How to animate tab bar's items

Question

In my Swift app I have this class that handles a UITabBar.

class CustomTabBar: UITabBar {
    override func awakeFromNib() {
        super.awakeFromNib()
    }
}

How can I animate the items when the user tap their? I mean a CGAffine(scaleX: 1.1, y: 1.1) So how I can animate the tab bar's items?

Answer 1

First:

create a custom UITabBarController as follows:

import UIKit

enum TabbarItemTag: Int {
    case firstViewController = 101
    case secondViewConroller = 102
}

class CustomTabBarController: UITabBarController {
    var firstTabbarItemImageView: UIImageView!
    var secondTabbarItemImageView: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let firstItemView = tabBar.subviews.first!
        firstTabbarItemImageView = firstItemView.subviews.first as? UIImageView
        firstTabbarItemImageView.contentMode = .center

        let secondItemView = self.tabBar.subviews[1]
        self.secondTabbarItemImageView = secondItemView.subviews.first as? UIImageView
        self.secondTabbarItemImageView.contentMode = .center
    }

    private func animate(_ imageView: UIImageView) {
        UIView.animate(withDuration: 0.1, animations: {
            imageView.transform = CGAffineTransform(scaleX: 1.25, y: 1.25)
        }) { _ in
            UIView.animate(withDuration: 0.25, delay: 0.0, usingSpringWithDamping: 0.5, initialSpringVelocity: 3.0, options: .curveEaseInOut, animations: {
                imageView.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
            }, completion: nil)
        }
    }

    override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
        guard let tabbarItemTag = TabbarItemTag(rawValue: item.tag) else {
            return
        }

        switch tabbarItemTag {
        case .firstViewController:
            animate(firstTabbarItemImageView)
        case .secondViewConroller:
            animate(secondTabbarItemImageView)
        }
    }
}

Second:

Set the tag values for the tabBarItem for each view controller:

First ViewController:

import UIKit

class FirstViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        tabBarItem.tag = TabbarItemTag.firstViewController.rawValue
    }
}

Second ViewController:

import UIKit

class SecondViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        tabBarItem.tag = TabbarItemTag.secondViewConroller.rawValue
    }
}

Make sure that everything has been setup with your storyboard (if you are using one) and that's pretty much it!

Output:

You could check the repo:

https://github.com/AhmadFayyas/Animated-TabbarItem/tree/master

for demonstrating the answer.