Customize MKAnnotation Callout View?

Question

I have a MKPointAnnotation:

let ann = MKPointAnnotation()
self.ann.coordinate = annLoc
self.ann.title = "Customize me"
self.ann.subtitle = "???"
self.mapView.addAnnotation(ann)

It looks like this:

How can I customize this callout view to create my own view instead of the predefined one?

Answer 1

It should first be noted that the simplest changes to the callout are enabled by simply adjusting the properties of the system provided callout, but customizing the right and left accessories (via rightCalloutAccessoryView and leftCalloutAccessoryView). You can do that configuration in viewForAnnotation.

Since iOS 9, we have access to the detailCalloutAccessoryView which, replaces the subtitle of the callout with a potentially visually rich view, while still enjoying the automatic rendition of the callout bubble (using auto layout makes this easier).

For example, here is a callout that used a MKSnapshotter to supply the image for an image view in the detail callout accessory as demonstrated in WWDC 2015 video What's New in MapKit:

You can achieve this with something like:

class SnapshotAnnotationView: MKPinAnnotationView {
    override var annotation: MKAnnotation? { didSet { configureDetailView() } }

    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        configure()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        configure()
    }
}

private extension SnapshotAnnotationView {
    func configure() {
        canShowCallout = true
        configureDetailView()
    }

    func configureDetailView() {
        guard let annotation = annotation else { return }

        let rect = CGRect(origin: .zero, size: CGSize(width: 300, height: 200))

        let snapshotView = UIView()
        snapshotView.translatesAutoresizingMaskIntoConstraints = false

        let options = MKMapSnapshotter.Options()
        options.size = rect.size
        options.mapType = .satelliteFlyover
        options.camera = MKMapCamera(lookingAtCenter: annotation.coordinate, fromDistance: 250, pitch: 65, heading: 0)

        let snapshotter = MKMapSnapshotter(options: options)
        snapshotter.start { snapshot, error in
            guard let snapshot = snapshot, error == nil else {
                print(error ?? "Unknown error")
                return
            }

            let imageView = UIImageView(frame: rect)
            imageView.image = snapshot.image
            snapshotView.addSubview(imageView)
        }

        detailCalloutAccessoryView = snapshotView
        NSLayoutConstraint.activate([
            snapshotView.widthAnchor.constraint(equalToConstant: rect.width),
            snapshotView.heightAnchor.constraint(equalToConstant: rect.height)
        ])
    }
}

Of course, you would then register that annotation view with your map, and no mapView(_:viewFor:) would be needed at all:

mapView.register(SnapshotAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)

If you're looking for a more radical redesign of the callout or need to support iOS versions prior to 9, it takes more work. The process entails (a) disabling the default callout; and (b) adding your own view when the user taps on the existing annotation view (i.e. the visual pin on the map).

The complexity then comes in the design of the callout, where you have to draw everything you want visible. E.g. if you want to draw a bubble to yield the popover feel of the call out, you have to do that yourself. But with some familiarity with how to draw shapes, images, text, etc., you should be able to render a callout that achieves the desired UX:

Just add the view as a subview of the annotation view itself, and adjust its constraints accordingly:

func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
    let calloutView = ...
    calloutView.translatesAutoresizingMaskIntoConstraints = false
    calloutView.backgroundColor = UIColor.lightGray
    view.addSubview(calloutView)

    NSLayoutConstraint.activate([
        calloutView.bottomAnchor.constraint(equalTo: view.topAnchor, constant: 0),
        calloutView.widthAnchor.constraint(equalToConstant: 60),
        calloutView.heightAnchor.constraint(equalToConstant: 30),
        calloutView.centerXAnchor.constraint(equalTo: view.centerXAnchor, constant: view.calloutOffset.x)
    ])
}

See https://github.com/robertmryan/CustomMapViewAnnotationCalloutSwift for an example of creating your own callout view. This only adds two labels, but it illustrates the fact that you can draw the bubble any shape you want, use constraints to dictate the size of the callout, etc.

