Make multiple buttons highlight when touch begins

Question

I have placed three buttons together in a view each of which will have a different profile image. I need all three buttons to highlight when touch begins on any individual one so that the three together appear to be one button. I have tried the following code but it does not work. Any ideas?

    let tapGesture = UITapGestureRecognizer(target: self, action: #selector(normalTap))
    tapGesture.numberOfTapsRequired = 1
    friendsBtn1.addGestureRecognizer(tapGesture)

    func normalTap(sender: UITapGestureRecognizer){
        if sender.state == .began {
            friendsBtn2.isHighlighted = true
            friendsBtn3.isHighlighted = true
        }
        if sender.state == .ended {
            friendsBtn2.isHighlighted = false
            friendsBtn3.isHighlighted = false
        }
        print("Normal tap")
    }

Answer 1

I did solve the problem. Here is the code.

[friendsBtn1, friendsBtn2, friendsBtn3].forEach { button in
        button?.addTarget(self, action:#selector(highlightAllButtons(sender:)), for: .touchDown)
        button?.addTarget(self, action:#selector(unhighlightAllButtons(sender:)), for: [.touchUpInside, .touchUpOutside])
    }

func highlightAllButtons(sender: UIButton) {
    [friendsBtn1, friendsBtn2, friendsBtn3].forEach { button in
        button.isHighlighted = true
    }
}
func unhighlightAllButtons(sender: UIButton) {
    [friendsBtn1, friendsBtn2, friendsBtn3].forEach { button in
        button.isHighlighted = false
    }
}