I'm using a custom UIPresentationController to present a view modally. After presenting the view, the first textfield in the presented view becomes the first responder and the keyboard shows up. To ensure that the view is still visible, I move it up. However, when I do this the frameOfPresentedViewInContainerView
is not matching the actual frame of the view anymore. Because of this, when I tap on the view it's being dismissed, because there's a tapGestureRecogziner on the backgroundView which is on top of the presentingView. How to notify the presentingController that the frame/position of the presentedView has changed?
In the UIPresentationController:
override var frameOfPresentedViewInContainerView: CGRect {
var frame = CGRect.zero
let safeAreaBottom = self.presentingViewController.view.safeAreaInsets.bottom
guard let height = presentedView?.frame.height else { return frame }
if let containerBounds = containerView?.bounds {
frame = CGRect(x: 0,
y: containerBounds.height - height - safeAreaBottom,
width: containerBounds.width,
height: height + safeAreaBottom)
}
return frame
}
override func presentationTransitionWillBegin() {
if let containerView = self.containerView, let coordinator = presentingViewController.transitionCoordinator {
containerView.addSubview(self.dimmedBackgroundView)
self.dimmedBackgroundView.backgroundColor = .black
self.dimmedBackgroundView.frame = containerView.bounds
self.dimmedBackgroundView.alpha = 0
coordinator.animate(alongsideTransition: { _ in
self.dimmedBackgroundView.alpha = 0.5
}, completion: nil)
}
}
Presenting the view modally:
let overlayVC = CreateEventViewController()
overlayVC.transitioningDelegate = self.transitioningDelegate
overlayVC.modalPresentationStyle = .custom
self.present(overlayVC, animated: true, completion: nil)
Animation when keyboard appears (in the presented view):
@objc func animateWithKeyboard(notification: NSNotification) {
let userInfo = notification.userInfo!
guard let keyboardHeight = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.height,
let duration = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as? Double,
let curve = userInfo[UIResponder.keyboardAnimationCurveUserInfoKey] as? UInt else {
return
}
// bottomContraint is the constraint that pins content to the bottom of the superview.
let moveUp = (notification.name == UIResponder.keyboardWillShowNotification)
bottomConstraint.constant = moveUp ? (keyboardHeight) : originalBottomValue
let options = UIView.AnimationOptions(rawValue: curve << 16)
UIView.animate(withDuration: duration, delay: 0,
options: options,
animations: {
self.view.layoutIfNeeded()
}, completion: nil)
}