'''
public class GpsActivity extends FragmentActivity implements OnMapReadyCallback {
private static final int PRIORITY_HIGH_ACCURACY = 100;
private GoogleMap mMap;
private static final int PERMISSIONS_FINE_LOCATION = 99;
Location loc;
LatLng curPo;
boolean state = false;
private LocationRequest locationRequest;
private FusedLocationProviderClient fusedLocationProviderClient;
Button rstart;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
locationRequest = LocationRequest.create()
.setInterval(5000)
.setPriority(PRIORITY_HIGH_ACCURACY)
.setSmallestDisplacement(5);
LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder();
builder.addLocationRequest(locationRequest);
fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(GpsActivity.this);
setContentView(R.layout.activity_gps);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
rstart = findViewById(R.id.rstart);
rstart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
changeState();
}
});
askforPermission();
}
@SuppressLint("MissingPermission")
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
if(checkPermission()){
mMap.setMyLocationEnabled(true);
}
mMap.getUiSettings().setMyLocationButtonEnabled(true);
}
@Override
protected void onStart() {
super.onStart();
Log.d(TAG, "onStart");
if (checkPermission()) {
Log.d(TAG, "onStart : call mFusedLocationClient.requestLocationUpdates");
fusedLocationProviderClient.requestLocationUpdates(locationRequest, locationCallback, null);
if (mMap!=null)
mMap.setMyLocationEnabled(true);
}
}
@Override
protected void onStop() {
super.onStop();
if(fusedLocationProviderClient != null){
fusedLocationProviderClient.removeLocationUpdates(locationCallback);
}
}
// Methods
private void askforPermission(){
if(ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED){
LocationCallback mCallback = new LocationCallback() {
@Override
public void onLocationResult(@NonNull LocationResult locationResult) {
super.onLocationResult(locationResult);
for(Location location : locationResult.getLocations()){
setCurrentLocation(location);
}
}
};
fusedLocationProviderClient.requestLocationUpdates(locationRequest,mCallback,null);
fusedLocationProviderClient.removeLocationUpdates(mCallback);
}else{
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
requestPermissions(new String[] {Manifest.permission.ACCESS_FINE_LOCATION}, PERMISSIONS_FINE_LOCATION);
}
}
}
private boolean checkPermission() {
int hasFineLocationPermission = ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION);
int hasCoarseLocationPermission = ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_COARSE_LOCATION);
if (hasFineLocationPermission == PackageManager.PERMISSION_GRANTED &&
hasCoarseLocationPermission == PackageManager.PERMISSION_GRANTED ) {
return true;
}
return false;
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode){
case PERMISSIONS_FINE_LOCATION:
if(grantResults[0] == PackageManager.PERMISSION_GRANTED){
askforPermission();
}else{
Toast.makeText(this,"this App requires permission for gps", Toast.LENGTH_SHORT).show();
finish();
}
}
}
public void setCurrentLocation(Location location) {
LatLng startLatLng = new LatLng(location.getLatitude(), location.getLongitude());
CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(startLatLng, 15);
mMap.moveCamera(cameraUpdate);
//mMap.addMarker(new MarkerOptions().position(currentLatLng)); //확인용
}
LocationCallback locationCallback = new LocationCallback() {
@Override
public void onLocationResult(@NonNull LocationResult locationResult) {
super.onLocationResult(locationResult);
List<Location> savedLocation = locationResult.getLocations();
if(savedLocation.size() > 0){
loc = savedLocation.get(savedLocation.size() - 1);
curPo = new LatLng(loc.getLatitude(), loc.getLongitude());
String curPoLog = "Lat: " loc.getLatitude() "Long: " loc.getLongitude();
Log.d(TAG,"OnLocationResult: " curPoLog);
setCurrentLocation(loc);
}
}
};
public void changeState() {
if(!state){
mMap.clear();
state = true;
