A custom modal transition that presents and dismiss a controller inside an expanding and shrinking bubble.

Screenshot

Usage

Just need to import BubbleTransition.swift into your project.

Setup

Have your view controller conform to UIViewControllerTransitioningDelegate. Set the transitionMode, the startingPoint, the bubbleColor and the duration.

let transition = BubbleTransition()

public override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
  let controller = segue.destination
  controller.transitioningDelegate = self
  controller.modalPresentationStyle = .custom
}

// MARK: UIViewControllerTransitioningDelegate

public func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
  transition.transitionMode = .present
  transition.startingPoint = someButton.center
  transition.bubbleColor = someButton.backgroundColor!
  return transition
}

public func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
  transition.transitionMode = .dismiss
  transition.startingPoint = someButton.center
  transition.bubbleColor = someButton.backgroundColor!
  return transition
}

Swipe to dismiss

You can use an interactive gesture to dismiss the presented controller. To enable this gesture, prepare the interactive transition:

let interactiveTransition = BubbleInteractiveTransition()

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
  if let controller = segue.destination as? ModalViewController {
    controller.transitioningDelegate = self
    controller.modalPresentationStyle = .custom
    controller.interactiveTransition = interactiveTransition
    interactiveTransition.attach(to: controller)
  }
}

and implement interactionControllerForDismissal in your presenting controller:

func interactionControllerForDismissal(using animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
  return interactiveTransition
}

In the presented controller make sure to call finish() on the interactive gesture if you need to quickly dismiss from a button press instead. Check the sample code for more info.

You can decide the gesture threshold and the swipe direction:

interactiveTransition.interactionThreshold = 0.5
interactionThreshold.swipeDirection = .up

Properties

var startingPoint = CGPointZero

The point that originates the bubble.

var duration = 0.5

The transition duration.

var transitionMode: BubbleTranisionMode = .present

The transition direction. Either .present, .dismiss or .pop.

Checkout the sample project for the full implementation.