Toggling an UISwitch Programmatically

Question

I'm trying to toggle an UISwitch through an objc function, however the switch is not recognizing the UITapGestureRecognizer I implemented.

StatusAvailabilityCell

// MARK: - Properties

lazy var toggle: UISwitch = {
    let toggle = UISwitch()
    toggle.isOn = false
    toggle.isEnabled = true
    toggle.onTintColor = .darkPurpleTint
    return toggle
}()

// MARK: - Lifecycle

override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
    super.init(style: style, reuseIdentifier: reuseIdentifier)
    
    configureUI()
    handleToggle()
}

// MARK: - Selectors

@objc func toggleSwitch(_ sender: UISwitch) {
    if sender.isOn == true {
        sender.tintColor = .darkPurpleTint
        sender.setOn(true, animated: true)
    } else {
        sender.tintColor = .white
        sender.setOn(false, animated: true)
    }
}

// MARK: - Helper Functions

fileprivate func handleToggle() {
    
    let tap = UITapGestureRecognizer(target: self, action: #selector(toggleSwitch(_:)))
    tap.numberOfTapsRequired = 1
    toggle.addGestureRecognizer(tap)
    
}

StatusAvailabilityController

// MARK: - UITableViewDataSource

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: CellIdentifiers.StatusAvailabilityCell, for: indexPath) as! StatusAvailabilityCell
    cell.selectionStyle = .none
    cell.separatorInset = UIEdgeInsets.init(top: 0, left: cell.bounds.size.width, bottom: 0, right: 0)
    return cell
}

I have tried to do an addTarget implementation to the UISwitch instead of an UITapGestureRecognizer. I also tried to implement setOn() but it still isn't switching on and off. Thank you in advance.

score 1 · Answer 1 · answered Jul 05 '23 at 02:32

The key issue here is that you are attempting to use your own tap gesture to toggle the switch. That's unnecessary. A switch already handles touch events to toggle itself.

You need to add a target/action handler to the switch to be notified when it is changed. You then handle the updated state as needed.

Here's an updated version of your posted code:

lazy var toggle: UISwitch = {
    let toggle = UISwitch()
    toggle.isOn = false
    toggle.isEnabled = true
    toggle.onTintColor = .darkPurpleTint
    toggle.addTarget(self, action: #selector(toggleSwitch), for: .valueChanged)

    return toggle
}()

// MARK: - Lifecycle

override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
    super.init(style: style, reuseIdentifier: reuseIdentifier)
    
    configureUI()
}

// MARK: - Selectors

@objc func toggleSwitch(_ sender: UISwitch) {
    if sender.isOn {
        sender.tintColor = .darkPurpleTint
    } else {
        sender.tintColor = .white
    }

    // Or just the following:
    // sender.tintColor = sender.isOn ? .darkPurpleTint : .white
}

Delete your handleToggle function.

And I'm not sure why you are changing the switch's tint colors when it changes. You already set the onTintColor when you created it.

Toggling an UISwitch Programmatically

1 Answers1