I want to reload MainActivity after data change. So I wrote this code and it working well.
This is from MainActivity, that i want to reload:
public class MainActivity extends Activity {
private static final int RESULT_SETTINGS = 1;
LinearLayout horizontalForecast, todayForecast, tomorrowForecast;
TextView ViewSunRise, ViewSunSet, NowTatva, NextTejas, Longitude, Latitude, BeziT, TatvicForecast;
TextView Today, Tomorrow, NextTatva;
GPSTracker gps;
ImageView img;
TabHost th;
public void reload() {
finish();
Intent i2 = new Intent(MainActivity.this, MainActivity.class);
startActivityForResult(i2, RESULT_SETTINGS);
}
}
But when I call this from another Class (not an activity), it doesn't work.
This is from another Class:
package com.reversity.simpletatva;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
MainActivity MA;
boolean ch = false;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location = null; // location
double latitude = Double.NaN; // latitude
double longitude = Double.NaN; // 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
protected static final int RESULT_SETTINGS = 1;
// 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;
// First get location from Network Provider
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long 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/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS");
// Setting Dialog Message
alertDialog.setMessage("GPS není zapnuta, lokace byla nastavena na 0. Chcete přejít do nastavení nebo nastavit vlastní?");
// On pressing Settings button
alertDialog.setPositiveButton("Nastavení", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Použít vlastní", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent i = new Intent(mContext, Preference.class);
mContext.startActivity(i);
}
});
// Showing Alert Message
alertDialog.show();
}
#Override
public void onLocationChanged(Location location) {
/*
Toast changed = Toast.makeText(mContext, "Location changes", Toast.LENGTH_LONG);
changed.show();
MA.reload();
startActivity(new Intent(mContext, MainActivity.class));
invalidate();
*/
stopUsingGPS();
MainActivity mainActivity = new MainActivity ();
mainActivity.reload();
}
#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;
}
public Boolean locChanged(){
return ch;
}
}
So I want to Reload MainActivity from GPSTracker Class when onLocationChanged();
I don't find answer that will be usefull for me. So I ask this question. Don't blame me.
I just need how can I call the MainActivity to reload from GPSTracker Class.
I tried everything I know. But it isn't working and Aplication will close.
Error NullPointerException
You're trying to call a non-static method from a static context.
Either make your reload method static, or use a reference to an instance of MainActivity (e.g. MainActivity myActivity; myActivity.reload())
Alternatively, perhaps you meant for Activity2 to extend MainActivity?
You need to pass the second class a reference to MainActivity, and call reload() on that reference.
For a generic class:
public class SecondClass {
MainActivity mActivity;
// Constructor where you pass a reference to MainActivity
public SecondClass(Activity activity) {
mActivity = activity;
}
public onChange() {
mActivity.reload();
}
}
When you initialize the SecondClass in MainActivity you pass a reference to MainActivity
SecondClass secondClass = new SecondClass(this);
Then you can use onChange(), and MainActivity.reload() should get called.
secondClass.onChange();
EDIT:
Well, now that you updated your question, my answer is no longer correct. Since your second class is a Service, keeping references to your MainActivity might create memory leaks.
I would solve this with registering a BroadcastReceiver in your MainActivity. In your Service, you broadcast an Intent when an updated is needed.
This would look something like this:
In MainActivity:
public void MainActivity extends Activity {
private BroadcastReceiver mReceiver;
#Override
public void onCreate(Bundle savedInstanceState) {
.
.
.
// We listen for a broadcasted Intent with
// action = com.example.ACTION_RELOAD_MAINACTIVITY
IntentFilter filter = new IntentFilter();
filter.addAction("com.example.ACTION_RELOAD_MAINACTIVITY");
// Init the receiver
mReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Reload when we receive the broadcast
MainActivity.this.reload();
}
}
// Register the receiver
registerReceiver(mReceiver, filter);
}
// In onDestroy() we unregister the receiver
#Override
public void onDestroy() {
unregisterReceiver(mReceiver);
}
}
In your Service, you now have to broadcast an Intent when you want to reload MainActivity.
public class GPSTracker extends Service implements LocationListener {
.
.
.
