fullscreendialog.swift

import Foundation
import SwiftUI

class DialogPresenter: NSObject, UIViewControllerTransitioningDelegate {
    
    private var transitionStyle: PopupDialogTransitionStyle = .zoomIn
    private var popupContentViewController: UIViewController = UIViewController()
    private var overlayController: PresentationController?

    override init() {
        super.init()
        self.popupContentViewController.modalPresentationStyle = .custom
        self.popupContentViewController.transitioningDelegate = self
        self.popupContentViewController.view.backgroundColor = .clear
    }
    
    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
        let presentationController = PresentationController(presentedViewController: presented, presenting: source)
        self.overlayController = presentationController
        self.overlayController?.onTapOverlay = { [weak self] in
            self?.dismiss()
        }
        return presentationController
    }

    func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {

        var transition: TransitionAnimator
        switch transitionStyle {
        case .bounceUp:
            transition = BounceUpTransition(direction: .in)
        case .bounceDown:
            transition = BounceDownTransition(direction: .in)
        case .zoomIn:
            transition = ZoomTransition(direction: .in)
        case .fadeIn:
            transition = FadeTransition(direction: .in)
        }

        return transition
    }

    func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        var transition: TransitionAnimator
        switch transitionStyle {
        case .bounceUp:
            transition = BounceUpTransition(direction: .out)
        case .bounceDown:
            transition = BounceDownTransition(direction: .out)
        case .zoomIn:
            transition = ZoomTransition(direction: .out)
        case .fadeIn:
            transition = FadeTransition(direction: .out)
        }
        return transition
    }
    
    func present<Content: View>(style: PopupDialogTransitionStyle = .zoomIn,
                                content: () -> Content) {
        self.transitionStyle = style
        self.popupContentViewController = UIHostingController(rootView: content())
        self.popupContentViewController.modalPresentationStyle = .custom
        self.popupContentViewController.transitioningDelegate = self
        self.popupContentViewController.view.backgroundColor = .clear
        UIApplication.shared.topMostViewController?.present(self.popupContentViewController, animated: true)
    }

    func dismiss() {
        self.popupContentViewController.dismiss(animated: true)
    }

}


extension UIApplication {
    
    var keyWindow: UIWindow? {
        UIApplication
            .shared
            .connectedScenes
            .map({$0 as? UIWindowScene})
            .compactMap {$0}
            .first?
            .windows
            .filter { $0.isKeyWindow }
            .first!
    }
    
    var topMostViewController: UIViewController? {
        var topMostVC = self.keyWindow?.rootViewController
        while let presentedVC = topMostVC?.presentedViewController {
            topMostVC = presentedVC
        }
        return topMostVC
    }
    
    
}


extension View {
    
    func fullScreenDialog<Content: View>(
        isPresented: Binding<Bool>,
        modalTransitionStyle: UIModalTransitionStyle = .crossDissolve,
        modalPresentationStyle: UIModalPresentationStyle = .overCurrentContext,
        backgroundColor: UIColor = .clear,
        content: () -> Content
    ) -> some View{
        let vc = UIHostingController(rootView: content())
        vc.modalTransitionStyle = modalTransitionStyle
        vc.modalPresentationStyle = modalPresentationStyle
        vc.view.backgroundColor = backgroundColor
        vc.definesPresentationContext = true
        
        return self.onChange(of: isPresented.wrappedValue, perform: { show in
            if show {
                UIApplication.shared.topMostViewController?.present(vc, animated: true)
            } else {
                UIApplication.shared.topMostViewController?.dismiss(animated: true)
            }
        })
    }
    
}

/*!
 Presentation transition styles for the popup dialog

 - BounceUp:   Dialog bounces in from bottom and is dismissed to bottom
 - BounceDown: Dialog bounces in from top and is dismissed to top
 - ZoomIn:     Dialog zooms in and is dismissed by zooming out
 - FadeIn:     Dialog fades in and is dismissed by fading out
 */
@objc public enum PopupDialogTransitionStyle: Int {
    case bounceUp
    case bounceDown
    case zoomIn
    case fadeIn
}

