How to tell which button is being pressed in calloutAcessoryControlTapped? - ios

Question

I'm using MapKit and I have 2 callout accessories in my pins.
I'm trying to implement a button for updating the pin's title and one for deleting the pin.
Right now, anytime I press a button on the annotation, it only deletes the pin.
How do I get it to respond differently for the right button vs the left button?
-(void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control {
id <MKAnnotation> annotation = [view annotation];
if ([annotation isKindOfClass:[MKPointAnnotation class]])
{
NSLog(#"Clicked");
if(view.rightCalloutAccessoryView){
[self.mapView removeAnnotation:annotation];
}
else{
float lat= annotation.coordinate.latitude;
float longitude = annotation.coordinate.longitude;
[self.mapView removeAnnotation:annotation];
MKPointAnnotation *pointAnnotation = [[MKPointAnnotation alloc] init];
pointAnnotation.title = _titleOut.text;
pointAnnotation.subtitle = _subtitle.text;
pointAnnotation.coordinate = CLLocationCoordinate2DMake(lat, longitude);
[self.mapView addAnnotation:pointAnnotation];
}
}
}

Answer 1

This line:
if(view.rightCalloutAccessoryView){
says essentially "if view.rightCalloutAccessoryView is not nil".
Since you are setting the right-side accessory on all annotation views, that if condition will always be true and so tapping either accessory will execute the code inside that if which is to remove the annotation.
Instead, you want to check what button or control was tapped in this specific case of the delegate method being called (not whether the view has a right-side accessory defined).
Fortunately, the delegate method passes exactly what control was tapped in the control parameter.
The control parameter can be directly compared against the view's right/left accessory view to tell which was tapped:
if (control == view.rightCalloutAccessoryView) {
Some unrelated points:
The latitude and longitude properties in annotations are of type CLLocationDegrees (aka double) which has higher precision than float so to avoid losing accuracy, use CLLocationDegrees or double:
CLLocationDegrees lat= annotation.coordinate.latitude;
The MKPointAnnotation allows you to change the title directly (it's not read-only like the default id<MKAnnotation>) so you don't need to remove and create a new annotation. It simplifies the code a bit:
-(void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control {
if ([view.annotation isKindOfClass:[MKPointAnnotation class]])
{
NSLog(#"Clicked");
if (control == view.rightCalloutAccessoryView) {
[self.mapView removeAnnotation:view.annotation];
}
else {
// Cast view.annotation as an MKPointAnnotation
// (which we know it is) so that compiler sees
// title is read-write instead of the
// default id<MKAnnotation> which is read-only.
MKPointAnnotation *pa = (MKPointAnnotation *)view.annotation;
pa.title = _titleOut.text;
pa.subtitle = _subtitle.text;
//If you want callout to be closed automatically after
//title is changed, uncomment the line below:
//[mapView deselectAnnotation:pa animated:YES];
}
}
}