Can a UIView assign a UITapGestureRecognizer to itself? - ios

Question

I'm trying to make a UIView that recognizes tap gestures, however taps are not ever correctly registered by the UIView. Here's the code for the UIView subclass itself:
import UIKit
class ActionCell: SignalTableCell, UIGestureRecognizerDelegate {
var icon: UIImageView!
var actionType: UILabel!
var actionTitle: UILabel!
var a:Action?
var tap:UITapGestureRecognizer?
required init(frame: CGRect) {
//
super.init(frame:frame)
tap = UITapGestureRecognizer(target: self, action: #selector(self.touchTapped(_:)))
tap?.delegate = self
addGestureRecognizer(tap!)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
tap = UITapGestureRecognizer(target: self, action: #selector(self.touchTapped(_:)))
tap?.delegate = self
addGestureRecognizer(tap!)
}
#objc func touchTapped(_ sender: UITapGestureRecognizer) {
print("OK")
}
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
self.isUserInteractionEnabled = true
}
override func layoutSubviews() {
if(icon == nil) {
let rect = CGRect(origin: CGPoint(x: 10,y :20), size: CGSize(width: 64, height: 64))
icon = UIImageView(frame: rect)
addSubview(icon)
}
icon.image = UIImage(named:(a?.icon)!)
if(actionType == nil) {
let rect = CGRect(origin: CGPoint(x: 100,y :20), size: CGSize(width: 200, height: 16))
actionType = UILabel(frame: rect)
addSubview(actionType)
}
actionType.text = a.type
if(actionTitle == nil) {
let rect = CGRect(origin: CGPoint(x: 100,y :80), size: CGSize(width: 200, height: 16))
actionTitle = UILabel(frame: rect)
addSubview(actionTitle)
}
actionTitle.text = a?.title
}
func configure( a:Action ) {
self.a = a
}
override func setData( type:SignalData ) {
a = (type as! Action)
}
}
I'm simply trying to make it so that this UIView can, you know, know when it's tapped. Is this possible without adding a separate UIViewController? This seems as though it should be fairly simple but it doesn't appear to be, confusingly.
I've stepped through the code and the init method is called and the Gesture Recognizer is added but it doesn't trigger.

Answer 1

If its a table view cell, I'd recommend not using a tap gesture, since it might interfere with the didSelectRowAtIndexPath: and other delegate methods. But if you still wanna keep the tap gesture, try adding tap?.cancelsTouchesInView = false before addGestureRecognizer(tap!) and see if that works.
If you just want to know when its tapped, you could also override the following UIResponder method:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesBegan(touches, with: event)
// do your stuff
}

Answer 2

I think, it is easier to override touchesBegan method. Something like this:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
print("touched")
super.touchesBegan(touches, with: event)
}

Answer 3

Most likely the actionType, ActionTitle, and icon are being tapped and the tap is not falling through because user interaction is disabled by default for labels and images. Set isUserInteractionEnabled = true for each of those fields that are subviews of the main view.
override func layoutSubviews() {
if(icon == nil) {
let rect = CGRect(origin: CGPoint(x: 10,y :20), size: CGSize(width: 64, height: 64))
icon = UIImageView(frame: rect)
icon.isUserInteractionEnabled = true
addSubview(icon)
}
icon.image = UIImage(named:(a?.icon)!)
if(actionType == nil) {
let rect = CGRect(origin: CGPoint(x: 100,y :20), size: CGSize(width: 200, height: 16))
actionType = UILabel(frame: rect)
actionType.isUserInteractionEnabled = true
addSubview(actionType)
}
actionType.text = a.type
if(actionTitle == nil) {
let rect = CGRect(origin: CGPoint(x: 100,y :80), size: CGSize(width: 200, height: 16))
actionTitle = UILabel(frame: rect)
actionTitle.isUserInteractionEnabled = true
addSubview(actionTitle)
}
actionTitle.text = a?.title
}