How to handle taps on a custom callout view?

Question

I am adding a callout view like this:

func mapView(mapView: MKMapView!,
        didSelectAnnotationView view: MKAnnotationView!) {
    let calloutView = UIView(frame:
        CGRect(x: 0, y: 0, width: 300, height: 120))

    calloutView.backgroundColor = UIColor.purpleColor()
    calloutView.center = CGPointMake(CGRectGetWidth(view.bounds) / 2.0, 0.0)
    calloutView.layer.anchorPoint = CGPointMake(0.5, 1.0)
    calloutView.layer.masksToBounds = false

    calloutView.userInteractionEnabled = true
    let calloutViewTapRecognizer = UITapGestureRecognizer(target: self,
        action: "onCalloutViewTap")
    calloutView.addGestureRecognizer(calloutViewTapRecognizer)

    view.addSubview(calloutView)
}

Though my onCalloutViewTap function is never called... I am curious to understand why and to get something that works to handle interactions with my callout view.

Answer 1

It's because your annotation view only detects touches inside its bounds. Since your callout view extends beyond the bounds, the subview doesn't recognize the tap. You need to override the pointInside:withEvent: method in the annotation view so your callout will actually detect the touch.

Here's an example in Objective-C:

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent*)event
{
    CGRect rect = self.bounds;
    BOOL isInside = CGRectContainsPoint(rect, point);

    if (!isInside)
    {
        for (UIView *view in self.subviews)
        {
            isInside = CGRectContainsPoint(view.frame, point);

            if (isInside)
            {
                break;
            }
        }
    }

    return isInside;
}

EDIT:

Swift version:

override func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool {
    let rect = self.bounds
    var isInside = CGRectContainsPoint(rect, point)

    if (!isInside) {
        for subview in subviews {
            isInside = CGRectContainsPoint(subview.frame, point)

            if (isInside) {
                break
            }
        }
    }

    println(isInside)

    return isInside;
}