#Override
public void onLocationChanged(Location location) {
// Create an Intent with
// action = com.example.ACTION_RELOAD_MAINACTIVITY
Intent i = new Intent("com.example.ACTION_RELOAD_MAINACTIVITY");
// As a side note; You can use this Intent to send data to MainActivity.
// If you want to pass the Location object of onLocationChanged() to
// MainActivity, you would simply call i.putExtra("current_location", location)
// The data can then be fetched using the supplied Intent in onReceive().
// Broadcast that Intent
sendBroadcast(i);
}
}
what you can do just add this in the Androidmanifest.xml file where you declared your main activity inside the activity tag
android:finishOnTaskLaunch="true"
and remove finish(); from the reload method.
Now in GPSTracker class just start the activity by calling
Intent intent=new Intent(mContext,MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
mContext.startActivity(intent);
Related
I used async task for upload image in the background thread to show a progress dialog. But while getting a location from async task, it throws the following error:
java.lang.RuntimeException: Can't create handler inside thread that
has not called Looper.prepare()
Although it is work without an async task. I want that process of getting location done in a background thread so that main thread can work without disturbance.
I got error in GPSlocater.java at locationmanager.requestLocationUpdates() while calling from async task.
So what should I do?
This is onLocate function which calls from mainActivity.java
public void onLocate(View view) {
asyncG asyncG1 = new asyncG(this);
asyncG1.execute();
}
This is a sub class which created in mainActivity.java
class asyncG extends AsyncTask
{
Context context;
ProgressDialog progressDialog;
public asyncG(MainActivity mainActivity) {
this.context = mainActivity;
}
#Override
protected Object doInBackground(Object[] objects) {
GPSlocater gpSlocater = new GPSlocater(context);
gpSlocater.getLocation();
lat = gpSlocater.getLatitude();
longi = gpSlocater.getLongitude();
return null;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog = new ProgressDialog(context);
progressDialog.setMessage("Finding Location");
progressDialog.show();
}
#Override
protected void onPostExecute(Object o) {
super.onPostExecute(o);
progressDialog.dismiss();
Geocoder geocoder = new Geocoder(context, Locale.getDefault());
try {
List<Address> arr;
arr = geocoder.getFromLocation(lat,longi,1);
String pincode = arr.get(0).getPostalCode();
String stat = arr.get(0).getAdminArea();
String city1 = arr.get(0).getLocality();
String city2 = arr.get(0).getSubAdminArea();
String area1 = arr.get(0).getSubLocality();
String area2 = arr.get(0).getLocality();
if(pincode!=null && stat!=null)
{
state.setText(stat);
pin.setText(pincode);
}
if(city1!=null)
{
city.setText(city1);
}
else if(city2!=null)
{
city.setText(city2);
}
if(area1!=null)
{
area.setText(area1);
}
else if(area2!=null)
{
area.setText(area2);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
This is GPSlocater class which called from doInBackground
package com.example.samarth.serviceprovider1;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;
public class GPSlocater 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 GPSlocater(Context context) {
this.mContext = context;
}
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
showSettingsAlert();
} else {
this.canGetLocation = true;
// First get location from Network Provider
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long 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(GPSlocater.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/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing 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 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;
}
}
you need to create a handler to access UI elements from a thread.
https://developer.android.com/training/multiple-threads/communicate-ui.html
This tutorial should get you going, good luck (:
I'm really sorry ahead of time, but this question is pretty lengthy.
I have a functioning GPSTracker class that contains the means of pinging GPS Location for a device. In my MainActivity, I have a button that uses the GPS tracker to display the location in a toast. I'm trying to convert this button into an automatic action to be repeated every X minutes, let's go with 10.(Right now the alarm receiver is setup for 10 seconds)
Even when the app is in the background. So I set up an AlarmReceiver to try to do this, but I can't quite get it working.
