I want to create an application of distance tracker in android. I have a Spinner, button and a TextView.Initially text view will be 0.00km.When I click the button (GPS tracking start) and start walking in the text view it will show the distance continuously. When I click the button again(GPS tracking terminate) and show the full distance between clicking button.
Here is the screenshot that the application will look like:
Here is My Code:
public class Gps extends Activity {
TextView display;
double currentLon=0 ;
double currentLat=0 ;
double lastLon = 0;
double lastLat = 0;
double distance;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_test);
display = (TextView) findViewById(R.id.textView1);
LocationManager lm =(LocationManager) getSystemService(LOCATION_SERVICE);
lm.requestLocationUpdates(lm.GPS_PROVIDER, 0,0, Loclist);
Location loc = lm.getLastKnownLocation(lm.GPS_PROVIDER);
if(loc==null){
display.setText("No GPS location found");
}
else{
//set Current latitude and longitude
currentLon=loc.getLongitude();
currentLat=loc.getLatitude();
}
//Set the last latitude and longitude
lastLat=currentLat;
lastLon=currentLon ;
}
LocationListener Loclist = new LocationListener(){
#Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
//start location manager
LocationManager lm =(LocationManager) getSystemService(LOCATION_SERVICE);
//Get last location
Location loc = lm.getLastKnownLocation(lm.GPS_PROVIDER);
//Request new location
lm.requestLocationUpdates(lm.GPS_PROVIDER, 0,0, Loclist);
//Get new location
Location loc2 = lm.getLastKnownLocation(lm.GPS_PROVIDER);
//get the current lat and long
currentLat = loc.getLatitude();
currentLon = loc.getLongitude();
Location locationA = new Location("point A");
locationA.setLatitude(lastLat);
locationA.setLongitude(lastLon);
Location locationB = new Location("point B");
locationB.setLatitude(currentLat);
locationB.setLongitude(currentLon);
double distanceMeters = locationA.distanceTo(locationB);
double distanceKm = distanceMeters / 1000f;
display.setText(String.format("%.2f Km",distanceKm ));
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
};
}
Please help me. Thanks.
You should register a listener on the GPS when the location changed. You basically have to store the previous known location and compare it with the new one.
The simplest way to get the distance between two points would be to use:
sqrt( (x2 - x1)^2 + (y2 - y1)^2 + (z2 - z1)^2 )
X may be the latitude
Y may be the longitude
Z may be the altitude
Here is a pseudo code sample to help you
public class GpsCalculator
{
private LocationManager locationManager = null;
private Location previousLocation = null;
private double totalDistance = 0D;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 100; // 100 meters
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minutes
public void run(Context context)
{
// Get the location manager
locationManager = (LocationManager) context.getSystemService(Service.LOCATION_SERVICE);
// Add new listeners with the given params
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, locationListener); // Network location
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, locationListener); // Gps location
}
public void stop()
{
locationManager.removeUpdates(locationListener);
}
private LocationListener locationListener = new LocationListener() {
#Override
public void onLocationChanged(Location newLocation)
{
if (previousLocation != null)
{
double latitude = newLocation.getLatitude() + previousLocation.getLatitude();
latitude *= latitude;
double longitude = newLocation.getLongitude() + previousLocation.getLongitude();
longitude *= longitude;
double altitude = newLocation.getAltitude() + previousLocation.getAltitude();
altitude *= altitude;
GpsCalculator.this.totalDistance += Math.sqrt(latitude + longitude + altitude);
}
// Update stored location
GpsCalculator.this.previousLocation = newLocation;
}
#Override
public void onProviderDisabled(String provider) {}
#Override
public void onProviderEnabled(String provider) {}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
}
And the Activty should look like that:
public class MainActivity extends Activity
{
private Button mainButton = null;
private boolean isButtonPressed = false;
private GpsCalculator gpsCalculator = null;
public void onCreate(Bundle savedInstance)
{
super.onCreate(savedInstance);
// Create a new GpsCalculator instance
this.gpsCalculator = new GpsCalculator();
// Get your layout + buttons
this.mainButton = (Button) findViewById(R.id.main_button);
this.mainButton.addOnClickListener(new OnClickListener() {
#Override
public void onClick()
{
// Enable or diable gps
if (MainActivity.this.isButtonPressed) gpsCalculator.run(this);
else gpsCalculator.stop();
// Change button state
MainActivity.this.isButtonPressed = !MainActivity.this.isButtonPressed;
}
});
}
}
This is my code. Please tell me y it is not able to calculate the distance.. In this code res is a long variable which is supposed to store the total distance covered. This code is supposed to calculate distance based on GPS as soon as there is a change in the latitude and longitude..
