How to zoom a MapView so it always includes two geopoints?

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

Check out his answer in a different post: Google Map V2 how to set ZoomToSpan?

It solves it without much hassle. Note that you can only use that function AFTER the map has been loaded at least once. If not use function with specified map size on screen

LatLngBounds bounds = new LatLngBounds.Builder()
                    .include(new LatLng(CURRENTSTOP.latitude, CURRENTSTOP.longitude))
                    .include(new LatLng(MYPOSITION.latitude, MYPOSITION.longitude)).build();

Point displaySize = new Point();
getWindowManager().getDefaultDisplay().getSize(displaySize);

map.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds, displaySize.x, 250, 30));

Works like a charm and very dynamic!

Answer 2

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();