Messages-like taller / standard navigation bar during push / pop

Very interesting problem. I spent some time to achieve something like this in the Messages app and that is what I've done.

Finally, I use this trick to animate navigationBar height during push/pop and also pop with swipe gesture.

UIView.beginAnimations(nil, context: nil)self.frame = navFrameUIView.commitAnimations()

Below you can see my implementation:

extension UINavigationBar {    func applyHeight(_ height: CGFloat, animated: Bool = true) {        var navFrame = self.frame        navFrame.size.height = height        if animated {            UIView.beginAnimations(nil, context: nil)            self.frame = navFrame            UIView.commitAnimations()        } else {            self.frame = navFrame        }    }}class ViewControllerA: UIViewController {    override func loadView() {        super.loadView()        title = "A"        view.backgroundColor = .blue        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "NEXT", style: .plain, target: self, action: #selector(self.showController))        navigationController?.navigationBar.isTranslucent = false    }    override func viewWillAppear(_ animated: Bool) {        super.viewWillAppear(animated)    }    func showController() {        navigationController?.pushViewController(ViewControllerB(), animated: true)    }}class ViewControllerB: UIViewController {    override func loadView() {        super.loadView()        title = "B"        view.backgroundColor = .red    }    override func viewWillAppear(_ animated: Bool) {        navigationController?.navigationBar.applyHeight(100)        super.viewWillAppear(animated)    }    override func willMove(toParentViewController parent: UIViewController?) {        if parent == nil { // here you know that back button was tapped            navigationController?.navigationBar.applyHeight(44)        }        super.willMove(toParentViewController: parent)    }}

Things to improve

• Title jumps to top

Jumping title is visible while you swipe to pop, but personally, I think this is a small problem :)

Hope it helps you, and maybe someone can improve this implementation. Of course, I will still try to figure out how to make this better :)Here it's a github repository. Please use navigation_bar_height branch.

I think now you can achieve something similar with just this, just set large title to always: