Map marker doesn't point to exact location - android

So I'm storing markers from my map into a sqlite database. I am trying to query the markers by latitude and longitude. So for testing I am adding the marker to a specific location. When I check the markers position it gives me another location. What is causing this?
private void drawMarker(LatLng point, String title, String snippet){
// Creating an instance of MarkerOptions
MarkerOptions markerOptions = new MarkerOptions();
// Setting latitude and longitude for the marker
LatLng l = new LatLng(37.52100000000001, -77.44800000000001);
markerOptions.position(l);
markerOptions.title(title);
markerOptions.snippet(snippet);
// Adding marker on the Google Map
googleMap.addMarker(markerOptions);
}
This is the code to extract the marker position
googleMap.setOnInfoWindowClickListener(new OnInfoWindowClickListener() {
#Override
public void onInfoWindowClick(Marker marker) {
marker1 = marker;
LatLng mlatlong = marker1.getPosition();
markerLat = Double.toString(mlatlong.latitude);
markerLng = Double.toString(mlatlong.longitude);
latitude = mlatlong.latitude;
longitude = mlatlong.longitude;
Log.i("Marker", mlatlong.latitude +","+mlatlong.longitude);
markerDialog();
}
});
This gives me the position
06-20 21:53:52.447: I/Marker(15221): 37.52100000569583,-77.44800008833408

In Java, and most other languages you'll come accross, double is not stored as a precise value.
You can read more here.
Also, it shouldn't really matter the locations you posted are extremely close to each other.

Related

Is it possible to add markers from an AsyncTask?

There is a Google map on my Android and I am new to the new Google Maps API. There is an initial marker on it.
This is the method to show the map and the initial marker:
#Override
public void onMapReady(GoogleMap map) {
//map is ready
// latitude and longitude
double latitude = latitud_del_hotel;
double longitude =longitud_del_hotel;
// create marker
MarkerOptions marker = new MarkerOptions().position(new LatLng(latitude, longitude)).title(nombre_del_hotel).icon(BitmapDescriptorFactory.fromResource(R.drawable.poi));
// Changing marker icon
// marker.icon(BitmapDescriptorFactory
// .defaultMarker(BitmapDescriptorFactory.HUE_ROSE));
// adding marker
map.addMarker(marker);
map.setMapType(GoogleMap.MAP_TYPE_HYBRID);
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(new LatLng(latitud_del_hotel, longitud_del_hotel)).zoom(15).build();
map.animateCamera(CameraUpdateFactory
.newCameraPosition(cameraPosition));
}
Now, I need to put other markers on it. These markers are JSON objects that I am retrieving on another method from the activity.
May be my question is stupid, but I don't know how to add markers on the same map but created on another method.
This is how am I creating a new marker on another method:
hotel.setNombre(obj.getString("nombre_hotel"));
hotel.setLatitud(obj.getDouble("latitud_hotel"));
hotel.setLongitud(obj.getDouble("longitud_hotel"));
hotel.setDireccion(obj.getString("direccion_hotel"));
String nombre = obj.optString("nombre_hotel");
Log.d("NOMBRE=", nombre);
String latitud = obj.optString("latitud_hotel");
double latitud_del_hotel = Double.parseDouble(latitud);
String longitud = obj.optString("longitud_hotel");
double longitud_del_hotel = Double.parseDouble(longitud);
// create marker
MarkerOptions marker = new MarkerOptions().position(new LatLng(latitud_del_hotel, longitud_del_hotel)).title(nombre).icon(BitmapDescriptorFactory.fromResource(R.drawable.poi));
map.addMarker(marker);
But obviously, the line map.addMarker(marker); shows a warning: Cannot resolve symbol map.
Sorry if it is easy to solve, but I cannot.
Thank you.
In your onMapReady(...) add a field reference to the returned map.
public void onMapReady(GoogleMap map) {
this.googleMap = map;
Then, you can do:
// create marker
if(this.googleMap != null) {
MarkerOptions marker = new MarkerOptions(...);
this.googleMap.addMarker(marker);
}
This might create what's known as a race condition - if your network call to retrieve hotel location information returns a result before the map is ready, you will never get the results added into the map.
You could combat this by doing:
// Create this as a field:
List<MarkerOptions> markerOptions = new ArrayList<>();
MarkerOptions marker = new MarkerOptions(...);
if(this.googleMap != null) {
this.googleMap.addMarker(marker);
} else {
this.markerOptions.add(marker);
}
Then, at the bottom of onMapReady(...):
if(this.markerOptions != null && !this.markerOptions.isEmpty()) {
for(MarkerOption markerOption : this.markerOptions) {
this.googleMap.addMarker(markerOption);
}
}

