Android Open Source - ElevationLogger Sensor Service

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From Project

Back to project page ElevationLogger.

License

The source code is released under:

GNU General Public License

Java Source Code

package de.smashnet.elevationlogger;
//from   ww  w.j a  v a2s .c  o  m
import java.io.File;
import java.util.LinkedList;

import jsqlite.Exception;
import jsqlite.Stmt;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.Environment;
import android.os.IBinder;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;

/**
 * SensorService lets GPS and air pressure sensors run even
 * if the app is not on foreground.
 * 
 * If the HomeActivity is in foreground the sensor values are passed
 * there using LocalBroadcastManager.
 * 
 * @author Nicolas Inden
 * @contact nicolas.inden@smashnet.de
 * @date 29.12.2013
 */
public class SensorService extends Service
       implements LocationListener, SensorEventListener{

  /**
   * Handles sensor service
   */
  SensorManager mSensorManager;
  
  /**
   * Handles location service
   */
  LocationManager mLocationManager;
  
  /**
   * We use the air pressure sensor
   */
  Sensor mPressure;
  
  /**
   * Source for location information
   */
  String mProvider;
  
  /**
   * Last measured air pressure
   */
  float mCurrentPressure = 0.0f;
  
  /**
   * Used to Schmitt-triggering data recording
   */
  boolean mRecording;
  
  /**
   * The trace DB
   */
  TraceDB mTraceDB;
  
  /**
   * Spatialite Database
   */
  jsqlite.Database mDatabase;
  
  /**
   * Receives query from HomeActivity to send current TraceList
   */
  private BroadcastReceiver mMessageReceiverGetTraceList;

  @Override
  public IBinder onBind(Intent intent) {
    return null;
  }
  
  @Override
  public void onCreate() {
    
  }
  
  /**
   * Do some cleanup if the Service is destroyed/stopped:
   * <ul>
   *   <li>Unregister SensorManager listener</li>
   *   <li>Stop LocationManager updates</li>
   *   <li>Write GPX footer and flush to file</li>
   * </ul>
   */
  @Override
  public void onDestroy() {
    super.onDestroy();
    
    // Unregister sensors and finish GPX file
    mSensorManager.unregisterListener(this);
    mLocationManager.removeUpdates(this);
    try {
      mDatabase.close();
    } catch (Exception e) {
      e.printStackTrace();
      Log.w("SensorService", "Error closing database!");
    }
    //Serialize trace DB to storage
    mTraceDB.writeTraceDBFile();
    
    Log.i("SensorService", "Service stopped!");
  }
  
  /**
   * This is invoked when the Service is started. It initializes the air pressure sensor,
   * the GPS LocationManager and the GpxWriter.
   * 
   * @param intent the intent
   * @param flags the flags
   * @param startId the startId
   * @return The service mode. In this case: START_STICKY (only stop if explicitly asked to stop)
   */
  @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
    Log.i("SensorService", "Received start id " + startId + ": " + intent);
    mRecording = false;
    
    mTraceDB = new TraceDB(this, "traces.db");
    
    mMessageReceiverGetTraceList = new GetTraceListReceiver(mTraceDB);
    
    LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiverGetTraceList,
          new IntentFilter("get-trace-list"));
        
    // Init air pressure sensor
    mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    mPressure = mSensorManager.getDefaultSensor(Sensor.TYPE_PRESSURE);
    mSensorManager.registerListener(this, mPressure, 500000); // 500ms
    Log.i("SensorService", "Started air pressure");
          
    // Init GPS
    mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    mProvider = LocationManager.GPS_PROVIDER;
    if(mProvider != null){
      mLocationManager.requestLocationUpdates(mProvider, 400, 0, this);
      Log.i("SensorService", "Started GPS");
    }
    
    //Init Spatialite database
    mDatabase = new jsqlite.Database();
    try {
      mDatabase.open(getStorageDir("ElevationLog","map") + "/" + getString(R.string.osm_db), jsqlite.Constants.SQLITE_OPEN_READONLY);
      Log.i("SensorService", "Successfully opened spatialite database :)");
    } catch (Exception e) {
      e.printStackTrace();
      Log.w("SensorService", "Error opening spatialite database!");
    }
          
    // GpxWriter is initialized in onLocationChanged()
    
    // We want this service to continue running until it is explicitly
        // stopped, so return sticky.
        return START_STICKY;
    }

  @Override
  public void onAccuracyChanged(Sensor sensor, int accuracy) {
    // TODO Nothing to do here so far ;-)
    
  }

  /**
   * We use this function to broadcast air pressure values to the HomeActivity to have
   * a more frequent update for the air pressure. Nevertheless, no data recording here
   * without a position.
   * 
   * @param event the SensorEvent containing the sensor value
   */
  @Override
  public void onSensorChanged(SensorEvent event) {
    mCurrentPressure = event.values[0];
    Intent intent = new Intent("sensor-data-pressure");
    intent.putExtra("pres", mCurrentPressure);
    LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
  }

  /**
   * This is invoked each time we receive a new location from the LocationManager. The values
   * are stored into a GPX file and additionally are broadcasted to the HomeActivity
   * for displaying purposes.
   * 
   * @param location the location object
   */
  @Override
  public void onLocationChanged(Location location) {
    boolean emulator = false;
    
