AppStore app has an icon with an image on the right side of the NabBar with Large Title:
Would really appreciate if anyone knows how to implement it or ideas on how to do it.
BTW: Setting an image for UIButton inside of UIBarButtonItem won't work. Tried already. The button sticks to the top of the screen:
After several hours of coding, I finally managed to make it work. I also decided to write a detailed tutorial: link. Follow it in case you prefer very detailed instructions.
Demo:
Complete project on GitHub: link.
Here are 5 steps to accomplish it:
Step 1: Create an image
private let imageView = UIImageView(image: UIImage(named: "image_name"))
Step 2: Add Constants
/// WARNING: Change these constants according to your project's design
private struct Const {
/// Image height/width for Large NavBar state
static let ImageSizeForLargeState: CGFloat = 40
/// Margin from right anchor of safe area to right anchor of Image
static let ImageRightMargin: CGFloat = 16
/// Margin from bottom anchor of NavBar to bottom anchor of Image for Large NavBar state
static let ImageBottomMarginForLargeState: CGFloat = 12
/// Margin from bottom anchor of NavBar to bottom anchor of Image for Small NavBar state
static let ImageBottomMarginForSmallState: CGFloat = 6
/// Image height/width for Small NavBar state
static let ImageSizeForSmallState: CGFloat = 32
/// Height of NavBar for Small state. Usually it's just 44
static let NavBarHeightSmallState: CGFloat = 44
/// Height of NavBar for Large state. Usually it's just 96.5 but if you have a custom font for the title, please make sure to edit this value since it changes the height for Large state of NavBar
static let NavBarHeightLargeState: CGFloat = 96.5
}
Step 3: setup UI:
private func setupUI() {
navigationController?.navigationBar.prefersLargeTitles = true
title = "Large Title"
// Initial setup for image for Large NavBar state since the the screen always has Large NavBar once it gets opened
guard let navigationBar = self.navigationController?.navigationBar else { return }
navigationBar.addSubview(imageView)
imageView.layer.cornerRadius = Const.ImageSizeForLargeState / 2
imageView.clipsToBounds = true
imageView.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
imageView.rightAnchor.constraint(equalTo: navigationBar.rightAnchor,
constant: -Const.ImageRightMargin),
imageView.bottomAnchor.constraint(equalTo: navigationBar.bottomAnchor,
constant: -Const.ImageBottomMarginForLargeState),
imageView.heightAnchor.constraint(equalToConstant: Const.ImageSizeForLargeState),
imageView.widthAnchor.constraint(equalTo: imageView.heightAnchor)
])
}
Step 4: create image resizing method
private func moveAndResizeImage(for height: CGFloat) {
let coeff: CGFloat = {
let delta = height - Const.NavBarHeightSmallState
let heightDifferenceBetweenStates = (Const.NavBarHeightLargeState - Const.NavBarHeightSmallState)
return delta / heightDifferenceBetweenStates
}()
let factor = Const.ImageSizeForSmallState / Const.ImageSizeForLargeState
let scale: CGFloat = {
let sizeAddendumFactor = coeff * (1.0 - factor)
return min(1.0, sizeAddendumFactor + factor)
}()
// Value of difference between icons for large and small states
let sizeDiff = Const.ImageSizeForLargeState * (1.0 - factor) // 8.0
let yTranslation: CGFloat = {
/// This value = 14. It equals to difference of 12 and 6 (bottom margin for large and small states). Also it adds 8.0 (size difference when the image gets smaller size)
let maxYTranslation = Const.ImageBottomMarginForLargeState - Const.ImageBottomMarginForSmallState + sizeDiff
return max(0, min(maxYTranslation, (maxYTranslation - coeff * (Const.ImageBottomMarginForSmallState + sizeDiff))))
}()
let xTranslation = max(0, sizeDiff - coeff * sizeDiff)
imageView.transform = CGAffineTransform.identity
.scaledBy(x: scale, y: scale)
.translatedBy(x: xTranslation, y: yTranslation)
}
Step 5:
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
guard let height = navigationController?.navigationBar.frame.height else { return }
moveAndResizeImage(for: height)
}
Hope it's clear and helps you! Please let me know in comments if you have any additional questions.
If anyone is still looking how to do this in SwiftUI. I made a package named NavigationBarLargeTitleItems to deal with this. It mimics the behavior you see in the AppStore and Messages-app.
Please note to be able to accomplish this behavior we need to add to the '_UINavigationBarLargeTitleView' which is a private class and therefor might get your app rejected when submitting to the App Store.
I'm also including the full relevant source code here for those who dislike links or just want to copy/paste.
// Copyright © 2020 Mark van Wijnen
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the “Software”), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
import SwiftUI
public extension View {
func navigationBarLargeTitleItems<L>(trailing: L) -> some View where L : View {
overlay(NavigationBarLargeTitleItems(trailing: trailing).frame(width: 0, height: 0))
}
}
fileprivate struct NavigationBarLargeTitleItems<L : View>: UIViewControllerRepresentable {
typealias UIViewControllerType = Wrapper
private let trailingItems: L
init(trailing: L) {
self.trailingItems = trailing
}
func makeUIViewController(context: Context) -> Wrapper {
Wrapper(representable: self)
}
func updateUIViewController(_ uiViewController: Wrapper, context: Context) {
}
class Wrapper: UIViewController {
private let representable: NavigationBarLargeTitleItems?
