Is there any limit to drawing path using Geocoder (Android)?

Question

I am able to draw a path between two locations, but if the distance is too long - more than 300 Kilometers - the path is not drawn completely.

I am using the code below in order to draw the path:

class MapOverlay extends com.google.android.maps.Overlay {
    Road mRoad;
    ArrayList<GeoPoint> mPoints;

    public MapOverlay(Road road, MapView mv) {
            mRoad = road;
            if (road.mRoute.length > 0) {
                    mPoints = new ArrayList<GeoPoint>();
                    for (int i = 0; i < road.mRoute.length; i++) {
                            mPoints.add(new GeoPoint((int) (road.mRoute[i][1] * 1000000),
                                            (int) (road.mRoute[i][0] * 1000000)));
                    }
                    int moveToLat = (mPoints.get(0).getLatitudeE6() + (mPoints.get(
                                    mPoints.size() - 1).getLatitudeE6() - mPoints.get(0)
                                    .getLatitudeE6()) / 2);
                    int moveToLong = (mPoints.get(0).getLongitudeE6() + (mPoints.get(
                                    mPoints.size() - 1).getLongitudeE6() - mPoints.get(0)
                                    .getLongitudeE6()) / 2);
                    GeoPoint moveTo = new GeoPoint(moveToLat, moveToLong);

                    MapController mapController = mv.getController();
                    mapController.animateTo(moveTo);
                    mapController.setZoom(8);
            }
    }

    @Override
    public boolean draw(Canvas canvas, MapView mv, boolean shadow, long when) {
            super.draw(canvas, mv, shadow);
            drawPath(mv, canvas);
            return true;
    }

    public void drawPath(MapView mv, Canvas canvas) {
            int x1 = -1, y1 = -1, x2 = -1, y2 = -1;
            Paint paint = new Paint();
            paint.setColor(Color.GREEN);
            paint.setStyle(Paint.Style.STROKE);
            paint.setStrokeWidth(3);
            for (int i = 0; i < mPoints.size(); i++) {
                    Point point = new Point();
                    mv.getProjection().toPixels(mPoints.get(i), point);
                    x2 = point.x;
                    y2 = point.y;
                    if (i > 0) {
                            canvas.drawLine(x1, y1, x2, y2, paint);
                    }
                    x1 = x2;
                    y1 = y2;
            }
    }
    
}

Answer 1

First of all, you should be using Google Maps API V2 instead of the old deprecated V1 API

In the Activity, create the Google Map and Polyline references:

public class MapsActivity extends AppCompatActivity implements OnMapReadyCallback{

    private GoogleMap mMap;
    Polyline line;
    //......

First define your waypoint list:

List<LatLng> latLngWaypointList = new ArrayList<>();

Get your route, draw the Polyline for the route, and then draw the waypoint Markers:

class GetDirectionsAsync extends AsyncTask<LatLng, Void, List<LatLng>> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected List<LatLng> doInBackground(LatLng... params) {
           List<LatLng> route = new ArrayList<>();
           //populate route......
           return route;
    }

    @Override
    protected void onPostExecute(List<LatLng> route) {

        if (route == null) return;

        if (line != null){
            line.remove();
        }

        PolylineOptions options = new PolylineOptions().width(5).color(Color.MAGENTA).geodesic(true);
        for (int i = 0; i < pointsList.size(); i++) {
            LatLng point = route.get(i);
            //If this point is a waypoint, add it to the list
            if (isWaypoint(i)) {
                latLngWaypointList.add(point);
            }

            options.add(point);
        }
        //draw the route:
        line = mMap.addPolyline(options);

        //draw waypoint markers:
        for (LatLng waypoint : latLngWaypointList) {
            mMap.addMarker(new MarkerOptions().position(new LatLng(waypoint.latitude, waypoint.longitude))
                    .title("Waypoint").icon(BitmapDescriptorFactory
                            .defaultMarker(BitmapDescriptorFactory.HUE_VIOLET)));
        }

    }
}

Here is just a placeholder implementation of isWaypoint():

public boolean isWaypoint(int i) {
    //replace with your implementation
    if (i % 17 == 0) {
        return true;
    }
    return false;
}

Result for a route from the west coast to the east coast, about 2500 miles:

Result of a smaller route:

Note that I'm also using the Google Directions Api in this example in order to make the route snap to the roads. For a full example of how to use the Google Directions api, see here: https://stackoverflow.com/a/32940175/4409409