Swift - Refresh Custom UITabBarController Bar

Question

I have a custom TabBar, with a raised middle button, above the TabBar. When the user has not completed a daily task, the setupIncompleteMiddleButton() should appear, indicating that. However, once the user completes the task, I would like setupCompleteMiddleButton() to appear, indicating the have completed the task. I don't know how to do this - I shouldn't call viewDidLoad() in the controller and when calling it, it does nothing to refresh the view. Refreshing the TabBar does nothing.

This is my TabBar controller:

class TabBarController: UITabBarController, UITabBarControllerDelegate {

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)!
}

override func viewDidLoad() {
    super.viewDidLoad()

    // This is where I currently decide which button to show the "complete" one if the task is done, and the incomplete one if not. 
    self.delegate = self
    if UserData.hasCompletedDailyTask() == true {
        setupCompleteMiddleButton()
    } else {
        setupIncompleteMiddleButton()
    }
}

// Incomplete button 
func setupIncompleteMiddleButton() {
    let middleButton = UIButton(frame: CGRect(x: (self.view.bounds.width / 2) - 25, y: -20, width: 50, height: 50))
    
    middleButton.backgroundColor = UIColor.systemYellow
    middleButton.setImage(UIImage(systemName: "sun.max.fill"), for: .normal)
    middleButton.imageView?.tintColor = UIColor.white
    middleButton.layer.cornerRadius = middleButton.frame.width / 2
    middleButton.clipsToBounds = true
    
    self.tabBar.addSubview(middleButton)
    middleButton.addTarget(self, action: #selector(self.middleButtonAction), for: .touchUpInside)
    self.view.layoutIfNeeded()
}

// Complete button
func setupCompleteMiddleButton() {
    let middleButton = UIButton(frame: CGRect(x: (self.view.bounds.width / 2) - 25, y: -20, width: 50, height: 50))

    middleButton.backgroundColor = UIColor.systemGreen
    middleButton.setImage(UIImage(systemName: "checkmark"), for: .normal)
    middleButton.imageView?.tintColor = UIColor.white
    middleButton.layer.cornerRadius = middleButton.frame.width / 2
    middleButton.clipsToBounds = true

    self.tabBar.addSubview(middleButton)
    middleButton.addTarget(self, action: #selector(self.middleButtonAction), for: .touchUpInside)
    self.view.layoutIfNeeded()
}

@objc func middleButtonAction(sender: UIButton) {
    self.selectedIndex = 1  
}
}

Thank you!

Do you want to change middle button from the particular vc action? — Raja Kishan, Jan 08 '21 at 08:58
Does this answer your question? [How to refresh Tab Bar Items in swift ios](https://stackoverflow.com/questions/44262038/how-to-refresh-tab-bar-items-in-swift-ios) — Dmytro Rostopira, Jan 08 '21 at 09:34
@DimaRostopira I did see that response. However, mine is a button that sits on top of the bar and is not really part of the bar itself... the solution in there works for items in the bar but not so for a button above? Correct me if I'm wrong... — Anthony, Jan 08 '21 at 09:37
OKay, retracted close vote. In such case I would suggest using `NotificationCenter` — Dmytro Rostopira, Jan 08 '21 at 09:40
@DimaRostopira Understand, how do I trigger the reload of TabBar though, in order for the new button to show? This is where I don't get it — Anthony, Jan 08 '21 at 09:42
From your `UserData` class pass notification to your `TabBarController` and execute `setupIncompleteMiddleButton` — Dmytro Rostopira, Jan 08 '21 at 10:15

score 1 · Accepted Answer · answered Jan 08 '21 at 10:11

You can try this for globally single object of button and just change the image whenever task is complete or not.

class TabBarController: UITabBarController, UITabBarControllerDelegate {

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)!
}

// TabbarController hode this button
var middleButton: UIButton!

override func viewDidLoad() {
    super.viewDidLoad()
    setupButton()
    // This is where I currently decide which button to show the "complete" one if the task is done, and the incomplete one if not.
    self.delegate = self
    // taskCompletion is a call back when UserData finish its task
    if UserData.taskCompletion {
        setupCompleteMiddleButton()
    } else {
    setupIncompleteMiddleButton()
    }
}

func setupButton() {
    middleButton = UIButton(frame: CGRect(x: (self.view.bounds.width / 2) - 25, y: -20, width: 50, height: 50))
    middleButton.backgroundColor = UIColor.systemYellow
    middleButton.layer.cornerRadius = middleButton.frame.width / 2
    middleButton.clipsToBounds = true
    self.tabBar.addSubview(middleButton)
    middleButton.addTarget(self, action: #selector(self.middleButtonAction), for: .touchUpInside)
    self.view.layoutIfNeeded()
}
//  Incomplete button
func setupIncompleteMiddleButton() {
  middleButton.backgroundColor = UIColor.systemYellow
    middleButton.setImage(UIImage(systemName: "sun.max.fill"), for: .normal)
    
}

// Complete button
func setupCompleteMiddleButton() {
    // change button color and image
    middleButton.backgroundColor = UIColor.systemGreen
    middleButton.setImage(UIImage(systemName: "checkmark"), for: .normal)
}

@objc func middleButtonAction(sender: UIButton) {
    self.selectedIndex = 1
}

I added a delegate to trigger the change in the middle button as well. Thanks! — Anthony, Jan 09 '21 at 00:12

score 0 · Answer 2 · edited Jan 08 '21 at 10:05

Maybe you can try this:

import UIKit

class TabBarController: UITabBarController, UITabBarControllerDelegate {
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)!
    }
    
    // TabbarController hode this button
    var middleButton: UIButton!

    override func viewDidLoad() {
        super.viewDidLoad()
        
        // This is where I currently decide which button to show the "complete" one if the task is done, and the incomplete one if not.
        self.delegate = self
        // taskCompletion is a call back when UserData finish its task
        if UserData.taskCompletion {
            setupCompleteMiddleButton()
        }
        setupIncompleteMiddleButton()
    }
    
    //  Incomplete button 
    func setupIncompleteMiddleButton() {
        // initialize button  
        middleButton = UIButton(frame: CGRect(x: (self.view.bounds.width / 2) - 25, y: -20, width: 50, height: 50))

        middleButton.backgroundColor = UIColor.systemYellow
        middleButton.setImage(UIImage(systemName: "sun.max.fill"), for: .normal)
        middleButton.imageView?.tintColor = UIColor.white
        middleButton.layer.cornerRadius = middleButton.frame.width / 2
        middleButton.clipsToBounds = true
        self.tabBar.addSubview(middleButton)
        middleButton.addTarget(self, action: #selector(self.middleButtonAction), for: .touchUpInside)
        self.view.layoutIfNeeded()
    }
    
    // Complete button
    func setupCompleteMiddleButton() {
        // change button color and image
        middleButton.backgroundColor = UIColor.systemGreen
        middleButton.setImage(UIImage(systemName: "checkmark"), for: .normal)
    }
    
    @objc func middleButtonAction(sender: UIButton) {
        self.selectedIndex = 1
    }
}

Swift - Refresh Custom UITabBarController Bar

2 Answers2