init(representable: NavigationBarLargeTitleItems) {
self.representable = representable
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
self.representable = nil
super.init(coder: coder)
}
override func viewWillAppear(_ animated: Bool) {
guard let representable = self.representable else { return }
guard let navigationBar = self.navigationController?.navigationBar else { return }
guard let UINavigationBarLargeTitleView = NSClassFromString("_UINavigationBarLargeTitleView") else { return }
navigationBar.subviews.forEach { subview in
if subview.isKind(of: UINavigationBarLargeTitleView.self) {
let controller = UIHostingController(rootView: representable.trailingItems)
controller.view.translatesAutoresizingMaskIntoConstraints = false
subview.addSubview(controller.view)
NSLayoutConstraint.activate([
controller.view.bottomAnchor.constraint(
equalTo: subview.bottomAnchor,
constant: -15
),
controller.view.trailingAnchor.constraint(
equalTo: subview.trailingAnchor,
constant: -view.directionalLayoutMargins.trailing
)
])
}
}
}
}
}
import SwiftUI
import NavigationBarLargeTitleItems
struct ContentView: View {
var body: some View {
NavigationView {
List {
ForEach(1..<50) { index in
Text("Sample Row \(String(index))")
}
}
.navigationTitle("Navigation")
.navigationBarLargeTitleItems(trailing: ProfileIcon())
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
struct ProfileIcon: View {
var body: some View{
Button(action: {
print("Profile button was tapped")
}) {
Image(systemName: "person.circle.fill")
.resizable()
.aspectRatio(contentMode: .fit)
.foregroundColor(.red)
.frame(width: 36, height: 36)
}
.offset(x: -20, y: 5)
}
}
Thanks to @TungFam, I think I have a better solution. check it out
two points:
change button frame according to navigation bar height
// adjust topview height
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
guard let navBar = self.navigationController?.navigationBar else {
return
}
// hardcoded .. to improve
if navBar.bounds.height > 44 + 40 + 10 {
NSLayoutConstraint.deactivate(heightConstraint)
heightConstraint = [topview.heightAnchor.constraint(equalToConstant: 40)]
NSLayoutConstraint.activate(heightConstraint)
} else {
NSLayoutConstraint.deactivate(heightConstraint)
var height = navBar.bounds.height - 44 - 10
if height < 0 {
height = 0
}
heightConstraint = [topview.heightAnchor.constraint(equalToConstant: height)]
NSLayoutConstraint.activate(heightConstraint)
}
}
change button alpha according to pop/push progress
@objc func onGesture(sender: UIGestureRecognizer) {
switch sender.state {
case .began, .changed:
if let ct = navigationController?.transitionCoordinator {
topview.alpha = ct.percentComplete
}
case .cancelled, .ended:
return
case .possible, .failed:
break
}
}
Nice answer about adding it as a subview. I would add the fact that you could use pure auto layout only without the need of CGAffineTransform and all those calculations. If you add vertical constraints as well it will automatically scale. If you still need to use calculations you can use navigationController?.navigationBar.publisher(for: \.frame) publisher instead of doing it inside scroll view. That way you'll be able to do it more globally rather than being dependent on the scroll view.
This is how I did it for example (I needed to do it on leading and have large title hidden but you can change those constraints to add it wherever you'd like):
imageView as a property as I also need to hide it in some cases. (e.g., when opening other screen)private lazy var imageView: UIImageView = {
let imageView = UIImageView()
imageView.kf.setImage(with: URL(string: "https://img.buzzfeed.com/buzzfeed-static/static/2021-07/21/15/campaign_images/b4661163b3f8/24-times-michael-scott-from-the-office-made-us-bu-2-7356-1626879661-2_dblbig.jpg?resize=1200:*")!)
imageView.cornerRadiusStyle = .heightFraction(1/2) // This is an extension in the codebase I'm working on but you can set the corner radius normally as you would. Inside layoutSubviews most probably.
imageView.clipsToBounds = true
imageView.translatesAutoresizingMaskIntoConstraints = false
imageView.contentMode = .scaleAspectFill
imageView.isUserInteractionEnabled = true
return imageView
}()
navigationController is set and not nil)func setupCustomImage() {
// Adding imageView inside stackView just for convenience of hiding it later.
let stackView = UIStackView()
stackView.axis = .horizontal
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.addArrangedSubview(imageView)
NSLayoutConstraint.activate([
imageView.heightAnchor.constraint(lessThanOrEqualToConstant: 52), // In my case I needed max image size to be 52. You can change that.
imageView.widthAnchor.constraint(equalTo: imageView.heightAnchor) // I needed aspect ratio to be 1:1. You can change that also by adding multiplier.
])
guard let navigationBar = navigationController?.navigationBar else { return }
navigationBar.addSubview(stackView)
NSLayoutConstraint.activate([
stackView.leadingAnchor.constraint(equalTo: navigationBar.leadingAnchor, constant: 16), // For leading padding
stackView.centerYAnchor.constraint(equalTo: navigationBar.centerYAnchor),
// You can play around with those constants as well to provide minimum size of the image needed.
navigationBar.bottomAnchor.constraint(greaterThanOrEqualTo: stackView.bottomAnchor, constant: 7),
stackView.topAnchor.constraint(greaterThanOrEqualTo: navigationBar.topAnchor, constant: 7)
])
}
It will automatically do all the scaling and stuff.
You could create the UIBarButtonItem using a custom view. This custom view will be a UIView with the actual UIButton (as a subview) placed x pixels from the top (x=the number of pixels you want to move it down).
