Question

This is a pretty strange problem. I have a book that I have been going through (The Android Developer’s Cookbook)

I am making a pretty basic app (at least, I think it is basic)

The problem I am having is this. When the service I create is stopped, the activity does the service’s work.

I want to monitor the Z Axis reading on my phone (in the background, always)

Here is my project structure:
TiltMonitorActivity
TiltMonitorService

From TiltMonitorActivity:

@Override
        public void onClick(View v) {

            boolean error = false;
            if (tbService.isChecked()) {                    
                try {
                    startService(backgroundService);
                }

                catch (Exception e) {                          
                       error = true;
                }
                finally {
                    if (error)
                    {
                        errorToast();
                    }
                }
            }
            else if (!tbService.isChecked()) {
                try {
                    stopService(backgroundService);
                }

                catch (Exception e){                           
                       error = true;
                }
                finally {
                    if (error)
                    {
                        errorToast();
                    }
                }

            }
        }
});

I also put this in onBackPressed(), onPause, onDestroy

finish();

The intent I create when starting/stopping service

final Intent backgroundService = new Intent(this, TiltMonitorService.class);

From TiltMonitorService:

  import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.IBinder;
import android.os.Vibrator;
import android.widget.Toast;

public class TiltMonitorService extends Service {

    private SensorManager sensorManager = null;

    private Vibrator vibrator = null;

    private float[] accData = new float[3];

    // These are for manual config
    private float FORWARD_THRESHOLD = 5f;
    private float BACKWARD_THRESHOLD = -5f;

    // These are for auto config

    // The phone will face forward, so a positive Z Axis means user is leaning backwards
    // and that a negative Z Axis the user is leaning forward
    private float AUTO_FORWARD_THRESHOLD = -1.5f;
    private float AUTO_BACKWARD_THRESHOLD = 3.5f;

    public static TiltMonitorActivity MAIN_ACTIVITY = null;

    public static void setMainActivity(TiltMonitorActivity activity)
    {
        MAIN_ACTIVITY = activity;
    }

    @Override
    public IBinder onBind(Intent arg0) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();

        sensorManager = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
        vibrator = (Vibrator)getSystemService(Context.VIBRATOR_SERVICE);

        sensorManager.registerListener( tiltListener, 
                                        sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), 
                                        SensorManager.SENSOR_DELAY_NORMAL);

        Toast.makeText(this, "Service created", Toast.LENGTH_LONG).show();

    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Toast.makeText(this, "Service destroyed", Toast.LENGTH_LONG).show();
    }

    private SensorEventListener tiltListener = new SensorEventListener() {

        @Override
        public void onAccuracyChanged(Sensor sensor, int accuracy) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onSensorChanged(SensorEvent event) {
            accData[0] = event.values[0];
            accData[1] = event.values[1];
            accData[2] = event.values[2];

            checkData(accData);

        }

    };

    private void checkData(float[] accData)
    {
        if ((accData[2] < AUTO_FORWARD_THRESHOLD) || (accData[2] > AUTO_BACKWARD_THRESHOLD))
        {
            vibrator.vibrate(100);
        }

    }

    @Override
    public void onStart(Intent intent, int startId) {
        super.onStart(intent, startId);

    }



}

Again, I get the Toast that the service has been started and stopped when hitting the ToggleButton in the activity.

But the task still happens. (Vibrates when below or above set thresholds)

When I open up a task killer, the service isn’t running. Only the activity is (and killing it kills the vibration)

I’m not sure what words to search for, I couldn’t find any one else with the same problem. I tried to post only relevant code in the Activity to avoid clutter. The service is posted in its entirety. If more is needed, I will put it up promptly.

Thanks you guys for any insight given

Answer 1

at a guess, because you register the listener in onCreate without unregistering it in onDestroy

in the service, that is.