Draw circle of certain radius on map view in Android

Question

I want to draw a circle on map view. I want the user to input the radius and for that radius I have to show circle on map. After that I have to display markers on some locat

Answer 1

In case someone was looking for an answer using Google Maps API v2, here's a snippet of what I did. It's really more of a geographical approach.

public class MapDrawer {

private GoogleMap map;
private static int EARTH_RADIUS = 6371000;

public MapDrawer(GoogleMap map) {
    this.map = map;
}

private LatLng getPoint(LatLng center, int radius, double angle) {
    // Get the coordinates of a circle point at the given angle
    double east = radius * Math.cos(angle);
    double north = radius * Math.sin(angle);

    double cLat = center.latitude;
    double cLng = center.longitude;
    double latRadius = EARTH_RADIUS * Math.cos(cLat / 180 * Math.PI);

    double newLat = cLat + (north / EARTH_RADIUS / Math.PI * 180);
    double newLng = cLng + (east / latRadius / Math.PI * 180);

    return new LatLng(newLat, newLng);
}

public Polygon drawCircle(LatLng center, int radius) {
    // Clear the map to remove the previous circle
    map.clear();
    // Generate the points
    List points = new ArrayList();
    int totalPonts = 30; // number of corners of the pseudo-circle
    for (int i = 0; i < totalPonts; i++) {
        points.add(getPoint(center, radius, i*2*Math.PI/totalPonts));
    }
    // Create and return the polygon
    return map.addPolygon(new PolygonOptions().addAll(points).strokeWidth(2).strokeColor(0x700a420b));
}

}

The good thing about this is that you don't have to redraw anything after zooming or panning the map - the circle gets resized and moved accordingly. The downside is that this doesn't work if you want a circle on either north or south pole - it'll all go bezerk, but, hopefully, that's not the case 99% of the time :)