CopyableLabel.swift

import UIKIt

class CopyableLabel: UILabel {
    override init(frame: CGRect) {
        super.init(frame: frame)
        _commonInit()
    }

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

    private func _commonInit() {
        isUserInteractionEnabled = true
        let recognizer = UILongPressGestureRecognizer(target: self, action: #selector(didPressedLong(_:)))
        addGestureRecognizer(recognizer)
    }

    @objc
    private func didPressedLong(_ recognizer: UILongPressGestureRecognizer) {
        guard recognizer.state == .recognized else {
            return
        }

        let menuController = UIMenuController.shared
        guard !menuController.isMenuVisible else {
            return
        }
        if #available(iOS 13.0, *) {
            menuController.showMenu(from: self, rect: bounds)
        } else {
            menuController.setTargetRect(bounds, in: self)
            menuController.setMenuVisible(true, animated: true)
        }
    }

    override var canBecomeFirstResponder: Bool {
        true
    }

    override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        if [#selector(UIResponderStandardEditActions.copy)].contains(action) {
            return true
        }
        // next responderに流す
        return super.canPerformAction(action, withSender: sender)
    }

    override func copy(_ sender: Any?) {
        UIPasteboard.general.string = text
    }
}