Develop Reference

How to update the user location after enabling the GPS from an in App prompt

I am currently developing an Android app which prompts the user to enable GPS if it's not on and I have used AlertDialog for this purpose. After I enable the GPS from settings and come back to my app by pressing back button, the mapView doesn't reflect my current location. Although If I have my GPS on before running the app, the app properly displays my location. I want to know to which method to use for this refresh user location after enabling GPS purpose. Any relevant article would really help.
Following is my code for the GPS part:
GPSTracker.java
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// Flag for GPS status
boolean isGPSEnabled = false;
// Flag for network status
boolean isNetworkEnabled = false;
// Flag for GPS status
boolean canGetLocation = false;
Location location; // Location
double latitude; // Latitude
double longitude; // Longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
/******/
/****/
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// Getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// Getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// No network provider is enabled
} else {
this.canGetLocation = true;
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// If GPS enabled, get latitude/longitude using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app.
*/
public void stopUsingGPS() {
if (locationManager != null) {
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
*/
public double getLatitude() {
if (location != null) {
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
*/
public double getLongitude() {
if (location != null) {
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/Wi-Fi enabled
*
* #return boolean
*/
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog.
* On pressing the Settings button it will launch Settings Options.
*/
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing the Settings button.
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// On pressing the cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}
The following class makes use of above class to display location in a mapView
LocationActivity.java
public class LocationActivity extends Activity {
Button btnGPSShowLocation;
Button btnSendAddress;
Button find_rick;
TextView tvAddress;
AppLocationService appLocationService;
Button btnShowLocation;
// GPSTracker class
GPSTracker gps;
//Google maps implementation
GoogleMap googleMap;
private static final String TAG = LocationActivity.class.getSimpleName();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.location_layout);
createMapView();
btnShowLocation = (Button) findViewById(R.id.btnGPSShowLocation);
btnSendAddress = (Button) findViewById(R.id.btnSendAddress);
gps = new GPSTracker(LocationActivity.this);
// Check if GPS enabled and if enabled after popup then call same fn
MapMyCurrentLoction();
btnShowLocation.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
MapMyCurrentLoction();
}
});
btnSendAddress.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String tag_string_req_send_data = "req_send";
StringRequest strReq = new StringRequest(Request.Method.POST,
AppConfig.URL_AUTOWALA_DHUNDO, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d(TAG, "Autowala Response: " + response.toString());
try {
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("error");
if (!error) {
// User successfully stored in MySQL
// Now store the user in sqlite
Log.d("Autowale ka data","success");
} else {
// Error occurred in data sending. Get the error
// message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Data sending Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting params to register url
Map<String, String> params = new HashMap<String, String>();
params.put("tag", "data_send");
params.put("latitude", Double.toString(gps.getLatitude()));
params.put("longitude", Double.toString(gps.getLongitude()));
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req_send_data);
}
});
}
#Override
protected void onPause(){
super.onPause();
MapMyCurrentLoction();
//super.onResume();
}
#Override
protected void onResume(){
super.onResume();
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
addMarker(latitude,longitude);
//super.onResume();
}
private void createMapView(){
/**
* Catch the null pointer exception that
* may be thrown when initialising the map
*/
try {
if(null == googleMap){
googleMap = ((MapFragment) getFragmentManager().findFragmentById(
R.id.map)).getMap();
googleMap.getUiSettings().setZoomGesturesEnabled(true);
/**
* If the map is still null after attempted initialisation,
* show an error to the user
*/
if(null == googleMap) {
Toast.makeText(getApplicationContext(),
"Error creating map",Toast.LENGTH_SHORT).show();
}
}
} catch (NullPointerException exception){
Log.e("mapApp", exception.toString());
}
}
/**
* Adds a marker to the map
*/
private void addMarker(double lat,double lng){
/** Make sure that the map has been initialised **/
if(null != googleMap){
googleMap.addMarker(new MarkerOptions()
.position(new LatLng(lat,lng))
.title("Your Location")
.draggable(true)
);
//zooming to my location
float zoomLevel = 16.0F; //This goes up to 21
LatLng coordinate = new LatLng(lat, lng);
CameraUpdate yourLocation = CameraUpdateFactory.newLatLngZoom(coordinate, zoomLevel);
googleMap.animateCamera(yourLocation);
}
}
private void MapMyCurrentLoction(){
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
addMarker(latitude,longitude);
/*------- To get city name from coordinates -------- */
String area = null;
Geocoder gcd = new Geocoder(getBaseContext(), Locale.getDefault());
List<Address> addressList = null;
try {
addressList = gcd.getFromLocation(latitude, longitude, 1);
} catch (IOException e) {
e.printStackTrace();
}
if (addressList != null && addressList.size() > 0) {
Address address = addressList.get(0);
StringBuilder sb = new StringBuilder();
for (int i = 0; i < address.getMaxAddressLineIndex(); i++) {
sb.append(address.getAddressLine(i)).append("\n");
}
sb.append(address.getLocality()).append("\n");
sb.append(address.getPostalCode()).append("\n");
sb.append(address.getCountryName());
area = sb.toString();
}
// \n is for new line
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude + "\n"+area, Toast.LENGTH_SHORT).show();
} else {
// Can't get location.
// GPS or network is not enabled.
// Ask user to enable GPS/network in settings.
gps.showSettingsAlert();
//Again search and map my location after enabling gps
}
}
}