Here's my GPSTracker class:
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
public class GPSTracker extends Service implements LocationListener {
private final Context context;
boolean isGPSEnabled = false;
boolean canGetLocation = false;
boolean isNetworkEnabled = false;
Location location;
double latitude;
double longitude;
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10;
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1;
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.context = context.getApplicationContext();
getLocation();
}
public Location getLocation(){
try {
locationManager = (LocationManager) context.getSystemService(LOCATION_SERVICE);
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if(!isGPSEnabled && !isNetworkEnabled) {
}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(isGPSEnabled){
if(location == null){
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
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;
}
public void stopUsingGPS() {
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
public double getLatitude() {
if(location!= null){
latitude = location.getLatitude();
}
return latitude;
}
public double getLongitude() {
if(location !=null){
longitude = location.getLongitude();
}
return longitude;
}
public boolean canGetLocation(){
return this.canGetLocation;
}
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);
alertDialog.setTitle("GPS is settings");
alertDialog.setMessage("GPS isn't enabled. Do you want to go to settings menu?");
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
context.startActivity(intent);
}
});
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int i) {
dialog.cancel();
}
});
alertDialog.show();
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
#Override
public void onProviderEnabled(String s) {
}
#Override
public void onProviderDisabled(String s) {
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
And here's my MainActivity:
package com.example.gwyn.locationnabtest;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
public class MainActivity extends ActionBarActivity {
Button btnShowLocation;
Button btnStartService;
Button btnStopService;
GPSTracker gps;
//GoogleMap mMap;
private PendingIntent pendingIntent;
private AlarmManager manager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnShowLocation = (Button) findViewById(R.id.show_location);
btnShowLocation.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View view) {
FragmentActivity activity = (FragmentActivity)view.getContext();
FragmentManager manager = activity.getSupportFragmentManager();
//MapFragment myMap = (MapFragment) (MainActivity.getFragmentManager()).findFragmentById((R.id.mapFragment));
// Test, remove me.
// mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.mapFragment)).getMap();
gps = new GPSTracker(MainActivity.this);
if(gps.canGetLocation()) {
// Location Achieved.
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// Draw Marker for Current Location on Fragment
// Currently Crashing App
// mMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).title("Marker"));
// Toast a popup of the location data.
Toast.makeText(getApplicationContext(), "Your Location is -\nLat:" + latitude + "\nLong:" + longitude, Toast.LENGTH_LONG).show();
} else {
gps.showSettingsAlert();
}
}
});
Intent alarmIntent = new Intent(this, AlarmReceiver.class);
pendingIntent = PendingIntent.getBroadcast(this, 0, alarmIntent, 0);
btnStartService = (Button) findViewById(R.id.start_service);
btnStartService.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
manager = (AlarmManager)getSystemService(Context.ALARM_SERVICE);
int interval = 10000;
// 10 Second Interval. Good for testing, but turn this off.
manager.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), interval, pendingIntent);
Toast.makeText(getApplicationContext(), "Service Started", Toast.LENGTH_SHORT).show();
//startService(new Intent(getBaseContext(), MyServices.class));
}
});
btnStopService = (Button) findViewById(R.id.stop_service);
btnStopService.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Cancel pending intents
manager.cancel(pendingIntent);
Toast.makeText(getApplicationContext(), "Pending Intents Cancelled", Toast.LENGTH_SHORT).show();
}
});
}
}
To highlight specifically, this is the part in MainActivity that works to display the GPS:
public void onClick(View view) {
FragmentActivity activity = (FragmentActivity)view.getContext();
FragmentManager manager = activity.getSupportFragmentManager();
//MapFragment myMap = (MapFragment) (MainActivity.getFragmentManager()).findFragmentById((R.id.mapFragment));
// Test, remove me.
// mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.mapFragment)).getMap();
gps = new GPSTracker(MainActivity.this);
if(gps.canGetLocation()) {
// Location Achieved.
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// Draw Marker for Current Location on Fragment
// Currently Crashing App
// mMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).title("Marker"));
// Toast a popup of the location data.
Toast.makeText(getApplicationContext(), "Your Location is -\nLat:" + latitude + "\nLong:" + longitude, Toast.LENGTH_LONG).show();
} else {
gps.showSettingsAlert();
}
}
My AlarmReceiver is as follows, and produces an error when creating the GPSTracker:
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;
public class AlarmReceiver extends BroadcastReceiver {
GPSTracker gps;
#Override
public void onReceive(Context arg0, Intent arg1) {
// Here's where we'd grab location and store it into DB.
