When I zoom my mapView to show my annotations, the selected annotations are partially off screen

Question

When I execute the following code snippet, the map zooms correctly to encompass all annotations, however the callouts are partially offscreen. What is the most elegant way of fixing that?

func mapView(mapView: MKMapView!, didAddAnnotationViews views: [AnyObject]!) {
// once annotationView is added to the map, get the last one added unless it is the user's location:
  if let annotationView = views.last as? MKAnnotationView where !(annotationView.annotation is MKUserLocation) {
  // show callout programmatically:
  mapView.selectAnnotation(annotationView.annotation, animated: false)
  // zoom to all annotations on the map:
  mapView.showAnnotations(mapView.annotations, animated: true)
}

Answer 1

If I understand correctly, then I had the same issue. I'm not sure if this is the most "elegant" solution, but a simple delay did the trick for me. You could try something similar, like this:

    //Assuming this is how you center
    mapView.setCenterCoordinate(annotation.coordinate, animated: true)

    //Delaying the showing of annotation because otherwise the popover appears at "old" location before zoom finishes
    let delayTime = dispatch_time(DISPATCH_TIME_NOW,Int64(0.75 * Double(NSEC_PER_SEC)))
    dispatch_after(delayTime, dispatch_get_main_queue()) {

    mapView.selectAnnotation(annotationView.annotation, animated: false)
    }

Note that I used an arbitrary time of 0.75 seconds; this may be more or less than what you need - if you really want (I was lazy), you could make that number dependent on the distance you have to zoom in; or, be extra clever and find out how to get the zoom in time.

Enjoy!

Answer 2

I had this exact problem, I tried @Jona approach of a delay, but I found that on certain devices it works and others it doesn't. Its all down to the device setup/performance, so using delays isn't really the best solution.

My problem was that I was trying to move/zoom the map (with animation) before opening the callout view (with animation) on the specific pin I wanted to show. Doing this lead to poor performance and the callout being partially off screen.

I decided to use the UIView animateWithDuration method, this method has its own completion block and thus no delay is needed. Note: when using the UIView animateWithDuration method, you can set the animated method to NO (or false in Swift). As the UIView animation block will take care of the animation for us.

-(void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views {

    // Loop through the pins on the
    // map and find the added pin.

    for (MKAnnotationView *annotationView in views) {

        // If the current pin is the
        // added pin zoom in on it.

        if (annotationView.annotation != mapView.userLocation) {

            // Set the map region to be
            // close to the added pin.
            MKCoordinateSpan span = MKCoordinateSpanMake(0.15, 0.15);
            MKCoordinateRegion region = MKCoordinateRegionMake(annotationView.annotation.coordinate, span);
            [mapView regionThatFits:region];

            // Only perform the annotation popup
            // when the animation has been completed.
            [UIView animateWithDuration:0.4 delay:0.0 options:(UIViewAnimationOptionAllowUserInteraction | UIViewAnimationOptionCurveEaseOut) animations:^{

                // Set the map region.
                [mapView setRegion:region];

             } completion:^(BOOL finished) {

                 // Force open the annotation popup.
                 [usersMap selectAnnotation:annotationView.annotation animated:YES];
             }];
        }
    }
}