Swift normal class cannot receive touch events from UIButton - ios

Question

I'm trying to create a separate class for a group of buttons to handle a logic of only one button get selected at one time (Radio button)
The logic is not important here. I just cannot receive the touchUpIndside event when tapping on one of these buttons.
I set the target to self (the custom RadionButtonsController class) but this class cannot receive the event.
I tried to add UIResponder as a superclass. But still cannot receive the event in this class.
Here is my code:
import UIKit
class RadioButtonsController: UIResponder
{
var buttons = [UIButton]()
var selectedValue: String?
init(numberOfButtons: Int, titles: [String], values: [String])
{
guard titles.count == numberOfButtons && values.count == numberOfButtons else
{
fatalError("number of items in `titles` and `values` must equal to the `numberOfButtons`")
}
super.init()
for i in 0..<numberOfButtons
{
let button = UIButton(type: .system)
button.setTitle(titles[i], for: .normal)
button.backgroundColor = [UIColor.red, UIColor.blue, UIColor.gray, UIColor.yellow].randomElement()
button.addTarget(self, action: #selector(radioButtonSelected(sender:)), for: .touchUpInside)
buttons.append(button)
}
}
#objc private func radioButtonSelected(sender: UIButton)
{
print("Selected Button: \(sender)") // this is will never get printed
}
}
And I use this buttons controller in a table view cell. In cellForRowAtIndexPath:
let itemOptionsCell = tableView.dequeueReusableCell(withIdentifier: "ItemOptionsCell", for: indexPath) as! ItemOptionsTableViewCell
let itemOption = logicController.item.options[indexPath.row]
itemOptionsCell.optionsTitleLabel.text = itemOption.name
let radioButtonsController = RadioButtonsController(numberOfButtons: itemOption.values.count,
titles: itemOption.values.map({ $0.name }),
values: itemOption.values.map({ $0.valueID }))
for button in radioButtonsController.buttons
{
itemOptionsCell.buttonsStackView.addArrangedSubview(button)
}
return itemOptionsCell
The buttons appear to be clicked, but the method radionButtonSelected(snder:) never get called.

Answer 1

The problem is that your code creates a RadioButtonsController object and then throws it away. Your buttons thus have no one to send their action to.

Answer 2

if you want to create a RadioButton without using any external pods
you can use this code :
import Foundation
import UIKit
class HRadioButton: UIButton {
#IBOutlet var otherButtons: [HRadioButton]!
var hSelected = false {
didSet {
if hSelected {
if imageView != nil{
self.setImage(checkedImage, for: .normal)
}else{
self.setImage(checkedImage, for: .normal)
print("image null")
}
if self.otherButtons != nil {
for button in self.otherButtons {
button.hSelected = false
button.imageView?.image = self.unCheckedImage
}
} else {
print("Button is null ")
}
}
}
}
var checkedImage: UIImage!, unCheckedImage: UIImage!
override func awakeFromNib() {
super.awakeFromNib()
checkedImage = #imageLiteral(resourceName: "ic_radio_button_checked").maskWithColor(color: tintColor)
unCheckedImage = #imageLiteral(resourceName: "ic_radio_button_unchecked").maskWithColor(color: tintColor)
setImage(unCheckedImage, for: .normal)
alignImageRight()
self.onTap {
self.imageView?.image = self.checkedImage
self.hSelected = true
if self.otherButtons != nil {
for button in self.otherButtons {
button.hSelected = false
button.imageView?.image = self.unCheckedImage
}
}
}
}
}
extension UIImage {
func maskWithColor(color: UIColor) -> UIImage? {
let maskImage = cgImage!
let width = size.width
let height = size.height
let bounds = CGRect(x: 0, y: 0, width: width, height: height)
let colorSpace = CGColorSpaceCreateDeviceRGB()
let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedLast.rawValue)
let context = CGContext(data: nil, width: Int(width), height: Int(height), bitsPerComponent: 8, bytesPerRow: 0, space: colorSpace, bitmapInfo: bitmapInfo.rawValue)!
context.clip(to: bounds, mask: maskImage)
context.setFillColor(color.cgColor)
context.fill(bounds)
if let cgImage = context.makeImage() {
let coloredImage = UIImage(cgImage: cgImage)
return coloredImage
} else {
return nil
}
}
}
extension UIView {
// In order to create computed properties for extensions, we need a key to
// store and access the stored property
fileprivate struct AssociatedObjectKeys {
static var tapGestureRecognizer = "MediaViewerAssociatedObjectKey_mediaViewer"
}
fileprivate typealias Action = (() -> Void)?
// Set our computed property type to a closure
fileprivate var tapGestureRecognizerAction: Action? {
set {
if let newValue = newValue {
// Computed properties get stored as associated objects
objc_setAssociatedObject(self, &AssociatedObjectKeys.tapGestureRecognizer, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN)
}
}
get {
let tapGestureRecognizerActionInstance = objc_getAssociatedObject(self, &AssociatedObjectKeys.tapGestureRecognizer) as? Action
return tapGestureRecognizerActionInstance
}
}
// This is the meat of the sauce, here we create the tap gesture recognizer and
// store the closure the user passed to us in the associated object we declared above
public func onTap(action: (() -> Void)?) {
self.isUserInteractionEnabled = true
self.tapGestureRecognizerAction = action
let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleTapGesture))
self.addGestureRecognizer(tapGestureRecognizer)
}
// Every time the user taps on the UIImageView, this function gets called,
// which triggers the closure we stored
#objc fileprivate func handleTapGesture(sender: UITapGestureRecognizer) {
if let action = self.tapGestureRecognizerAction {
action?()
} else {
print("no action")
}
}
}
from xcode storyboard ui assign the class HRadioButton as the class of Button then you will find the otherButtons in Connection Inspector image of Connection Inspector Icon in Xcode
in xcode you will find otherButtons Appear there so drag and drop it to other buttons
and repeat this process on all buttons you want make it as Radio Group
for example
i have A Button,B Button,C Button
I will assign class to A Button then drag and drop otherbuttons from Connection Inspector to B and C Buttons
then Assign The Class To B button and make otherButtons refere to A,C Buttons and so on.
Later you can get the selected Btn from hSelected Property