You just need to initialize this
gps = new GPSTracker(LocationActivity.this);
at onResume() and at onCreate() and if needed then at onRestart() too.
This is not the correct way but for making it working you can do this.

you`re probably interest in 'onResume' method. After getting back to Activity this one is invoked. Sho in there you should update the position

ensure location accuracy and track user on Google map

My android application function is to track the user location when it walk/run or when he never moves(then location should not change)First, the location is inaccurate and red marker keeps popping out on the map even if i never move. the position where it pops out is also inaccurate.
For those who did similar location tracking app before, the blue dot should be the same place as the latest red marker right? but my blue dot is always away most of the time. red marker shows a more accurate position(although still inaccurate)
i have tested it in my house, outside, in a vehicle. when it is in my house, sometimes location keeps changing, sometimes location never change. i cannot predict it. usually gps don't work well in-house so i leave it first
when i test it outside, sometimes it is better but it is still inaccurate. when i never move/move or move slow it update on the wrong location. althought it is sometimes little better then in roof. but in the end it is still unuseable.
when i test it in the car, it is better as it won't pop out so much location should be more accurate blue dot and red marker are sometimes together. although there are still inaccurate sometimes. but it does not matter as my app is supposed to use when the user is walking/running not in a moving vehicle.
for all three, red marker appears(no matter how frequently) around the correct environment(house, road, certain building) sometimes, but the blue dot is not, most of the times it is wrong. but i wanted the blue dot as a tracker for the user. user would not know which red marker is his current location even if it is accurate. the title "you are here" could appear on any marker when i tap on it, where it is new or old. so it is not effective. and when a new one appear, the title does not appear by itself.
the problem i am trying to solve is to ensure location accuracy, even if not good or perfect at lease be useable, and have the blue dot track the user continuously,or red marker as long as sometimes tell the where is he accurately(title only appears on the latest marker by itself).
i am research for a long time and i do not know what else i can implement to make it more accurate. the distance calculation i believe should be accurate but it depends on the location so it will becomes inaccurate too. sorry for the large text i just thought i should explain myself clearer...
public class MainActivity extends FragmentActivity implements LocationListener{
protected LocationManager locationManager;
private GoogleMap googleMap;
Button btnStartMove,btnPause,btnResume,btnStop;
static double n=0;
Long s1,r1;
double dis=0.0;
Thread t1;
EditText userNumberInput;
boolean bool=false;
int count=0;
double speed = 1.6;
double lat1,lon1,lat2,lon2,lat3,lon3,lat4,lon4;
double dist = 0.0;
double time = 0.0;
double velocity = 0.0;
TextView distance;
Button btnDuration;
float[] result;
private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES =1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 4000; //in milliseconds
boolean startDistance = false;
boolean startButtonClicked = false;
MyCount counter;
int timer = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MINIMUM_TIME_BETWEEN_UPDATES,MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, this);
if(isGooglePlay())
{
setUpMapIfNeeded();
}
distance=(TextView)findViewById(R.id.Distance);
btnDuration=(Button)findViewById(R.id.Duration);
btnStartMove=(Button)findViewById(R.id.Start);//start moving
btnStop=(Button)findViewById(R.id.Stop);
//prepare distance...........
Log.d("GPS Enabled", "GPS Enabled");
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
String provider = locationManager.getBestProvider(criteria, true);
Location location=locationManager.getLastKnownLocation(provider);
btnStartMove.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
Log.d("GPS Enabled", "GPS Enabled");
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
String provider = locationManager.getBestProvider(criteria, true);
Location location=locationManager.getLastKnownLocation(provider);
lat3 = location.getLatitude();
lon3 = location.getLongitude();
startButtonClicked=true;
startDistance=true;
counter= new MyCount(30000,1000);
counter.start();
btnStartMove.setText("Started...");
}
});
btnStop.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
startButtonClicked=false;
startDistance=false;
//Double.valueOf(distance.getText().toString()
Double value=dist;
Double durationValue=time;
Double speedValue=velocity;
Intent intent = new Intent(MainActivity.this, FinishActivity.class);
intent.putExtra("dist", value);
intent.putExtra("time",durationValue);
intent.putExtra("velocity",speedValue);
startActivity(intent);
counter.cancel();