Toast.makeText(this, "Recording Start", Toast.LENGTH_SHORT).show();
if(state && checkPermission()){
fusedLocationProviderClient.requestLocationUpdates(locationRequest, locationCallback, Looper.myLooper());
addMarkerSingle();
}
rstart.setText("Stop");
}else{
state = false;
Toast.makeText(this, "Recording Stop", Toast.LENGTH_SHORT).show();
if(!state) {
addMarkerSingle();
fusedLocationProviderClient.removeLocationUpdates(locationCallback);
}
rstart.setText("Start");
}
}
public void addMarkerSingle(){
if(checkPermission()){
fusedLocationProviderClient.getLastLocation()
.addOnSuccessListener(new OnSuccessListener<Location>() {
@Override
public void onSuccess(Location location) {
double markerLat = location.getLatitude();
double markerLong = location.getLongitude();
LatLng startEnd = new LatLng(markerLat, markerLong);
mMap.addMarker(new MarkerOptions().position(startEnd));
}
});
}
}
}
'''
Hi I'm a noob to programming this is my first project after learning 3month and I have no idea how to make it happen
I want to draw a real time foot print tracking polyline but no matter what I do, it never works I tried to get a LatLng and draw a polyline from inside LocationCallback and I also tried making a new Thread to handle it I tried in onCreate, onMapReady and everything but it never works. so I came here to ask how you guys handle these kindda stuff.
I know it's shitty code and I know I suck plz understand, among 3 month of lessons java class went for only 2weeks we never even got to using Thread part, plz help me out.
the code above is code with out any errors. I can check my location on real time and there is start marker and end marker. What I want to do is track the paths I walked and show it with polyline. not after i finish I want it to keep updating real time
Thank you for your time and help
CodePudding user response：
You need to store/cache the list of LatLng you get from LocationCallback.
Create a property
private ArrayList<String> myPath = new ArrayList<>();
Now every time a new location is received in the LocationCallback you add it to the myPath and update your map
LocationCallback locationCallback = new LocationCallback() {
@Override
public void onLocationResult(@NonNull LocationResult locationResult) {
super.onLocationResult(locationResult);
List<Location> savedLocation = locationResult.getLocations();
if(savedLocation.size() > 0){
loc = savedLocation.get(savedLocation.size() - 1);
curPo = new LatLng(loc.getLatitude(), loc.getLongitude());
String curPoLog = "Lat: " loc.getLatitude() "Long: " loc.getLongitude();
Log.d(TAG,"OnLocationResult: " curPoLog);
setCurrentLocation(loc);
//add this
myPath.add(loc)
updateMap()
}
}
};
Your updateMap() method might look like this
PolylineOptions polylineOptions = new PolylineOptions();
polylineOptions.addAll(myPath);
polylineOptions.width(10f)
.color(Color.RED)
.geodesic(true);
if(mMap != null {
mMap.addPolyline(polylineOptions);
}
polyLineCollection.addPolyline(polylineOptions)
tempLine.tag = MarkerID(line.id, line.layerId , null)
CodePudding user response：
try this code
//...
LocationCallback locationCallback = new LocationCallback() {
@Override
public void onLocationResult(@NonNull LocationResult locationResult) {
super.onLocationResult(locationResult);
List<Location> savedLocation = locationResult.getLocations();
Polyline polyline1 = googleMap.addPolyline(new PolylineOptions()
.clickable(false);
for(int i = 0; i<savedLocation.size; i ){
polyline1.add(new LatLng(savedLocation[i].latitude, savedLocation[i].longitude)));
}
// Store a data object with the polyline, used here to indicate an arbitrary type.
polyline1.setTag("A");
// Style the polyline.
stylePolyline(polyline1);
if(savedLocation.size() > 0){
loc = savedLocation.get(savedLocation.size() - 1);
curPo = new LatLng(loc.getLatitude(), loc.getLongitude());
String curPoLog = "Lat: " loc.getLatitude() "Long: " loc.getLongitude();
Log.d(TAG,"OnLocationResult: " curPoLog);
setCurrentLocation(loc);
}
}
};
...//