String serviceString = Context.LOCATION_SERVICE;
LocationManager locationManager;
locationManager= (LocationManager)getSystemService(serviceString);
String provider = LocationManager.GPS_PROVIDER;
final Location loc1=locationManager.getLastKnownLocation(provider);
//Location loc1=new Location("");
String netprovider=LocationManager.NETWORK_PROVIDER;
lat1=loc1.getLatitude();
lon1=loc1.getLongitude();
LocationListener myLocationListener = new LocationListener()
{
public void onLocationChanged(Location loc1)
{
Location loc2=new Location("");
lat2=loc2.getLatitude();
lon2=loc2.getLongitude();
dtvalue.setText(lat1+","+lon1+","+lat2+","+lon2);
Location.distanceBetween(lat1,lon1,lat2,lon2,dist);
res=res+(long)dist[0];
lat1=lat2;
lon1=lon2;
}
public void onProviderDisabled(String provider)
{
// Update application if provider disabled.
}
public void onProviderEnabled(String provider)
{
// Update application if provider enabled.
}
public void onStatusChanged(String provider, int status,
Bundle extras)
{
// Update application if provider hardware status changed.
}
};
locationManager.requestLocationUpdates(provider, 5000, 1, myLocationListener);
locationManager.requestLocationUpdates(netprovider, 5000, 1, myLocationListener);
The problem that you are defining an empty location Location loc2=new Location(""); and then using it.
You can define lat1 and lon1 in your class.
public void onLocationChanged(Location loc1)
{
if(lat1 != 0 && long1 != 0) {
Location.distanceBetween(lat1,lon1,loc1.getLatitude(),loc1.getLongitude(),dist);
res+=(long)dist[0];
}
lat1=loc1.getLatitude();
lon1=loc1.getLongitude();
}
When my map activity is called I make a call in the onCreate to addUserMapPoint. This function contains two instances where I try to get the location information using myOverlay.getMyLocation. On the initial load of this activity the result of the first attempt returns a null GeoPoint and after the main UI thread completes the second attempt located in the listener thread of myOverlay.runOnFirstFix(new Runnable()… is call after a second and does contain a GeoPoint that does contain a lat and lon. The call inside this listener function does appear to put the dot on the map and the line mapController.animateTo(gp) does move the map to my location. My app has a refresh button that when clicked fires off this activity again. I need the lat and lon in order to fetch location data from another service. After the refresh, the second time through the map activity code I was expecting the first call to myOverlay.getMyLocation() would now be able to get the GeoPoint, but it is still null.
If I’m not able to get the GeoPoint by this first call to myOverlay.getMyLocation then how can I pass the lat and lon value from the second call found in the myOverlay.runOnFirstFix(new Runnable()… thread. You will notice that I have been trying to add the lat and lon to MyApp which is helper bean class but the lat and lon in this class is null even after the refresh. If I manually set a lat and lon manually in the addUserMapPoint function the first time the activity is accessed these values are retained. I’m guessing that this is because it is being set on the main UI thread.
