Fix for broken layout of large navigation titles when building with Xcode 26 and running on iOS 18.

LargeNavTitlesOniOS18Fixer.swift

//
//  LargeNavTitlesOniOS18Fixer.swift
//
//  Created by Lukas Petr on 30.08.2025.
//  Licensed under the MIT License.
//  See https://opensource.org/licenses/MIT for details.
//

//
//  When compiling with Xcode 26 and running on iOS 18, large navigation titles have wrong layout (no leading margin).
//  In case Apple doesn't fix this for the iOS 26 RC, this class provides a clean workaround for this issue.
//
//  Usage: Just call LargeNavTitlesOniOS18Fixer.shared.register(self.navigationController?.navigationBar)
//  in -viewDidLoad and -viewDidAppear of your view controllers where you need the fix.
//

import UIKit

@objc public class LargeNavTitlesOniOS18Fixer : NSObject {
    @objc public static let shared = LargeNavTitlesOniOS18Fixer()
    
    @objc(registerNavigationBar:)
    public func register(_ navigationBar: UINavigationBar?) {
        guard let navigationBar, ProcessInfo.processInfo.operatingSystemVersion.majorVersion < 26 else {
            return
        }
        if let largeTitleLabelView: UIView = navigationBar.subviews.first(where: { NSStringFromClass(type(of: $0)).contains("LargeTitleView") })?.subviews.first {
            if largeTitleLabelView.frame.origin.x < 0.1 {
                largeTitleLabelView.frame.origin.x = 16
            }
            largeTitleLabelView.addObserver(self, forKeyPath: "bounds", options: .new, context: nil)
        }
    }
    
    public override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
        if let newFrame = change?[NSKeyValueChangeKey.newKey] as? CGRect, newFrame.origin.x < 0.1 {
            (object as? UIView)?.frame.origin.x = 16
        }
    }
}

Another solution is to set UINavigationBar.appearance().layoutMargins.left = 16 in didFinishLaunchingWithOptions of AppDelegate for iOS below 26.