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Can't perform action on locking/turning off screen using onPause

I've implemented something similar to Android notification of screen off/on, but it's not working the way it should. All I want to do is stop music when the screen is turned off. I created a screen action class like this
public class ScreenAction extends BroadcastReceiver {
public static boolean wasScreenOn = true;
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
// DO WHATEVER YOU NEED TO DO HERE
wasScreenOn = false;
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
// AND DO WHATEVER YOU NEED TO DO HERE
wasScreenOn = true;
}
}
}
Then, in my main activities on create I have this
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
BroadcastReceiver mReceiver = new ScreenAction();
registerReceiver(mReceiver, filter);
In my main activities onPause, I have something like this:
public void onPause() {
super.onPause();
if (ScreenAction.wasScreenOn) {
final MediaPlayer mp = MediaPlayer.create(this, R.raw.pcmouseclick1);
mp.setVolume(.1f, .1f);
mp.start();
if (buttonState) {
mServ.reduceVolume();
}
}
}
I found this from an online source, but I am having issues. It seems that the screen state is always set as true, and I'm not sure how to change this.
How do I utilize this ScreenAction class to turn off music in on Pause ONLY when the user has locked the screen? I feel like I am missing something in the onPause because in onCreate I link to the class.

#Override
protected void onPause() {
// when the screen is about to turn off
// or when user is switching to another application
super.onPause();
}
#Override
protected void onResume() {
// only when screen turns on
// or when user returns to application
super.onResume();
}
Here you can see the entire lifecycle of an Activity in android:
Activity Lifecycle

Maybe you could also start and stop your music directly from the receiver:
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
// Pause music player
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
// Resume music player
}
}

You're checking ScreenAction.wasScreenOn in onPause, but that's happening before the BroadcastReceiver is called to notify you that the screen is being turned off. So at that point, ScreenAction.wasScreenOn is still true, and then it's set to false, but onPause has already run, so your music never gets paused.
To solve this, you should take the action directly in response to the screen turning off in the BroadcastReceiver. If you need to interact with your UI, consider a solution like LiveData as an abstraction so that you're not reliant on your Activity being paused at the exact moment the screen is turned off (consider also that the onPause solution wouldn't work if your Activity weren't currently visible).

Start a one-time sound when app starts [duplicate]

I'd like to implement an update checker in an application, and I obviously only need this to show up once when you start the application. If I do the call in the onCreate() or onStart() method, it'll be shown every time the activity is created and this is not a viable solution.
So my question is: Is there a way to do something, like check for updates, just once per application start / launch?
I'm sorry if it's a bit hard to understand, I'm having difficulties explaning myself on this one.

SharedPreferences seems like ugly solution to me. It's much more neat when you use application constructor for such purposes.
All you need is to use your own Application class, not default one.
public class MyApp extends Application {
public MyApp() {
// this method fires only once per application start.
// getApplicationContext returns null here
Log.i("main", "Constructor fired");
}
#Override
public void onCreate() {
super.onCreate();
// this method fires once as well as constructor
// but also application has context here
Log.i("main", "onCreate fired");
}
}
Then you should register this class as your application class inside AndroidManifest.xml
<application android:label="#string/app_name" android:name=".MyApp"> <------- here
<activity android:name="MyActivity"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
You even can press Back button, so application go to background, and will not waste your processor resources, only memory resource, and then you can launch it again and constructor still not fire since application was not finished yet.
You can clear memory in Task Manager, so all applications will be closed and then relaunch your application to make sure that your initialization code fire again.

looks like you might have to do something like this
PackageInfo info = getPackageManager().getPackageInfo(PACKAGE_NAME, 0);
int currentVersion = info.versionCode;
this.versionName = info.versionName;
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
int lastVersion = prefs.getInt("version_code", 0);
if (currentVersion > lastVersion) {
prefs.edit().putInt("version_code", currentVersion).commit();
// do the activity that u would like to do once here.
}
You can do this every time, to check if the app has been upgraded, so it runs only once for app upgrade