public class MapActivity extends com.google.android.maps.MapActivity {
private MapView mapView = null;
private MapController mapController = null;
private MyLocationOverlay myOverlay = null;
public static MyApp app;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
app = (MyApp) getApplicationContext();
mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
mapController = mapView.getController();
List<Overlay> mapOverlays = mapView.getOverlays();
mapOverlays.clear();
addUserMapPoint(mapView);
if (!app.isLocServOff()) {
//map other points – service call to get items from our service near lat and lon
addOtherMapPoints(mapOverlays);
} else {
Toast.makeText(app.getApplicationContext(),"Current location could not be found.",Toast.LENGTH_LONG).show();
}
}
private void addUserMapPoint(MapView mapView){
myOverlay = new MyLocationOverlay(app.getApplicationContext(), mapView);
myOverlay.disableCompass();
myOverlay.enableMyLocation();
if(app.getMyLat()==null||app.getMyLon()==null){
GeoPoint gp = myOverlay.getMyLocation();
if(gp!=null){
app.setMyLat(Helper.latLon1E6Calc(gp.getLatitudeE6()));
app.setMyLon(Helper.latLon1E6Calc(gp.getLongitudeE6()));
app.setLocServOff(false);
}else{
app.setLocServOff(true);
}
}
myOverlay.runOnFirstFix(new Runnable() {
public void run() {
GeoPoint gp = myOverlay.getMyLocation();
if(gp!=null){
app.setMyLat(Helper.latLon1E6Calc(gp.getLatitudeE6()));
app.setMyLon(Helper.latLon1E6Calc(gp.getLongitudeE6()));
app.setLocServOff(false);
mapController.animateTo(gp);
}else{
app.setLocServOff(true);
}
}
});
mapView.getOverlays().add(myOverlay);
}
}
Your help is being requested for the following question.
How can I get a GeoPoint that contains a lat and lon in the main UI thread or how can I pass these values from GeoPoint I am able to get from the myOverlay.runOnFirstFix(new Runnable()… thread?
If you are going to suggest that I use Handler or runOnUiThread please provide code example that passes the lat and lon back to something that can be used by the main UI thread/map view. I have tried things like the following code that did not produce the desired outcome. I was able to get the toast message to show up, but was not able to get the lat and lon passed in a way I could use.
final Handler handler = new Handler();
myOverlay.runOnFirstFix(new Runnable() {
#Override public void run() {
handler.post(new Runnable() {
#Override public void run() {
GeoPoint gp = myOverlay.getMyLocation();
if(gp!=null){
app.setMyLat(Helper.latLon1E6Calc(gp.getLatitudeE6()));
app.setMyLon(Helper.latLon1E6Calc(gp.getLongitudeE6()));
app.setLocServOff(false);
mapController.animateTo(gp);
}else{
app.setLocServOff(true);
}
//Toast.makeText(getApplicationContext(),"wowoowowowoowoowowow",Toast.LENGTH_LONG).show();
}
});
}
});
I've also used code like the following to get the lat and lon and it works, but because the current location would sometimes be a different lat and lon than whas was being returned becuase for example I could not get a gps signal but yet an old value was returned. I added checks to see if the lat/lon data was older than 2 minutes, but I still could not match up the most recent lat and lon with that that is returned by myOverlay.getMyLocation.
LocationManager locMgr = (LocationManager)appcontext.getSystemService(Context.LOCATION_SERVICE);
MyLocationListener locLstnr = new MyLocationListener();
//fetch current location for current location
locMgr.requestSingleUpdate(LocationManager.GPS_PROVIDER, locLstnr, appcontext.getMainLooper());
Bellow you can find some examples on how to get the current location in the UI thread, but first of all, some background information.
GPS may take some time (15 seconds to 1 minute) to get the first fix after the request for new location is made. This is the reason you your first attempt to get it from myOverlay fails, and only after the first fix you can get the value.
During this blackout period you can use getLastKnownLocation() to get the last good known GPS location if you are in a hurry. If not availble it returns null
The code:
Last Known Location
LocationManager locMgr=(LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
Location loc = locMgr.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(loc != null){
//we have a valid location. Check location date
}
Requesting a Single Location Update
LocationManager locMgr=(LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
locMgr.requestSingleUpdate(LocationManager.GPS_PROVIDER, locationListener, appcontext.getMainLooper);
Requesting a Continuous Location Update
LocationManager locMgr = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
//use 0 for minDistance and minDistance between updates if you need the maximum update frequency.
locMgr.requestLocationUpdates(LocationManager.GPS_PROVIDER, minDistance, minTime, locationListener);
Location Listener for Single and Continuous position update
This is the last piece of code, and is the place where you get the new fresh locations requested above.
