I am working on google map application,i want to find the area of irregular polygon with 4 markers,i have latitude and longitude of 4 points i want to find polygon area between points,please reply
code:
#Override
public void onMapClick(LatLng latLng) {
count++;
if (count <= 4) {
mMap.addMarker(new MarkerOptions().position(latLng).title(latLng.toString()));
markerClicked = false;
}
}
#Override
public boolean onMarkerClick(Marker marker) {
if (markerClicked) {
if (polygon != null) {
polygon.remove();
polygon = null;
}
polygonOptions.add(marker.getPosition());
polygonOptions.strokeColor(Color.parseColor("#cc0000"));
polygonOptions.fillColor(Color.parseColor("#332256"));
polygon = mMap.addPolygon(polygonOptions);
} else {
if (polygon != null) {
polygon.remove();
polygon = null;
}
polygonOptions = new PolygonOptions().add(marker.getPosition());
markerClicked = true;
}
return true;
}
Use Google Maps Android API Utility Library: computeArea.
You can use GeographicLib library , here documentation about computing polygon area by points.
Related
I have googleMap (v2) with polyline that presents a route between the user current location and the destination point. Now, I want to update the polyline according to the user moving.
I tried to redrawing the whole polyline when location is changed but the polyline is flickering.
I didn't find any appropriate function in the PolylineOptions class (the function add() is only to add a vertex but not to update or remove)
do you have any idea how to update the polyline ???
thank you for giving your time.
The only way as of version 3.1.36:
List<LatLng> points = polyline.getPoints();
points.add(newPoint);
polyline.setPoints(points);
Hopefully the API will be enhanced in later versions.
*I have already done working on updating polyline path without removing the polyline. We can do this by changing the points of that polyline. Check below code.
This is the logic of setting new points to polyline.
/*Here the routes contain the points(latitude and longitude)*/
for (int i = 0; i < routes.size(); i++) {
Route route = routes.get(i);
if(polyline_path != null){
polyline_path.setPoints(route.points);
}
}
Detail Explanation:
private GoogleMap map_object;
private Marker marker_driver;
private Marker marker_drop_off;
private Polyline polyline_path;
private PolylineOptions polylineOptions_path;
...
...
...
/*HelperDirectionFinder is a class that I create to call google API and I used this
class to get directions routes*/
/*I have created Service, and I'm calling this lines below after 5 sec. to get the
updated routes from google API.*/
HelperDirectionFinder directionFinder = new HelperDirectionFinder(
JobEndScreen.this, source, destinations);
try {
directionFinder.showDirection();
} catch (UnsupportedEncodingException e) {
HelperProgressDialog.closeDialog();
}
...
...
...
#Override
public void onDirectionFinderStart() {
if(polylineOptions_path == null){
HelperProgressDialog.showDialog(getActivity(), "", getString(R.string.text_loading));
}
}
/*This interface method is called after getting routes from google API.*/
/*Here the routes contains the list of path or routes returned by Google Api*/
#Override
public void onDirectionFinderSuccess(List<Route> routes) {
HelperProgressDialog.closeDialog();
/*When polylineOptions_path is null it means the polyline is not drawn.*/
/*If the polylineOptions_path is not null it means the polyline is drawn on map*/
if(polylineOptions_path == null){
for (Route route : routes) {
polylineOptions_path = new PolylineOptions().
geodesic(true).
color(ContextCompat.getColor(getActivity(), R.color.color_bg_gray_dark)).
