How to pass a reference to a Boolean rather than its value? - swift

Question

I want to use booleans as state storage.
In order to do that, I need to be able to change their state from difference places in the project.
To do that, I need somewhere to store them, and a way to pass a reference to them.
I've tried storing them as static variables in a GameManager, but passing references to these only seems to pass the value of true of false, not a reference.
How do I achieve this goal of having a passable boolean reference I can change the state of it from any part of the project?
UPDATE:
This can't be the best way to do this, but this achieves the goal of having a bunch of state booleans that I can use around the game world:
class GameManager {
static let sharedInstance = GameManager()
var previewAudioIsON: Bool = false
var previewVisuaIsOn: Bool = false
var timerDisplayIsOn: Bool = false
var quickStartIsOn: Bool = false
func touchedPreviewAudioButton() -> Bool {
if previewAudioIsON { previewAudioIsON = false}
else { previewAudioIsON = true }
return previewAudioIsON
}
func touchedPreviewVisualButton() -> Bool {
if previewVisuaIsOn { previewVisuaIsOn = false }
else { previewVisuaIsOn = true }
return previewVisuaIsOn
}
func touchedTimeDisplayButton() -> Bool {
if timerDisplayIsOn { timerDisplayIsOn = false }
else { timerDisplayIsOn = true }
return timerDisplayIsOn
}
func touchedQuickStartButton() -> Bool {
if quickStartIsOn { quickStartIsOn = false }
else { quickStartIsOn = true }
return quickStartIsOn
}
}

Answer 1

I gave you partially wrong information the other day ( I was having a brain fart), and need to apologize for that. I had overlooked something in my testing...
Here is what you need if you don't want to make the RefBool instances as I suggested (requires more legwork, not recommended):
/// Mutates a boolean:
func toggle(_ boolean: inout Bool) -> Bool {
boolean ? (boolean = false) : (boolean = true)
return boolean
}
/// Static state manager for Booleans
struct IsOn {
private static var
_previewAudio = false,
_previewVisual = false,
_timerDisplal = false,
_quickStart = false
enum State { case toggle, get }
static func previewAudio(_ toggleVal: State = .get) -> Bool {
if toggleVal == .toggle { toggle(&_previewAudio) }; return _previewAudio
}
// ... others
}
Testing:
let referenceToPA = IsOn.previewAudio
print ( IsOn.previewAudio() ) // False (default pram works)
print ( referenceToPA(.get) ) // False (can't use default pram)
referenceToPA(.toggle)
print ( IsOn.previewAudio() ) // True
print ( referenceToPA(.get) ) // True
IsOn.previewAudio(.toggle)
print ( IsOn.previewAudio() ) // False
print ( referenceToPA(.get) ) // False
But honestly, it would be easier to just do the RefBool from my other answer, then you wouldn't need the enum or the functions:
/// Holds a boolean in .val:
final class RefBool { var val: Bool; init(_ boolean: Bool) { val = boolean } }
/// Static state manager for Booleans
struct IsOn {
static var
previewAudio = RefBool(false),
previewVisual = RefBool(false),
timerDisplal = RefBool(false),
quickStart = RefBool(false)
}
Convenience Funcs (not necessary):
/// Mutates a boolean:
func toggle(_ boolean: inout Bool) -> Bool {
boolean ? (boolean = false) : (boolean = true)
return boolean
}
/// Mutates .val:
func toggle(_ refBool: RefBool) -> Bool {
refBool.val ? (refBool.val = false) : (refBool.val = true)
return refBool.val
}
Testing2:
let refToPA = IsOn.previewAudio
refToPA.val = true
print(refToPA.val) // true
print(IsOn.previewAudio.val) // true
toggle(&refToPA.val)
print(refToPA.val) // false
print(IsOn.previewAudio.val) // false
toggle(refToPA) // Using our fancy second toggle
print(refToPA.val) // true
print(IsOn.previewAudio.val) // true

Answer 2

try something like that:
Full example
import UIKit
enum ButtonType {
case PreviewAudio;
case PreviewVisua;
case TimerDisplay;
case QuickStart;
}
class SwitchProperty {
var type: ButtonType
var value: Bool
init (type: ButtonType) {
self.type = type
self.value = false
}
var description: String {
var result = "type = \(type)\n"
result += "value = \(value)"
return result
}
func switchValue() {
value.invertValue()
}
}
class GameManager {
static var previewAudioIsON = SwitchProperty(type: .PreviewAudio)
static var previewVisuaIsOn = SwitchProperty(type: .PreviewVisua)
static var timerDisplayIsOn = SwitchProperty(type: .TimerDisplay)
static var quickStartIsOn = SwitchProperty(type: .QuickStart)
}
class Button: UIButton {
var switchValue: SwitchProperty
init (type: ButtonType, frame: CGRect) {
switch type {
case .PreviewAudio:
switchValue = GameManager.previewAudioIsON
case .PreviewVisua:
switchValue = GameManager.previewVisuaIsOn
case .TimerDisplay:
switchValue = GameManager.timerDisplayIsOn
case .QuickStart:
switchValue = GameManager.quickStartIsOn
}
super.init(frame: frame)
addTarget(self, action: #selector(Button.buttonTouched), for: .touchUpInside)
}
func buttonTouched() {
switchValue.switchValue()
print(switchValue.description)
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
extension Bool {
mutating func invertValue() {
self = !self
}
}
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
addButton(type: .PreviewVisua, frame: CGRect(x: 40, y: 40, width: 200, height: 40));
addButton(type: .PreviewAudio, frame: CGRect(x: 40, y: 100, width: 200, height: 40));
}
func addButton(type: ButtonType, frame: CGRect) {
let button = Button(type: type, frame: frame);
button.setTitleColor(UIColor.blue, for: .normal)
button.setTitle("\(type)", for: .normal)
view.addSubview(button)
}
}
Properties accsess from another code
// change value
GameManager.previewAudioIsON.value = false
// check type
if (GameManager.previewAudioIsON.type == .PreviewAudio) {
print("previewAudioIsON")
}
Result