n=0;
r1=null;
time=0.0;
btnStartMove.setText("Start Move");
finish();
}
});
btnDuration.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
if(startButtonClicked=true)
{
time=n*30+r1;
velocity=dist/time;
DecimalFormat df = new DecimalFormat("#.##");
Toast.makeText(MainActivity.this,"Duration :"+String.valueOf(time) + "Speed :"+String.valueOf(df.format(velocity)),Toast.LENGTH_LONG).show();
}
}
});
if(location!= null)
{
//Display current location in Toast
String message = String.format(
"Current Location \n Longitude: %1$s \n Latitude: %2$s",
location.getLongitude(), location.getLatitude()
);
Toast.makeText(MainActivity.this, message,
Toast.LENGTH_LONG).show();
}
else if(location == null)
{
Toast.makeText(MainActivity.this,
"Location is null",
Toast.LENGTH_LONG).show();
}
}
private void setUpMapIfNeeded() {
if(googleMap == null)
{
googleMap =((SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.displayMap)).getMap();
if(googleMap != null)
{
setUpMap();
}
}
}
private void setUpMap()
{
//Enable MyLocation Layer of Google Map
googleMap.setMyLocationEnabled(true);
//Get locationManager object from System Service LOCATION_SERVICE
//LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
//Create a criteria object to retrieve provider
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
//Get the name of the best provider
String provider = locationManager.getBestProvider(criteria, true);
if(provider == null)
{
onProviderDisabled(provider);
}
//set map type
googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
//Get current location
Location myLocation = locationManager.getLastKnownLocation(provider);
if(myLocation != null)
{
double latitude = myLocation.getLatitude();
//Get longitude of the current location
double longitude = myLocation.getLongitude();
//Create a LatLng object for the current location
LatLng latLng = new LatLng(latitude, longitude);
//Show the current location in Google Map
googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
//Zoom in the Google Map
googleMap.animateCamera(CameraUpdateFactory.zoomTo(20));
googleMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).snippet("You are here!").title("You are here!"));
}
locationManager.requestLocationUpdates(provider, 0, 0, this);
}
private boolean isGooglePlay()
{
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (status == ConnectionResult.SUCCESS)
{
Toast.makeText(MainActivity.this, "Google Play Services is available",
Toast.LENGTH_LONG).show();
return(true);
}
else
{
GooglePlayServicesUtil.getErrorDialog(status, this, 10).show();
}
return (false);
}
#Override
public void onLocationChanged(Location myLocation) {
System.out.println("speed " + myLocation.getSpeed());
//show location on map.................
//Get latitude of the current location
double latitude = myLocation.getLatitude();
//Get longitude of the current location
double longitude = myLocation.getLongitude();
//Create a LatLng object for the current location
LatLng latLng = new LatLng(latitude, longitude);
//Show the current location in Google Map
googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
//Zoom in the Google Map
googleMap.animateCamera(CameraUpdateFactory.zoomTo(20));
googleMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).snippet("You are here!").title("You are here!"));
//show distance............................
if(startDistance == true)
{
Toast.makeText(MainActivity.this,
"Location has changed",
Toast.LENGTH_LONG).show();
if(myLocation != null)
{
//latitude.setText("Current Latitude: " + String.valueOf(loc2.getLatitude()));
//longitude.setText("Current Longitude: " + String.valueOf(loc2.getLongitude()));
float[] results = new float[1];
Location.distanceBetween(lat3, lon3, myLocation.getLatitude(), myLocation.getLongitude(), results);
System.out.println("Distance is: " + results[0]);
dist += results[0];
DecimalFormat df = new DecimalFormat("#.##"); // adjust this as appropriate
if(count==1)
{
distance.setText(df.format(dist) + "meters");
}
lat3=myLocation.getLatitude();
lon3=myLocation.getLongitude();
count=1;
}
}
if(startButtonClicked == true)
{
startDistance=true;
}
}
#Override
public void onProviderDisabled(String provider) {
Toast.makeText(MainActivity.this,
"Provider disabled by the user. GPS turned off",
Toast.LENGTH_LONG).show();
}
#Override
public void onProviderEnabled(String provider) {
Toast.makeText(MainActivity.this,
"Provider enabled by the user. GPS turned on",
Toast.LENGTH_LONG).show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Toast.makeText(MainActivity.this, "Provider status changed",
Toast.LENGTH_LONG).show();
}
#Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}
#Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MINIMUM_TIME_BETWEEN_UPDATES,MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, this);
}
public class MyCount extends CountDownTimer{
public MyCount(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
}
#Override
public void onFinish() {
counter= new MyCount(30000,1000);
counter.start();
n=n+1;
}
#Override
public void onTick(long millisUntilFinished) {
s1=millisUntilFinished;
r1=(30000-s1)/1000;
}
}}

