CODEWITHSUNDEEP
javaandroidgoogle-mapsgoogle-maps-markersandroid-geofence
Diksha
Diksha

Reputation: 416

Adding multiple Geofence to a map

So far I'm able to add single geofence to the map with help of this tutorial. Actually I'm adding markers to the map on map click event allowing me to add multiple markers on touch. I wan't to add geofence to all the markers that I'm adding. I've tried making few changes in particular methods of the above tutorial as 

ArrayList<LatLng> locs= new ArrayList<LatLng>();
    // Create a marker for the geofence creation
private void markerForGeofence(LatLng latLng) {
    Log.i(TAG, "markerForGeofence(" + latLng + ")");
    String title = latLng.latitude + ", " + latLng.longitude;
    // Define marker options
    MarkerOptions markerOptions = new MarkerOptions()
            .position(latLng)
            .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_ORANGE))
            .title(title);
    if (map != null) {
        // Remove last geoFenceMarker
      //  if (geoFenceMarker != null)
      //      geoFenceMarker.remove();

        geoFenceMarker = map.addMarker(markerOptions);  
        gfmarkr.add(geoFenceMarker);
    }
}
...
   // Start Geofence creation process
private void startGeofence() {
    Log.i(TAG, "startGeofence()");
    if (geoFenceMarker != null) {
        for (int i = 0; i < gfmarkr.size(); i++) {
            Geofence geofence = createGeofence(locs.get(i), GEOFENCE_RADIUS);
            GeofencingRequest geofenceRequest = createGeofenceRequest(geofence);
            addGeofence(geofenceRequest);
        }
    } else {
        Log.e(TAG, "Geofence marker is null");
    }
}

In short what is the method of adding more than one geofence. Any solution will be of great help. Thankyou.

Upvotes: 0

Views: 2698

Answers (2)

Diksha
Diksha

Reputation: 416

It is solved. I passed locs.get(i) to all the methods that are responsible for creating a particular Geofence and used it as a point of reference for position. Also, I removed the statements

 if (geoFenceLimits != null)
    geoFenceLimits.remove();

from drawGeofence() method.

Upvotes: 1

Konstantin Shendenkov
Konstantin Shendenkov

Reputation: 287

When you get a location update, if the ArrayList of all your geofences is more than 100, remove all geofences been monitored and then calculate the 100 nearest geofences using the harvesine formula:

public static final double R = 6372.8; // In kilometers

public static double haversine(double lat1, double lon1, double lat2, double lon2) {
  double dLat = Math.toRadians(lat2 - lat1);
  double dLon = Math.toRadians(lon2 - lon1);
  lat1 = Math.toRadians(lat1);
  lat2 = Math.toRadians(lat2);

  double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);
  double c = 2 * Math.asin(Math.sqrt(a));
  return R * c;
}

That will give you the distance between the two locations. After that you could compare that distance with the geofence region radius to know if is inside the region. Note: This distance will be in kilometers if your radius is on meters then just multiply the haversine method result with 1000 so that it's converted to meters.

Reference

Upvotes: 0

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