Polylines Android for a beginner

[Allecsxx]

Hi ,

I;ve god this code below ... it will add markers up to 7 on the map and will draw a polyline between them markers... the only trouble is .. how to make the polyline redraw after dragging a marker to another location? it might be something really easy... please open my eyes.... ! thank youuuu







ArrayList<LatLng> points;





/* Location createNewLocation(double longitude, double latitude) {
Location location = new Location("dummyprovider");
location.setLongitude(0.0982);
location.setLatitude(51.3762);
return location;
}*/
@override
protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
points= new ArrayList<>();
}


/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;


mMap.getUiSettings().setZoomControlsEnabled(true);
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, LOCATION_REQUEST);


// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
mMap.setMyLocationEnabled(true);
mMap.setOnMapLongClickListener(new GoogleMap.OnMapLongClickListener(){
@override
public void onMapLongClick(LatLng point) {
// Instantiating the class MarkerOptions to plot marker on the map
MarkerOptions markerOptions = new MarkerOptions();
// Setting latitude and longitude of the marker position
markerOptions.position(point);
// Setting titile of the infowindow of the marker
markerOptions.title("Position");
// Setting the content of the infowindow of the marker
markerOptions.snippet("Latitude:" + point.latitude + "," + "Longitude:" + point.longitude);
markerOptions.draggable(true);
mMap.addMarker(markerOptions);
// Instantiating the class PolylineOptions to plot polyline in the map
PolylineOptions polylineOptions = new PolylineOptions();
// Setting the color of the polyline
polylineOptions.color(Color.RED);
// Setting the width of the polyline
polylineOptions.width(3);
// Adding the taped point to the ArrayList
points.add(point);
// Setting points of polyline
polylineOptions.addAll(points);
// Adding the polyline to the map
mMap.addPolyline(polylineOptions);
// Adding the marker to the map
if(points.size() ==7){
points.clear();
mMap.clear();
}
mMap.setOnMarkerDragListener(new GoogleMap.OnMarkerDragListener() {
@override
public void onMarkerDragStart(Marker point) {
}
@override
public void onMarkerDrag(Marker point) {

mMap.clear();

}
@override
public void onMarkerDragEnd(Marker point) {
}
});

}
});


}