Swiftの便利なextension

Util.swift

//
//  Util.swift
//  
//
//  Created by himara2 on 2015/11/01.
//
//

import Foundation

extension NSObject {
    class var className: String {
        get {
            return NSStringFromClass(self).componentsSeparatedByString(".").last!
        }
    }
    
    var className: String {
        get {
            return self.dynamicType.className
        }
    }
}


extension UITableView {
    func registerCell<T: UITableViewCell>(type: T.Type) {
        let className = type.className
        let nib = UINib(nibName: className, bundle: nil)
        registerNib(nib, forCellReuseIdentifier: className)
    }
    
    func dequeueCell<T: UITableViewCell>(type: T.Type, indexPath: NSIndexPath) -> T {
        return self.dequeueReusableCellWithIdentifier(type.className, forIndexPath: indexPath) as! T
    }
}


extension UICollectionView {
    func registerCell<T: UICollectionViewCell>(type: T.Type) {
        let className = type.className
        let nib = UINib(nibName: type.className, bundle: nil)
        registerNib(nib, forCellWithReuseIdentifier: className)
    }
    
    func registerReusableView<T: UICollectionReusableView>(type: T.Type, kind: String) {
        let className = type.className
        let nib = UINib(nibName: className, bundle: nil)
        registerNib(nib, forSupplementaryViewOfKind: kind, withReuseIdentifier: className)
    }
    
    func dequeueCell<T: UICollectionViewCell>(type: T.Type, forIndexPath indexPath: NSIndexPath) -> T {
        return dequeueReusableCellWithReuseIdentifier(type.className, forIndexPath: indexPath) as! T
    }
    
    func dequeueReusableView<T: UICollectionReusableView>(kind: String, type: T.Type, indexPath: NSIndexPath) -> T {
        return dequeueReusableSupplementaryViewOfKind(kind,
            withReuseIdentifier: type.className,
            forIndexPath: indexPath) as! T
    }
}


extension UIColor {
    class func color(hex: Int, alpha: Double = 1.0) -> UIColor {
        let red = Double((hex & 0xFF0000) >> 16) / 255.0
        let green = Double((hex & 0xFF00) >> 8) / 255.0
        let blue = Double((hex & 0xFF)) / 255.0
        
        return UIColor(red: CGFloat(red), green: CGFloat(green), blue: CGFloat(blue), alpha: CGFloat(alpha))
    }
    
    class func defaultColor(alpha: Double = 1.0) -> UIColor {
        return UIColor.color(0x00ACED, alpha: alpha)
    }
}


extension UIApplication {
    func topViewController() -> UIViewController? {
        if var topViewController = UIApplication.sharedApplication().keyWindow?.rootViewController {
            while (topViewController.presentedViewController != nil) {
                topViewController = topViewController.presentedViewController!
            }
            return topViewController
        } else {
            return nil
        }
    }
}


private let isFirstSessionDoneKey = "IS_FIRST_SESSION_DONE"

extension NSUserDefaults {
    var isFirstSessionDone: Bool? {
        get {
            return self.objectForKey(isFirstSessionDoneKey) as? Bool
        }
        set {
            self.setObject(true, forKey: isFirstSessionDoneKey)
            self.synchronize()
        }
    }
}


func instantiate<T: UIViewController where T: NSObject>(_: T.Type) -> T {
    let storyboard = UIStoryboard(name: T.className, bundle: nil)
    return storyboard.instantiateInitialViewController() as! T
}

func instantiate<T: UIViewController where T: NSObject>(_: T.Type, storyboard: String) -> T {
    let storyboard = UIStoryboard(name: storyboard, bundle: nil)
    return storyboard.instantiateViewControllerWithIdentifier(T.className) as! T
}


func instantiateFromNib<T: UIView, U: AnyObject where T: NSObject>(_: T.Type, owner: U) -> T {
    return UINib(nibName: T.className, bundle: nil).instantiateWithOwner(owner, options: nil)[0] as! T
}