How to set map rect with user location at the centre? - iphone

Question

I have a mapView with one pin and the users location. I have made it so the VisibleMapRect is set so both pins can be seen.
The problem Im having is that I am using MKUserTrackingModeFollowWithHeading to show the users move movements and when I set the rect like this the movement is very jerky. I believe this is because the user location pin is not in the centre of the map.
How can I get both pins to be visible but keep the user location in the centre?
This is my code that starts the location and sets the rect.
[locationManager startUpdatingLocation];
// Start heading updates.
if ([CLLocationManager headingAvailable]) {
locationManager.headingFilter = kCLHeadingFilterNone;
[locationManager startUpdatingHeading];
//set the view to fit both the pins
MKMapPoint annotationPoint = MKMapPointForCoordinate(MapView.userLocation.coordinate);
MKMapRect zoomRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0, 0);
for (id <MKAnnotation> annotation in MapView.annotations)
{
if (![annotation isKindOfClass:[MKUserLocation class]] ) {
MKMapPoint annotationPoint = MKMapPointForCoordinate(annotation.coordinate);
MKMapRect pointRect = MKMapRectMake(annotationPoint.x, annotationPoint.y, 0, 0);
zoomRect = MKMapRectUnion(zoomRect, pointRect);
}
}
NSLog(#"%f",zoomRect.size.height);
NSLog(#"%f",zoomRect.size.width);
[MapView setVisibleMapRect:zoomRect animated:NO];
}
I have tried commenting out the part that sets the rect and the movement of the user is smooth so I can tell my problem is this code.
I have also tried setting the centre point after the rect using
[MapView setCenterCoordinate:MapView.userLocation.coordinate animated:YES];
This did not seem to work. Also setting this after may make it so the other pin is not shown anymore.

Answer 1

I use this method:
- (void)setRegionFromCoordinates:(NSArray *)waypoints animated:(BOOL)animated {
if (waypoints != nil) {
CLLocationDegrees maxX = -DBL_MAX;
CLLocationDegrees maxY = -DBL_MAX;
CLLocationDegrees minX = DBL_MAX;
CLLocationDegrees minY = DBL_MAX;
for (NSUInteger i=0; i < waypoints.count; i++) {
CLLocationCoordinate2D currentLocation = [waypoints objectAtIndex:i];
MKMapPoint mapPoint = MKMapPointForCoordinate(currentLocation);
if (mapPoint.x > maxX) {
maxX = mapPoint.x;
}
if (mapPoint.x < minX) {
minX = mapPoint.x;
}
if (mapPoint.y > maxY) {
maxY = mapPoint.y;
}
if (mapPoint.y < minY) {
minY = mapPoint.y;
}
}
if (maxX != -DBL_MAX && minX != DBL_MAX) {
MKMapRect mapRect = MKMapRectMake(minX,minY,maxX-minX,maxY-minY);
[map setVisibleMapRect:mapRect edgePadding:UIEdgeInsetsMake(50.f, 50.f, 50.f, 50.f) animated:animated];
}
}
}

Answer 2

For Display All the Annotation with Your Current location use following method
- (void)zoomToFitMapAnnotations:(MKMapView *)mapView {
if ([mapView.annotations count] == 0) return;
CLLocationCoordinate2D topLeftCoord;
topLeftCoord.latitude = -90;
topLeftCoord.longitude = 180;
CLLocationCoordinate2D bottomRightCoord;
bottomRightCoord.latitude = 90;
bottomRightCoord.longitude = -180;
for(id<MKAnnotation> annotation in mapView.annotations) {
topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude);
topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);
bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude);
bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude);
}
MKCoordinateRegion region;
region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5;
region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5;
region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1;
// Add a little extra space on the sides
region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1;
region = [mapView regionThatFits:region];
[mapView setRegion:region animated:YES];
}