How to use OnMarkerClickListener to get location of that marker?

I have a map with 3 options. A search function, a nearby locations function, and a click on the map to set marker option. I want to save these locations in my Parse backend, but the only one I was able to figure out how to do is the set marker option.
When I do a nearby search and get a bunch of results I want to be able to click on one of the markers (see the title and location) and then click on the save button to save to my backend. Here's what I have:
#Override
protected void onPostExecute(List<HashMap<String,String>> list){
// Clears all the existing markers
mGoogleMap.clear();
for(int i=0;i<list.size();i++){
// Creating a marker
markerOptions = new MarkerOptions();
// Getting a place from the places list
HashMap<String, String> hmPlace = list.get(i);
// Getting latitude of the place
double lat = Double.parseDouble(hmPlace.get("lat"));
// Getting longitude of the place
double lng = Double.parseDouble(hmPlace.get("lng"));
// Getting name
final String name = hmPlace.get("place_name");
// Getting vicinity
final String vicinity = hmPlace.get("vicinity");
latLng = new LatLng(lat, lng);
// Setting the position for the marker
markerOptions.position(latLng);
// Setting the title for the marker.
//This will be displayed on taping the marker
markerOptions.title(name + " : " + vicinity);
// Placing a marker on the touched position
mGoogleMap.addMarker(markerOptions);
}
}
I have tried to add setOnMarkerClickListener, but it ends up not showing me anything (right now I at least get the title and location).
I know how to save the location to my backend but I'm not sure how to get the location of the clicked marker.
Just set the onMarkerClickListener for your map object, the callback returns to you the Marker object.
Marker has an attribute called Position which has the LatLng value that you require. Also you have to add a infoWindow, using the details the Marker object has to display name and other details.
#Override
public boolean onMarkerClick(Marker marker) {
LatLng markerLocation=marker.getPosition();
return false;
}

Google Map does not moving to the new LatLng location

I'm developing an Android app which traces the path from current location to a specific destination. It works well. But there is an exception scenario.
When user clicks on a destination marker, it needs to move the map to another location with zoom. But only get zoomed without moving to the second location.
This is my relating code segment with that. If you can please help me with this. Thanks in advance.
double Kumana1_Latitude = 6.573022;
double Kumana1_Longitude = 81.666875;
double Kumana2_Latitude = 6.649353;
double Kumana2_Longitude = 81.770114;
final LatLng Kumana = new LatLng(Kumana1_Latitude, Kumana1_Longitude);
final LatLng Kumana2 = new LatLng(Kumana2_Latitude,Kumana2_Longitude);
Marker Kumana_marker = mGoogleMap.addMarker(new MarkerOptions()
.title("Kumana National Park")
.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_GREEN))
.position(Kumana));
Kumana_marker.showInfoWindow();
mGoogleMap.setOnMarkerClickListener(new OnMarkerClickListener() {
#Override
public boolean onMarkerClick(Marker m) {
//here it get Zoomed, but does not move to the new location
mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(Kumana2, 13));
m.remove();
Toast.makeText(getApplicationContext(),
"Tap on the Kumana National Park entreance", Toast.LENGTH_LONG)
.show();
});
}
Put the marker in onLocationChanged() and plot the marker. First remove the marker and then add the new marker with the new location.
All this code must come under onLocationChanged()
Check first
(if marker == null){
//plot marker
}
else{
//remove first marker..
//add new marker
}
Try to call super.onMarkerClick(m) in your overriden function ònMarkekClick(Marker m)`.

