Develop Reference

To detect the screenlock even when the app is sleeping

I have an android application that needs to be locked (redirect to the login page) whenever the user presses the lock button. The user can lock the phone while on my application or while on other applications/home screen. In both of these scenarios, I need my application to be locked.
This is working fine in case the phone is locked from an application :
#Override
protected void onStop() {
super.onStop();
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
boolean isScreenOn = pm.isInteractive();
if (!isScreenOn) {
LogUtils.logD(TAG, "Screen is off, Locking the application");
// Lock the application code
}
}
But I am not able to figure out the second scenario when the user has moved away from the application and then locks it. I do not want to start a service or any background thread for this purpose.

Try to add else and return at the end of the code so the activity will still awake in background process
#Override
protected void onStop() {
super.onStop();
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
boolean isScreenOn = pm.isInteractive();
if (!isScreenOn) {
LogUtils.logD(TAG, "Screen is off, Locking the application");
// Lock the application code
} else{
return true;
}

How to wake up Android Wear when it is in sleep mode?

When Android Wear goes to sleep mode (screen dimmed), some parts of my code are not executed. I use Timer in background service to trigger some actions, such as sending data from wear to mobile, but the data is not sent. It is sent when I tap the screen to wake it up.
I also try to use Timer trigger a notification with vibration when the screen is off, but it doesn't appear until I tap the screen.
In debug mode (either Bluetooth or USB), data sending and notification work fine.
I suspect this is because when Android Wear is in sleep mode, its CPU works at minimum level because the Timer is still running, but not for GoogleApiClient, IntentService, or Notification.
I have tried many ways to wake CPU up such as AlarmManager, PowerManager, Wakelock, but it did not work for Android Wear.
Anyone has encountered this problem? What is the solution?

I'm using PowerManger to wakeup my wearable device each time i receive message from handled device.
Do not forget to release PowerManager.WakeLock
public abstract class WatchFaceActivity extends Activity {
private PowerManager.WakeLock mWakeLock;
private Handler mWakeLockHandler;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_clock_watch_face);
PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
mWakeLock = powerManager.newWakeLock((PowerManager.SCREEN_BRIGHT_WAKE_LOCK | PowerManager.FULL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP), "MyWakelockTag");
mWakeLockHandler = new Handler();
IntentFilter messageFilter = new IntentFilter("message-forwarded-from-data-layer");
MessageReceiver messageReceiver = new MessageReceiver();
LocalBroadcastManager.getInstance(this).registerReceiver(messageReceiver, messageFilter);
}
public class MessageReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (!mWakeLock.isHeld()) {
mWakeLock.acquire();
}
mWakeLockHandler.removeCallbacksAndMessages(null);
mWakeLockHandler.postDelayed(mReleaseRunnable, 5000);
}
}
private Runnable mReleaseRunnable = new Runnable() {
#Override
public void run() {
mWakeLock.release();
}
};
#Override
protected void onDestroy() {
super.onDestroy();
mWakeLockHandler.removeCallbacksAndMessages(null);
mWakeLock.release();
}
}
And allow WAKE_UP permission in your Manifest.
<uses-permission android:name="android.permission.WAKE_LOCK" />

You should use AlarmManager along with WakefulBroadcastReceiver and startWakefulService(). See this working solution.
You may find answers for your further questions in chat history on that post here.This is the only solution worked for our app.
#SeaDog is successful in making http calls when device in deep sleep mode with this solution. Try it.

Application is being killed while on background

My application sends gps updates to a API. I need my application to run in background all the time. But unfortunately, my application always end at some point while on background. I have read that when the cpu usage of the application is low, the application is will be killed automatically. I don't want this to happen. I already included a partial wake lock on my onCreate method in my application using this code:
powerManager = (PowerManager) getSystemService(Context.POWER_SERVICE);
wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "MyWakeLock");
Then on pause:
protected void onPause()
{
super.onPause();
onBackground = true;
wakeLock.acquire();
Log.w("OnPause", "OnPause");
}
I really don't know how to prevent my application being killed. I also tried using full wake lock but it is deprecated. Any ideas on how will I keep my application alive on background? I never want my application to be killed while on background. Thanks!