The shared preferences approach is messy, and the application class has no access to an activity.
Another alternative I've used is to have a retained fragment instance, and within that instance, a lot more stuff can be done especially if you need access to the main activity UI.
For this example, I've used asynctask within the retained fragment. My AsyncTask has callbacks to the parent activity. It is guaranteed to run only once per application because the fragment is never destroyed-recreated when the same activity is destroyed-recreated. It is a retained fragment.
public class StartupTaskFragment extends Fragment {
public interface Callbacks {
void onPreExecute();
void onProgressUpdate(int percent);
void onCancelled();
void onPostExecute();
}
public static final String TAG = "startup_task_fragment";
private Callbacks mCallbacks;
private StartupTask mTask;
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
mCallbacks = (Callbacks) activity;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRetainInstance(true); // this keeps fragment in memory even if parent activity is destroyed
mTask = new StartupTask();
mTask.execute();
}
#Override
public void onDetach() {
super.onDetach();
mCallbacks = null;
}
private class StartupTask extends AsyncTask<Void, Integer, Void> {
#Override
protected void onPreExecute() {
if (mCallbacks != null) {
mCallbacks.onPreExecute();
}
}
#Override
protected Void doInBackground(Void... ignore) {
// do stuff here
return null;
}
#Override
protected void onProgressUpdate(Integer... percent) {
if (mCallbacks != null) {
mCallbacks.onProgressUpdate(percent[0]);
}
}
#Override
protected void onCancelled() {
if (mCallbacks != null) {
mCallbacks.onCancelled();
}
}
#Override
protected void onPostExecute(Void ignore) {
if (mCallbacks != null) {
mCallbacks.onPostExecute();
}
}
}
}
Then, in main (or parent) activity where you want this startup task fragment to run once.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
FragmentManager fm = getFragmentManager();
StartupTaskFragment st = (StartupTaskFragment) fm.findFragmentByTag(StartupTaskFragment.TAG);
if(st == null) {
fm.beginTransaction().add(mStartupTaskFragment = new StartupTaskFragment(), StartupTaskFragment.TAG).commit();
}
...
}
Ideas for retained fragment came from here: http://www.androiddesignpatterns.com/2013/04/retaining-objects-across-config-changes.html. I just figured out its other uses aside from config changes.

Yes you can do it Using SharedPrefernce concept of android. Just create a boolean flag and save it in SharedPrefernce and check its value in your onCreate() method .

SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
if (!prefs.getBoolean("onlyonce", false)) {
// <---- run your one time code here
// mark once runned.
SharedPreferences.Editor editor = prefs.edit();
editor.putBoolean("onlyonce", true);
editor.commit();
}
}

This continues on #Vitalii's answer.
After having setup the Application class, if access to the Activity is required, we can use the aptly named android library "Once" https://github.com/jonfinerty/Once.
In the Application class's onCreate method
Once.initialise(this)
In the Activity / Fragment class's onCreate / onViewCreated method.
val helloTag = "hello"
if (!Once.beenDone(Once.THIS_APP_SESSION, helloTag)) {
//Do something that needs to be done only once
Once.markDone(helloTag) //Mark it done
}

I do this the same way as described in the other answer. I just have a global variable in the first activity which matches the release number from the manifest. I increment it for every upgrade and when the check sees a higher number, it executes the one-time code.
If successful, it writes the new number to shared preferences so it wont do it again until the next upgrade.
Make sure you assign the default to -1 when you retrieve the version from shared preferences so that you error on the side of running the code again as opposed to not running it and not having your app update correctly.

Use SharedPreference for this-
If you are not restarting your launcher activity again once your app is active then in that case you case use it.
Use this in a Splash screen if you are implementing it in the app.
If you are not using any splash screen then you need to create a activity with no view set and on it's oncreate call you can do start updation and start your main activity.
you can use counter value or boolean for this.
Here is SharedPreference doc:
http://developer.android.com/reference/android/content/SharedPreferences.html

try {
boolean firstboot = getSharedPreferences("BOOT_PREF",MODE_PRIVATE)
.getBoolean("firstboot", true);
if(firstboot){
//place your code that will run single time
getSharedPreferences("BOOT_PREF",MODE_PRIVATE).edit().
putBoolean("firstboot", false)
.commit();
}

