UIGestureRecognizer+Closures.swift

UIGestureRecognizer+Closures.swift

//
//  UIGestureRecognizer+Closures.swift
//  Closures
//
//  Created by Hector on 7/23/14.
//  Copyright (c) 2014 Hector Matos. All rights reserved.
//

import Foundation

extension UIGestureRecognizer {
    convenience init(trailingClosure: (() -> ())?) {
        self.init()

        let invokingTarget = InvokeTarget.sharedInstance
        invokingTarget.trailingClosure = trailingClosure

        self.addTarget(InvokeTarget.sharedInstance, action: "invokeTrailingClosure:")
    }

    convenience init(gestureClosure: ((gestureRecognizer: UIGestureRecognizer) -> ())?) {
        self.init()

        let invokingTarget = InvokeTarget.sharedInstance
        invokingTarget.gestureClosure = gestureClosure

        self.addTarget(InvokeTarget.sharedInstance, action: "invokeTrailingClosure:")
    }
}

class InvokeTarget: NSObject {
    class var sharedInstance: InvokeTarget {
        struct Singleton {
            static let instance = InvokeTarget()
        }
        return Singleton.instance
    }

    var trailingClosure: (() -> ())?
    var gestureClosure: ((recognizer: UIGestureRecognizer) -> ())?

    func invokeTrailingClosure(recognizer: UIGestureRecognizer) {
        if let unwrappedTrailingTarget = trailingClosure {
            unwrappedTrailingTarget()
        } else if let unwrappedTrailingTarget = gestureClosure {
            unwrappedTrailingTarget(recognizer: recognizer)
        }
    }
}