You can not.
Just make sure, you persist anything that should survive after being killed.
For anything that should run in background, even if the app is not shown to the user:
Use a Service and set it into foreground mode.

public class BGService extends Service {
private PowerManager powerManager;
private WakeLock wakeLock;
#Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
powerManager = (PowerManager) getSystemService(Context.POWER_SERVICE);
wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
"MyWakeLock");
wakeLock.acquire();
}
call and start service in your main activity
public class SendSMSActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.demo);
startService(new Intent(this, BGService.class));
}
}

Android: Wake & unlock phone

I am trying to figure out how to wake and unlock the phone with a service. I have been referring to this post but, I can't figure out why it isn't working. This is the code that I have so far:
public class WakephoneActivity extends Activity {
BroadcastReceiver mReceiver;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Log.v(TAG, "Screen OFF onReceive()");
screenOFFHandler.sendEmptyMessageDelayed(0, 2000);
}
};
}
private Handler screenOFFHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
// do something
// wake up phone
// Log.i(TAG, "ake up the phone and disable keyguard");
PowerManager powerManager = (PowerManager) WakephoneActivity.this
.getSystemService(Context.POWER_SERVICE);
long l = SystemClock.uptimeMillis();
powerManager.userActivity(l, false);// false will bring the screen
// back as bright as it was, true - will dim it
}
};
protected void onResume() {
super.onResume();
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
registerReceiver(mReceiver, filter);
// Log.i(TAG, "broadcast receiver registered!");
}
}
I have added the code in the manifest as well. Any ideas?

Use this code below in your service.
PowerManager pm = (PowerManager) getApplicationContext().getSystemService(Context.POWER_SERVICE);
mWakeLock = pm.newWakeLock((PowerManager.SCREEN_DIM_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP), "YourServie");
mWakeLock.acquire();
[...]
mWakeLock.release();
If you want to unlock the screen as well, register a receiver in your service that monitors if the screen is turned on/off and if it is turned off and you want to unlock the phone, start an activity with this code in onCreate:
Window window = getWindow();
window.addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
this.finish();
return;
I know, this is a rather dirty, but as far as I know, there is no other way of unlocking the lockscreen (and this will only work if there are no passwords etc set, so it must be the normal "slide to unlock" screen).
And don't forget to add android.permission.WAKE_LOCK ;-)
/edit: I just saw you are already using an Activity. If you have one and don't need the service at all, just put this code into the activity.

For the service to be allways active you need to have this permission on manifest:
<uses-permission android:name="android.permission.WAKE_LOCK" />
Another thing you need to do is to adquire a WakeLock. Without it the service will end passed some time. You can do it like this:
getApplicationContext();
PowerManager pm = (PowerManager)getApplicationContext().getSystemService(Context.POWER_SERVICE);
WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
wl.acquire();
You might need to change PowerManager.PARTIAL_WAKE_LOCK to the one that you need. You can see info about that here.

There is WakefulBroadcastReceiver which does this for you. Example use:
import android.content.Context;
import android.content.Intent;
import android.os.SystemClock;
import android.support.v4.content.WakefulBroadcastReceiver;
import android.util.Log;
public class SimpleWakefulReceiver extends WakefulBroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// This is the Intent to deliver to our service.
Intent service = new Intent(context, SimpleWakefulService.class);
// Start the service, keeping the device awake while it is launching.
Log.i("SimpleWakefulReceiver", "Starting service # " + SystemClock.elapsedRealtime());
startWakefulService(context, service);
}
}
After completing the action in the service, call SimpleWakefulReceiver.completeWakefulIntent(intent) to release the wake lock.
(as #Force already gave you the details about the wakeLock, they need not be repeated here ;-)
Mind that the class is deprecated from api level 26.1.0, reference here

How can I tell if the screen is on in android?

In Android 2.2 (Level 7) the function PowerManager.IsScreenOn() returns a boolean that is true if the screen is turned on and false if the screen is turned off. I am developing code for Android 1.5 (Level 3). How do I accomplish the same task in older versions of Android?
I do not want to turn the screen on or off in my code. I just want to know what it is.

