Multiple overlayed images in the Navigation bar title - swift

Question

I know how to center a single image in UINavigationBar but no idea how to do that with dynamic number of images. I have a chat app that supports group chats. The number of people in a group chat could be as little as 3 but there's no upper limit.
In the UINavigationBar, I have to set the title to show at least 4 or 5 overlayed images (but not more than that since it looks odd in the UINavigationBar) and a UILabel showing how many more users are in the same group chat (ie + 15 more). The title (all the images and the label) should be centered in the UINavigationBar. The images are being downloaded from the server.
When the user taps on the title (any of the images or the label in the UINavigationBar) it should trigger an action to show a full list of the users in a separate UIViewController
The number of the overlayed images is dynamic (based on each group chat) but I can't figure out how to do this. Here's what the image of what the end result should look like:
Has anyone done this before or have an idea how to accomplish this? Help is very much appreciated
UPDATE:
I've tried to accomplish this with UIStackView but I have multiple problems. Here's the code:
var navStackView : UIStackView = {
let stack = UIStackView()
stack.axis = .horizontal
stack.backgroundColor = .red
stack.alignment = .fill
stack.distribution = .fillEqually
stack.translatesAutoresizingMaskIntoConstraints = false
return stack
}()
var images = ["1", "2", "3", "4"]
override func viewDidLoad() {
super.viewDidLoad()
let navController = navigationController!
navController.navigationBar.addSubview(navStackView)
// x, y, w, h
navStackView.leadingAnchor.constraint(equalTo: navController.navigationBar.leadingAnchor).isActive = true
navStackView.trailingAnchor.constraint(equalTo: navController.navigationBar.trailingAnchor).isActive = true
navStackView.topAnchor.constraint(equalTo: navController.navigationBar.topAnchor).isActive = true
navStackView.bottomAnchor.constraint(equalTo: navController.navigationBar.bottomAnchor).isActive = true
for image in images {
let imageView = UIImageView()
imageView.image = UIImage(named: image)
imageView.layer.cornerRadius = imageView.bounds.height / 2
imageView.clipsToBounds = true
imageView.layer.masksToBounds = true
imageView.contentMode = .scaleAspectFill
// imageView.frame = CGRect(x: 0, y: 0, width: 30, height: 30)
navStackView.addArrangedSubview(imageView)
navStackView.layoutIfNeeded()
}
navigationItem.titleView = navStackView
}
Here's the result so far (I'm stuck though, not sure how to accomplish it):

Answer 1

I'm not sure about stackView. But for a simple implementation I've used collectionView. Check the below strategy. You should be able to modify accordingly per your requirement.
import UIKit
class OverlayCell: UICollectionViewCell {
func didplay(with number: String) {
let view = UIView(frame: CGRect(x: 0, y: 0, width: 40.0, height: 40.0))
view.backgroundColor = UIColor.blue
view.layer.cornerRadius = 20.0
view.layer.masksToBounds = true
view.layer.borderColor = UIColor.white.cgColor
view.layer.borderWidth = 2.0
let label = UILabel(frame: CGRect(x: 2, y: 2, width: view.bounds.width - 4, height: view.bounds.height - 4))
label.textColor = .white
label.text = number
label.textAlignment = .center
view.addSubview(label)
contentView.addSubview(view)
contentView.transform = CGAffineTransform(scaleX: -1, y: 1)
}
}
class OverlayedView: UIView {
var mainView: UIView!
var imageCollection: UICollectionView!
//Static for now
let cellWidth: CGFloat = 40.0
let cellHeight: CGFloat = 40.0
var collectionWidth: CGFloat = 115.0
override init(frame: CGRect) {
super.init(frame: frame)
loadNib()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
loadNib()
}
private func loadNib() {
if let view = Bundle.main.loadNibNamed("OverlayedView", owner: self, options: nil)?.first as? UIView {
mainView = view
mainView.frame = self.bounds
self.backgroundColor = .black
addSubview(view)
}
}
var dataSource = ["4","3","2","1"]
func loadData() {
//dynamically calculate collectionWidth to be able to kepp it in center
collectionWidth = dataSource.count >= 4 ? CGFloat(dataSource.count) * cellWidth - CGFloat((dataSource.count - 1) * 15) : CGFloat(dataSource.count) * cellWidth - CGFloat((dataSource.count - 1) * 15) //CGFloat(dataSource.count * 15) here is the item spacing from delegate -15 inward so that we can get overlapping effect
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .horizontal
imageCollection = UICollectionView(frame: CGRect(x: 0, y: 0, width: collectionWidth, height: self.bounds.height), collectionViewLayout: layout)
imageCollection.center = mainView.center
imageCollection.register(OverlayCell.self, forCellWithReuseIdentifier: "Cell")
//flip the collectionView so that it loads from right to left for overlapping effect
imageCollection.transform = CGAffineTransform(scaleX: -1, y: 1)
imageCollection.delegate = self
imageCollection.dataSource = self
mainView.addSubview(imageCollection)
}
}
extension OverlayedView: UICollectionViewDelegate, UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
if dataSource.count > 4 {
return 4
}
return dataSource.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! OverlayCell
cell.didplay(with: dataSource[indexPath.row])
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let size = CGSize(width: 40.0 , height: 40.0)
return size
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return 0.0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return -15.0
}
}
Usage:
let navOverlay = OverlayedView(frame: CGRect(x: 0, y: 0, width: 250.0, height: 44.0))
navOverlay.loadData() . //pass your data to this method
navigationItem.titleView = navOverlay