//gps = new GPSTracker(AlarmReceiver.this);
// if(gps.canGetLocation()) {
// double latitude = gps.getLatitude();
// double longitude = gps.getLongitude();
// Draw Marker for Current Location on Fragment
// Toast a popup of the location data.
// Toast.makeText(arg0, "Your Location is -\nLat:" + latitude + "\nLong:" + longitude, Toast.LENGTH_LONG).show();
// } else {
// gps.showSettingsAlert();
// }
// Toast that the alarm ran.
Toast.makeText(arg0, "Location Pinged.", Toast.LENGTH_SHORT).show();
}
More specifically, a part of the problem is the way I'm calling for the new gps Tracker object here:
//gps = new GPSTracker(AlarmReceiver.this);
I'm not sure how to achieve the original result while using the alarmreceiver instead of a button, which is the main source of my problem. Does anyone know exactly what I can tinker with here to get the alarm receiver to properly use the GPSTracker Class?
DO not use GPSTracker. Its broken in over a dozen ways. Forget it exists. If you want a better version, you can use http://gabesechansoftware.com/location-tracking/ That link also explains why GPSTracker is broken by design and why it should never be used. It basically kinda works if used in optimal circumstances, and gives you horrible data in all the others.
Secondly, if you're using GPS and not network- you need to give it time to get a location sync. This can take seconds to minutes (or hours, if the user is in a basement or something) so the immediate forms of getting a location won't work- you have to wait for it to actually sync the location.
I suggest you not look for libraries to solve this and actually try to understand how the base APIs work. Until you do, you're going to have troubles with anything you use as there's lots of corner cases here and its not a trivial thing to do.
I am using a LocationListener and I can't seem to get a lock using my app.
Here is my GPSTracker.java:
package com.example.gpstracking;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;
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);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long 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/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will launch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing 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 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;
}
}
It is called like this:
gps = new GPSTracker(AndroidGPSTrackingActivity.this);
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
}
However, I have tried everything to get GPS to actually lock. The only way I can get a lock is if I go to maps and acquire a lock then my app will display my actual location.
Location updates come to onLocationChanged() callback. You won't get them somewhere else, so be sure to handle handle them in callback. Also it may be really useful to let your activity implement this listener and pass YourActivity.this as instance of LocationListener to GPSTracker, where you later request location updates with activity parameter
now i am working with GPS for getting different latitude and longitude for every 1 minute while moving and that has to be stored into array list. I am using thread for this. I followed this link. http://www.androidhive.info/2012/08/android-working-with-google-places-and-maps-tutorial/
And my code is
Tracking.java
package com.example.getlatlang;
import java.util.ArrayList;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class Tracking extends Activity
{
Button btnShowLocation;
boolean isRepeat = true;
protected int splashTime = 1000;
int timer =0;
Thread th;
ArrayList<Double> lat_array = new ArrayList<Double>();
ArrayList<Double> lon_array = new ArrayList<Double>();
// GPSTracker class
GPSTracker gps;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.currentlocation);
btnShowLocation = (Button) findViewById(R.id.start_bt);
// show location button click event
btnShowLocation.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View arg0)
{
// create class object
if(isRepeat)
{
isRepeat = false;
btnShowLocation.setBackgroundResource(R.drawable.stop);
if(lat_array.size()>0 && lon_array.size()>0)
{
lat_array.clear();
lon_array.clear();
System.out.println("Array cleared...");
}
// check if GPS enabled th=new Thread()
th=new Thread()
{
#Override
public void run(){
try
{
for (timer = 0; timer < 20; timer++)
{
// int waited = 0;
// while(waited < splashTime)
// {
Thread.sleep(100);
runOnUiThread(new Runnable()
{
#Override
public void run()
{
try
{ gps = new GPSTracker(Tracking.this);
if(gps.canGetLocation())
{
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
lat_array.add(latitude);
lon_array.add(longitude);
// \n is for new line
System.out.println("lat_array"+lat_array+"lon_array"+lon_array);
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + lat_array + "\nLong: " + lon_array, Toast.LENGTH_LONG).show();
}
else
{
// can't get location
// GPS or Network is not enabled
// Ask user to enable GPS/network in settings
gps.showSettingsAlert();
}
}
catch(Exception e)
{
e.printStackTrace();
}
}
});
// waited += 100;
//}
}}
catch (InterruptedException e)
{
}
}
};
th.start();
}
else
{
isRepeat = true;
th.interrupt();
btnShowLocation.setBackgroundResource(R.drawable.start);
}
}
});
}
public void ohDestroy()
{
th.stop();
}
}
GPSTracker.java
package com.example.getlatlang;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;
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);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long 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/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing 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 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;
}
}
Now my issue is can't able to get different latitude and longitude points while moving. The first value only stored into an array for 20 times. Because i am setting the Tread must be run 20 times like that. But i want to get different points and stored into an array list. I don't know where i did the mistake. Can any body help me to resolve this problem? Thanks in advance.
