leftCalloutAccessoryView

The default value of this property is nil. The left callout view is typically used to display information about the annotation or to link to custom information provided by your application.

In an iOS app, if the view you specify is also a descendant of the UIControl class, you can use the map view’s delegate to receive notifications when your control is tapped. If it does not descend from UIControl, your view is responsible for handling any touch events within its bounds.

In a macOS app, the callout view’s view controller can implement an action method that responds when a user clicks the control in a callout view.