.COUNTDOWN_TS));
}
service.java
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
long length = intent.getExtras().getLong("totalLength");
countDownTimer = new CountDownTimer(length, 1000) {
#Override
public void onTick(long millisUntilFinished) {
timerServiceIntent.putExtra("millisUntilFinished", millisUntilFinished);
sendBroadcast(timerServiceIntent);
}
#Override
public void onFinish() {
}
};
countDownTimer.start();
return super.onStartCommand(intent, flags, startId);
}
What's the best way to process the broadcasts that the service sent while the activity was stopped?

Use the BroadcastReceiver to store the last request (SharedPreferences perhaps) it received and check it when the Activity starts.
Alternatively, instead of processing a countdown using broadcasts, just store the time that the countdown would end. The Activity can then handle the countdown all by itself as it knows when it should end. Using a service and broadcasts seem to be a little over-engineered for such a simple task.
Update:
From the way you have described your task, I see you needing to handle 2 scenarios. This is how I would likely do it.
Assuming that "XYZ" is the service\intent\whatever starting the countdown and "ABC" is the Activity displaying the progress. (ABC and XYZ could be the same activity if that is what you wanted)
Requirements:
When the countdown starts, I would make XYZ store the time that the countdown should end in SharedPreferences.
ABC is already running when the countdown starts. As Commonsware said, the Eventbus model is excellent for handling this scenario so long as XYZ and ABC are running in the same process. Just fire an event to read the preference value and count down to the specified time. If the user closes ABC and reopens it, Scenario 2 will kick in.
ABC is not running. Check in OnResume whether the countdown time has elapsed. If not, set up ABC to display the countdown again. If there is no countdown active, do something else.
If you also need to do something when the countdown has elapsed regardless of whether you have a UI active, then again Commonsware's suggestion of AlarmManager is perfect.

Let's pretend for a moment that using a Service with a CountDownTimer to track some passage of time for the purposes of updating an Activity actually is a good idea. It's not out of the question, assuming that the Service is actually doing something for real and this timing thing is some by-product.
An activity does not receive broadcasts while stopped, mostly for performance/battery reasons. Instead, the activity needs to pull in the current status when it starts, then use events (e.g., your current broadcasts) to be informed of changes in the data while it is started.
This would be simplified by using something like greenrobot's EventBus and their sticky events, as the activity would automatically get the last event when it subscribes to get events. Using greenrobot's EventBus for this purpose would also reduce the security and performance issues that you are introducing by your use of system broadcasts to talk between two Java classes in the same process.
Also, please stick with lifecycle pairs. onResume() is not the counterpart to onStop(). onStart() is the counterpart to onStop(); onResume() is the counterpart to onPause(). Initializing something in one pair (e.g., onResume()) and cleaning it up in the other pair (e.g., onStop()) runs the risk of double-initialization or double-cleanup errors.

What's the best way to process the broadcasts that the service sent
while the activity was stopped?
Using sticky broadcast intents from the service and then retrieving them from the activity would be a way to process the broadcasts that the service sent while the activity was stopped. I can only offer that as a possible solution rather than claiming it is the "best way".
http://developer.android.com/reference/android/content/Context.html#sendStickyBroadcast(android.content.Intent)
They have however, been deprecated since API level 21 due to security concerns.

Instead of using Normal broadcast you can use Ordered broadcast (sent with Context.sendOrderedBroadcast). For this along with defining a BroadcastReceiver in your activity you required to define BroadcastReceiver in your manifest with same intentfilter. Only change is while registering BroadcastReceiver in your activity you need to set priority to high, so that when your activity is running and activity's BroadcastReceiver is registered it gets called first, and inside onReceive of this BroadcastReceiver you can use abortBroadcast for getting the BroadcastReceiver called which is defined in your android manifest. Now when your activity is not running the BroadcastReceiver defined in your android manifest will get called. So this way you can have the status and if you wish you can display updates to user by notification even if your activity is not running.

Close app after some time in background

I'm looking for a way to close an android app after some time while the app has not been in focus. For example if the user open up an other app instead, the app should exit after 5 mins. I have tried using runnable and creating a thread. But those method don't seems to work while the app is in the background (maybe they are pause I'm not sure). So how do I close the app when it is not in focus?
For those who are wonder the reason I want to do this is that the app contains some sensitives data about the user so I want to be sure it is all cleared when they aren't using it.