When a new location that match your request critirea defined above is retrieved by GPS, this listener is immediately called, unless you device is busy doing something else that can't be interrupted (i.e. callback is on a paused thread or that hit a lock).
From within the onLocationChanged() you can set any class level filed as appropriate. If you registered the listener from the UI thread, then this will be running running on the UI.
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location fix) {
fix.setTime(fix.getTime() + timeZoneOffset); //Add Timezone offset if needed
//here you have a fresh new location in fix...
//You can set the value of any class level field from here
}
public void onProviderDisabled(String provider) {
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
Regards.
handler.post(new Runnable() {
#Override public void run() {
GeoPoint gp = myOverlay.getMyLocation();
if(gp!=null){
app.setMyLat(Helper.latLon1E6Calc(gp.getLatitudeE6()));
app.setMyLon(Helper.latLon1E6Calc(gp.getLongitudeE6()));
app.setLocServOff(false);
// HERE WE HAVE VALID gp VALUE AND WE NEED TO SHARE IT
mapController.animateTo(gp);
}else{
app.setLocServOff(true);
}
}
});
I think that your app.set/get|MyLat/Lon not working because you call them from different threads. To fix it synchronize set and get methods for MyLat/Long. (create Object for synchronization and sync on it)
Or if you like your way with handler this should work:
final Handler handler = new Handler(); // BE SURE TO RUN THIS LINE ON UI THREAD
...
myOverlay.runOnFirstFix(new Runnable() {
#Override public void run() {
// THIS PART WORKS AS BEFORE
final GeoPoint gp = myOverlay.getMyLocation();
mapController.animateTo(gp);
...
// AND THIS RUNNABLE TO UPDATE MyLat/MyLong FROM UI THREAD
handler.post(new Runnable() {
#Override public void run() {
app.setMyLat(Helper.latLon1E6Calc(gp.getLatitudeE6()));
app.setMyLon(Helper.latLon1E6Calc(gp.getLongitudeE6()));
});
}
});
Some of the most important points you must take into account while seeking Device's location are:
Satellite GPS fix is not guaranteed to be received in adequate amount of time. E.g. the device is inside a building / not under open sky.
Make sure the satellite GPS listeners are not kept active for long. Keeping the listener ON will imply keeping the GPS radio on all the time making it the biggest battery drain reason.
In the below code example, the poll method in LinkedBlockingQueue doesn't return until either a specified time interval is over or a Location is queued in.
Use something like the below to get the current Location:
Location getCurrentLocation() {
long startmillis = 0;
LinkedBlockingQueue<Location> mQueue = new LinkedBlockingQueue<Location>();
try{
long millisSinceLastCollection = System.currentTimeMillis() - startmillis;
startmillis = System.currentTimeMillis();
mQueue.clear();
// Register for Satellite GPS listener as well as Network GPS listener.
registerGPSListeners();
// Wait for a maximum of one minutes for a fix
Location firstfix = mQueue.poll(1, TimeUnit.MINUTES);
if(firstfix != null && firstfix.getProvider().equals(LocationManager.GPS_PROVIDER)) {
return firstfix;
}
long elapsedmillis = System.currentTimeMillis() - startmillis;
long remainingmillis = ONE_MINUTE_IN_MS - elapsedmillis;
if (remainingmillis <= 0){
return firstfix;
}
Location secondfix = mQueue.poll(remainingmillis, TimeUnit.MILLISECONDS);
if(secondfix != null && secondfix.getProvider().equals(LocationManager.GPS_PROVIDER)) {
return secondfix;
}
/*
* In case we receive fix only from Network provider, return it.
