As evident in the screenshot, there is a large space between the keyboard and the input bar.

What I expect to happen is for the input bar to be flush with the keyboard.

I have tried to follow the example code for MessageKit for MessageContainerController as closely as possible.

I have already tried disabling IQKeyboardManager altogether.

One thing to note here is that I am pushing this view controller whose navigation controller is a UITabBarController and by setting the view controller’s hideBottomBarWhenPushed property value to false so that it covers the whole screen

I have isolated this issue to the container view controller surrounding the main chat view controller.

Also, this code, which is marked as required in the example code for MessageKit

override var inputAccessoryView: UIView? {
    chatVC.inputAccessoryView
}

makes the app unresponsive for about a minute then crash

Here’s all the relevant code:

• ChatContainerViewController

import UIKit
import MessageKit
import InputBarAccessoryView

final class ChatContainerController: UIViewController {
    
    let headerView = ChatHeaderView()
    
    let navBar = NavBar(title: "")
    
    let unsafeAreaView: UIView = {
        
        let view = UIView()
        view.backgroundColor = .primary
        return view
        
    }()
    
    let noDataView = NoDataView(title: "No messages here yet...", body: "Send your first message")
    
    let chatVC = TestChatVC()
    
    override var canBecomeFirstResponder: Bool {
        chatVC.canBecomeFirstResponder
    }
//    
//    override var inputAccessoryView: UIView? {
//        chatVC.inputAccessoryView
//    }
   
    weak var delegate: ChatDelegate?
    
    let api = API()
    
    let senderID: String
    
    var refreshMessagesTimer: Timer? = nil
    
    var justLoaded = true
    
    var userPhoneNumber = String()
    
    init(title: String, senderID: String) {
        self.senderID = senderID
        super.init(nibName: nil, bundle: nil)
        
        navigationController?.setNavigationBarHidden(false, animated: true)
        navBar.titleLabel.text = title
        
        setupLayout()
        setupCallbacks()
        setupTimer()
        getChatsSync(senderID: senderID)
        
    }
    
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
    }
    
    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
    }
    

    func getChatsSync(senderID: String) {
        
        if justLoaded {
            
            justLoaded = false
            
            Task {
                
                LoadingIndicator.show()
                await getChats(senderID: senderID)
                LoadingIndicator.hide()
            }
            
        } else {
            
            Task { await getChats(senderID: senderID) }
        }
    }
    
    func setupTimer(){
        
        self.refreshMessagesTimer = Timer.scheduledTimer(withTimeInterval: 5, repeats: true, block: { [weak self] timer in
            guard let self else { return }
            self.getChatsSync(senderID: senderID)
        })
    
    }
    
    func getChats(senderID: String) async {
        
        do {
            
            let chatData = try await api.getChats(senderID: senderID)
            
            let chats = chatData?.conversations
            
            let users = chatData?.users
        
            let receiver = users?.first(where: {String($0.id ?? 0) == UserData.userID})
            
            let sender = users?.first(where: {String($0.id ?? 0) != UserData.userID})
            
            setupHeaderView(for: sender)
            
            chatVC.receiver = Sender(senderId: String(sender?.id ?? 0), displayName: UserData.username, avatarURL: receiver?.avatarURL ?? "")
            
            chatVC.sender = Sender(senderId: String(receiver?.id ?? 0), displayName: sender?.firstName ?? "", avatarURL: sender?.avatarURL ?? "")
            
            let mappedMessages: [Message] = chats?.compactMap { conversation in
                
                let sender = (conversation.senderID == Int(UserData.userID) ?? 0) ? chatVC.receiver : chatVC.sender
                let messageId = String(conversation.id ?? 0)
                let sentDate = iso8601formattedDate(date: conversation.createdAt)
                let messageText = conversation.message ?? ""
                
                return Message(sender: sender, messageId: messageId, sentDate: sentDate, kind: .text(messageText))
                
            }.reversed() ?? []
            
            chatVC.messages = mappedMessages
            
            noDataView.isHidden = (!(chats?.isEmpty ?? false))
            
        } catch {
            // Handle error
        }
    }
    
    func sendMessage(receiverID: String, message: String) async -> Bool {
        
        do {
            
            let isSent = try await api.sendMessage(receiverID: receiverID, message: message)
            
            if isSent {
                getChatsSync(senderID: senderID)
            }
            
            return isSent
            
        } catch {
          
            return true
        }
    }
    
    func setupHeaderView(for user: User?){
        
        guard let user else { print("user is nil"); return }
        
        headerView.nameLabel.text = user.firstName
        headerView.emailAddressLabel.text = user.email
        headerView.profileImage.setImageWith(user.avatarURL)
        userPhoneNumber = user.mobile.orEmptyString
        
