How to have custom UIControlState in Swift 2.2 using bit masks?

Question

I have a custom UIButton with some unique states that I want it to have like:

enum PositionControlState : Int {
    case Available = 0, Pending, Waiting, Approved, Declined
}

I've done a bit of Googling and found some stuff about bitmasks, and UIControlState.Application in objective-c. I feel like I have pieces of the puzzle, but not quite sure how to put it all together in swift 2.2.

So something like: \br `struct PositionControlState : OptionSetType { let rawValue: Int static let Available = UIControlState(rawValue: 0) static let Waiting = UIControlState(rawValue: 1 << 0) static let Pending = UIControlState(rawValue: 1 << 1) static let Approved = UIControlState(rawValue: 1 << 2) static let Declined = UIControlState(rawValue: 1 << 3) }` — eli_slade, Aug 23 '16 at 22:01
Yep, although you have to be careful not to have any of your raw values colliding with the ones already built in — Alexander, Aug 24 '16 at 14:59

score 1 · Answer 1 · answered Jul 19 '18 at 06:03

I'm not sure if you ever resolved this, but the way I have done something similar is like this.

extension UIControlState {
    static let available = UIControlState(rawValue: 1 << 5)
    static let pending   = UIControlState(rawValue: 1 << 6)
    static let waiting   = UIControlState(rawValue: 1 << 7)
}

class Button: UIButton {
    private var isAvailable = false
    private var isPending = false
    private var isWaiting = false

    private func aFuncCalledWhenPending() {
        isPending = true
    }

    override var state: UIControlState {
        var s = super.state

        if isAvailable {
            s.insert(.available)
        }
        if isPending {
            s.insert(.pending)
        }
        if isWaiting {
            s.insert(.waiting)
        }

        return s
    }
}

This will allow you to write code such as button.setTitleColor(.red, for: .pending).

The issue with this approach is your additional states will be publicly visible for all functions accepting the UIControlState. Similar to how UIControlEvents has a lot of states but some of them are only used on specific classes.

Keep in mind that if you move forward with this approach, the additional states you include should remain in the same contextual definition of 'control state'.

How to have custom UIControlState in Swift 2.2 using bit masks?

1 Answers1