*/
if(firstfix != null && firstfix.getProvider().equals(LocationManager.NETWORK_PROVIDER)) {
return firstfix;
}
} catch(Exception e){
Logger.e("GPS: Exception while listening for the current location", e);
} finally {
Logger.i("GPS: Unsubscribing from any existing GPS listeners");
unregisterGPSListeners();
}
}
// GPS issue fix edit.
private void registerGPSListeners() {
LocationManager locationManager = (LocationManager)AirWatchApp.getAppContext().getSystemService(Context.LOCATION_SERVICE);
if(locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER))
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 30000, 100, oneShotNetworkGPSLocationListener, MyAppApp.getAppContext().getMainLooper());
if(locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 30000, 100, oneShotSatelliteGPSLocationListener, AirWatchApp.getAppContext().getMainLooper());
}
}
private void unregisterGPSListeners(){
final LocationManager locationManager = (LocationManager)MyApp.getAppContext().getSystemService(Context.LOCATION_SERVICE);
locationManager.removeUpdates(oneShotSatelliteGPSLocationListener);
locationManager.removeUpdates(oneShotNetworkGPSLocationListener);
}
//One shot location listener
protected LocationListener oneShotSatelliteGPSLocationListener = new LocationListener() {
public void onLocationChanged(Location location) {
try {
mQueue.put(location);
} catch (InterruptedException e) {
Logger.e("Exception in putting new Location to the queue", e);
}
Logger.d("GPS: Location received from Satellite GPS Provider");
unregisterGPSListeners();
}
public void onProviderDisabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
};
//One shot location listener
protected LocationListener oneShotNetworkGPSLocationListener = new LocationListener() {
public void onLocationChanged(Location location) {
try {
mQueue.put(location);
} catch (InterruptedException e) {
Logger.e("Exception in putting new Location to the queue", e);
}
Logger.d("GPS: Location received from Network GPS Provider");
// Stop Listener for one-shot location fix from Network GPS provider.
final LocationManager locationManager = (LocationManager)AirWatchApp.getAppContext().getSystemService(Context.LOCATION_SERVICE);
locationManager.removeUpdates(oneShotNetworkGPSLocationListener);
Logger.d("GPS: Unsubscribed the network location listener.");
}
public void onProviderDisabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
};
Android modifies the user interface and handles input events from one single user interface thread(main thread).
If the programmer does not use any concurrency constructs, all code of an Android application runs in this thread.
GPS is the best way to determine a user's location, but pinging a global positioning satellite too much will quickly drain a mobile device's battery, take long time to get user location and this method doesn't always work indoors. You are not getting your location in first attempt that's why you are getting null over there.
Android's Network Location Provider figures out a user's location based on cell tower and Wi-Fi signals. It not only uses less battery power than GPS, but it's also faster and it works whether the user is outside or inside.
I am giving my Working Code below that show progress dialog, listen for user's location & after getting location show user's location overlay on Google-map
I assume that you have give below permissions in your Menifest file
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.INTERNET"/>
My main class
public class MyLocationOnMap extends MapActivity {
private MapView mapView;
private MyLocationOverlay itemizedoverlay;
private LocationManager locationManager;
private String provider;
private MyLocationListener locationListener;
MyBroadCastreceiver myBroadCastreceiver;
/**
* My current Location <i>longitude</i>.
*/
static int longitude;
/**
* My current Location <i>latitude</i>.
*/
static int latitude;
/**
*My progress indicator.
*/
ProgressDialog loadingDialog;
public static final String INTENT_FILTER_TAG="my location broadcast receiver";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_location_on_map);
loadingDialog = new ProgressDialog(this);
loadingDialog.setTitle("Hot Spots!");
loadingDialog.setMessage("Please wait ...");
loadingDialog.setIndeterminate(true);
loadingDialog.setCancelable(false);
loadingDialog.show();
// Configure the Map
mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
mapView.setStreetView(true);
/**
* Get your location manager and Location Listener...
*/
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationListener=new MyLocationListener();
myBroadCastreceiver = new MyBroadCastreceiver();
if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
Log.i("GPS_Enabled", "GPS enable! listening for gps location.");
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10000, 0, locationListener);
registerReceiver(myBroadCastreceiver, new IntentFilter(INTENT_FILTER_TAG));
} else if (locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) {
Log.i("Network_Enabled", "Network enable! listening for Network location.");
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 10000, 0, locationListener);
registerReceiver(myBroadCastreceiver, new IntentFilter(INTENT_FILTER_TAG));
} else {
loadingDialog.dismiss();
Toast.makeText(this, "No Provider enable!", Toast.LENGTH_LONG).show();
}
}//End of onCreate......