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        
        refreshMessagesTimer?.invalidate()
    }
    
    fileprivate func setupCallbacks(){
        headerView.callButton.addTarget(self, action: #selector(callButtonPressed), for: .touchUpInside)
    }
    
    @objc
    func callButtonPressed(){
        dialPhoneNumber(userPhoneNumber)
    }
    
    private func setupLayout() {
        
        chatVC.delegate = self
        
        chatVC.willMove(toParent: self)
        addChild(chatVC)
        view.addSubview(chatVC.view)
        chatVC.didMove(toParent: self)
        
        view.addSubview(headerView)
        view.addSubview(navBar)
        view.addSubview(noDataView)
        
        view.addSubview(unsafeAreaView)
        
        unsafeAreaView.translatesAutoresizingMaskIntoConstraints = false
        navBar.translatesAutoresizingMaskIntoConstraints = false
        chatVC.view.translatesAutoresizingMaskIntoConstraints = false
        headerView.translatesAutoresizingMaskIntoConstraints = false
        noDataView.translatesAutoresizingMaskIntoConstraints = false
        
    }
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        
        NSLayoutConstraint.activate([
            
            chatVC.view.topAnchor.constraint(equalTo: headerView.bottomAnchor),
            chatVC.view.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            chatVC.view.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            chatVC.view.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
            
            unsafeAreaView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            unsafeAreaView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            unsafeAreaView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            unsafeAreaView.heightAnchor.constraint(equalToConstant: 5000),
            
            navBar.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            navBar.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            navBar.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            
            headerView.topAnchor.constraint(equalTo: navBar.bottomAnchor),
            headerView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            headerView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
    
            
            noDataView.topAnchor.constraint(equalTo: headerView.bottomAnchor),
            noDataView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            noDataView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            noDataView.bottomAnchor.constraint(equalTo: chatVC.messageInputBar.topAnchor)
        ])
    
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

extension ChatContainerController: ChatDelegate {
    
    func sendMessage(message: String, receiverID: String, completed: @escaping ((Bool) -> Void)) {
        Task {
            let isSent = await sendMessage(receiverID: receiverID, message: message)
            completed(isSent)
        }
    }
}

• ChatViewController

import Foundation
import UIKit
import Stevia
import SDWebImage
import MessageKit
import InputBarAccessoryView

protocol ChatDelegate: AnyObject {
    func sendMessage(message: String, receiverID: String, completed: @escaping ((Bool) -> Void))
}

class ChatVC: MessagesViewController, MessagesDataSource, InputBarAccessoryViewDelegate {

    weak var delegate: ChatDelegate?
    
    var receiver = Sender(senderId: "0", displayName: "Maaz", avatarURL: "")
    
    var sender = Sender(senderId: "0", displayName: "Hussain", avatarURL: "")
    
    var messages: [MessageType] = [] {
        didSet {
            if messages.isEmpty {
                messagesCollectionView.reloadData()
                messagesCollectionView.scrollToLastItem(animated: true)
            } else {
                messagesCollectionView.reloadDataAndKeepOffset()
                messagesCollectionView.scrollToLastItem(animated: true)
            }
        }
    }
    
    override func viewDidLoad() {
        configureMessageCollectionView()
        configureMessageInputBar()
        super.viewDidLoad()
    }

    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        self.becomeFirstResponder()
    }

    
    func configureMessageCollectionView() {
        
        messagesCollectionView.messagesDataSource = self
        messagesCollectionView.messageCellDelegate = self
        messagesCollectionView.messagesLayoutDelegate = self
        messagesCollectionView.messagesDisplayDelegate = self
                
        scrollsToLastItemOnKeyboardBeginsEditing = true
        maintainPositionOnInputBarHeightChanged = true
        showMessageTimestampOnSwipeLeft = true
    }
    
    func configureMessageInputBar() {
        messageInputBar.delegate = self
        messageInputBar.inputTextView.tintColor = .primary
        messageInputBar.sendButton.setTitleColor(.primary, for: .normal)
        messageInputBar.sendButton.setTitleColor(.primary.withAlphaComponent(0.3), for: .highlighted)
        