There's a better way than using BroadcastReceivers:
// If you use API20 or more:
DisplayManager dm = (DisplayManager) context.getSystemService(Context.DISPLAY_SERVICE);
for (Display display : dm.getDisplays()) {
if (display.getState() != Display.STATE_OFF) {
return true;
}
}
return false;
// If you use less than API20:
PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
if (powerManager.isScreenOn()){ return true; }
Note that Display.getState() can also return STATE_DOZE and STATE_DOZE_SUSPEND which means that the screen is on in an special way. More info on Display.getState() and his return values here: http://developer.android.com/reference/android/view/Display.html#getState()
Also note that although official documentation recommends using isInteractive() instead of isScreenOn(), if you really want to know the status of the screen, Display.getState() is a better option because of the 'special' conditions that sets the screen on while the device is not interactive.

This is how you should do it:
PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
boolean result= VERSION.SDK_INT>=VERSION_CODES.KITKAT_WATCH&&powerManager.isInteractive()||VERSION.SDK_INT<VERSION_CODES.KITKAT_WATCH&&powerManager.isScreenOn();
return result;

I'm using the following function:
public boolean isInteractive() {
PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
return Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT_WATCH
? powerManager.isInteractive()
: powerManager.isScreenOn();
}

You can accomplish this by setting up broadcast receivers for ACTION_SCREEN_ON and ACTION_SCREEN_OFF.

I'm posting this because on a HUAWAI Prism II Android 4.1.1 (API 16) device the game I'm working on had the following annoying behavior:
I'm displaying my main menu which has some animation in a SurfaceView and plays a sound once in a while.
The device goes idle, dims, and then goes dark.
It calls onDestroy on my Activity, and then while the screen is off creates my Activity again, calling onCreate!
So the problem is my animations and sounds are playing while the screen is off. What I really want to happen is for my animation loop to not run at all if the screen is off. Broadcast receivers don't work because I can't store the state from the last time the screen went off. I thought about some hacks involving static booleans but it just seemed like a kluge that may not work and have horrible edge cases. The screen is already off when my Activity is created again, so I won't get an event through the broadcast receiver that my screen is off.
I solved this using both a broadcast receiver and the code listed above.
In my onCreate, I create the broadcast receiver. This will control my animation loop when the screen turns on and off.
if (mScreenReceiver == null) {
mScreenIntentFilter = new IntentFilter(Intent.ACTION_SCREEN_ON);
mScreenIntentFilter.addAction(Intent.ACTION_SCREEN_OFF);
mScreenReceiver = new ScreenReceiver();
registerReceiver(mScreenReceiver, mScreenIntentFilter);
}
public class ScreenReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
controlAnimLoop(false, false, true);
} else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
controlAnimLoop(false, false, false);
}
}
}
In my controlAnimLoop, I check isScreenOn, which is this code:
private boolean isScreenOn() {
if (android.os.Build.VERSION.SDK_INT >= 20) {
// I'm counting
// STATE_DOZE, STATE_OFF, STATE_DOZE_SUSPENDED
// all as "OFF"
DisplayManager dm = (DisplayManager) getSystemService(Context.DISPLAY_SERVICE);
for (Display display : dm.getDisplays ()) {
if (display.getState () == Display.STATE_ON ||
display.getState () == Display.STATE_UNKNOWN) {
return true;
}
}
return false;
}
PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
return powerManager.isScreenOn();
}

MainActivity.Java
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_HEADSET_PLUG);
filter.addAction(Intent.ACTION_POWER_CONNECTED);
filter.addAction(Intent.ACTION_POWER_DISCONNECTED);
filter.addAction(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
registerReceiver(new MyReceiver(), filter);
}
}
MyReciever.Java
public class MyReceiver extends BroadcastReceiver {
MainActivity mActivity;
#Override
public void onReceive(Context arg0, Intent arg1) {
mActivity = (MainActivity) arg0;
TextView tv = (TextView)mActivity.findViewById(R.id.textView1);
if(arg1.getAction().equals(Intent.ACTION_HEADSET_PLUG)) {
tv.setText("Headset Plugin ");
} else if(arg1.getAction().equals(Intent.ACTION_POWER_CONNECTED)) {
tv.setText("Power Connected ");
} else if(arg1.getAction().equals(Intent.ACTION_POWER_DISCONNECTED)) {
tv.setText("Power Disconnected ");
} else if(arg1.getAction().equals(Intent.ACTION_SCREEN_ON)) {
tv.setText("Screen ON ");
} else if(arg1.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
tv.setText("Screen OFF ");
}
}
}