Swift UI TextView placeholder

There is no placeholder in UITextView! ??

When I wanted to make a twitter-like app, I wrote the code like textView.placeholder =" " like textfield. I got angry with Value of type'UITextView' has no member'placeholder'. Eh, there is no placeholder for textView ... So, let's somehow implement placeholder in textView.

This time, create a class called TextView that inherits the UITextView and add a UILabel to the TextView.

TextView.swift

class TextView: UITextView {
    
    public let placeholderLabel: UILabel = {
        let label = UILabel()
        label.textColor = .lightGray
        label.font = .systemFont(ofSize: 18)
        label.numberOfLines = 0
        return label
    }()

    override init(frame: CGRect, textContainer: NSTextContainer?) {
        super.init(frame: frame, textContainer: textContainer)
        addSubview(placeholderLabel)
        
        placeholderLabel.translatesAutoresizingMaskIntoConstraints = false
        let cons = [
            placeholderLabel.topAnchor.constraint(equalTo: topAnchor, constant: 8),
            placeholderLabel.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 5),
            placeholderLabel.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -5),
        ]
        
        NSLayoutConstraint.activate(cons)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
}

I defined TextView like this.

All you have to do now is display textView with ViewController!

ViewController.swift

class ViewController: UIViewController {

    let textView: TextView = {
        let textView = TextView()
        textView.placeholderLabel.text = "It's a placeholder"
        textView.font = .systemFont(ofSize: 18)
        return textView
    }()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(textView)
        textView.frame = .init(x: 0, y: 100, width: view.frame.size.width, height: view.frame.size.height-200)
    }
}

This looks good! However, if you leave it as it is, the characters you entered and the characters of placeholder Label will overlap. Well, as a result of thinking about what to do, I decided to use textViewDidChange (_ textView: UITextView) of UITextViewDelegate.

ViewController.swift

extension ViewController: UITextViewDelegate {
    func textViewDidChange(_ textView: UITextView) {
        if textView.text.isEmpty {
            self.textView.placeholderLabel.alpha = 1
        } else {
            self.textView.placeholderLabel.alpha = 0
        }
    }
}

It's like this. Show placeholderLabel if textView.text is empty, otherwise hide placeholderLabel.

Summary

You have to write a lot of code just by implementing placehoder in textView lol Please let me know if there is an easier way to implement it!