    }
    
    func customizeNavigationBar() {
        navigationController?.navigationBar.tintColor = UIColor.black
        
        navigationController?.navigationBar.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.black, NSAttributedString.Key.font: UIFont.CustomFont(.bold, size: 19)]
        
        let backButtonImage: UIImage = isArabic ? .leftArrow.withHorizontallyFlippedOrientation() : .leftArrow
        let backButton = UIBarButtonItem(image: backButtonImage, style: .plain, target: self, action: #selector(backButtonPressed))
        navigationItem.leftBarButtonItem = backButton
        
        navigationController?.navigationBar.barTintColor = UIColor.black
        navigationController?.navigationBar.backgroundColor = .primary
        
        let unsafeAreaView = UIView()
        unsafeAreaView.backgroundColor = .primary
        
        view.subviews { unsafeAreaView }
        
        NSLayoutConstraint.activate([
            unsafeAreaView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            unsafeAreaView.heightAnchor.constraint(equalToConstant: 500),
            unsafeAreaView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            unsafeAreaView.trailingAnchor.constraint(equalTo: view.trailingAnchor)
        ])
    }
    
    @objc
    func backButtonPressed(){
        self.navigationController?.popViewController(animated: true)
    }
    
}

extension ChatVC: MessagesLayoutDelegate, MessagesDisplayDelegate, MessageCellDelegate {
    
    //MARK: Message Data Source
    var currentSender: MessageKit.SenderType {
        return receiver
    }
    
    func messageForItem(at indexPath: IndexPath, in messagesCollectionView: MessageKit.MessagesCollectionView) -> MessageKit.MessageType {
        return messages[indexPath.section]
    }
    
    func numberOfSections(in messagesCollectionView: MessageKit.MessagesCollectionView) -> Int {
        print(messages.count)
        return messages.count
    }
    
    //MARK: Message styling
    
    func messageStyle(for message: MessageType, at index: IndexPath, in _: MessagesCollectionView) -> MessageStyle {
        let tail: MessageStyle.TailCorner = isFromCurrentSender(message: message) ? .bottomRight : .bottomLeft
        
        if isNextMessageSameSender(at: index){
            return .bubble
        } else {
            return .bubbleTail(tail, .pointedEdge)
        }
        
    }
    
    func configureAvatarView(_ avatarView: AvatarView, for message: MessageType, at indexPath: IndexPath, in _: MessagesCollectionView) {
        
        if let messageSender = messages[indexPath.section].sender as? Sender {
            let displayName = messageSender.initials
            let imageURL = URL(string:  messageSender.avatarURL)
            SDWebImageManager.shared.loadImage(with: imageURL, progress: nil) { image, _, _, _, _, _ in
                let avatar = Avatar(image: image, initials: displayName)
                avatarView.set(avatar: avatar)
                avatarView.isHidden = self.isNextMessageSameSender(at: indexPath)
            }
        }
    }
    
    //MARK: Helpers
    
    func isTimeLabelVisible(at indexPath: IndexPath) -> Bool {
        indexPath.section % 3 == 0 && !isPreviousMessageSameSender(at: indexPath)
    }
    
    func isPreviousMessageSameSender(at indexPath: IndexPath) -> Bool {
        guard indexPath.section - 1 >= 0 else { return false }
        return messages[indexPath.section].sender.senderId == messages[indexPath.section - 1].sender.senderId
    }
    
    func isNextMessageSameSender(at indexPath: IndexPath) -> Bool {
        guard indexPath.section + 1 < messages.count else { return false }
        return messages[indexPath.section].sender.senderId == messages[indexPath.section + 1].sender.senderId
    }
    
}

extension ChatVC {
    
    @objc
    func inputBar(_ inputBar: InputBarAccessoryView, didPressSendButtonWith text: String) {
        processInputBar(inputBar)
    }
    
    func processInputBar(_ inputBar: InputBarAccessoryView){
        
        inputBar.inputTextView.resignFirstResponder()
        
        let message = inputBar.inputTextView.text
        
        inputBar.inputTextView.text = String()
        inputBar.invalidatePlugins()
        inputBar.sendButton.startAnimating()
        inputBar.inputTextView.placeholder = "Sending...".localized()
        
        delegate?.sendMessage(message: message.orEmptyString, receiverID: receiver.senderId, completed: { completed in
            
            guard completed else { return }
            
            inputBar.sendButton.stopAnimating()
            
            inputBar.inputTextView.placeholder = "Aa".localized()
        })
    }
}

struct Sender: SenderType {
    
    var senderId: String
    
    var displayName: String
    
    var initials: String {
        
        let nameComponents = displayName.split(separator: " ")
        
        guard let firstNameInitial = nameComponents.first?.first else { return "" }
        
        return String(firstNameInitial).uppercased() + (nameComponents.count > 1 ? String(nameComponents.last!.first!).uppercased() : "")
    }
    
    var avatarURL: String
    
}

struct Message: MessageType {
    
    var sender: MessageKit.SenderType
    
    var messageId: String
    
    var sentDate: Date
    
    var kind: MessageKit.MessageKind
}