ohlulu

class UpToDownIneraction: UIPercentDrivenInteractiveTransition {

  // ...
    
    func wireGesture(on viewController: UIViewController) {
        presentingViewController = viewController
        let gesture = UIPanGestureRecognizer(target: self, action: #selector(handleGesture(_:)))
        viewController.view.addGestureRecognizer(gesture)
    }
  

ohlulu

class UpToDownIneraction: UIPercentDrivenInteractiveTransition {
  
    var interacting: Bool = false
    
    private var couldComplete: Bool = false
    private weak var presentingViewController: UIViewController? = nil
}

ohlulu

class CustomTransition: NSObject, UIViewControllerTransitioningDelegate {
    
    // ...
  
    let interaction = UpToDownIneraction()
    
    func interactionControllerForPresentation(using animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
        return nil
    }
    

ohlulu

class PrepareToPushViewController: UIViewController {
    
    let button = UIButton(type: .system)
    let animation = CustomTransition()
    
    override func viewDidLoad() {
        super.viewDidLoad()
		// set view layout
        }
    }

ohlulu

class CustomDismissAnimation: NSObject , UIViewControllerAnimatedTransitioning {
    
    let endPoint: CGPoint
    var grayView: UIView!
    private let durationTime = 0.45
    
    init(endPoint: CGPoint) {
        self.endPoint = endPoint
        super.init()
    }

ohlulu

func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
		
	// 取出 toView, 在上面的示意圖中代表的就是 A 畫面
        guard let toView = transitionContext.viewController(forKey: .to)?.view else {
                return
        }
        
	// 取出 container view
        let containerView = transitionContext.containerView

ohlulu

class CustomPresentAnimation: NSObject , UIViewControllerAnimatedTransitioning {
	
	var startPoint: CGPoint // 擴散的起始點
	private let durationTime = 0.45 // 動畫時間
	
    init(startPoint: CGPoint) {
        self.startPoint = startPoint
        super.init()
    }