wrong location on Google Map. cannot retrieve correct distance to next Activity

My android app is to track user location on a map and calculate the distance and duration he has walked or run. Then when i press stop, pass it over to the next page.
My distance and duration calculation should be correct, but the location is wrong. whether i don't move or move a few meters in my house, it sometimes never change or change a lot, result in the distance being inaccurate. how do i ensure accuracy for when i walked, even a few meters, because when i present i will be walking for a short distance.
second, i can pass my duration data over to the next page, but when i pass my distance it is 0.0 but the value shown is not 0.0 at all(got value although inaccurate). i pass my information when i press Stop button.
My MainActivity Java Code, display map, distance, duration.
protected LocationManager locationManager;
private GoogleMap googleMap;
Button btnStartMove,btnPause,btnResume,btnStop;
static double n=0;
Long s1,r1;
double dis=0.0;
Thread t1;
EditText userNumberInput;
boolean bool=false;
int count=0;
double speed = 1.6;
double lat1,lon1,lat2,lon2,lat3,lon3,lat4,lon4;
double dist = 0.0;
double time = 0.0;
TextView distance;
Button btnDuration;
float[] result;
private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES =1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 4000; //in milliseconds
boolean startDistance = false;
boolean startButtonClicked = false;
MyCount counter;
int timer = 0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MINIMUM_TIME_BETWEEN_UPDATES,MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, this);
if(isGooglePlay())
{
setUpMapIfNeeded();
}
distance=(TextView)findViewById(R.id.Distance);
btnDuration=(Button)findViewById(R.id.Duration);
btnStartMove=(Button)findViewById(R.id.Start);//start moving
btnStop=(Button)findViewById(R.id.Stop);
//prepare distance...........
Log.d("GPS Enabled", "GPS Enabled");
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
String provider = locationManager.getBestProvider(criteria, true);
Location location=locationManager.getLastKnownLocation(provider);
btnStartMove.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
Log.d("GPS Enabled", "GPS Enabled");
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
String provider = locationManager.getBestProvider(criteria, true);
Location location=locationManager.getLastKnownLocation(provider);
lat3 = location.getLatitude();
lon3 = location.getLongitude();
startButtonClicked=true;
startDistance=true;
counter= new MyCount(30000,1000);
counter.start();
Toast.makeText(MainActivity.this,
"Pressed Start",
Toast.LENGTH_LONG).show();
}
});
btnStop.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
startButtonClicked=false;
startDistance=false;
//Double.valueOf(distance.getText().toString()
Double value=dist;
Double durationValue=time;
Intent intent = new Intent(MainActivity.this, FinishActivity.class);
intent.putExtra("dist", "value");
intent.putExtra("time",durationValue);
startActivity(intent);
finish();
}
});
btnDuration.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
if(startButtonClicked=true)
{
time=n*30+r1;
Toast.makeText(MainActivity.this,"Duration :"+String.valueOf(time),Toast.LENGTH_LONG).show();
}
}
});
if(location!= null)
{
//Display current location in Toast
String message = String.format(
"Current Location \n Longitude: %1$s \n Latitude: %2$s",
location.getLongitude(), location.getLatitude()
);
Toast.makeText(MainActivity.this, message,
Toast.LENGTH_LONG).show();
}
else if(location == null)
{
Toast.makeText(MainActivity.this,
"Location is null",
Toast.LENGTH_LONG).show();
}
}
private void setUpMapIfNeeded() {
if(googleMap == null)
{
Toast.makeText(MainActivity.this, "Getting map",
Toast.LENGTH_LONG).show();
googleMap =((SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.displayMap)).getMap();
if(googleMap != null)
{
setUpMap();
}
}
}
private void setUpMap()
{
//Enable MyLocation Layer of Google Map
googleMap.setMyLocationEnabled(true);
//Get locationManager object from System Service LOCATION_SERVICE
//LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
//Create a criteria object to retrieve provider
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
//Get the name of the best provider
String provider = locationManager.getBestProvider(criteria, true);
if(provider == null)
{
onProviderDisabled(provider);
}
//set map type
googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
//Get current location
Location myLocation = locationManager.getLastKnownLocation(provider);
if(myLocation != null)
{
onLocationChanged(myLocation);
}
locationManager.requestLocationUpdates(provider, 0, 0, this);
}
private boolean isGooglePlay()
{
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (status == ConnectionResult.SUCCESS)
{
Toast.makeText(MainActivity.this, "Google Play Services is available",
Toast.LENGTH_LONG).show();
return(true);
}
else
{
GooglePlayServicesUtil.getErrorDialog(status, this, 10).show();
}
return (false);
}
#Override
public void onLocationChanged(Location myLocation) {
System.out.println("speed " + myLocation.getSpeed());
//show location on map.................
//Get latitude of the current location
double latitude = myLocation.getLatitude();
//Get longitude of the current location
double longitude = myLocation.getLongitude();
//Create a LatLng object for the current location
LatLng latLng = new LatLng(latitude, longitude);
//Show the current location in Google Map
googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
//Zoom in the Google Map
googleMap.animateCamera(CameraUpdateFactory.zoomTo(20));
googleMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).title("You are here!"));
//show distance............................
if(startDistance == true)
{
Toast.makeText(MainActivity.this,
"Location has changed",
Toast.LENGTH_LONG).show();
if(myLocation != null)
{
//latitude.setText("Current Latitude: " + String.valueOf(loc2.getLatitude()));
//longitude.setText("Current Longitude: " + String.valueOf(loc2.getLongitude()));
float[] results = new float[1];
Location.distanceBetween(lat3, lon3, myLocation.getLatitude(), myLocation.getLongitude(), results);
System.out.println("Distance is: " + results[0]);
dist += results[0];
DecimalFormat df = new DecimalFormat("#.##"); // adjust this as appropriate
if(count==1)
{
distance.setText(df.format(dist) + "meters");
}
lat3=myLocation.getLatitude();
lon3=myLocation.getLongitude();
count=1;
}
}
if(startButtonClicked == true)
{
startDistance=true;
}
}
#Override
public void onProviderDisabled(String provider) {
Toast.makeText(MainActivity.this,
"Provider disabled by the user. GPS turned off",
Toast.LENGTH_LONG).show();
}
#Override
public void onProviderEnabled(String provider) {
Toast.makeText(MainActivity.this,
"Provider enabled by the user. GPS turned on",
Toast.LENGTH_LONG).show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Toast.makeText(MainActivity.this, "Provider status changed",
Toast.LENGTH_LONG).show();
}
#Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}
#Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MINIMUM_TIME_BETWEEN_UPDATES,MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, this);
}
public class MyCount extends CountDownTimer{
public MyCount(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
}
#Override
public void onFinish() {
counter= new MyCount(30000,1000);
counter.start();
n=n+1;
}
#Override
public void onTick(long millisUntilFinished) {
s1=millisUntilFinished;
r1=(30000-s1)/1000;
}
}}
pass information to this page,distance 0.0(inaccurate) duration is ok
public class FinishActivity extends Activity {
TextView displayDistance;
TextView displayDuration;
TextView displaySports;
TextView userID;
TextView sportID;
TextView caloriesBurned;
Button back;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_finish);
Bundle extras = getIntent().getExtras();
if (extras != null)
{
Double value = extras.getDouble("dist");
Double durationValue = extras.getDouble("time");
displayDistance=(TextView)findViewById(R.id.finishDistance);
displayDistance.setText("Distance: " + value);
displayDuration=(TextView)findViewById(R.id.finishDuration);
displayDuration.setText("Duration: " + durationValue + " seconds");
}
back=(Button)findViewById(R.id.Back);
back.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
Intent intent = new Intent(FinishActivity.this, MainActivity.class);
startActivity(intent);
finish();
}
});}
My output for my map, inaccurate location. i search for long but there seem to be no solution for this..please help..thanks. the starting location, speed where it change location, all seem to be different each time i run. it appear to be out of my control(or i can but i do not know..i'm a beginner at gps... most of the time it needs to wait a while before displaying the distance.