/// Dialog bounces in from bottom and is dismissed to bottom
final internal class BounceUpTransition: TransitionAnimator {

    init(direction: AnimationDirection) {
        super.init(inDuration: 0.22, outDuration: 0.2, direction: direction)
    }

    override func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        super.animateTransition(using: transitionContext)

        switch direction {
        case .in:
            to.view.bounds.origin = CGPoint(x: 0, y: -from.view.bounds.size.height)
            UIView.animate(withDuration: 0.6, delay: 0.0, usingSpringWithDamping: 0.6, initialSpringVelocity: 0, options: [.curveEaseOut], animations: { [weak self] in
                guard let self = self else { return }
                self.to.view.bounds = self.from.view.bounds
            }, completion: { _ in
                transitionContext.completeTransition(true)
            })
        case .out:
            UIView.animate(withDuration: outDuration, delay: 0.0, options: [.curveEaseIn], animations: { [weak self] in
                guard let self = self else { return }
                self.from.view.bounds.origin = CGPoint(x: 0, y: -self.from.view.bounds.size.height)
                self.from.view.alpha = 0.0
            }, completion: { _ in
                transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
            })
        }
    }
}


/// Dialog bounces in from top and is dismissed to top
final internal class BounceDownTransition: TransitionAnimator {

    init(direction: AnimationDirection) {
        super.init(inDuration: 0.22, outDuration: 0.2, direction: direction)
    }

    override func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        super.animateTransition(using: transitionContext)

        switch direction {
        case .in:
            to.view.bounds.origin = CGPoint(x: 0, y: from.view.bounds.size.height)
            UIView.animate(withDuration: 0.6, delay: 0.0, usingSpringWithDamping: 0.6, initialSpringVelocity: 0, options: [.curveEaseOut], animations: { [weak self] in
                guard let self = self else { return }
                self.to.view.bounds = self.from.view.bounds
            }, completion: { _ in
                transitionContext.completeTransition(true)
            })
        case .out:
            UIView.animate(withDuration: outDuration, delay: 0.0, options: [.curveEaseIn], animations: { [weak self] in
                guard let self = self else { return }
                self.from.view.bounds.origin = CGPoint(x: 0, y: self.from.view.bounds.size.height)
                self.from.view.alpha = 0.0
            }, completion: { _ in
                transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
            })
        }
    }
}

/// Dialog zooms in and is dismissed by zooming out
final internal class ZoomTransition: TransitionAnimator {

    init(direction: AnimationDirection) {
        super.init(inDuration: 0.22, outDuration: 0.2, direction: direction)
    }

    override func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        super.animateTransition(using: transitionContext)

        switch direction {
        case .in:
            to.view.transform = CGAffineTransform(scaleX: 0.1, y: 0.1)
            UIView.animate(withDuration: 0.6, delay: 0.0, usingSpringWithDamping: 0.6, initialSpringVelocity: 0, options: [.curveEaseOut], animations: { [weak self] in
                guard let self = self else { return }
                self.to.view.transform = CGAffineTransform(scaleX: 1, y: 1)
            }, completion: { _ in
                transitionContext.completeTransition(true)
            })
        case .out:
            UIView.animate(withDuration: outDuration, delay: 0.0, options: [.curveEaseIn], animations: { [weak self] in
                guard let self = self else { return }
                self.from.view.transform = CGAffineTransform(scaleX: 0.1, y: 0.1)
                self.from.view.alpha = 0.0
            }, completion: { _ in
                transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
            })
        }
    }
}

/// Dialog fades in and is dismissed by fading out
final internal class FadeTransition: TransitionAnimator {

    init(direction: AnimationDirection) {
        super.init(inDuration: 0.22, outDuration: 0.2, direction: direction)
    }

    override func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        super.animateTransition(using: transitionContext)

        switch direction {
        case .in:
            to.view.alpha = 0
            UIView.animate(withDuration: 0.6, delay: 0.0, options: [.curveEaseOut],
            animations: { [weak self] in
                guard let self = self else { return }
                self.to.view.alpha = 1
            }, completion: { _ in
                transitionContext.completeTransition(true)
            })
        case .out:
            UIView.animate(withDuration: outDuration, delay: 0.0, options: [.curveEaseIn], animations: { [weak self] in
                guard let self = self else { return }
                self.from.view.alpha = 0.0
            }, completion: { _ in
                transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
            })
        }
    }
}

/// Used for the always drop out animation with pan gesture dismissal
final internal class DismissInteractiveTransition: TransitionAnimator {

    init() {
        super.init(inDuration: 0.22, outDuration: 0.32, direction: .out)
    }

    override func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        super.animateTransition(using: transitionContext)
        UIView.animate(withDuration: outDuration, delay: 0.0, options: [.beginFromCurrentState], animations: { [weak self] in
            guard let self = self else { return }
            self.from.view.bounds.origin = CGPoint(x: 0, y: -self.from.view.bounds.size.height)
            self.from.view.alpha = 0.0
        }, completion: { _ in
            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
        })
    }
}