Question

I’m using handler to repeatedly prompt user for an input every e.g. 5 minutes. When the device goes into sleeping mode and screen is locked, how can I wake the device up when my app prompts user for input? I’ve tried this but it doesn’t seem to work. I’ve added WAKE_LOCKpermission in the manifest.

class BtHandler extends Handler {
    private PowerManager pm;
    private WakeLock wl;

    @Override
    public void handleMessage(Message msg) {
        pm = (PowerManager)FixedNode.this.getSystemService(Context.POWER_SERVICE);
        if (!pm.isScreenOn()) {
            wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK, "TAG");
            wl.acquire();
        }
        FixedNode.this.setAlwaysDiscoverable();
        wl.release();
    }
}

Any ideas?

Edit: Using AlarmManagerto broadcast custom intent.

mReceiver = new BroadcastReceiver() {

    @Override
    public void onReceive(Context context, Intent intent) {
        Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
        v.vibrate(300);
        PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
        KeyguardManager km = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE);
        WakeLock wl = null;

        if (!pm.isScreenOn()) {
            KeyguardLock kl = km.newKeyguardLock("TAG");
            kl.disableKeyguard();
            wl = pm.newWakeLock(
                PowerManager.SCREEN_BRIGHT_WAKE_LOCK | 
                PowerManager.ACQUIRE_CAUSES_WAKEUP, "TAG");
            wl.acquire();
        }

        Toast.makeText(context, "Alarm worked", Toast.LENGTH_LONG).show();
        wl.release();
    }
};

mFilter = new IntentFilter(ACTION_NAME);

Intent mIntent = new Intent(ACTION_NAME);        
PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, mIntent, 0);
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + (120 * 1000), pendingIntent);
Toast.makeText(this, "Alarm set", Toast.LENGTH_LONG).show();

Answer 1

Normally wakelock doesnt actual turn on the screen. So you should get the wake lock with

ACQUIRE_CAUSES_WAKEUP

as an additional flag.