Gps may not work well under the roof. So try it outside the house.
Also you have
intent.putExtra("dist", "value")
key is dist
value is a string not a double
SO you are passing string
But when you get you get the double
Double value = extras.getDouble("dist"); // wrong
If you pass a double value then you can get the double in the next activity. But you pass string and then you try to get the double value and that is wrong.
What you need
public Intent putExtra (String name, double value)
and
public double getDoubleExtra (String name, double defaultValue)

jumping location on google maps by gps. (inaccurate distance)

my app should display the distance and location in real time when the user walked, but there are errors with my output.
the distance did not start immediately but when it start it increase a lot until it slows down a bit.
the red marker and blue dot should be together according to one example I've seen but they are separate in my app. both of them point my current location right?
both red marker and blue dot jumps around in a short time that i was not moving that is away from my true location. which i believe lead to the inaccuracy of the distance as well.
please see my output for more details
java code
public class MainActivity extends FragmentActivity implements LocationListener{
protected LocationManager locationManager;
private GoogleMap googleMap;
Button btnStartMove,btnPause,btnResume,btnStop;
static double n=0;
Long s1,r1;
double dis=0.0;
Thread t1;
EditText userNumberInput;
boolean bool=false;
int count=0;
double speed = 1.6;
double lat1,lon1,lat2,lon2,lat3,lon3,lat4,lon4;
double dist = 0;
TextView distanceText;
float[] result;
private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES =1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 3000; //in milliseconds
boolean startDistance = false;
boolean firstTime = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MINIMUM_TIME_BETWEEN_UPDATES,MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, this);
if(isGooglePlay())
{
setUpMapIfNeeded();
}
distanceText=(TextView)findViewById(R.id.Distance);
btnStartMove=(Button)findViewById(R.id.Start);//start moving
//prepare distance...........
Log.d("GPS Enabled", "GPS Enabled");
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
String provider = locationManager.getBestProvider(criteria, true);
Location location=locationManager.getLastKnownLocation(provider);
btnStartMove.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
startDistance = true;
// lat3 = location.getLatitude();
// lon3 = location.getLongitude();
}
});
if(location!= null)
{
//Display current location in Toast
String message = String.format(
"Current Location \n Longitude: %1$s \n Latitude: %2$s",
location.getLongitude(), location.getLatitude()
);
Toast.makeText(MainActivity.this, message,
Toast.LENGTH_LONG).show();
//Display current location in textview
//latitude.setText("Current Latitude: " + String.valueOf(location.getLatitude()));
//longitude.setText("Current Longitude: " + String.valueOf(location.getLongitude()));
//lat3 = location.getLatitude();
//lon3 = location.getLongitude();
}
else if(location == null)
{
Toast.makeText(MainActivity.this,
"Location is null",
Toast.LENGTH_LONG).show();
}
}
private void setUpMapIfNeeded() {
if(googleMap == null)
{
Toast.makeText(MainActivity.this, "Getting map",
Toast.LENGTH_LONG).show();
googleMap =((SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.displayMap)).getMap();
