SafariViewControllerDidFinish does not fire when swiping down to dismiss

Question

I have a delegate on a SFSafariViewController that does clean up tasks in the safariViewControllerDidFinish event. In iOS 13+, the user is able to swipe down to dismiss, but this event is not fired in that case. I do not want to disable this gesture by enabling isModalInPresentation.

Is there a way to make the safariViewControllerDidFinish fire for this case, or how can I detect the user swiping down to dismiss the Safari view controller?

Answer 1

You can know when the user dismisses the SFSafariViewController by swiping down by making yourself the presentation controller's delegate and overriding presentationControllerDidDismiss(_:). Check out the documentation on this topic.

Note: This method will not get called if you use dismiss(animated:) programmatically.

Answer 2

@Frankenstein's answer worked for me, but it took me a while to setup my code correctly, so just want to add some code snippets here

class MyViewController: UIViewController {

  func presentSafariVC() {
    let url = //...
    let config = SFSafariViewController.Configuration()
    let safariVC = SFSafariViewController(url: url, configuration: config)
    safariVC.modalPresentationStyle = .formSheet
    safariVC.delegate = self
    safariVC.presentationController?.delegate = self
    present(safariVC, animated: true)
  }

}

extension MyViewController: SFSafariViewControllerDelegate, UIAdaptivePresentationControllerDelegate {

  // click top left "Done" button and dismissed
  func safariViewControllerDidFinish(_ controller: SFSafariViewController) {
        // do your stuff
  }
    
  // swipe down and dismissed
  func presentationControllerDidDismiss(_ presentationController: UIPresentationController) {
        // do your stuff
  }

}

Also, I was originally looking for a way to prevent swipe down to dismiss the presented vc, but it seems setting safariVC.isModalInPresentation = true has no effect, I can still swipe down to dismiss it. This is observed on XCode 12, iOS 14.2 simulator.