I just solved doing this myself, I reopen my main activity multiple times throughout the application's execution. While the constructor is a valid approach for some things it doesn't let you access the current Application context to write toasts among other things.
My solution was to create a simple 'firstRun' boolean set to true in the class of my MainActivity, from there I run the contents of the if statement then set it to true. Example:
public class MainActivity extends AppCompatActivity
{
private static boolean firstRun = true;
#Override
protected void onCreate(Bundle savedInstanceState)
{
if(firstRun)
{
Toast.makeText(getApplicationContext(), "FIRST RUN", Toast.LENGTH_SHORT).show();
//YOUR FIRST RUN CODE HERE
}
firstRun = false;
super.onCreate(savedInstanceState);
//THE REST OF YOUR CODE
}

Recurring background task Android - Handler vs AlarmManager

I am working on an application for research purposes. We want to track some user activity on the phone: if some actions are easily detactable with broadcast receivers, we want also to check current running applications.
This application works only on Android devices that runs android 5.0 or lower.
My problem is that I post a Runnable Obj in a handler, Runnable posts again itself in handler after HALF_SECOND (see code for details). In runnable I get information and send them to IntentService to perform work.
Everything works fine: app starts at boot, handler and runnable do their job in background UNLESS I open the main Activity.
The app is able to keep going for days, but if I open the main Activity and then close it from "recent open activities" with a swipe, or from the memory task manager, handler and runnable stop, even if they are not called/accessed by the activity (they are in a Separate Service).
Moreover, not always a call to onDestroy (of the activity or Service) is made.
Reading online I understand that swipe or task manager remove the app from memory abrouptly thus not always calling onDestory.
What I want to achive is to make the handler start again soon after the main activity is closed.
What I have tried is to put some check in onPause method of the activity, making sure to remove this check if onStart is called again (like in case the the app switches from vertical to horizontal layout, or if home button is pressed and then app is opend again). Also implemented a way to make the handler send "ImAlive" intent to a broadcast receiver, which should restart the service that starts the handler, if intents do not arrive before a count down is finished. Unfortunately, as soon the main activty stops existing, even the broadcast is automatically unregistered and destroyed.
My question is, is there a way to create something that is able to make my handler restart if the activity is closed? Or is there some other pattern that can help me as workaround for what I want to achieve? Because I am polling data every half second I read is better to use handler, because Timer augments small interval to a greater interval, and AlarmManager is not precise enough for very small interval.
What I want to achieve is something similar to Facebook, Instagram, Whatsapp, Telegram app, that are always in memory, and even if you force to terminate them, after a few seconds are back again there... how?
We are not interested in battery issues because of continuous polling to data. As for research purposes we don't mind if the phone on which we are testing last 2 days straight, 1 day or 12 hours or less.
Here the code: OnBootService is started from broadcast receiver, declared in manifest when onBootCompleted and ShutDown actions are received, in order to start and stop handler.
public class OnBootService extends Service{
private static final Handler handler = new Handler();
private final long HALF_SEC = 500;
private RunnableTest r = null;
private Context myContext = this;
private final String TAG = "BootService";
// Extras
public static final String START = "start";
public static final String STOP = "stop";
#Override
public IBinder onBind(Intent intent){
return null;
}
#Override
public int onStartCommand(Intent intent, int flag, int startId){
String action = intent.getAction();
switch(action){
case START: startHandler();
break;
case STOP: stopHandler();
break;
}
return START_NOT_STICKY;
}
private void startHandler(){
if(r == null){
r = new RunnableTest();
handler.post(r);
Log.i(TAG, "----Handler started!");
}
}
private void stopHandler(){
if(r != null){
Log.i(TAG, "----calling STOP");
handler.removeCallbacks(r);
r = null;
}
}
private class RunnableTest implements Runnable {
private String TAG = "RunnableTest";
public RunnableTest(){}
#Override
public void run(){
handler.removeCallbacks(this);
// Do stuff
Intent i = new Intent(myContext, MyIntentService.class);
i.putExtra("addStuff", myStuff);
myContext.startService(i);
handler.postDelayed(this, HALF_SEC);
}
}
Activity is empty: all method overridden just to understand proper Activity lifecycle, but else is empty for now.
public class MainActivity extends AppCompatActivity {
private final String TAG = "Activity";
private Context myContext = this;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// access a file and get stored information to show
setContentView(R.layout.activity_main);
Toast.makeText(getBaseContext(), "Application open successfully", Toast.LENGTH_LONG).show();
}
#Override
protected void onRestart(){
super.onRestart();
Log.e(TAG, "----onRestart Called");
}
#Override
protected void onStart(){
super.onStart();
Log.e(TAG, "----onSTART Called");
}
#Override
protected void onResume(){
super.onResume();
Log.e(TAG, "----onRESUME Called");
}
#Override
protected void onPause(){
super.onPause();
Log.e(TAG, "----onPAUSE Called");
}
#Override
protected void onStop(){
super.onStop();
Log.e(TAG, "----onSTOP Called");
}
#Override
protected void onDestroy(){
super.onDestroy();
Log.e(TAG, "----onDestroy Called");
}
}
Any help is really appreciated, if you need some more information on the code, I will update the post.
Thank you!

