Develop Reference

How to get polyline latitude and longitude by click on polyline android?

I have set Polyline click listener like this :
map.setOnPolylineClickListener(new GoogleMap.OnPolylineClickListener() {
public void onPolylineClick(Polyline polyline) {
int strokeColor = polyline.getColor() ^ 0x0000CC00;
polyline.setColor(strokeColor);
Log.e("TAG", "Polyline points # " + polyline.getPoints());
Toast.makeText(Draw_Route.this, "Polyline klick: " + polyline.getPoints(), Toast.LENGTH_LONG).show();
}
});
But i need to get coordinates of that point when user click on polyline, i also used this code to get the codrinates -- >
map.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
#Override
public void onMapClick(LatLng clickCoords) {
Log.e("TAG", "Found # " + clickCoords.latitude + " " + clickCoords.longitude);
}
});
But it only works when i click on map, i need to get that point coordinates on click on polyline so please help me, how to get that.
Thanks

How to set correct Lat and Lng based on current location

My goal is to do autocomplete prediction using Google Places API, and now I want to make some kind algorithm that will take current location lat and lng, and make a prediction of places only in 100-200 km diameter.
So, at this moment I get user's current location lat and lng, how to set 100-200 km?
private void getCurrentLocation() {
mLastLocation = LocationServices.FusedLocationApi
.getLastLocation(mGoogleApiClient);
if (mLastLocation != null) {
double latitude = mLastLocation.getLatitude();
double longitude = mLastLocation.getLongitude();
mLatLonBounds = new LatLngBounds(new LatLng(latitude,longitude),
new LatLng(latitude,longitude));
Log.d("myTag","lat = "+mLatLonBounds.northeast.latitude+" ,lon = "+mLatLonBounds.northeast.longitude);
//Log.d("myTag","lat = "+mLatLonBounds.southwest.latitude+" ,lon = "+mLatLonBounds.southwest.longitude);
}else {
//some code
}
}
Here is how I set bounds to auto prediction:
#Nullable
private ArrayList<AutoCompletePlace> getAutocomplete(CharSequence constraint) {
if (mGoogleApiClient.isConnected()) {
Log.i(Constants.AUTO_COMPLETE_TAG, "Starting autocomplete query for: " + constraint);
// Submit the query to the autocomplete API and retrieve a PendingResult that will
// contain the results when the query completes.
PendingResult<AutocompletePredictionBuffer> results = Places.GeoDataApi
.getAutocompletePredictions(mGoogleApiClient, constraint.toString(),
**mBounds**, mPlaceFilter);
// This method should have been called off the main UI thread. Block and wait for at most 60s
// for a result from the API.
AutocompletePredictionBuffer autocompletePredictions = results.await(60, TimeUnit.SECONDS);
// Confirm that the query completed successfully, otherwise return null
final Status status = autocompletePredictions.getStatus();
if (!status.isSuccess()) {
Toast.makeText(getContext(), "Error contacting API: " + status.toString(),
Toast.LENGTH_SHORT).show();
Log.e(Constants.AUTO_COMPLETE_TAG, "Error getting autocomplete prediction API call: " + status.toString());
autocompletePredictions.release();
return null;
}
Log.i(Constants.AUTO_COMPLETE_TAG, "Query completed. Received " + autocompletePredictions.getCount()
+ " predictions.");
// Copy the results into our own data structure, because we can't hold onto the buffer.
// AutocompletePrediction objects encapsulate the API response (place ID and description).
Iterator<AutocompletePrediction> iterator = autocompletePredictions.iterator();
ArrayList resultList = new ArrayList<>(autocompletePredictions.getCount());
while (iterator.hasNext()) {
AutocompletePrediction prediction = iterator.next();
// Get the details of this prediction and copy it into a new PlaceAutocomplete object.
resultList.add(new AutoCompletePlace(prediction.getPlaceId(),
prediction.getDescription()));
}
// Release the buffer now that all data has been copied.
autocompletePredictions.release();
return resultList;
}
Log.e(Constants.AUTO_COMPLETE_TAG, "Google API client is not connected for autocomplete query.");
return null;
Example my current location 48.6180288,22.2984587.
UPDATE: Before the Francois Wouts give me the answer, I found another solution on stackoverflow, you can use it too.
public static final LatLngBounds setBounds(Location location, int mDistanceInMeters ){
double latRadian = Math.toRadians(location.getLatitude());
double degLatKm = 110.574235;
double degLongKm = 110.572833 * Math.cos(latRadian);
double deltaLat = mDistanceInMeters / 1000.0 / degLatKm;
double deltaLong = mDistanceInMeters / 1000.0 / degLongKm;
double minLat = location.getLatitude() - deltaLat;
double minLong = location.getLongitude() - deltaLong;
double maxLat = location.getLatitude() + deltaLat;
double maxLong = location.getLongitude() + deltaLong;
Log.d("Location", "Min: " + Double.toString(minLat) + "," + Double.toString(minLong));
Log.d("Location","Max: "+Double.toString(maxLat)+","+Double.toString(maxLong));
// Set up the adapter that will retrieve suggestions from the Places Geo Data API that cover
// the entire world.
return new LatLngBounds(new LatLng(minLat,minLong),new LatLng(maxLat,maxLong));

