background sensing of shake and GPS problems

Question

MainAcivity.java

    package com.example.background_shake;

import java.util.List;
import java.util.Locale;
import android.app.Activity;
import android.content.Intent;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;


public class MainActivity extends Activity implements OnClickListener {
    Button ON,OFF;
private SensorManager sensorManager;
private long lastUpdate;

Intent i1;
public static final String TAG = "ServicesDemo";
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);

    //reseting the window propertys
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    //super method
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ON=(Button)findViewById(R.id.ON);
    OFF=(Button)findViewById(R.id.OFF);
    ON.setOnClickListener(this);
    OFF.setOnClickListener(this);
}
public void onClick(View src) {
    switch (src.getId()) {
    case R.id.ON:
      Log.d(TAG, "onClick: starting srvice");
      startService(new Intent(this, Background_service.class));
      break;
    case R.id.OFF:
      Log.d(TAG, "onClick: stopping srvice");
      stopService(new Intent(this, Background_service.class));
      break;
    }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}
  }

Background_service.java

    package com.example.background_shake;

import java.util.List;
import java.util.Locale;
import android.app.Service;
import android.content.Intent;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.location.Address;
import android.location.Geocoder;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;

public class Background_service extends Service implements SensorEventListener{
    boolean flag=false;
    private long lastUpdate;
    SensorManager sensorManager;
            int count=0;
@Override
public IBinder onBind(Intent intent) {

    return null;
}
public void onCreate()
{
    flag=true;
    Log.d(MainActivity.TAG, "onCreate");
    super.onCreate();

}
public void onDestroy() {

    flag=false;
    Log.d(MainActivity.TAG, "onDestroy");
    super.onDestroy();

}
public void onStart(Intent intent, int startId)
{
    sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    sensorManager.registerListener(this,
            sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
            SensorManager.SENSOR_DELAY_NORMAL);
    lastUpdate = System.currentTimeMillis();
}
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {


}
private void getAccelerometer(SensorEvent event) {
    if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
    float[] values = event.values;
    // Movement
    float x = values[0];
    float y = values[1];
    float z = values[2];
    double latitude=0;
    double longitude=0;
    String location_message;
    GPSTracker gps;

    float accelationSquareRoot = (x * x + y * y + z * z)
        / (SensorManager.GRAVITY_EARTH * SensorManager.GRAVITY_EARTH);
    long actualTime = System.currentTimeMillis();
    if (accelationSquareRoot >= 2) //
    {
      if (actualTime - lastUpdate < 2000) {
            count++;
        return;
      }

      lastUpdate = actualTime;

      {
          gps=new GPSTracker(Background_service.this);
          if((gps.canGetLocation())&&(count==3)){
                      count=0;    
              latitude = gps.getLatitude();
              longitude = gps.getLongitude();
        //  \n is for new line
        //  Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();    
              Geocoder gcd = new Geocoder(Background_service.this, Locale.getDefault());
              try{
                  List<Address> addresses = gcd.getFromLocation(latitude, longitude, 1);
                  location_message= addresses.get(0).getLocality();
                  if ((addresses.size() > 0)&&(flag))
                  {
                      Toast.makeText(getApplicationContext(), "Your Location is " +addresses.get(0).getLocality()
                              , Toast.LENGTH_LONG).show();
                                      count=0;
                  }

              }catch(Exception e)
              {
                  System.out.print(e);
              }
          }else{
        //  can't get location
        //  GPS or Network is not enabled
        // Ask user to enable GPS/network in settings
        Toast.makeText(getApplicationContext(), "Switch on gps"
                , Toast.LENGTH_LONG).show();
        gps.showSettingsAlert();
    }}


      /*Toast.makeText(this, "Device was shuffed", Toast.LENGTH_SHORT)
          .show();
      if (color) {
        view.setBackgroundColor(Color.GREEN);

      } else {
        view.setBackgroundColor(Color.RED);
      }*/

    }}
  }
public void onSensorChanged(SensorEvent event) {

    getAccelerometer(event);


}
protected void onResume() {
    //super.onResume();
    // register this class as a listener for the orientation and
    // accelerometer sensors
            sensorManager.registerListener(this,
            sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
            SensorManager.SENSOR_DELAY_NORMAL);
}

protected void onPause()
{
    // unregister listener
    sensorManager.unregisterListener(this);

}

}

The above code is for an app that senses the shake parameter and gives you the current location. But the problem is even though my GPS is off i am getting my current location.

Also i want to know two things 1. Does a Service work even if you lock your phone?If no, what modifications must be made to my code so that it works? 2. My app gives the output if i shake my mobile once but i want my app to give the desired result only if i shake it continuously for 3-4 times.Is it possible to do that?

score 3 · Answer 1 · edited Sep 23 '14 at 02:32

To answer your questions: 1. Does a Service work even if you lock your phone?If no, what modifications must be made to my code so that it works?

yes once a service has been launched it continues running infinitely, if however the phone is switched of and you want the service to start as soon as the phone is launched you can try creating a broadcast receiver that is triggered on boot

public class Broadcastreceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        Intent startSMSServiceIntent = new Intent(context, SOMEservice.class);
        context.startService(startSMSServiceIntent);
    }
}

In the manifest

<receiver android:name=".Broadcastreceiver">             
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />  
    </intent-filter>         
</receiver>

Dont forget permissions

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

it means that if i lock my phone and try sending message to another person on shaking it will work right? — mani bharataraju, Mar 19 '13 at 06:21
yes It will work even if the phone is locked. Read through this for more info http://www.vogella.com/articles/AndroidServices/article.html — James Wahome, Mar 19 '13 at 06:24

score 0 · Accepted Answer · answered Mar 19 '13 at 09:51

0

Q1 is already answered here by akajaymo.

For Q2, instead of having the app produce the desired output every time the phone is shaken, create two static variables int count and long last.

Every time the phone is shaken, you check to see if (System.currentTimeMillis() - last) < 1000/* considering the shakes are not more than 1 second apart */ and, if so, you increase count.

If count reaches 3 or 4, you're done: just produce the desired output. If not, produce nothing.

If the shakes are more than 1000ms apart, just set count to 1.

Also, every time you detect a shake, make last = System.currentTimeMillis(). This update to last must be done after the first check that I mentioned.

answered Mar 19 '13 at 09:51

lucian.pantelimon

3,673
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i have made the necessary modifications in my code. but the app is not working(force close). can you please check the code i have posted and help me in finding the error. – mani bharataraju Mar 19 '13 at 10:37
Can you please post the error (Exception as shown by logcat) ? It's easier to figure out a problem once you know what the problem actually is. – lucian.pantelimon Mar 19 '13 at 13:06
i tried to print the value of count in my program but it is never getting incremented – mani bharataraju Mar 20 '13 at 10:20
hey it worked man but only if u give that count=1 part after displaying the output.thanks for your help – mani bharataraju Mar 22 '13 at 06:06
i have edited the code above and now it works. thanks everyone for the help. – mani bharataraju Mar 22 '13 at 06:40
Sorry, i've been quite busy lately and I just got the chance to look at the comments. Good job on solving the issue. I've upvoted akajaymo's answer and he deserves an accept for his answer as well as I got for mine, as he answered the first of your questions. You can only accept an answer at a time so you cannot accept both out answers at a time. As a tip for next time, try not to ask multiple questions in the same post. It's best that you split the questions into multiple posts (even if they are related) so that whoever answers each of the questions gets credited for his/her effort. – lucian.pantelimon Mar 22 '13 at 16:57

background sensing of shake and GPS problems

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