UnregisterListener does not work with PROXIMITY_SCREEN_OFF_WAKE_LOCK

Question

I have this code

public class MainActivity extends AppCompatActivity implements SensorEventListener { private SensorManager mSensorManager; private Sensor mProximity; private PowerManager mPowerManager; private PowerManager.WakeLock mWakeLock; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE); mProximity = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY); mPowerManager = (PowerManager) getSystemService(Context.POWER_SERVICE); } @Override protected void onResume() { super.onResume(); mSensorManager.registerListener(this, mProximity, SensorManager.SENSOR_DELAY_NORMAL); } @Override protected void onPause() { super.onPause(); mSensorManager.unregisterListener(this); } @Override public void onSensorChanged(SensorEvent event) { if (event.sensor.getType() == Sensor.TYPE_PROXIMITY) { if (event.values[0] == 0) { //near Toast.makeText(getApplicationContext(), "near", Toast.LENGTH_SHORT).show(); turnOffScreen(); } else { //far Toast.makeText(getApplicationContext(), "far", Toast.LENGTH_SHORT).show(); turnOnScreen(); } } } @Override public void onAccuracyChanged(Sensor sensor, int accuracy) { } public void turnOffScreen() { mWakeLock = mPowerManager.newWakeLock(PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK, "tag"); mWakeLock.acquire(); } public void turnOnScreen() { mWakeLock = mPowerManager.newWakeLock(PowerManager.SCREEN_BRIGHT_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP, "tag"); mWakeLock.acquire(); } } 

When the application sleeps or switches to another activity, the sensor is still working. Any idea?

Answer 1

I used another way to fix this problem, because no one knows how to fix it, so with this code I do not need to use SensorManager. Now I use two functions to start and stop the sensor, I think this is the only solution.

 import android.content.Context; import android.os.PowerManager; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.Toast; public class MainActivity extends AppCompatActivity { private PowerManager mPowerManager; private PowerManager.WakeLock mWakeLock; private static final String TAG = "MainActivity"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mPowerManager = (PowerManager) getSystemService(Context.POWER_SERVICE); } public void activateSensor(View v) { Toast.makeText(MainActivity.this, "Proximity On", Toast.LENGTH_LONG).show(); if (mWakeLock == null) { mWakeLock = mPowerManager.newWakeLock(PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK, "incall"); } if (!mWakeLock.isHeld()) { Log.d(TAG, "New call active : acquiring incall (CPU only) wake lock"); mWakeLock.acquire(); } else { Log.d(TAG, "New call active while incall (CPU only) wake lock already active"); } } public void deactivateSensor(View v) { Toast.makeText(MainActivity.this, "Proximity Off", Toast.LENGTH_LONG).show(); if (mWakeLock != null && mWakeLock.isHeld()) { mWakeLock.release(); Log.d(TAG, "Last call ended: releasing incall (CPU only) wake lock"); } else { Log.d(TAG, "Last call ended: no incall (CPU only) wake lock were held"); } } } 

And this is my activity_main.xml

  <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.javier.proximitysensor.MainActivity"> <Button android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_above="@+id/activity_main_turn_on_screen" android:onClick="activateSensor" android:text="@string/activity_main_activate_sensor" /> <Button android:id="@+id/activity_main_turn_on_screen" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:onClick="deactivateSensor" android:text="@string/activity_main_deactivate_sensor" /> </RelativeLayout> 

Thanks...

You can also check this example on GitHub

Answer 2

In the source code, you did not manage to correctly set the tracking lock. When your activity is in onStop, unregister your listener and also release the tracking lock.

Answer 3

Use the wakeLock.setReferenceCounted(false) function. I used it and it works.