Centering MKMapView on spot N-pixels below pin

Question

Want to center MKMapView on a point N-pixels below a given pin (which may or may not be visible in the current MapRect).

I\'ve been trying

Answer 1

after reading this thread ad playing around, especially with the zooming on annotation, I ended up with following procedures:

** Centering on annotation:**

- (void) centerOnSelection:(id)annotation
{
    MKCoordinateRegion region = self.mapView.region;
    region.center = annotation.coordinate;

    CGFloat per = ([self sizeOfBottom] - [self sizeOfTop]) / (2 * self.mapView.frame.size.height);
    region.center.latitude -= self.mapView.region.span.latitudeDelta * per;

    [self.mapView setRegion:region animated:YES];
}

** Zooming on annotation:**

- (void) zoomAndCenterOnSelection:(id)annotation
{
    DLog(@"zoomAndCenterOnSelection");

    MKCoordinateRegion region = self.mapView.region;
    MKCoordinateSpan span = MKCoordinateSpanMake(0.005, 0.005);

    region.center = annotation.coordinate;

    CGFloat per = ([self sizeOfBottom] - [self sizeOfTop]) / (2 * self.mapView.frame.size.height);
    region.center.latitude -= self.mapView.region.span.latitudeDelta * span.latitudeDelta / region.span.latitudeDelta * per;

    region.span = span;

    [self.mapView setRegion:region animated:YES];
}

-(CGFloat) sizeOfBottom and -(CGFloat) sizeOfTop both return height of panels covering the mapview from the layout guides