Simple yet elegant push transition from the rect and back to the same rect.

PushFromItemAnimator.swift

//
//  PushFromItemAnimator.swift
//  Between
//
//  Created by Shial on 11/9/18.
//  Copyright © 2018 Szymon Lorenz Solutions. All rights reserved.
//

import UIKit

class PushFromItemAnimator: NSObject, UIViewControllerAnimatedTransitioning {
    var duration: TimeInterval
    var isPresenting: Bool
    var rect: CGRect?
    
    init(duration: TimeInterval, rect: CGRect?, isPresenting: Bool) {
        self.isPresenting = isPresenting
        self.duration = duration
        self.rect = rect
    }
    
    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        let container = transitionContext.containerView
        guard let fromView = transitionContext.view(forKey: .from) else {
            transitionContext.completeTransition(false)
            return
        }
        guard let toView = transitionContext.view(forKey: .to) else {
            transitionContext.completeTransition(false)
            return
        }

        let tabBar = transitionContext.viewController(forKey: .to)?.tabBarController?.tabBar
        let tabBarHeight = tabBar?.frame.height ?? 0
        let tabBarWidth = tabBar?.frame.width ?? 0
        if self.isPresenting {
            container.addSubview(toView)
            toView.transform = transform(from: toView,
                                         to: (self.rect ?? container.bounds).offsetBy(dx: 0, dy: tabBarHeight),
                                         in: container)
            tabBar?.transform = .identity
        } else {
            container.insertSubview(toView, belowSubview: fromView)
            tabBar?.transform = CGAffineTransform(translationX: tabBarWidth, y: tabBarHeight)
        }
        UIView.animate(withDuration: duration, delay: 0, options: .curveEaseOut, animations: {
            if self.isPresenting {
                tabBar?.transform = CGAffineTransform(translationX: tabBarWidth, y: tabBarHeight)
                toView.transform = .identity
            } else {
                tabBar?.transform = .identity
                fromView.transform = self.transform(from: fromView,
                                                    to: (self.rect ?? container.bounds).offsetBy(dx: 0, dy: tabBarHeight),
                                                    in: container)
                fromView.alpha = 0
            }
        }) { finished in
            tabBar?.transform = .identity
            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
        }
    }
    
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return duration
    }
    
    func transform(from source: UIView, to destination: CGRect, in view: UIView) -> CGAffineTransform {
        let destinationRect = view.convert(destination, to: view)
        let sourceRect = source.convert(source.frame, to: view)
        return CGAffineTransform.identity
            .translatedBy(x: destinationRect.midX - sourceRect.midX, y: destinationRect.midY - sourceRect.midY)
            .scaledBy(x: destination.width / source.frame.width, y: destination.height / source.frame.height)
    }
}

YourPushedViewController.swift

extension YourPushedViewController: UINavigationControllerDelegate {
    func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        switch operation {
        case .push:
            return PushFromItemAnimator(duration: TimeInterval(0.35), rect: rect, isPresenting: true)
        default:
            return PushFromItemAnimator(duration: TimeInterval(UINavigationControllerHideShowBarDuration), rect: rect, isPresenting: false)
        }
    }
}

Custom push animation

Simple yet elegant push transition from the rect and back to the same rect.

Important

Remember to assign UINavigationControllerDelegate to YourPushedViewController so it can use custom transition coordinator.

Example