Answer 2

I've figured it out finally. Not sure if this is the right way to accomplish it, but it's a way to accomplish it and it works great. The thing to notice - I have to calculate the navStackView width based on the number of images we have. More than 5-6 images gets too crouded, so, no more than 5 images.
The navStackView.spacing also is calculated based the width and the space you'd like between the images.
var navStackView : UIStackView = {
let stack = UIStackView()
stack.axis = .horizontal
stack.alignment = .fill
stack.distribution = .fillEqually
stack.translatesAutoresizingMaskIntoConstraints = false
return stack
}()
var moreLabel: UILabel = {
let label = UILabel()
label.text = "+ 5 more"
label.textColor = .black
label.textAlignment = .left
label.translatesAutoresizingMaskIntoConstraints = false
return label
}()
var images = ["1", "2", "3", "4", "3", "3"]
override func viewDidLoad() {
super.viewDidLoad()
let navController = navigationController!
navController.navigationBar.addSubview(navStackView)
// x, y, w, h
navStackView.widthAnchor.constraint(equalToConstant: 95).isActive = true
navStackView.centerYAnchor.constraint(equalTo: navController.navigationBar.centerYAnchor).isActive = true
navStackView.heightAnchor.constraint(equalToConstant: 35).isActive = true
navStackView.centerXAnchor.constraint(equalTo: navController.navigationBar.centerXAnchor).isActive = true
// image height = 35, image width = 35
// when subtracting spacing from NavStackView, we need to subtrack from the width as well for (items - 1)
switch images.count {
case 0:
print("0 images")
case 1:
changeNavStackWidth(constant: 60, spacing: 0)
moreLabel.isHidden = true
case 2:
changeNavStackWidth(constant: 80, spacing: 10)
moreLabel.isHidden = true
case 3:
changeNavStackWidth(constant: 95, spacing: -5)
moreLabel.isHidden = true
case 4:
changeNavStackWidth(constant: 110, spacing: -10)
moreLabel.isHidden = true
case 5:
changeNavStackWidth(constant: 95, spacing: -20)
moreLabel.isHidden = true
case 6...1000:
changeNavStackWidth(constant: 95, spacing: -20)
moreLabel.isHidden = false
default:
print("default")
}
for image in images {
let imageView = UIImageView()
imageView.image = UIImage(named: image)
imageView.layer.borderColor = UIColor.white.cgColor
imageView.layer.borderWidth = 1
imageView.contentMode = .scaleAspectFill
imageView.clipsToBounds = true
navStackView.addArrangedSubview(imageView)
navStackView.layoutIfNeeded()
}
navController.navigationBar.addSubview(moreLabel)
// x, y ,w, h
moreLabel.leadingAnchor.constraint(equalTo: navStackView.trailingAnchor, constant: 50).isActive = true
moreLabel.topAnchor.constraint(equalTo: navStackView.topAnchor).isActive = true
moreLabel.bottomAnchor.constraint(equalTo: navStackView.bottomAnchor).isActive = true
navigationItem.titleView = navStackView
let stackTap = UITapGestureRecognizer()
stackTap.addTarget(self, action: #selector(stackTapped))
navStackView.isUserInteractionEnabled = true
navStackView.addGestureRecognizer(stackTap)
}
#objc func stackTapped() {
print("tapp")
}
func changeNavStackWidth(constant: CGFloat, spacing: CGFloat) {
navStackView.constraints.forEach { constraint in
if constraint.firstAttribute == .width {
constraint.constant = constant
}
}
navStackView.spacing = spacing
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
navStackView.subviews.forEach { $0.layer.cornerRadius = $0.frame.height / 2 }
}