Android MapView overlay disappearing when zooming in

Question

I\'m working on a simple Android app for plotting routes on a map. All is going well, but I have an issue when zooming in on my Samsung Galaxy S2. It works fine on a Galaxy S3

Answer 1

The problem is that you are painting the overlay yourself for a very specific state of the mapview. You should use OverlayItem instead.

The OverlayItem is added to the MapView overlays collection, and the MapView handles all the re-drawing depending on it's own state ( zoom, location, etc )

@Override
public void draw( Canvas canvas, MapView mapView, boolean shadow )
{
    super.draw( canvas, mapView, shadow );

    int x1 = -1;
    int y1 = -1;
    int x2 = -1;
    int y2 = -1;

    Paint paint = new Paint();
    paint.setStyle( Paint.Style.STROKE );
    paint.setColor( GeoLocation.ROUTE_COLOR );
    paint.setStrokeWidth( STROKE_WIDTH );

    for ( int i = 0; i < mRouteGeoPoints.size(); i++ )
    {
        Point point = new Point();
        mapView.getProjection().toPixels( geoPoints.get( i ), point );
        x2 = point.x;
        y2 = point.y;
        if ( i > 0 )
        {
            canvas.drawLine( x1, y1, x2, y2, paint );
        }
        x1 = x2;
        y1 = y2;
    }
}