/**
* My BroadCast Receiver, that is called when i get the location of user.
* #author Rupesh Yadav.
*
*/
class MyBroadCastreceiver extends BroadcastReceiver{
#Override
public void onReceive(Context context, Intent intent) {
//Remove location update when you get user`s location very first time.
locationManager.removeUpdates(locationListener);
//Remove the broadcast listener that update my location on map.
unregisterReceiver(myBroadCastreceiver);
GeoPoint point = new GeoPoint(latitude, longitude);
mapView.getController().animateTo(point);
List<Overlay> mapOverlays = mapView.getOverlays();
Drawable drawable = MyLocationOnMap.this.getResources().getDrawable(R.drawable.hs_mapoverlay);
itemizedoverlay = new MyLocationOverlay(drawable, MyLocationOnMap.this);
OverlayItem overlayitem = new OverlayItem(point, "Hello!", "My Current Location :)");
itemizedoverlay.addOverlay(overlayitem);
mapOverlays.add(itemizedoverlay);
loadingDialog.dismiss();
}
}
/**
* My Location listener...
*/
class MyLocationListener implements LocationListener{
#Override
public void onLocationChanged(Location location) {
latitude=(int) ((location.getLatitude())*1E6);
longitude=(int) ((location.getLongitude())*1E6);
//Send broadcast to update my location.
Intent sendLocationIntent=new Intent(INTENT_FILTER_TAG);
sendBroadcast(sendLocationIntent);
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
#Override
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
}
MyLocationOverlay class
public class MyLocationOverlay extends ItemizedOverlay<OverlayItem> {
Context mContext;
private ArrayList<OverlayItem> hsOverlays = new ArrayList<OverlayItem>();
public MyLocationOverlay(Drawable defaultMarker) {
super(boundCenterBottom(defaultMarker));
// TODO Auto-generated constructor stub
}
public MyLocationOverlay(Drawable defaultMarker, Context context) {
super(boundCenterBottom(defaultMarker));
mContext = context;
}
#Override
protected OverlayItem createItem(int i) {
// TODO Auto-generated method stub
return hsOverlays.get(i);
}
#Override
public int size() {
// TODO Auto-generated method stub
return hsOverlays.size();
}
/**
* add new OverlayItem objects to map OverlayItem ArrayList.
*
* #param overlay
*/
public void addOverlay(OverlayItem overlay) {
hsOverlays.add(overlay);
populate();
}
/**
* Called when user clicks on map overlay.
*/
#Override
protected boolean onTap(int index) {
// TODO Auto-generated method stub
// return super.onTap(index);
OverlayItem item = hsOverlays.get(index);
AlertDialog.Builder dialog = new AlertDialog.Builder(mContext);
dialog.setTitle(item.getTitle());
dialog.setMessage(item.getSnippet());
dialog.show();
return true;
}
You can modify the Location Listener & Broadcasr Receiver according to your need.
I hope this will solve your problem.
Best regards!
I have used this class for detecting my lat & lon:
Hope this is useful for you too.