    //Check if required information is available
    if(!location.hasAccuracy() || !location.hasAltitude() || !location.hasSpeed()) {
      if(emulator) {
        location.setAccuracy(7.0f);
        location.setAltitude(200.0d);
        location.setSpeed(0.0f);
        mCurrentPressure = 980.0f;
      } else {
        return;
      }
    }
    
    // Schmitt-trigger data recording depending on GPS accuracy
    if(location.getAccuracy() <= 14.0 && !mRecording){
      mRecording = true;
      mTraceDB.startNewCurrentTrace();
    }else if(location.getAccuracy() > 18.0 && mRecording){
      mRecording = false;
      mTraceDB.closeCurrentTrace();
    }
    
    String res = getNearestOSMNode(location, 0.001, 30, 1);
    long osm_id = -1;
    double dist = -1.0d;
    if(res != null){
      osm_id = Long.valueOf(res.split(",")[0]);
      dist = Double.valueOf(res.split(",")[1]);
    }
    
    // Broadcast sensor-data to HomeActivity
    Intent intent = new Intent("sensor-data-complete");
    intent.putExtra("lat", location.getLatitude());
    intent.putExtra("lon", location.getLongitude());
    intent.putExtra("alt", location.getAltitude());
    intent.putExtra("acc", location.getAccuracy());
    intent.putExtra("pres", mCurrentPressure);
    intent.putExtra("osm_id", osm_id);
    intent.putExtra("osm_distance", dist);
    intent.putExtra("time", location.getTime());
    LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
    
    // Sensor data log output
    Log.i("SensorService", "Lat: " + location.getLatitude());
    Log.i("SensorService", "Lon: " + location.getLongitude());
      Log.i("SensorService", "Alt: " + location.getAltitude());
      Log.i("SensorService", "Acc: " + location.getAccuracy());
      Log.i("SensorService", "Pres: " + mCurrentPressure);
      Log.i("SensorService", "Osm_id: " + osm_id);
      Log.i("SensorService", "Dist: " + dist);
      Log.i("SensorService", "Time: " + location.getTime());
      
      // Save sensor-data if GPS accuracy is <= 15 meters
      if(!mRecording)
      return;
      
     mTraceDB.addNodeToCurrentTrace(new LocationNode(location, osm_id, dist, mCurrentPressure));
  }

  private String getNearestOSMNode(Location location, double radius, double distance, int limit) {
    try {
      //jsqlite.Database mDatabase = new jsqlite.Database();
      //mDatabase.open(SensorService.getStorageDir("ElevationLog","map") + "/" + getApplicationContext().getString(R.string.osm_db), jsqlite.Constants.SQLITE_OPEN_READONLY);
      
      String slGetNearestNode = "SELECT osm_id, ST_Distance(geometry, MakePoint(" + location.getLongitude() + ", " + location.getLatitude() + "), 0) AS distance "
          + "FROM 'regbez-koeln_nodes' "
          + "WHERE ROWID IN (SELECT ROWID FROM SpatialIndex WHERE f_table_name='regbez-koeln_nodes' "
          + "AND search_frame=BuildCircleMbr(" + location.getLongitude() + ", " + location.getLatitude() +", " + radius + ")) "
          + "AND distance < " + distance + " ORDER BY distance LIMIT " + limit + ";";
      
      //mDatabase.exec(slGetNearestNode, new SpatialiteCallback());
      //mDatabase.close();
      Stmt stmt = mDatabase.prepare(slGetNearestNode);
      
      if(stmt.step()){
        String res = stmt.column_int(0) + "," + stmt.column_double(1);
        stmt.close();
        return res;
      }
      stmt.close();
    } catch (Exception e) {
      e.printStackTrace();
      Log.e("DBquery", "DB error");
    }
    return null;
  }

  @Override
  public void onProviderDisabled(String provider) {
    // TODO Nothing to do here so far ;-)
    
  }

  @Override
  public void onProviderEnabled(String provider) {
    // TODO Nothing to do here so far ;-)
    
  }

  @Override
  public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Nothing to do here so far ;-)
    
  }
  
  public LinkedList<LocationTrace> getTraces() {
    return mTraceDB.getTraces();
  }

  /**
   * Returns a File object for ExternalStoragePublicDirectory/$progname/$dirname
   * If the directories do not exists yet, they are created
   * 
   * @param progname the name of this app
   * @param dirname the name of the subdirectory where data should be stored
   * @return the File object representing the storage directory
   */
  public static File getStorageDir(String progname, String dirname) {
        // Get the directory for the user's public pictures directory. 
        File file = new File(Environment.getExternalStoragePublicDirectory(progname), dirname);
        if (!file.exists()) {
          if(!file.mkdirs())
            System.out.println("Directory not created");
        } else {
          System.out.println("Directory exists!");
        }
        return file;
    }
  /**
   * Custom receiver to receive trace list query from HomeActivity
   * @author Nicolas Inden
   */
  public class GetTraceListReceiver extends BroadcastReceiver {
    private TraceDB mTraceDB;
    
    public GetTraceListReceiver(TraceDB db) {
      mTraceDB = db;
    }

    @Override
    public void onReceive(Context context, Intent intent) {
      Intent res = new Intent("send-trace-list");
      res.putExtra("Traces", mTraceDB.getTraces());
      LocalBroadcastManager.getInstance(context).sendBroadcast(res);
    }
    
  }
}

Java Source Code List

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