you have used sleep(100) on the loop of collecting latitude.
The unit of time is micro-second here.(as far as i know)
20*100 = 2000 which is just 2 second. and i don't think GPS update that fast.
Have a look at this.
Rather you can use the same loop but store the value only if it is different from previous one.
if(oldLat != curLat){
//store curLat to array
//and make oldLat = curLat
}
Apply this. It will refresh every 10 seconds.
Handler mHandler1 = new Handler();
new Thread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
while (true) {
try {
Thread.sleep(10000);
mHandler1.post(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
// creating GPS Class object
GPSTracker gps = new GPSTracker (Tracking .this);
// check if GPS location have some values
if (gps.canGetLocation()) {
double currentlat = gps.getLatitude();
double currentlong = gps.getLongitude();
} else {
// no current location
gps.showSettingsAlert();
}
}
});
} catch (Exception e) {
// TODO: handle exception
}
}
}
}).start();
I found this class I'd like to use to obtain location updates but I'm trying to find out how to implement callbacks to the activity when location updates.
Do I use some callback or other type of method to implement this?
note I got the code from http://www.androidhive.info/2012/07/android-gps-location-manager-tutorial/
GPSTracker.java
package com.example.gpstracking;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;
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;
// First get location from Network Provider
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long 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/wifi enabled
* #return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing 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 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;
}
}
Yeah you should add a callback method like that :
public GPSTracker(Context context, Activity calleractivity) {
this.mContext = context;
getLocation();
this.calleractivity=calleractivity
}
And your update method would be something like
public void update(){
calleractivity.getback();
}
And in your activity :
gps = new GPSTracker(Context context, this);
I hope it helps
Some notes:
Services run on the UI thread by default. This class might block your UI if getting location from a particular source takes a long time. How often do you need updates? You could run a timer to send out requests to an IntentService to get GPS info.
If you really do need GPS "tracking", then you're doing the right thing, but remember that GPS drains the battery quickly.
The best way to communicate from one Android component to another is to use a BroadcastReceiver. This provides a clear, straightforward callback that can handle more than one "message" from various components.
This code can be used to get location using your GPSTracker class, Paste your code on your activity onCreate method for testing purpose. Yes it will block your UI thread for now but you will get the location. After that you can read about using Service in Android to get a better idea.
LocationResult locationResult = new LocationResult() {
#Override
public void gotLocation(Location location) {
Log.d("Activity","In gotLocation Listener");
boolean hasAddedQr = false;
if(hasAddedQr){
return;
}
hasAddedQr = true;
if (location != null) {
Log.d("Activity","Got the location");
// Got the location!
try {
double lati = location.getLatitude();
double longi = location.getLongitude();
text.setText("Got Location: La="+lati+", Lo="+longi);
} catch (Exception e) {
// TODO: handle exception
}
} else {
GetLocation.this.runOnUiThread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
text.setText("Location was returned null");
}
});
}
}
};
GPSTracker myLocation = new GPSTracker();
boolean isEnabled = myLocation.getLocation(GetLocation.this, locationResult);
if(!isEnabled){
Log.d("Activity", "LOCATION SERVICES WERE NOT ENABLED");
text.setText("Location service not available");
getLocationBtn.setEnabled(true);
}
else{
Log.d("Activity", "LOCATION SERVICES ENABLED");
}