Answer 2

Create Cocoa file with classtype MKAnnotationView

CustomeAnnotationView.h file

@interface CustomeAnnotationView : MKAnnotationView
@property (strong, nonatomic) UIButton *buttonCustomeCallOut;
- (void)setSelected:(BOOL)selected animated:(BOOL)animated;
@end

CustomeAnnotationView.m file

@implementation CustomeAnnotationView

-(id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}


- (void)setSelected:(BOOL)selected animated:(BOOL)animated{

    [super setSelected:selected animated:animated];

    if(selected)
    {



            self.buttonCustomeCallOut = [UIButton buttonWithType:UIButtonTypeCustom];//iconShare//iconShareBlue

            [self.buttonCustomeCallOut addTarget:self action:@selector(buttonHandlerCallOut:) forControlEvents:UIControlEventTouchDown];
        [self.buttonCustomeCallOut setBackgroundColor:[UIColor blueColor]];

            [self.buttonCustomeCallOut setFrame:CGRectMake(-40,-80, 100, 100)];



            [self addSubview:self.buttonCustomeCallOut];

        [self.buttonCustomeCallOut setUserInteractionEnabled:YES];
    }
    else
    {
        //Remove your custom view...
        [self.buttonCustomeCallOut setUserInteractionEnabled:NO];
        [self.buttonCustomeCallOut removeFromSuperview];

        self.buttonCustomeCallOut=nil;
    }
}
-(void)buttonHandlerCallOut:(UIButton*)sender{
    NSLog(@"Annotation Clicked");
}

- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent*)event
{
    UIView* v = [super hitTest:point withEvent:event];
    if (v != nil)
    {
        [self.superview bringSubviewToFront:self];
    }
    return v;
}

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent*)event
{
    CGRect rec = self.bounds;
    BOOL isIn = CGRectContainsPoint(rec, point);
    if(!isIn)
    {
        for (UIView *v in self.subviews)
        {
            isIn = CGRectContainsPoint(v.frame, point);
            if(isIn)
                break;
        }
    }
    return isIn;
}
@end

place this code where u want to create custome call out

- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation {
    static NSString *identifier = @"CustAnnotation";

        CustomeAnnotationView *annotationView = (CustomeAnnotationView *) [self.mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
        if (annotationView == nil) {
            annotationView = [[CustomeAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
        }

        annotationView.enabled = YES;
        annotationView.canShowCallout = NO;
        annotationView.centerOffset = CGPointMake(0,-10);//-18

        return annotationView;
}

Answer 3

No need to make MKAnnotationView Custom class just create an empty view .xib and design .xib as your requirement. Write your business login in UIView swift class.

Add the view on

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {

...

}

method like annotationView?.detailCalloutAccessoryView = customView

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
    let annotationIdentifier = "AnnotationIdentifier"
    var annotationView: MKAnnotationView?
    if let dequeuedAnnotationView = mapView.dequeueReusableAnnotationView(withIdentifier: annotationIdentifier) {
        annotationView = dequeuedAnnotationView
        annotationView?.annotation = annotation
    } else {
        annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: annotationIdentifier)
    }
    if let annotation = annotation as? HPAnnotation {
       annotationView?.canShowCallout = true
       let customView = Bundle.main.loadNibNamed("HPAnnotationView", owner: self, options: nil)?.first as! HPAnnotationView
       customView.labelName.text = annotation.annotationTitle
       annotationView?.detailCalloutAccessoryView = customView
    }
    return annotationView
 }

If you want dynamic value show on callout view then first make MKAnnotation custom class where you can pass objects as you need.

import MapKit
import AddressBook
import UIKit

class HPAnnotation: NSObject, MKAnnotation {

   let title: String?
   let annotationTitle: String
   init(title: String, annotationTitle: String = "") {
      self.title = title
      self.annotationTitle = annotationTitle
   }

   var subtitle: String? {
     return details
   }

}

and pass value when creating annotation

 for index in 0..<searchPeopleArray.count {
    let annotation = HPAnnotation(title: "", annotationTitle: "")
    mapView.addAnnotation(annotation)
}

N.B: Here HPAnnotationView is my custom view class and xib name. HPAnnotation is my custom MKAnnotation.