Android system can restart the service if u return START_STICKY inside onStartCommand().
It works perfectly on all lower version than Lollipop in Android.
No need of CountDownTimer.

Android Wear app running double

I have made the beginning of what will be a pretty cool wear app, for now it is just a metronome that vibrates on the tempo the user selects.
My problem is that when you exit the app or when the screen goes into "ambient mode" the vibration keeps going, which is great, but when you open the app again it opens a new "instance" (or however you say that) of the app so the vibration tempo previously selected keeps vibrating and when you select a new one you basically have 2 tempos vibrating.
Maybe this has something to do with the fact that I use a new Thread for the timing and that Thread keeps running. Is there a way to prevent this? Thank you!
public void buttonTempoOnClick(final View v) {
Running = !Running;
Button button = (Button) v;
Thread Timer = new Thread(new Runnable() {
public void run() {
while (Running == true) {
vibrate(150);
try {
Thread.sleep(60000 / Tempo);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
Timer.start();
(vibrate refers to a void I created in the class, which works.)
public void vibrate(int duration){
Vibrator vibrator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
vibrator.vibrate(duration);
}
Edit: I already have a public boolean Running that is false by default, when the "start' button is pressed it toggles the boolean and starts a new threat with a while(Running == true) loop in it. Stopping the vibration by pressing the button one more time works like a charm.

Try setting a variable in the class managing the thread, like
boolean isTempoOn = true;
In your main activity, in the onResume() function, check if it's already running. If so, don't start again.
Perhaps posting the applicable portion of code will help.

Using the java timer

Until now I have been using the Timer that's in javax.swing.timer - all I had to do was to choose the speed and have a method with a specific name that executes what I want the timer to do every time.
I have now started programming an Android application recently and I have faced a couple of problems...
It wouldn't let me use or import javax.swing.timer
I tried using java.util.timer but I couldnt figure out how it works
All I want my timer for is so I can display my logo for 3 seconds and then proceed to the main menu - even if there is an easier solution for this, I'd still like to know how to use the timer
For the person who told me to try using a thread - here is my code - it doesnt paint the first screen at all, it just stays blank for 3 seconds then moves on to the next line of code...
public class logo extends Activity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try {
setContentView(R.layout.logoview);
Thread.sleep(3000);
}
catch (InterruptedException e){
e.printStackTrace();
}
setContentView(R.layout.main);
}
public void startup (View view){
Intent intent0 = new Intent (this,ExpiramantingActivity.class);
startActivity(intent0);}
}
}

in onCreate() function of your SplashActivity class, schedule a handler to display your main menu activity after 3 seconds. this should be done after setContentView(R.layout.splashscreen);
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
startActivity(new Intent(SplashActivity.this,
YourMainMenuActivity.class));
finish();
}
}, 3000);

I believe that what you are trying to do is similar to the exhibition Splash Screen. If so, please check this Oracle tutorial.

try this:
// logo
Thread timer = new Thread(){
public void run(){
try{
sleep(3000);
} catch (InterruptedException e){
e.printStackTrace();
}
};
};
timer.start();
//next code

Maybe you can use a Thread? I think it's the simplest way to do what you want:
Where you display your logo:
try {
//show your logo here
Thread.sleep(3000); //3 seconds
} catch (InterruptedException e) {
e.printStackTrace();
}
Surrounding the code in a try/catch block is very important, because of the posibility of an Exception.