How to show received latitude/longitude from server on google map?

How to show latitude and longitude which I received from server on android map. I implemented google map V2 but don't know how to show gps coordinates on map. I came here after a lot of research and wasn't able to find a single reasonable solution for it. Can anyone please help me out?
So far my code of latitude and longitude values which I am reviving from server.
String lat, lon;
double l1,l2;
DB db = new DB(getApplicationContext());
HashMap<String,String> gps = new HashMap<String, String>();
gps = db.getGps();
lat = user.get("lati");
lon = user.get("longi");
Okay when I try to add marker on map according to latitude and longitude from server my app got force close and gives NullPointerException.
free.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
String lat, lon;
double l1,l2;
DB db = new DB(getApplicationContext());
HashMap<String,String> gps = new HashMap<String, String>();
gps = db.getGps();
lat = user.get("lati");
lon = user.get("longi");
l1 = Double.parseDouble(lat);
l2 = Double.parseDouble(lon);
map.addMarker(new MarkerOptions().position(new LatLng(l1, l2))
.title("My Map Title"));
Your "map" variable may not be initialized. I add a marker like this:
SupportMapFragment smf = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mMap = smf.getMap();
if ( mMap != null ) {
LatLng newLatLong = new LatLng(dblLat, dblLong);
mMap.addMarker(new MarkerOptions().position(newLatLong)
.title(name)
.snippet(fullStrAddr));
}
Add a marker like this
Marker mymarker= map.addMarker(new MarkerOptions().position(new LatLng(lat, lon))
.title("My Map Title"));
This will set a marker at the latitude and longitude which was sent from the server..
Try it..

Google places retrieves same value in all the execution

I was working with a Google map v2 oriented android project. In my program i retrieves the name,vicinity,latitude&longitude from the places api while touching on the info boxes of the markers.But it every time retrieves the same value.But it shows the correct result in the info boxes.How to solve this bug .Someone please solve this.
Code
for(final Place place : nearPlaces.results){
// Creating a marker
MarkerOptions markerOptions = new MarkerOptions();
// Getting latitude of the place
double latitude = place.geometry.location.lat;
double longitude = place.geometry.location.lng;
// Getting name
String NAME = place.name;
// Getting vicinity
String VICINITY = place.vicinity;
//final String REFERENCE = place.reference;
final String slat = String.valueOf(latitude);
final String slon = String.valueOf(longitude);
LatLng latLng = new LatLng(latitude, longitude);
// Setting the position for the marker
markerOptions.position(latLng);
// Setting the title for the marker.
//This will be displayed on taping the marker
markerOptions.title(NAME + " : " + VICINITY);
markerOptions.icon(bitmapDescriptor);
// Placing a marker on the touched position
mGoogleMap.addMarker(markerOptions);
mGoogleMap.setOnInfoWindowClickListener(
new OnInfoWindowClickListener(){
#Override
public void onInfoWindowClick(Marker arg0) {
// TODO Auto-generated method stub
arg0.hideInfoWindow();
alert.showpickAlertDialog2(PlacesMapActivity.this, slat, slon, place.reference,KEY_TAG);
}
}
);
}
LatLng mylatLng = new LatLng(mylatitude, mylongitude);
// Creating CameraUpdate object for position
CameraUpdate updatePosition = CameraUpdateFactory.newLatLng(mylatLng);
// Creating CameraUpdate object for zoom
CameraUpdate updateZoom = CameraUpdateFactory.zoomBy(10);
// Updating the camera position to the user input latitude and longitude
mGoogleMap.moveCamera(updatePosition);
// Applying zoom to the marker position
mGoogleMap.animateCamera(updateZoom);
What you are doing wrong is setting OnInfoWindowClickListener in a loop.
Take that code outside and retrieve slat and slon from Marker arg0 by using getPosition.
There are other people who are struggling with this issue as well.
You are assuming that the slat and slong values are going to carry through to the onInfoWindowClick() method, but you are always getting the same values there.
Here is a discussion some other folks were having on this topic.

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