width(10);
for (int i = 0; i < route.points.size(); i++)
polylineOptions_path.add(route.points.get(i));
polyline_path = map_object.addPolyline(polylineOptions_path);
}
}
else {
for (int i = 0; i < routes.size(); i++) {
Route route = routes.get(i);
if(polyline_path != null){
polyline_path.setPoints(route.points);
}
}
}
}
//Declare on global
PolylineOptions polyOptions, polyOptions2;
Polyline polyline2;
List<LatLng> ltln;
private Double lat_decimal = 0.0,lng_decimal=0.0;
//initialize
ltln = new ArrayList<>();
//if you are using routing library
compile 'com.github.jd-alexander:library:1.0.7'
#Override
public void onRoutingSuccess(ArrayList<Route> arrayList, int i) {
//Add this code snippet on onRoutingSuccess to store latlan list
ltln = new ArrayList<>();
System.out.println("-----arrayList------" + arrayList.get(0).getPoints());
ltln = arrayList.get(0).getPoints();
// NOTE here already we draw polyLine 1
}
//below mentioned how to update polyline
private void UpdatePoliline(){
System.out.println("-------runnablePolyline-------"+ltln.size());
try {
if (ltln.size() > 0) {
for (int i = 0; i < ltln.size(); i++) {
ltln.remove(i);
if (CalculationByDistance(ltln.get(i), new LatLng(lat_decimal, lng_decimal)) >= 10) {
break;
}
}
polyOptions2 = new PolylineOptions();
polyOptions2.color(getResources().getColor(R.color.app_color));
polyOptions2.width(7);
polyOptions2.addAll(ltln);
if (polyline2 == null) {
polyline2 = googleMap.addPolyline(polyOptions2);
if (polyLines.size() > 0) {
for (Polyline poly : polyLines) {
poly.remove();
}
}
polyLines.add(polyline2);
if (polyline != null) {
polyline.remove();
polyline = null;
}
} else {
polyline = googleMap.addPolyline(polyOptions2);
if (polyLines.size() > 0) {
for (Polyline poly : polyLines) {
poly.remove();
}
}
polyLines.add(polyline);
if (polyline2 != null) {
polyline2.remove();
polyline2 = null;
}
}
System.out.println("=====waypoints new===" + ltln);
}
} catch (IndexOutOfBoundsException e) {
e.printStackTrace();
}
}
// Calculating distance between 2 points
public float CalculationByDistance(LatLng StartP, LatLng EndP) {
Location locationA = new Location("Source");
locationA.setLatitude(StartP.latitude);
locationA.setLongitude(StartP.longitude);
Location locationB = new Location("Destination");
locationB.setLatitude(EndP.latitude);
locationB.setLongitude(EndP.longitude);
float distance = locationA.distanceTo(locationB);
return distance;
}
//Redraw Polyline vehicle is not in current polyline with particular distance
if (ltln.size() > 0) {
if (PolyUtil.isLocationOnPath(new LatLng(currentlat, currentLon), ltln, false, 60.0f) ){
System.out.println("===tolarance===" + true);
} else {
//Redraw Polyline
}
}
UpdatePoliline();
I want to draw and remove Marker according to the previous conditions must be how
Example:
int a ;
if( a > 0 ) {
draw Marker
}
if(a == 0) {
remove Marker
}
You almost had it:
private Marker marker;
// ...
private void draw(int a) {
if (a == 0) {
if (marker != null) {
marker.remove();
marker = null;
}
} else if (a > 0) {
marker = mMap.addMarker(new MarkerOptions().position(new LatLng(40,-4)));
}
}
I monitor current location and register GoogleMap.MyLocationChangeListener. I want to draw a polyline (track on the map) that represents my own route. On each location update, I'd like to add new point to the route, so that the track on the map is updated.
Here is my code that doesn't work:
private GoogleMap mMap;
private boolean drawTrack = true;
private Polyline route = null;
private PolylineOptions routeOpts = null;
private void startTracking() {
if (mMap != null) {
routeOpts = new PolylineOptions()
.color(Color.BLUE)
.width(2 /* TODO: respect density! */)
.geodesic(true);
route = mMap.addPolyline(routeOpts);
route.setVisible(drawTrack);
mMap.setOnMyLocationChangeListener(this);
}
}
private void stopTracking() {
if (mMap != null)
mMap.setOnMyLocationChangeListener(null);
if (route != null)
route.remove();
route = null;
}
routeOpts = null;
}
public void onMyLocationChange(Location location) {
if (routeOpts != null) {
LatLng myLatLng = new LatLng(location.getLatitude(), location.getLongitude());
routeOpts.add(myLatLng);
}
}
How to add points to the polyline, so that the changes will be reflected in the UI? Right now the polyline is not rendered.