According to Wikipedia, you probably want to allow around 1 degree in each direction around the user's location to cover 100-200km. The exact area covered will depend on where the user is, but this should be a good enough approximation for most use cases.
Try the following, for example:
double radiusDegrees = 1.0;
LatLng center = /* the user's location */;
LatLng northEast = new LatLng(center.latitude + radiusDegrees, center.longitude + radiusDegrees);
LatLng southWest = new LatLng(center.latitude - radiusDegrees, center.longitude - radiusDegrees);
LatLngBounds bounds = LatLngBounds.builder()
.include(northEast)
.include(southWest)
.build();
I believe this should work correctly even across the antemeridian. Let me know how you go!

How to use Latitud and Longitud as a variable in Android?

I have an SQLITE3 database where I defined lat and long as text.
I need to use those lat, and long as the final destination in a map.
The intent is defined as:
if(locationMap != null){
Intent theIntent = new Intent(getApplication(), displayMap.class);
theIntent.putExtra("_Id", locationMap.get("_Id"));
theIntent.putExtra("locCode", locationMap.get("locCode"));
theIntent.putExtra("locDesc", locationMap.get("locDesc"));
theIntent.putExtra("locLat", locationMap.get("locLat"));
theIntent.putExtra("locLong", locationMap.get("locLong"));
theIntent.putExtra("locTelephone", locationMap.get("locTelephone"));
theIntent.putExtra("locComments", locationMap.get("locComments"));
startActivity(theIntent); // display map with coordinates
}
In the next activity I recover the values in the On create method:
// Parameters
String locCode = i.getStringExtra("locCode");
String locDesc = i.getStringExtra("locDesc");
String locLat = i.getStringExtra("locLat");
String locLong = i.getStringExtra("locLong");
String locTelephone = i.getStringExtra("locTelephone");
String locComments = i.getStringExtra("locComments");
String Text = "Current location is: " +
i.getStringExtra("locLat");
Toast.makeText( getApplicationContext(),Text,
Toast.LENGTH_SHORT).show();
System.out.println("locCode: " + locCode);
System.out.println("LocDesc: " + locDesc);
System.out.println("LocLat: " + locLat);
System.out.println("LocLong: " + locLong);
System.out.println("LocTelephone: " + locTelephone);
System.out.println("LocComment: " + locComments);
getLocation(ORIGIN);
setContentView(R.layout.map);
if (mLastSelectedMarker != null && mLastSelectedMarker.isInfoWindowShown()) {
// Refresh the info window when the info window's content has changed.
mLastSelectedMarker.showInfoWindow();
}
setUpMapIfNeeded();
}
I need to use those locLat and Loclong instead of the numbers:
public class displayMap extends FragmentActivity implements
OnMarkerClickListener,
OnInfoWindowClickListener {
public LatLng ORIGIN = new LatLng(34.02143074239393, -117.61349469423294);
public LatLng DESTINY = new LatLng(34.022365269080886, -117.61271852999926);
private GoogleMap mMap;
private Marker mDestiny;
private Marker mOrigin;
private Marker mLastSelectedMarker; // keeps track of last selected marker
I've tried transforming the text to double and It won't allow me to.
I've tried many solutions I found on stack overflow, but no luck yet.
I appreciate any help
Thanks in advance.

You need to parse the latitude and longitude from String to double to use in new LatLng();
double latitude = Double.parseDouble(locLat);
double longitude = Double.parseDouble(locLong);
and then,
public LatLng ORIGIN = new LatLng(latitude, longitude);

you need cast them into double. As GPRathour says.

Change the type of Lat Long Text to REAL in your SQL Lite,
when inserting values use this
values.put(Latitude_Column, ORIGIN.latitude);
values.put(Longitude__Column,ORIGIN.longitude);
And for retrieving values
LatLng origin = new LatLng(cursor.getDouble(cursor.getColumnIndex(Latitude_Column)),cursor.getDouble(cursor.getColumnIndex(Longitude__Column)));
No need to parsing values

MarkerOptions position() set value is different from Marker getPosition() in Android