Example how to use:
GPSUtility.getInstance(Context).getLatitude();
GPSUtility.getInstance(CamPhotoModeAct.this).getLongitude()
public class GPSUtility {
public static final String TAG = "GPSUtility";
private Context ctx;
Timer timer1;
LocationManager lm;
LocationResult locationResult;
boolean gps_enabled=false;
boolean network_enabled=false;
private double latitude;
private double longitude;
private static SharedPreferences SHARED_PREF;
private static SharedPreferences.Editor EDITOR_SHARED_PREF;
private static GPSUtility this_instance;
public GPSUtility(Context ctx){
this.ctx = ctx;
SHARED_PREF = ctx.getSharedPreferences(ConstantsG.SHARED_PREF_FILE, Context.MODE_PRIVATE);
EDITOR_SHARED_PREF = SHARED_PREF.edit();
this.getLocation(innerLocationResult);
}
public static GPSUtility getInstance(Context ctx){
if(this_instance == null)
this_instance = new GPSUtility(ctx);
return this_instance;
}
public static void updateLocation(Context ctx){
GPSUtility.getInstance(ctx);//this writes the latitude and longitude in sharable preference file
}
public double getLatitude(){
String latitudeStr = SHARED_PREF.getString(ConstantsG.KEY_LATITUDE,null);
if(latitudeStr == null){
latitude = 0.0;
}
else{
latitude = Double.parseDouble(latitudeStr);
}
return latitude;
}
public double getLongitude(){
String longitudeStr = SHARED_PREF.getString(ConstantsG.KEY_LONGITUDE,null);
if(longitudeStr == null){
longitude = 0.0;
}
else{
longitude = Double.parseDouble(longitudeStr);
}
return longitude;
}
private void updateWithNewLocation(Location location) {
if (location != null) {
latitude = location.getLatitude();
EDITOR_SHARED_PREF.putString(ConstantsG.KEY_LATITUDE, String.valueOf(latitude) );
longitude = location.getLongitude();
EDITOR_SHARED_PREF.putString(ConstantsG.KEY_LONGITUDE, String.valueOf(longitude));
EDITOR_SHARED_PREF.commit();
}
}
public boolean getLocation(LocationResult result)
{
//I use LocationResult callback class to pass location value from GPSUtility to user code.
locationResult=result;
if(lm==null)
lm = (LocationManager) this.ctx.getSystemService(Context.LOCATION_SERVICE);
//exceptions will be thrown if provider is not permitted.
try {
gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
} catch (Exception ex) {
Log.e(TAG, "Exception error: " + ex.getLocalizedMessage(), ex);
}
try {
network_enabled = lm
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
} catch (Exception ex) {
Log.e(TAG, "Exception error: " + ex.getLocalizedMessage(), ex);
}
//Toast.makeText(context, gps_enabled+" "+network_enabled, Toast.LENGTH_LONG).show();
//don't start listeners if no provider is enabled
if(!gps_enabled && !network_enabled){
Toast.makeText(this.ctx, "You should enable gps or be connected to network.", Toast.LENGTH_LONG).show();
return false;
}
if(gps_enabled)
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
if(network_enabled)
lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
timer1=new Timer();
timer1.schedule(new GetLastLocation(), 10000);
return true;
}
LocationListener locationListenerGps = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerNetwork);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult.gotLocation(location);
lm.removeUpdates(this);
lm.removeUpdates(locationListenerGps);
}
public void onProviderDisabled(String provider) {}
public void onProviderEnabled(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
class GetLastLocation extends TimerTask {
#Override
public void run() {
//Context context = getClass().getgetApplicationContext();
Location net_loc=null, gps_loc=null;
if(gps_enabled)
gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(network_enabled)
net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
//if there are both values use the latest one
if(gps_loc!=null && net_loc!=null){
if(gps_loc.getTime()>net_loc.getTime())
locationResult.gotLocation(gps_loc);
else
locationResult.gotLocation(net_loc);
return;
}
if(gps_loc!=null){
locationResult.gotLocation(gps_loc);
return;
}
if(net_loc!=null){
locationResult.gotLocation(net_loc);
return;
}
locationResult.gotLocation(null);
}
}
public static abstract class LocationResult{
public abstract void gotLocation(Location location);
}
LocationResult innerLocationResult = new LocationResult() {
#Override
public void gotLocation(Location location) {
updateWithNewLocation(location);
}
};
}
I'm building a service that will let me know if the location hasn't change in a period of time for a certain amount of metres.
Then thing is I have the event onLocationChanged on my Listener.. but I don't know how to do the opposite.. that is, send a broadcast if the location is within the distance I provided after some minutes.