I am using the latest play-services:6.1.71 (as of this date).
This appears to work for me:
public void onMyLocationChange(Location location) {
if (routeOpts != null) {
LatLng myLatLng = new LatLng(location.getLatitude(), location.getLongitude());
List<LatLng> points = route.getPoints();
points.add(myLatLng);
route.setPoints(points);
}
}
Is there a better way?
I'm drawing polylines in google map v2 using marker drag, this is my code
int startDraw = 1;
Polyline polyline;
List<LatLng> lineCordinates = new ArrayList<LatLng>();
List<Polyline> polylines = new ArrayList<Polyline>();
#Override
public void onMarkerDrag(Marker marker) {
// startDraw == 0 --> stop draw
// startDraw == 1 --> start draw
if (startDraw == 1) {
Integer markerId = markerMapHash.get(marker);
if (markerId == null) {
markerId = 1;
}
if (markerId == 1) {
lineCordinates.add(marker.getPosition());
}
for (int i = 0; i < lineCordinates.size(); i++) {
polyline = myMap.addPolyline(new PolylineOptions()
.addAll(lineCordinates)
.width(lineWidth)
.color(lineColor));
polylines.add(polyline);
}
}
}
#Override
public void onMarkerDragEnd(Marker marker) {
lineCordinates.clear();
if (startDraw == 1) {
startDraw = 0;
}else{
startDraw = 1;
}
}
and to remove all polylines, this is the code in a button onClick
for(Polyline line : polylines){
line.remove();
}
polylines.clear();
Now I want to remove a specific polyline, how can I do this ?
Hope anyone could help me.
Thanks in advance.
I've never messed with this code before, but I assume you just need to check to see if line matches the specific polyline you're looking for and then remove it. Something like this:
for(Polyline line : polylines)
{
if (isSpecificPolyline(line))
line.remove();
}
I have googleMap (v2) with polyline that presents a route between the user current location and the destination point. Now, I want to update the polyline according to the user moving.
I tried to redrawing the whole polyline when location is changed but the polyline is flickering.
I didn't find any appropriate function in the PolylineOptions class (the function add() is only to add a vertex but not to update or remove)
do you have any idea how to update the polyline ???
thank you for giving your time.
The only way as of version 3.1.36:
List<LatLng> points = polyline.getPoints();
points.add(newPoint);
polyline.setPoints(points);
Hopefully the API will be enhanced in later versions.
*I have already done working on updating polyline path without removing the polyline. We can do this by changing the points of that polyline. Check below code.
This is the logic of setting new points to polyline.
/*Here the routes contain the points(latitude and longitude)*/
for (int i = 0; i < routes.size(); i++) {
Route route = routes.get(i);
if(polyline_path != null){
polyline_path.setPoints(route.points);
}
}
Detail Explanation:
private GoogleMap map_object;
private Marker marker_driver;
private Marker marker_drop_off;
private Polyline polyline_path;
private PolylineOptions polylineOptions_path;
...
...
...
/*HelperDirectionFinder is a class that I create to call google API and I used this
class to get directions routes*/
/*I have created Service, and I'm calling this lines below after 5 sec. to get the
updated routes from google API.*/
HelperDirectionFinder directionFinder = new HelperDirectionFinder(
JobEndScreen.this, source, destinations);
try {
directionFinder.showDirection();
} catch (UnsupportedEncodingException e) {
HelperProgressDialog.closeDialog();
}
...
...
...
