Develop Reference

Why the Screen didn't wake up when I call acquire in Android?

I am trying to wake the screen when the screen is off (dark).
I create a class like the following code:
public class ScreenWakeLock {
private static PowerManager.WakeLock WakeLock;
#SuppressLint("Wakelock")
static void acquireCpuWakeLock(Context context) {
Log.i("ScreenWakeLock", "acquireCpuWakeLock");
PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
WakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP,"okTag");
WakeLock.acquire();
}
static void releaseCpuLock() {
if (WakeLock != null) {
WakeLock.release();
WakeLock = null;
}
}
}
When the Screen is off , the App call ScreenWakeLock.acquireCpuWakeLock(getActivity());.
But the Screen didn't wake up. I have seen the acquireCpuWakeLock in the log , I am sure the function acquireCpuWakeLock has been called. I also add the <uses-permission android:name="android.permission.WAKE_LOCK" /> in Manifest.xml.
Why the Screen didn't wake up when I call acquire in Android ?
Did I missing something?
Thanks in advance.

Straight from the PowerManager documentation:
In addition, you can add two more flags, which affect behavior of the
screen only. These flags have no effect when combined with a
PARTIAL_WAKE_LOCK.
Use something else instead of PowerManager.PARTIAL_WAKE_LOCK. Try SCREEN_DIM_WAKE_LOCK and see if that's good enough for your use case; if not, try SCREEN_BRIGHT_WAKE_LOCK.

Proximity sensor with wakelock issue: can't turn on screen again

I've been looking around for the last days and none of the answers to the questions made have helped me and I'm bumping my head with something that perhaps is simple to solve .... I want to work with the proximity sensor and what I'm doing is that if I put the finger on the sensor it turns off the screen and if I remove the finger away it turns back on the screen! I'm sucessfully turning off the screen and I'm getting the "Log.i("info", "trying to turn on!")" message when I remove the finger but somehow the screen doesn't turn on .... I've tried with wakelock (commented) and with flags with no sucess! If I remove the finger the lights on the keypad turn on but the screen won't .. If I press the power button two times it turns on the screen sucessfully! Can anyone give me an help with it? :(
#Override
public void onSensorChanged(SensorEvent event) {
if(event.sensor.getType()==Sensor.TYPE_PROXIMITY){
ProximityReading.setText("\nProximity Sensor Reading:" + String.valueOf(event.values[0]));
}
if(event.values[0] == 0) {
WindowManager.LayoutParams params = getWindow().getAttributes();
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
params.screenBrightness = 0f;
getWindow().setAttributes(params);
} else {
WindowManager.LayoutParams params = getWindow().getAttributes();
params.screenBrightness = 1f;
getWindow().setAttributes(params);
/*powermanager = (PowerManager) getSystemService(Context.POWER_SERVICE);
wakeLock = powermanager.newWakeLock(PowerManager.ACQUIRE_CAUSES_WAKEUP, "TAG");
wakeLock.acquire();
Log.i("info", "trying to turn on!");
}
}

if you want turn screen on,you can use the API such as "TurnScreenOn" in PowerManager,or use ACQUIRE_CAUSES_WAKEUP combined with FULL_WAKE_LOCK

I use the following method to unlock the phone,lighten it up and then reenable the keyguard lock.
public void unlockAndPowerup(){
KeyguardManager km = (KeyguardManager) mContext.getSystemService(Context.KEYGUARD_SERVICE);
final KeyguardManager.KeyguardLock kl = km.newKeyguardLock("MyKeyguardLock");
kl.disableKeyguard();
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
WakeLock wakeLock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK
| PowerManager.ACQUIRE_CAUSES_WAKEUP
| PowerManager.ON_AFTER_RELEASE, "MyWakeLock");
wakeLock.acquire();
wakeLock.release();
kl.reenableKeyguard();
}

Your procedure is wrong. It may work on some devices by chance, but that's not the way to do it.
FLAG_TURN_SCREEN_ON is supposed to be applied on the onCreate method of an activity. You need to modify your app logic.
Your screen off technique is incorrect. You're modifying brightness, that's a hacky way, and may not turn off screen at all, and drain battery.
You need to achieve it via Device Admin permission. That's the official way to do it
Locking sample code
public static void lockNow(Context c) {
DevicePolicyManager dpm = (DevicePolicyManager)c.getSystemService(Context.DEVICE_POLICY_SERVICE);
if(dpm.isAdminActive(new ComponentName(c.getApplicationContext(),DeviceAdmin.class)))
dpm.lockNow();
}
DeviceAdmin.java
import android.app.admin.DeviceAdminReceiver;
public class DeviceAdmin extends DeviceAdminReceiver {
}
In the manifest
<receiver
android:name=".admin.DeviceAdmin"
android:permission="android.permission.BIND_DEVICE_ADMIN" >
<meta-data
android:name="android.app.device_admin"
android:resource="#xml/admin" />
<intent-filter>
<action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
</intent-filter>
</receiver>
And asking for Device Admin permission
private void askAdminPerm(){
Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN,
new ComponentName(root.getContext(), DeviceAdmin.class));
intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION, getString(R.string.lock_msg_big));
startActivity(intent);
}