if(googleMap != null)
{
setUpMap();
}
}
}
private void setUpMap()
{
//Enable MyLocation Layer of Google Map
googleMap.setMyLocationEnabled(true);
//Get locationManager object from System Service LOCATION_SERVICE
//LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
//Create a criteria object to retrieve provider
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
//Get the name of the best provider
String provider = locationManager.getBestProvider(criteria, true);
if(provider == null)
{
onProviderDisabled(provider);
}
//set map type
googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
//Get current location
Location myLocation = locationManager.getLastKnownLocation(provider);
if(myLocation != null)
{
onLocationChanged(myLocation);
}
locationManager.requestLocationUpdates(provider, 0, 0, this);
}
private boolean isGooglePlay()
{
int status = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (status == ConnectionResult.SUCCESS)
{
Toast.makeText(MainActivity.this, "Google Play Services is available",
Toast.LENGTH_LONG).show();
return(true);
}
else
{
GooglePlayServicesUtil.getErrorDialog(status, this, 10).show();
}
return (false);
}
#Override
public void onLocationChanged(Location myLocation) {
System.out.println("speed " + myLocation.getSpeed());
// if(myLocation.getSpeed() > speed)
// {
//show location on map.................
//Get latitude of the current location
double latitude = myLocation.getLatitude();
//Get longitude of the current location
double longitude = myLocation.getLongitude();
//Create a LatLng object for the current location
LatLng latLng = new LatLng(latitude, longitude);
//Show the current location in Google Map
googleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
//Zoom in the Google Map
googleMap.animateCamera(CameraUpdateFactory.zoomTo(20));
googleMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).title("You are here!"));
//show distance............................
if(startDistance == true)
{
Toast.makeText(MainActivity.this,
"Location has changed",
Toast.LENGTH_LONG).show();
if(myLocation != null)
{
//latitude.setText("Current Latitude: " + String.valueOf(loc2.getLatitude()));
//longitude.setText("Current Longitude: " + String.valueOf(loc2.getLongitude()));
float[] results = new float[1];
Location.distanceBetween(lat3, lon3, myLocation.getLatitude(), myLocation.getLongitude(), results);
System.out.println("Distance is: " + results[0]);
dist += results[0];
DecimalFormat df = new DecimalFormat("#.##"); // adjust this as appropriate
if(count==1)
{
distanceText.setText(df.format(dist) + "meters");
}
lat3=myLocation.getLatitude();
lon3=myLocation.getLongitude();
count=1;
}
}
startDistance=true;
//}
}
#Override
public void onProviderDisabled(String provider) {
Toast.makeText(MainActivity.this,
"Provider disabled by the user. GPS turned off",
Toast.LENGTH_LONG).show();
}
#Override
public void onProviderEnabled(String provider) {
Toast.makeText(MainActivity.this,
"Provider enabled by the user. GPS turned on",
Toast.LENGTH_LONG).show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Toast.makeText(MainActivity.this, "Provider status changed",
Toast.LENGTH_LONG).show();
}
#Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}
#Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MINIMUM_TIME_BETWEEN_UPDATES,MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, this);
}}
there seem to be no way to solve my error.i was recommeded to use location.getSpeed but it returns 0.

