How to check if button is clicked from XIB file in Swift? - ios

Question

I run into the following. I have created a custom UIView using XIB file. I connected a VC that inherits from UIView and add it to the File Owner property. Connect two buttons with #IBOutlet and connected both buttons to the same #IBAction method, that will switch the background color, to get a boolean effect. By default no button is selected.
In my ViewController.swift file, that is connected with a View Controller in Storyboard, I add it as subview inside my UICollectionView cells.
Based on my two model classes (Messages and PermissionMessage), I determine what the text of the buttons should be.
My wish is to add functions to the buttons, so when button one is clicked, it will fire function A and if button two is selected, function B.
At this point I don't know where I should do this logic, to determine which function should be fired off. Also because I can create different instances of the same BooleanView.xib so I can't add the functions to the file owners class of that XIB file, am I right?
I am trying to get the button click inside the didSelectItemAt method of UICollectionView, but I can't get access to that programmatically added custom UIView called BooleanView().
How and what should be the correct way to add functions to each instance buttons, based on the button that is clicked?
In my example I want to determine for the current instance if the selected button is Manual or GPS. If Manual, it will do something, like print a text in my console, if GPS is selected, I would like to call the initializer for the LocationManager that I stored in a custom separate class/handler.
This function is placed inside the cellForItemAt method of UICollectionView:
if message is PermissionMessage {
let bool = BooleanView()
bool.frame = CGRect(x: 60, y: estimatedFrame.height + 15, width: estimatedFrame.width + 15 + 8, height: bool.frame.height)
let permissionType = (message as! PermissionMessage).getTypeOfPermission()
switch permissionType {
case .camera:
print("Case: camera")
bool.leftButton.setTitle("Yes", for: .normal)
bool.rightButton.setTitle("No", for: .normal)
cell.addSubview(bool)
case .location:
print("Case: location")
bool.leftButton.setTitle("Manual", for: .normal)
bool.rightButton.setTitle("GPS", for: .normal)
cell.addSubview(bool)
}
}
Note: the message variable is the selected array entry of indexPath.row.
The custom UIView class that is added to my BooleanView.xib:
class BooleanView: UIView {
#IBOutlet var contentView: UIView!
#IBOutlet weak var leftButton: UIButton!
#IBOutlet weak var rightButton: UIButton!
//MARK: Initialization
override init(frame: CGRect) {
super.init(frame: frame)
// Load the nib named 'CardView' into memory, finding it in the main bundle.
Bundle.main.loadNibNamed("BooleanView", owner: self, options: nil)
self.frame = contentView.frame
addSubview(contentView)
// Style the custom view
contentView.backgroundColor = UIColor.clear
leftButton.layer.cornerRadius = (leftButton.frame.height / 2)
rightButton.layer.cornerRadius = (rightButton.frame.height / 2)
}
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)!
}
#IBAction func pressedButton(_ sender: UIButton) {
if sender.backgroundColor == Constants.BOOL_BUTTON.enabled {
return
}
sender.backgroundColor = Constants.BOOL_BUTTON.enabled
sender.titleLabel?.font = UIFont(name: Constants.FONTS.bold, size: (sender.titleLabel?.font.pointSize)!)
if sender.tag == 0 {
self.rightButton.backgroundColor = Constants.BOOL_BUTTON.disabled
self.rightButton.titleLabel?.font = UIFont(name: Constants.FONTS.regular, size: (self.rightButton.titleLabel?.font.pointSize)!)
} else {
self.leftButton.backgroundColor = Constants.BOOL_BUTTON.disabled
self.leftButton.titleLabel?.font = UIFont(name: Constants.FONTS.regular, size: (self.leftButton.titleLabel?.font.pointSize)!)
}
}
}

Answer 1

First you need a way to communicate which, if either, button has been pressed, an enum will work for that:
enum BooleanViewState {
case none
case left
case right
}
Next your BooleanView needs to be able to communicate its state to interested parties. Given that you only care about the state of a given boolean view at specific moments in time the easiest is to use a computed property. Also, your current method of reaching into the view to set button titles isn't the best of practices so we will add an alternative to that as well:
class BooleanView: UIView {
var boolViewState: BooleanViewState {
get {
if leftButton.backgroundColor == Constants.BOOL_BUTTON.enabled {
return .left
} else if rightButton.backgroundColor == Constants.BOOL_BUTTON.enabled {
return .right
} else {
return .none
}
}
}
var buttonTitles = (leftTitle: "", rightTitle: "") {
didSet {
leftButton.setTitle(buttonTitles.leftTitle, for: .normal)
rightButton.setTitle(buttonTitles.rightTitle, for: .normal)
}
}
// The rest of you existing class
}
It is possible you will need to add a didSet to the outlets for the two buttons that gets the titles. The titles might get set before the buttons exist.
Next you need to switch from using a default UICollectionViewCell to a custom subclass that can hold a BooleanView and pass things back and forth:
class BooleanViewCell: UICollectionViewCell {
#IBOutlet private var boolView: BooleanView!
var boolViewState: BooleanViewState {
get {
return boolView.boolViewState
}
}
var buttonTitles = (leftTitle: "", rightTitle: "") {
didSet {
boolView.buttonTitles = buttonTitles
}
}
}
You'll need to change some code in your cellForItemAt method
if message is PermissionMessage {
let permissionType = (message as! PermissionMessage).getTypeOfPermission()
switch permissionType {
case .camera:
print("Case: camera")
cell.buttonTitles = (leftTitle: "Yes", rightTitle: "No")
case .location:
print("Case: location")
cell.buttonTitles = (leftTitle: "Manual", rightTitle: "GPS")
}
}
The last thing to do is read boolState from the cell in didSelectItemAt
guard let cell = collectionView.cellForItem(at: indexPath) as? BooleanViewCell else { return }
let theState = cell.boolState
// React to the state as needed
This does mean that you will need to add a generic UIView to your prototype collection view cell in the storyboard, set its class to BooleanView and connect it to the outlet in BooleanViewCell.
That should take care of it all for you though I did all of this with no compiler so I make no guarantees I haven't mistyped or missed something all together.