Question

I have two geo points that vary intermittently, and want the MapView to resize and translate to make sure both points are always visible. I can easily re-centre the map on the point mid-way between the two, but how do I set the zoom level to ensure my two points are visible?

Answer 1

Try this and see:

double latitudeSpan = Math.round(Math.abs(firstLat - 
                secLat));
double longitudeSpan = Math.round(Math.abs(firstLong - 
                secLong));

double currentLatitudeSpan = (double)mapView.getLatitudeSpan();
double currentLongitudeSpan = (double)mapView.getLongitudeSpan();

double ratio = currentLongitudeSpan/currentLatitudeSpan;
if(longitudeSpan < (double)(latitudeSpan+2E7) * ratio){
    longitudeSpan = ((double)(latitudeSpan+2E7) * ratio);
}

mapController.zoomToSpan((int)(latitudeSpan*2), (int)(longitudeSpan*2));                
mapView.invalidate();