In my Android application, I'm using Google Map to point some locations. But what I mark as latitude and longitude value is different from what I'm getting when click on a Marker. Here is the relevant code
import com.google.android.gms.maps.GoogleMap;
public class MyClass extends SupportMapFragment{
private GoogleMap mMap;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
mMap = getMap();
myMethod();
mMap.setOnMarkerClickListener(new OnMarkerClickListener() {
#Override
public boolean onMarkerClick(Marker marker) {
LatLng latLng = marker.getPosition();
Log.d(TAG, "# latLng.latitude : " + latLng.latitude + " # latLng.longitude : " + latLng.longitude);
/*
* Print for the above Log statement is
*
* # latLng.latitude : 45.446733371796135 # latLng.longitude : 6.97720717638731
*
*/
}
}
}
private void myMethod(){
MarkerOptions markerOptions = new MarkerOptions().position(new LatLng(coords.getDouble(1), coords.getDouble(0)));
Log.d(TAG, "# latitude : " + coords.getDouble(1) + " # longitude : " + coords.getDouble(0));
/*
* Print for the above Log statement is
*
* # latitude : 45.44673337246575 # longitude : 6.977207233013699
*
*/
}
}
Those printing values are almost same but not exactly. Can I know why is that? Because I need to get the exact value I'm feeding to the Map when I click on a particular Marker. If it is because how I include the value to the Map, how should I change it?

This sounds like the same bug as here:
https://code.google.com/p/gmaps-api-issues/issues/detail?id=5353
As one commentor pointed out, the LatLng's are being flattened to floats and when retrieving them to doubles again they lose their precision.
I found that getting the lat/lngs into strings and stripping everything but the first 8 characters before comparing them seems to work:
String lat1 = String.valueOf(marker.latitude).substring(0, 8);

How to get center of map for v2 android maps?

In Google Maps for Android v1, MapView had a convenience method:
getMapCenter(). Now I cannot figure out how to get map center with v2 of this api. I have perused the API documentation, but there is no mention of such a feature. Please advise.
Thanks,
Igor

I had the same problem. It seems you can get the center this way:
mMap.getCameraPosition().target
where mMap is the GoogleMap instance from your activity. This will return a LatLng object which basically represents the center of the map.
Note that the GeoPoint class is not available anymore.
According to http://developer.android.com/reference/com/google/android/gms/maps/model/CameraPosition.html
target is "The location that the camera is pointing at." (I tested it with the sample code and it worked okay for me)

I have found two ways of do this:
1) The easiest, The first is using the target property in the Map's CameraPosition Object
LatLng center = mMap.getCameraPosition().target;
2) The second is using a VisibleRegion object:
VisibleRegion visibleRegion = mMap.getProjection()
.getVisibleRegion();
Point x = mMap.getProjection().toScreenLocation(
visibleRegion.farRight);
Point y = mMap.getProjection().toScreenLocation(
visibleRegion.nearLeft);
Point centerPoint = new Point(x.x / 2, y.y / 2);
LatLng centerFromPoint = mMap.getProjection().fromScreenLocation(
centerPoint);
I have compared both answers:
Log.d("MapFragment: ", "Center From camera: Long: " + center.longitude
+ " Lat" + center.latitude);
Log.d("Punto x", "x:" + x.x + "y:" + x.y);
Log.d("Punto y", "y:" + y.x + "y:" + y.y);
Log.d("MapFragment: ", "Center From Point: Long: "
+ centerFromPoint.longitude + " Lat"
+ centerFromPoint.latitude);

You can use :
latlng=map.getProjection().getVisibleRegion().latLngBounds.getCenter();

to get center of map I used onMapReady() method in activity, then used googleMap.setOnCameraChangeListener() method to get position of Came:
#Override
public void onMapReady(GoogleMap googMap) {
googleMap.setOnCameraChangeListener(new GoogleMap.OnCameraChangeListener() {
#Override
public void onCameraChange(CameraPosition cameraPosition) {
Log.i("centerLat",cameraPosition.target.latitude);
Log.i("centerLong",cameraPosition.target.longitude);
}
});
}

If you only want to get the position once (e.g. after the user has stopped panning the map), use setOnCameraIdleListener:
https://developers.google.com/android/reference/com/google/android/gms/maps/GoogleMap.OnCameraIdleListener
mMap.setOnCameraIdleListener(new GoogleMap.OnCameraIdleListener() {
#Override
public void onCameraIdle() {
LatLng position = mMap.getCameraPosition().target;
Log.d("MapActivity", "Position: " + position);
}
});
or using a Java 8 lambda:
mMap.setOnCameraIdleListener(() -> {
LatLng position = mMap.getCameraPosition().target;
Log.d("MapActivity", "Position: " + position);
});
Note that the listener registered with setOnCameraChangeListener is called many times, and as the documentation states:
This may be called as often as once every frame and should not perform expensive operations.

best way use cameraPosition
java:
LatLng centerMap = googleMap.getCameraPosition().target;
kotlin:
googleMap?.cameraPosition?.target?.let {
// it is LatLng center
}