Help with PROXIMITY_SCREEN_OFF_WAKE_LOCK in Android

Question

I've enabled the proximity wakelock in my app, and it turns off the screen when the proximity sensor detects something. But there is a problem when the screen wakes back up -- it goes to the lockscreen, not my app. This happens regardless of the time that the screen was off (even if the sensor is cleared after a few seconds). Here's the code I used:

int PROXIMITY_SCREEN_OFF_WAKE_LOCK = 32;    
mProximityWakeLock = pm.newWakeLock(PROXIMITY_SCREEN_OFF_WAKE_LOCK, LOG_TAG);
if(!mProximityWakeLock.isHeld()){
    mProximityWakeLock.acquire();
}

Is there any way to correct that behavior?

Answer 1

You can dismiss the lock screen, if it is not a secure one, using:

getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);

You can either call it on creation to prevent the lock screen from ever appearing or when you need to. I use it in combination with:

getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

Which does not seem to interfere with the proximity lock.

Answer 2

I use this code

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");
        }
    }

}

In the manifest:

<uses-permission android:name="android.permission.WAKE_LOCK" />

In my layout:

<?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.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>