Only Plotting Markers Within A Drawn Circle Or Perimeter Google Maps V2 Android

Basically the title says it all. Rather than plotting every single entry in my database on a map as I do at the moment, I want to query the database and only plot the entries whose

Solution 1:

I believe the circle has a fixed Radius and a center point.

So, go with this method to get the distance between the center and some LatLng and set a condition

distance <= radius

publicstatic String getDistance(LatLng ll_source, LatLng ll_destination,
        int unit){


    int Radius = 6371;// radius of earth in Kmdouble lat1 = ll_source.latitude;
    double lat2 = ll_destination.latitude;
    double lon1 = ll_source.longitude;
    double lon2 = ll_destination.longitude;
    double dLat = Math.toRadians(lat2 - lat1);
    double dLon = Math.toRadians(lon2 - lon1);
    double a = Math.sin(dLat / 2) * Math.sin(dLat / 2)
            + Math.cos(Math.toRadians(lat1))
            * Math.cos(Math.toRadians(lat2)) * Math.sin(dLon / 2)
            * Math.sin(dLon / 2);
    double c = 2 * Math.asin(Math.sqrt(a));
    double valueResult = Radius * c;
    double km = valueResult / 1;
    DecimalFormat newFormat = newDecimalFormat("####");
    Integer kmInDec = Integer.valueOf(newFormat.format(km));
    double meter = valueResult % 1000;
    Integer meterInDec = Integer.valueOf(newFormat.format(meter));
    DecimalFormat df = newDecimalFormat("#.#");
    return df.format(valueResult);
}

Solution 2:

Ok, I've figured out a solution using the LatLngBounds class I referred to in my question. What it does is:

1. Creates a new rectangular perimeter around the user's current latitude and longitude co-ordinates (this example is roughly one square kilometer).
2. It then checks if the perimeter contains the co-ordinates stored in the database.

3. If it does, the marker is plotted on the map.

   publicvoidgetNearbyMarkers(){
       LatLngBounds perimeter = new LatLngBounds(new LatLng(currentLat - 0.004,
               currentLon - 0.004), new LatLng(currentLat + 0.004, currentLon + 0.004));
   
   
       if (perimeter.contains(LatlongFromDatabase)) {
           //Plot Marker on Map
       } else {
           Toast.makeText(getApplicationContext(), "Co-ordinates not in perimeter!", 8).show();
       }
   }