This is the code I have so far
LocationService
public class LocationService extends Service {
public static final String LOC_INTENT = "com.xxx.intent.action.LOCATION";
private Thread triggerService;
protected LocationManager locationManager;
protected MyLocationListener MyLocationListener;
protected Criteria criteria;
public static final int MIN_TIME = 300000; // 5 Minutes
public static final long MIN_DISTANCE_MOTOR = 50; // 50 Metres
private SharedPreferences settings;
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId)
{
settings = getSharedPreferences(getString(R.string.settings_prefsName), 0);
addLocationListener();
return START_STICKY;
}
private void addLocationListener()
{
triggerService = new Thread(new Runnable(){
public void run(){
try{
Looper.prepare();//Initialise the current thread as a looper.
locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
final String PROVIDER = locationManager.getBestProvider(criteria, true);
updateLocation(getLastBestLocation(MIN_TIME, MIN_DISTANCE_MOTOR));
MyLocationListener = new MyLocationListener();
locationManager.requestLocationUpdates(PROVIDER, MIN_TIME, MIN_DISTANCE_MOTOR, MyLocationListener);
Log.d("LOC_SERVICE", "Service RUNNING! ("+PROVIDER+")");
Looper.loop();
}catch(Exception ex){
ex.printStackTrace();
}
}
}, "LocationThread");
triggerService.start();
}
public Location getLastBestLocation(int minDistance, long minTime) {
Location bestResult = null;
float bestAccuracy = Float.MAX_VALUE;
long bestTime = Long.MIN_VALUE;
List<String> matchingProviders = locationManager.getAllProviders();
for (String provider: matchingProviders) {
Location location = locationManager.getLastKnownLocation(provider);
if (location != null) {
float accuracy = location.getAccuracy();
long time = location.getTime();
if ((time > minTime && accuracy < bestAccuracy)) {
bestResult = location;
bestAccuracy = accuracy;
bestTime = time;
}
else if (time < minTime && bestAccuracy == Float.MAX_VALUE && time > bestTime) {
bestResult = location;
bestTime = time;
}
}
}
return bestResult;
}
public static void updateLocation(Location location)
{
Context appCtx = MyApplication.getAppContext();
double latitude, longitude;
float speed;
latitude = location.getLatitude();
longitude = location.getLongitude();
speed = location.getSpeed();
Intent filterRes = new Intent();
filterRes.setAction(LOC_INTENT);
filterRes.putExtra("latitude", latitude);
filterRes.putExtra("longitude", longitude);
filterRes.putExtra("speed", speed);
appCtx.sendBroadcast(filterRes);
}
class MyLocationListener implements LocationListener
{
#Override
public void onLocationChanged(Location location)
{
if(settings.getBoolean("active", false))
updateLocation(location);
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
}
Set a timer for however long you want to test this. When it goes off, check if the last location you got in onLocationChanged is older than the timer length.
EDIT
Here is how I would imagine your service looking
Service starting
requestLocationUpdates called with appropriate minimum time and minimum distance that that you will be notified after
Repeating task set where you check if an update was received (check out Timer.scheduleAtFixedRate
Service running
Perform necessary actions when your timer goes off or onLocationChanged is called
Service stopping
Remove location updates with removeUpdates
Stop your timer
I am writing a service that records your gps location every 30 mins. what should I write to turn on a location listener, wait x mins until my location.accuracy is less than 25 meters, then turn off the location listener.
Right now my method is draining too much battery and its not acceptable.
Thank you
I may have a simple piece of code here for you.
When you're starting the GPS, you just define time and distance limitations.
Also don't forget to kill this when you exit your app (last method below)
private static LocationListener gpsLocationListener = null;
/* GPS will not detach and update every 30 minutes if the delta > 25 meters */
private void getGPSLocation(Context context){
gpsLocationListener = new GPSLocationListener();
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1800000, 25, gpsLocationListener);
}
private class GPSLocationListener implements LocationListener{
public void onLocationChanged(Location location){
if(location != null){
final double lat = location.getLatitude();
final double lng = location.getLongitude();
// can do your other implementation here //
}
}
#Override
public void onProviderDisabled(String provider){ }
#Override
public void onProviderEnabled(String provider){ }
#Override
public void onStatusChanged(String provider, int status, Bundle extras){ }
}
private void killGPS(){
if(locationManager != null && gpsLocationListener != null){
locationManager.removeUpdates(gpsLocationListener); }
}
}
Hope this helps
-serkan