Android Open Source - sana Gps Element

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License

The source code is released under:

Copyright (c) 2010, Moca All rights reserved. The source code for Moca is licensed under the BSD license as follows: Redistribution and use in source and binary forms, with or without modification, ...

Java Source Code

package org.moca.procedure;
/*from  w  ww .  j  av a 2 s.c  o  m*/
import org.w3c.dom.Node;

import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.location.LocationProvider;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

/**
 * GpsElement is a ProcedureElement that is created when a "GPS" element is put into 
 * an XML procedure description. It allows the user to click on a button to grab the 
 * current GPS coordinates. 
 * 
 * For field workers, this is often a useful feature to track patients and where they 
 * are seen by the health workers.
 */
public class GpsElement extends ProcedureElement implements OnClickListener {
    private Button getLocationButton;
    private TextView gpsTextView;    
    private LocationManager locationManager; 
    private LocationListener locationListener;
    private boolean gotCoordinates = false;
    private Handler handler = null;
    
    protected void finalize() throws Throwable {
      // We need to make sure that we are not leaving the GPS on.
      if (locationManager != null && locationListener != null) {
        locationManager.removeUpdates(locationListener);
      }
      
        super.finalize(); //not necessary if extending Object.
    } 
    
    @Override
    public ElementType getType() {
        return ElementType.GPS;
    }

    protected View createView(Context c) {
        LinearLayout gpsContainer = new LinearLayout(c);
        gpsContainer.setOrientation(LinearLayout.VERTICAL);
        locationManager = (LocationManager)c.getSystemService(Context.LOCATION_SERVICE);
        
      if (locationListener == null) {
        locationListener = new MocaGPSListener();
      }
        
        if(question == null) {
            question = "Please enter GPS coordinates:";
        }
        gpsTextView = new TextView(c);
        gpsTextView.setText(question);
        gpsTextView.setGravity(Gravity.CENTER);
        gpsTextView.setTextAppearance(c, android.R.style.TextAppearance_Medium);
        gpsContainer.addView(gpsTextView, new LinearLayout.LayoutParams(-1,-1,0.1f));
        getLocationButton = new Button(c);
        getLocationButton.setText("Grab GPS Location");
        getLocationButton.setOnClickListener(this);
        gpsContainer.addView(getLocationButton, new LinearLayout.LayoutParams(-1,-1,0.1f));
        return gpsContainer;
    }
    
    public void onClick(View v) {
        if (v == getLocationButton) {
          Log.i(TAG, "Requesting GPS updates to get the current location. ");
          gotCoordinates = false;
          locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
          getLocationButton.setEnabled(false);
          getLocationButton.setText("Waiting for GPS...");
          Thread gpsWatchdog = new Thread() {
            public void run() {
              Log.i(TAG, "GPS watchdog turning off GPS.");
              locationManager.removeUpdates(locationListener);
              if (!gotCoordinates) {
                Log.i(TAG, "GPS coordinates were not acquired.");
                getLocationButton.setEnabled(true);
                    getLocationButton.setText("Couldn't acquire location. Try again.");
              }
            }
          };
          if (handler == null)
            handler = new Handler();
          handler.postDelayed(gpsWatchdog, 10000);
          
        }
    }
    
    public void setAnswer(String answer) {
      this.answer = answer;
    }
    
    /**
     * Get the acquired GPS coordinates.
     */
    public String getAnswer() {
      return answer;
    }
    
    /**
     * Make question and response into an XML string for storing or transmission.
     */
    public void buildXML(StringBuilder sb) {
        sb.append("<Element type=\"" + getType().name() + "\" id=\"" + id);
        sb.append("\" answer=\"" + getAnswer());
        sb.append("\" concept=\"" + getConcept());
        sb.append("\"/>\n");
    }
    
    private GpsElement(String id, String question, String answer, String concept, String figure, String audio) {
        super(id, question, answer, concept, figure, audio);
        setAnswer("Coordinates not acquired.");
    }
    
    /**
     * Create a GpsElement from an XML procedure definition.
     */
    public static GpsElement fromXML(String id, String question, String answer, String concept, String figure, String audio, Node node) {
        return new GpsElement(id, question, answer, concept, figure, audio);
    }
    
    private class MocaGPSListener implements LocationListener {
      public void onLocationChanged(Location location) {
            // Called when the location has changed.
      Log.d(TAG, "Got location update :" + location.toString() + ". Disabling GPS");
      getLocationButton.setEnabled(false);
      getLocationButton.setText("Coordinates acquired.");
      gotCoordinates = true;
      setAnswer("Latitude: " + location.getLatitude() + " Longitude: " + location.getLongitude());
      locationManager.removeUpdates(locationListener);
        }
        public void onProviderDisabled(String provider) {
            // Called when the provider is disabled by the user.
          Log.d(TAG, "Provider disabled: " + provider);
          getLocationButton.setEnabled(true);
      getLocationButton.setText("GPS turned off -- check settings.");
      locationManager.removeUpdates(locationListener);
        }
        public void onProviderEnabled(String provider) {
            // Called when the provider is enabled by the user.
          Log.d(TAG, "Provider enabled: " + provider);
          // Do nothing, we should get a location update soon which will disable the listener.
        }
        public void onStatusChanged (String provider, int status, Bundle extras) {
            // Called when the provider status changes.
          Log.d(TAG, "Provider status changed: " + provider + " status: " + status);
          if (status == LocationProvider.AVAILABLE) {
            // Do nothing, we should get a location update soon which will disable the listener.
          } else if (status == LocationProvider.OUT_OF_SERVICE || status == LocationProvider.TEMPORARILY_UNAVAILABLE) {
            getLocationButton.setEnabled(true);
          getLocationButton.setText("GPS service not available. Try again.");
              locationManager.removeUpdates(locationListener);
          }
        }      
    }
}

Java Source Code List

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