Anmiation : - Apply zoom out and bounce animation together when user tap on view and swipe down to reverse animation (like in Photo library of IOS)

ZoomOutAndBounceVC.swift

//
//  ZoomOutAndBounceVC.swift
//  Cartoonize Image
//
//  Created by Coder ACJHP on 15.03.2019.
//  Copyright © 2019 Onur Işık. All rights reserved.
//
//  ********************************************************************
//  Be careful and don't use AutoLayout Constraints for animating view *
//  This animations works with AutoResizing only!                      *
//  ********************************************************************


import UIKit

class ZoomOutAndBounceVC: UIViewController, UIGestureRecognizerDelegate {
    
    // Outlets for this example I'm gonna use imageViews
    //  ********************************************************************
    //  AGAIN!! Be careful and don't use AutoLayout Constraints for        *
    //  animating view This animations works with AutoResizing only!       *
    //  ********************************************************************
    @IBOutlet var imageViewsCollection: [UIImageView]!
    
    // Store animation state
    var isAlreadyAnimated: Bool = false
    // Store view center position before animation
    var oldCenter: CGPoint = CGPoint.zero
    // Store view center position before pan began
    var initialTouchPoint: CGPoint = CGPoint.zero
    // Apply blur effect behind focused image view
    lazy var blurView: UIVisualEffectView = {
        let blurEffectView = UIVisualEffectView(effect: UIBlurEffect(style: .prominent))
        blurEffectView.frame = self.view.frame
        blurEffectView.alpha = 0
        return blurEffectView
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Optional
        self.view.backgroundColor = .orange
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        
        // Setup image views (add gesture regognizers etc.)
        setupImageViews()
    }
    
    private func setupImageViews() {
        
        self.imageViewsCollection.forEach { (imageView) in
            imageView.isUserInteractionEnabled = true
            let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleTap(_:)))
            tapGestureRecognizer.numberOfTapsRequired = 1
            tapGestureRecognizer.delegate = self
            imageView.addGestureRecognizer(tapGestureRecognizer)
            
            let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(panGestureRecognizerHandler(_:)))
            panGestureRecognizer.delegate = self
            imageView.addGestureRecognizer(panGestureRecognizer)
            panGestureRecognizer.require(toFail: tapGestureRecognizer)
            
        }
    }
    
    @objc private func handleTap(_ gestureRecognizer: UITapGestureRecognizer) {
        
        // be sure gesture view is not empty and it kind of image view class
        guard let tappedView = gestureRecognizer.view, tappedView.isKind(of: UIImageView.self) else { return }
        
        // if view isn't animated in advance
        if !isAlreadyAnimated {
            
            // add blur view as a subview to main view
            if self.blurView.superview == nil {
                
                view.addSubview(blurView)
                blurView.center = view.center
                // store old position of animating view
                oldCenter = tappedView.center
                view.bringSubview(toFront: tappedView)
            }
            
            UIView.animate(withDuration: 1.0, delay: 0.0,
                           usingSpringWithDamping: 1.0,
                           initialSpringVelocity: 1.0,
                           options: [.curveEaseInOut],
                           animations: {
                            
                            self.blurView.alpha = 1.0
                            // equal center of animating view with blurView center
                            tappedView.center = self.blurView.center
                            // and make it bigger
                            tappedView.transform = CGAffineTransform.init(scaleX: 1.6, y: 1.6)
                            
            }, completion: nil)
            // Set this variable as view is animated
            self.isAlreadyAnimated = true
            
        } else {
            
            // User tapped on image again so in this case we will restore view position and scale
            UIView.animate(withDuration: 1.0, delay: 0.0,
                           usingSpringWithDamping: 1.0,
                           initialSpringVelocity: 1.0,
                           options: [.curveEaseInOut],
                           animations: {
                            
                            self.blurView.alpha = 0.0
                            tappedView.center = self.oldCenter
                            tappedView.transform = CGAffineTransform.identity
                            
            }, completion: { (_) in
                self.blurView.removeFromSuperview()
            })
            
            isAlreadyAnimated = false
            
        }
    }
    
    
    @objc private func panGestureRecognizerHandler(_ gestureRecognizer: UIPanGestureRecognizer) {
        
        guard let pannedView = gestureRecognizer.view, pannedView.isKind(of: UIImageView.self) else { return }
        let touchPoint = gestureRecognizer.location(in: self.view?.window)
        
        // In this case user tapped on image
        if isAlreadyAnimated {
            
            // Let check user swiping it down to dismiss it ?
            switch gestureRecognizer.state {
            case .began:
                // Store old center to use it after
                initialTouchPoint = touchPoint
                
            case .changed:
                // Current touch point is greater than old and smaller than 100
                // Because 100 is good value to allowing swipe distance
                // finally check if new y point is greater than old y (user swiping down?)
                if touchPoint.y - initialTouchPoint.y > 0 &&
                    touchPoint.y - initialTouchPoint.y < 100 &&
                    touchPoint.y > blurView.center.y {
                    
                    pannedView.center = CGPoint(x: initialTouchPoint.x, y: touchPoint.y)
                    
                } else { return }
                
            case .ended, .cancelled:
                // Swipped distance greater than 50 and current y point is greater than old y point ?
                if touchPoint.y - initialTouchPoint.y > 50
                    && touchPoint.y > blurView.center.y {
                    
                    UIView.animate(withDuration: 1.0, delay: 0.0,
                                   usingSpringWithDamping: 1.0,
                                   initialSpringVelocity: 1.0,
                                   options: [.curveEaseInOut],
                                   animations: {
                                    
                                    self.blurView.alpha = 0.0
                                    pannedView.center = self.oldCenter
                                    pannedView.transform = CGAffineTransform.identity
                                    
                    }, completion: { (_) in
                        self.blurView.removeFromSuperview()
                        self.isAlreadyAnimated = false
                    })
                    
                } else {
                    // None of them thats mean return view to it's old position without dismissing
                    UIView.animate(withDuration: 1.0, delay: 0.0,
                                   usingSpringWithDamping: 1.0,
                                   initialSpringVelocity: 1.0,
                                   options: [.curveEaseInOut],
                                   animations: {
                                    
                                    pannedView.center = self.blurView.center
                                    
                    }, completion: nil)
                }
                
            default: break;
            }
        }
    }
    
}

Here is screenshot for how it's look like