Something like this might work:
A field inside activity class:
private Thread t = null;
Inside onResume():
if(t!=null) {
if(t.isAlive()) {
t.interrupt();
t.join();
}
t=null;
}
Inside onPause():
t = new Thread() {
public void run() {
try {
sleep(5*60*1000);
// Wipe your valuable data here
System.exit(0);
} catch (InterruptedException e) {
return;
}
}.start();
}

I recommend calling finish() in the onPause() or onStop() callbacks. A TimerTask will not survive onPause() and a Service does not appear, on face value, to give you options. Maybe you can start a service, sleep the thread the service runs on, then kill the processes your app has after the sleep timer expires.
Alternatively, you can just implement some security libraries to help secure the data from other apps.
Here is the Google Services link.

Get the process ID of your application, and kill that process onDestroy() method
#Override
public void onDestroy()
{
super.onDestroy();
int id= android.os.Process.myPid();
android.os.Process.killProcess(id);
}
Refer- how to close/stop running application on background android
Edit- Use this with AlarmManager

The fundamental problem with what you're trying to do is that your Activity may not exist in memory at all when it's "running" in the background. The Android framework may have destroyed the activity instance and even the process it was running in. All that exists may be the persistent state you saved in onSaveInstanceState(...) and a screenshot for the recent apps list. There may be nothing for you to get a reference to and kill.
Frank Brenyah's suggestion to call finish() in onPause() will prevent your activity from running in the background at all, but this is the closest you can get to what you want. You probably only want to do this when isChangingConfigurations() is false. But even when all your app's activities are finished, Android may keep the process and Application instance around to avoid recreating them later. So you may also want to use Bhush_techidiot's suggestion of killing the process. Do this in onPause() because the activity may be destroyed without a call to onDestroy().

Android GCM: different way of handling push depending on whether the app is visible or not

I've got a couple of activities and an intent service which handles GCM incoming messages.
Right now for every push, I'm sending a Notification, and after the user clicks it, he is redirected to appropriate screen.
I would like to alter this behavior that if the app is visible (any activity is in the foreground), instead of the notification a dialog message is shown (with appropriate action).
Any idea how to implement it?
I have 2 ideas but none of them is perfect:
Keep track of every activity in the application, if the activity is visible, don't show notification, but sent an intent to the activity (not nice solution)
register/unregister the second broadcast receiver in each activity's onResume/onPause, "catch" the incoming GCM broadcast (I'm not sure if it is possible).
Any other solutions?

A possible solution (idea 1):
To detect whether your app is running back- or foreground, you can simply set a boolean in onPause/onResume:
#Override
protected void onResume() {
super.onResume();
runningOnBackground = false;
}
#Override
protected void onPause() {
super.onPause();
runningOnBackground = true;
}
When you start a new intent from an notification this method gets called: (if you are using singleTop), with the boolean you can determine what to do in the onNewIntent method.
#Override
protected void onNewIntent (Intent intent){
if(runningOnBackground){
//do this
}
else{
//do that
}
}
Hope it helps!

I didn't test it, but the docs say you can get the number of running activities per each task.
Try to find your application's task among currently running tasks:
ActivityManager acitivityManager = (ActivityManager)
context.getSystemService(Context.ACTIVITY_SERVICE);
// Get the top of running tasks, limit by 100
List<RunningTaskInfo> tasks = acitivityManager.getRunningTasks(100);
for (RunningTaskInfo taskInfo : tasks) {
if (YOUR_PACKAGE_NAME.equals(taskInfo.baseActivity.getPackageName())) {
if (taskInfo.numRunning > 0) {
// Show dialog
} else {
// Show notification
}
break;
}
}
Google added a note on getRunningTasks():
Note: this method is only intended for debugging and presenting task management user interfaces. This should never be used for core logic in an application, such as deciding between different behaviors based on the information found here. Such uses are not supported, and will likely break in the future. For example, if multiple applications can be actively running at the same time, assumptions made about the meaning of the data here for purposes of control flow will be incorrect.
So use it at your own risk.
Also check if GCM broadcasts are ordered. If so, you can "override" your default BroadcastReceiver with the other ones in each Activity. Just play with the priority of IntentFilters. When the BroadcastReceiver with higher priority receives the message, it can abort it's further propagation. For your application this means that when some Activity is running, it registers the receiver which shows the dialog and aborts broadcast. If no activity is active, then your default receiver shows the notification.