Question

in this my gps application i want to draw circle around my current location i did it …but now i find out other users which are come in cirle range so i want popoup in my application screen so can anyboby help me…

Answer 1

you have just to compute the distance between each point and the center of the circle.

This can be done with something like this:

double d2r = (180 / Math.PI);
double distance = 0;

try{
    double dlong = (endpoint.getLon() - startpoint.getLon()) * d2r;
    double dlat = (endpoint.getLat() - startpoint.getLat()) * d2r;
    double a =
        Math.pow(Math.sin(dlat / 2.0), 2)
            + Math.cos(startpoint.getLat() * d2r)
            * Math.cos(endpoint.getLat() * d2r)
            * Math.pow(Math.sin(dlong / 2.0), 2);
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
    double d = 6367 * c;

    return d;

} catch(Exception e){
    e.printStackTrace();
}

and then

if (distance < CIRCLE_RADIUS)
//The point is inside circle.