Lock Android Phone after user dials a phone number

I am developing a security application whereby, if a user dials a phone number that is not frequently called and he has never called before, the user will have to reauthenticate himself. For this purpose I want to lock the phone after checking the phone number.
public class outgoingCalls extends BroadcastReceiver {
public void onReceive(Context context, Intent intent) {
Log.v("onReceive", "In onReceive()");
if (confidence == 0) {
Log.v("onReceive","confidence zeroed");
Intent i = new Intent();
i.setClassName("abc.xyz.SECURITY","abc.xyz.SECURITY.lockActivity");
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
}
}
In this new Activity lockActivity, I need to lock the phone where I have commented // LOCK PHONE
public class lockActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.v("lock","lockActivity onCreate method called");
// setContentView(R.layout.main);
Log.v("lock","locking");
// LOCK PHONE
}
}
The phone is not getting locked with the methods I have tried. These include the following:
1. KeyguardManager mgr = (KeyguardManager) getSystemService(Activity.KEYGUARD_SERVICE);
KeyguardLock lock = mgr.newKeyguardLock("edu.Boston.SECURITY.lockActivity");
((KeyguardLock) lock).reenableKeyguard();
2. PowerManager manager = (PowerManager) getSystemService(Context.POWER_SERVICE);
manager.goToSleep(100);//int amountOfTime
3. PowerManager.WakeLock wl = manager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "Tag");
wl.acquire();
wl.release();
4. WindowManager.LayoutParams params = getWindow().getAttributes();
params.screenBrightness = 0;
getWindow().setAttributes(params);
Android manifest file has below permissions
<uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS" />
<uses-permission android:name="android.permission.READ_CONTACTS"/>
<uses-permission android:name="android.permission.DISABLE_KEYGUARD"/>
<uses-permission android:name="android.permission.WAKE_LOCK" />
Why am I not able to lock the phone? Any pointers?
Thanks a lot in advance for your help. Appreciate it!

Try creating a DevicePolicyManager
http://developer.android.com/training/enterprise/device-management-policy.html
and then call:
DevicePolicyManager mDPM = (DevicePolicyManager)context.getSystemService(Context.DEVICE_POLICY_SERVICE);
mDPM.lockNow();

Android Turn screen Off

I can't turn off the screen using this code. I used PowerManager and wl.release() method, but it doesn't work. Can somebody show me an example?
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK, "DoNotDimScreen");
This is part of my function:
stateString = "nextone";
if(stateString=="nextone"){
wl.release();
}
I also added permission in the manifest but no result.

I found the answer over here on stack overflow: Turn off screen on Android
Copied from there:
WindowManager.LayoutParams params = getWindow().getAttributes();
params.flags |= LayoutParams.FLAG_KEEP_SCREEN_ON;
params.screenBrightness = 0;
getWindow().setAttributes(params);
I tried this out and it seems to work.

If you don't use a permission, the program will crash with a SecurityException when it tries to lock, so that isn't the problem. The correct method is: (obtains WakeLock on start, gives it up when the application loses focus (onPause)
//declared globally so both functions can access this
public PowerManager.WakeLock wl;
///////////onCreate
//stop phone from sleeping
PowerManager powman = (PowerManager) getSystemService(Context.POWER_SERVICE);
wl = powman.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK, "NameOfLock");
wl.acquire();
///////////onPause
wl.release();
//////////for completion's sake, onResume
if(!wl.isHeld()){
wl.acquire();
}
However, your problem is actually in this check
if(stateString=="nextone")
This should be if(stateString.equals("nextone"))

please check this link before proceeding with wake lock. if it does not solve your problem then you can proceed with wake lock.
Force Screen On

You can use
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

try
{
Settings.System.putInt(getContentResolver(), Settings.System.SCREEN_OFF_TIMEOUT, 1000*15);
}
catch (NumberFormatException e)
{
Log.e("aa", "could not persist screen timeout setting", e);
}
How to detect switching between user and device

What should I do as power button do (turn off screen, lock keyboard)?

My goal is make same thing as power button do.
I try PARTIAL_WAKE_LOCK and this is my code..
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
wl.acquire();
after that I open WAKE_LOCK permission in AndroidManifest.xml
<uses-permission android:name="android.permission.WAKE_LOCK" />
But when I launch my application not thing happen.
Do I miss something ?
Thanks

From your question I'm not totally sure whether you:
Try to turn off the device by pressing a button
Want to make sure the device will not go to sleep (as this is what a WakeLock is supposed to help you with). It can't prevent user interaction though (just tested on HTC Desire).
For 1) You can't lock the device or turn it's power off without being signed as a system app, as written here: http://groups.google.com/group/android-developers/browse_thread/thread/36399f15724ac3ae/98d93e53616cf495?show_docid=98d93e53616cf495
For 2) You can prevent the device from sleeping using WakeLock, sample code can read like this:
/**
* Called when the activity is first created.
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK, TAG);
}
// Call me from a button
public void doLock(View view) {
Log.d(TAG, "Lock");
if (!wl.isHeld()) {
Log.d(TAG, "acquire");
wl.acquire();
} else {
Log.d(TAG, "release");
wl.release();
}
}