How to zoom MapView annotations below an overlay view? - iphone

Question

I need to zoom the map annotations below the over laid view.
Im using this method to zoom to the 2 annotations.
I can't seem to find a way to fit the 2 annotations below the over laid view, because:
Setting map edgePadding will hide the bottom pin
Setting the map center will hide the bottom pin
Setting the latitudeDelta would work I guess but if pins are horizontally parallel it would not be necessary + it would get messy with different cases.
So i'm wondering if there's an elegant solution for this problem that I might have missed?
This overlay also hides the annotation callout, I guess this could be fixed if I have a solution for the first problem.

Answer 1

Maybe you should try this code to handle perfect fit for Annotations :
- (void)zoomMapViewToFitAnnotations:(MKMapView *)mapView animated:(BOOL)animated
{
NSArray *annotations = mapView.annotations;
int count = [mapView.annotations count];
if ( count == 0) { return; } //return if no annotations
//convert NSArray of id <MKAnnotation> into an MKCoordinateRegion that can be used to set the map size
//can't use NSArray with MKMapPoint because MKMapPoint is not an id
MKMapPoint points[count]; //C array of MKMapPoint struct
for( int i=0; i<count; i++ ) //load points C array by converting coordinates to points
{
CLLocationCoordinate2D coordinate = [(id <MKAnnotation>)[annotations objectAtIndex:i] coordinate];
points[i] = MKMapPointForCoordinate(coordinate);
}
//create MKMapRect from array of MKMapPoint
MKMapRect mapRect = [[MKPolygon polygonWithPoints:points count:count] boundingMapRect];
//convert MKCoordinateRegion from MKMapRect
MKCoordinateRegion region = MKCoordinateRegionForMapRect(mapRect);
//add padding so pins aren't scrunched on the edges
region.span.latitudeDelta *= ANNOTATION_REGION_PAD_FACTOR;
region.span.longitudeDelta *= ANNOTATION_REGION_PAD_FACTOR;
//but padding can't be bigger than the world
if( region.span.latitudeDelta > MAX_DEGREES_ARC ) { region.span.latitudeDelta = MAX_DEGREES_ARC; }
if( region.span.longitudeDelta > MAX_DEGREES_ARC ){ region.span.longitudeDelta = MAX_DEGREES_ARC; }
//and don't zoom in stupid-close on small samples
if( region.span.latitudeDelta < MINIMUM_ZOOM_ARC ) { region.span.latitudeDelta = MINIMUM_ZOOM_ARC; }
if( region.span.longitudeDelta < MINIMUM_ZOOM_ARC ) { region.span.longitudeDelta = MINIMUM_ZOOM_ARC; }
//and if there is a sample of 1 we want the max zoom-in instead of max zoom-out
if( count == 1 )
{
region.span.latitudeDelta = MINIMUM_ZOOM_ARC;
region.span.longitudeDelta = MINIMUM_ZOOM_ARC;
}
[mapView setRegion:region animated:animated];
}
So, you have to define the Padding, Maximum degree arc and Minimum zoom arc. For Ex. should belike this :
#define MINIMUM_ZOOM_ARC 0.05 //approximately 1 miles (1 degree of arc ~= 69 miles)
#define ANNOTATION_REGION_PAD_FACTOR 1.25
#define MAX_DEGREES_ARC 360
Hopefully, You will like it, Cheers

Answer 2

Set userintercation disabled for the overlay if you want touch points on the overlay.
For setting the zoom level I made a few adjustments after plotting the points. You can calculate the average of the lat longs and then adjust the lat longs as per size of the overlay. Here's what I did:
float latAvg,longAvg;
latAvg = (location1.latitude + location.latitude)/2;
longAvg = (location1.longitude + location.longitude)/2;
MKCoordinateSpan span;// = MKCoordinateSpanMake(0.006, 0.006);
span.latitudeDelta = fabs(location1.latitude - location.latitude);
span.longitudeDelta = fabs(location1.longitude - location.longitude);
//Then adjust the lat longs delta according to your need.
span.latitudeDelta = span.latitudeDelta + 0.0010;
span.longitudeDelta = span.longitudeDelta + 0.0010;
CLLocationCoordinate2D locationLatlng;
locationLatlng.latitude = latAvg;
locationLatlng.longitude = longAvg;
MKCoordinateRegion viewRegion = MKCoordinateRegionMake(locationLatlng, span);
[map setRegion:viewRegion animated:YES];
[map regionThatFits:viewRegion];