#Override
public void onDirectionFinderStart() {
if(polylineOptions_path == null){
HelperProgressDialog.showDialog(getActivity(), "", getString(R.string.text_loading));
}
}
/*This interface method is called after getting routes from google API.*/
/*Here the routes contains the list of path or routes returned by Google Api*/
#Override
public void onDirectionFinderSuccess(List<Route> routes) {
HelperProgressDialog.closeDialog();
/*When polylineOptions_path is null it means the polyline is not drawn.*/
/*If the polylineOptions_path is not null it means the polyline is drawn on map*/
if(polylineOptions_path == null){
for (Route route : routes) {
polylineOptions_path = new PolylineOptions().
geodesic(true).
color(ContextCompat.getColor(getActivity(), R.color.color_bg_gray_dark)).
width(10);
for (int i = 0; i < route.points.size(); i++)
polylineOptions_path.add(route.points.get(i));
polyline_path = map_object.addPolyline(polylineOptions_path);
}
}
else {
for (int i = 0; i < routes.size(); i++) {
Route route = routes.get(i);
if(polyline_path != null){
polyline_path.setPoints(route.points);
}
}
}
}
//Declare on global
PolylineOptions polyOptions, polyOptions2;
Polyline polyline2;
List<LatLng> ltln;
private Double lat_decimal = 0.0,lng_decimal=0.0;
//initialize
ltln = new ArrayList<>();
//if you are using routing library
compile 'com.github.jd-alexander:library:1.0.7'
#Override
public void onRoutingSuccess(ArrayList<Route> arrayList, int i) {
//Add this code snippet on onRoutingSuccess to store latlan list
ltln = new ArrayList<>();
System.out.println("-----arrayList------" + arrayList.get(0).getPoints());
ltln = arrayList.get(0).getPoints();
// NOTE here already we draw polyLine 1
}
//below mentioned how to update polyline
private void UpdatePoliline(){
System.out.println("-------runnablePolyline-------"+ltln.size());
try {
if (ltln.size() > 0) {
for (int i = 0; i < ltln.size(); i++) {
ltln.remove(i);
if (CalculationByDistance(ltln.get(i), new LatLng(lat_decimal, lng_decimal)) >= 10) {
break;
}
}
polyOptions2 = new PolylineOptions();
polyOptions2.color(getResources().getColor(R.color.app_color));
polyOptions2.width(7);
polyOptions2.addAll(ltln);
if (polyline2 == null) {
polyline2 = googleMap.addPolyline(polyOptions2);
if (polyLines.size() > 0) {
for (Polyline poly : polyLines) {
poly.remove();
}
}
polyLines.add(polyline2);
if (polyline != null) {
polyline.remove();
polyline = null;
}
} else {
polyline = googleMap.addPolyline(polyOptions2);
if (polyLines.size() > 0) {
for (Polyline poly : polyLines) {
poly.remove();
}
}
polyLines.add(polyline);
if (polyline2 != null) {
polyline2.remove();
polyline2 = null;
}
}
System.out.println("=====waypoints new===" + ltln);
}
} catch (IndexOutOfBoundsException e) {
e.printStackTrace();
}
}
// Calculating distance between 2 points
public float CalculationByDistance(LatLng StartP, LatLng EndP) {
Location locationA = new Location("Source");
locationA.setLatitude(StartP.latitude);
locationA.setLongitude(StartP.longitude);
Location locationB = new Location("Destination");
locationB.setLatitude(EndP.latitude);
locationB.setLongitude(EndP.longitude);
float distance = locationA.distanceTo(locationB);
return distance;
}
//Redraw Polyline vehicle is not in current polyline with particular distance
if (ltln.size() > 0) {
if (PolyUtil.isLocationOnPath(new LatLng(currentlat, currentLon), ltln, false, 60.0f) ){
System.out.println("===tolarance===" + true);
} else {
//Redraw Polyline
}
}
UpdatePoliline();