Current location from latitude and longitude

I am using two methods for it getAddress() and address()..One to get latitude and and other one to get address from latitude and longitude..
public String getAddress(){
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
location = locationManager.getLastKnownLocation(locationManager.NETWORK_PROVIDER);
latitude= location.getLatitude();
longitude= location.getLongitude();
try {
val = address(latitude, longitude);
} catch (IOException e) {
e.printStackTrace();
}
Toast.makeText( CurrentLoc.this, val,
Toast.LENGTH_LONG).show();
return val;
}
Using another method to get address():
public String address(double lt,double lg) throws IOException{
Geocoder geocoder;
List<Address> addresses;
geocoder = new Geocoder(this, Locale.getDefault());
addresses = geocoder.getFromLocation(lt, lg, 1);
String address = addresses.get(0).getAddressLine(0);
String city = addresses.get(0).getAddressLine(1);
String country = addresses.get(0).getAddressLine(2);
return address +"\n"+ city +"\n"+ country;
}
To get current location on map using InitializeMap():
private void initilizeMap() {
if (googleMap == null) {
googleMap = ((MapFragment) getFragmentManager().findFragmentById(
R.id.map)).getMap();
CameraPosition cameraPosition = new CameraPosition.Builder().target(
new LatLng(location.getLatitude(), location.getLongitude())).zoom(12).build();
googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
MarkerOptions marker = new MarkerOptions().position(new LatLng(location.getLatitude(), location.getLongitude())).title("Hello Maps ");
googleMap.addMarker(marker);
googleMap.isMyLocationEnabled();
// check if map is created successfully or not
if (googleMap == null) {
Toast.makeText(getApplicationContext(),
"Sorry! unable to create maps", Toast.LENGTH_SHORT)
.show();
}
}
}
And the full code is following but the problem is that not getting address:
public class CurrentLoc extends Activity {
// latitude and longitude
static double latitude ;
static double longitude ;
// Google Map
private GoogleMap googleMap;
private LocationManager locationManager;
private Location location;
private String val,val1;
private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 1000; // in Milliseconds
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.new3);
locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MINIMUM_TIME_BETWEEN_UPDATES,
MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
new MyLocationListener()
);
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MINIMUM_TIME_BETWEEN_UPDATES, MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, new MyLocationListener());
val1 = getAddress();
// Loading map
initilizeMap();
}
/**
* function to load map. If map is not created it will create it for you
* */
public String getAddress(){
location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
location = locationManager.getLastKnownLocation(locationManager.NETWORK_PROVIDER);
latitude= location.getLatitude();
longitude= location.getLongitude();
try {
val = address(latitude, longitude);
} catch (IOException e) {
e.printStackTrace();
}
Toast.makeText( CurrentLoc.this, val,
Toast.LENGTH_LONG).show();
return val;
}
public String address(double lt,double lg) throws IOException{
Geocoder geocoder;
List<Address> addresses;
geocoder = new Geocoder(this, Locale.getDefault());
addresses = geocoder.getFromLocation(lt, lg, 1);
String address = addresses.get(0).getAddressLine(0);
String city = addresses.get(0).getAddressLine(1);
String country = addresses.get(0).getAddressLine(2);
return address +"\n"+ city +"\n"+ country;
}
private class MyLocationListener implements LocationListener {
public void onLocationChanged(Location location) {
String message = String.format(
"New Location \n Longitude: %1$s \n Latitude: %2$s",
location.getLongitude(), location.getLatitude()
);
Toast.makeText(CurrentLoc.this, message, Toast.LENGTH_LONG).show();
}
public void onStatusChanged(String s, int i, Bundle b) {
Toast.makeText(CurrentLoc.this, "Provider status changed",
Toast.LENGTH_LONG).show();
}
public void onProviderDisabled(String s) {
Toast.makeText(CurrentLoc.this,
"Provider disabled by the user. GPS turned off",
Toast.LENGTH_LONG).show();
}
public void onProviderEnabled(String s) {
Toast.makeText(CurrentLoc.this,
"Provider enabled by the user. GPS turned on",
Toast.LENGTH_LONG).show();
}
}
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
#SuppressLint("NewApi")
private void initilizeMap() {
if (googleMap == null) {
googleMap = ((MapFragment) getFragmentManager().findFragmentById(
R.id.map)).getMap();
CameraPosition cameraPosition = new CameraPosition.Builder().target(
new LatLng(location.getLatitude(), location.getLongitude())).zoom(12).build();
googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
MarkerOptions marker = new MarkerOptions().position(new LatLng(location.getLatitude(), location.getLongitude())).title("Hello Maps ");
googleMap.addMarker(marker);
googleMap.isMyLocationEnabled();
// check if map is created successfully or not
if (googleMap == null) {
Toast.makeText(getApplicationContext(),
"Sorry! unable to create maps", Toast.LENGTH_SHORT)
.show();
}
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.mnew1, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle presses on the action bar items
switch (item.getItemId()) {
case R.id.home:
openSearch();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
private void openSearch(){
Intent intnt=new Intent(getApplicationContext(),SendSms.class);
intnt.putExtra("loct", val1);
startActivity(intnt);
}
}

First you have to do Googling:
Like This: Googling
You will get Following Link:
Displaying a Location Address

use the following code to get address using geocode. Make sure that you have INTERNET permission in your androidManifest.xml
List<Address> addressList = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
StringBuilder stringBuilder = new StringBuilder();
if (addressList.size() > 0) {
Address address = addressList.get(0);
for (int i = 0; i < address.getMaxAddressLineIndex(); i++) {
stringBuilder.append(address.getAddressLine(i)).append("\n");
stringBuilder.append(address.getLocality()).append("\n");
stringBuilder.append(address.getPostalCode()).append("\n");
stringBuilder.append(address.getCountryName()).append("\n");
}
addressString = stringBuilder.toString();
}