SwiftColors.swift

//  SwiftColors.swift
//
// Copyright (c) 2014 Doan Truong Thi
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#if os(iOS)
  import UIKit
  typealias SWColor = UIColor
#else
  import Cocoa
  typealias SWColor = NSColor
#endif

extension SWColor {
  /**
    Create non-autoreleased color with in the given hex string
    Alpha will be set as 1 by default
    
    - parameter   hexString:
    - returns: color with the given hex string
  */
  convenience init?(hexString: String) {
    self.init(hexString: hexString, alpha: 1.0)
  }

  /**
    Create non-autoreleased color with in the given hex string and alpha
    
    - parameter   hexString:
    - parameter   alpha:
    - returns: color with the given hex string and alpha
  */
  convenience init?(hexString: String, alpha: Float) {
    var hex = hexString

    // Check for hash and remove the hash
    if hex.hasPrefix("#") {
      hex = hex.substring(from: hex.characters.index(hex.startIndex, offsetBy: 1))
    }
    
    if let _ = hex.range(of: "(^[0-9A-Fa-f]{6}$)|(^[0-9A-Fa-f]{3}$)", options: .regularExpression) {
    
        // Deal with 3 character Hex strings
        if hex.characters.count == 3 {
          let redHex   = hex.substring(to: hex.characters.index(hex.startIndex, offsetBy: 1))
          let greenHex = hex.substring(with: (hex.characters.index(hex.startIndex, offsetBy: 1) ..< hex.characters.index(hex.startIndex, offsetBy: 2)))
          let blueHex  = hex.substring(from: hex.characters.index(hex.startIndex, offsetBy: 2))
          
          hex = redHex + redHex + greenHex + greenHex + blueHex + blueHex
        }

        let redHex = hex.substring(to: hex.characters.index(hex.startIndex, offsetBy: 2))
        let greenHex = hex.substring(with: (hex.characters.index(hex.startIndex, offsetBy: 2) ..< hex.characters.index(hex.startIndex, offsetBy: 4)))
        let blueHex = hex.substring(with: (hex.characters.index(hex.startIndex, offsetBy: 4) ..< hex.characters.index(hex.startIndex, offsetBy: 6)))
        
        var redInt:   CUnsignedInt = 0
        var greenInt: CUnsignedInt = 0
        var blueInt:  CUnsignedInt = 0

        Scanner(string: redHex).scanHexInt32(&redInt)
        Scanner(string: greenHex).scanHexInt32(&greenInt)
        Scanner(string: blueHex).scanHexInt32(&blueInt)

        self.init(red: CGFloat(redInt) / 255.0, green: CGFloat(greenInt) / 255.0, blue: CGFloat(blueInt) / 255.0, alpha: CGFloat(alpha))
    }
    else {
        // Note:
        // The swift 1.1 compiler is currently unable to destroy partially initialized classes in all cases,
        // so it disallows formation of a situation where it would have to.  We consider this a bug to be fixed
        // in future releases, not a feature. -- Apple Forum
        self.init()
        return nil
    }
  }

  /**
    Create non-autoreleased color with in the given hex value
    Alpha will be set as 1 by default
    
    - parameter   hex:
    - returns: color with the given hex value
  */
  convenience init?(hex: Int) {
    self.init(hex: hex, alpha: 1.0)
  }
  
  /**
    Create non-autoreleased color with in the given hex value and alpha
    
    - parameter   hex:
    - parameter   alpha:
    - returns: color with the given hex value and alpha
  */
  convenience init?(hex: Int, alpha: Float) {
    let hexString = NSString(format: "%2X", hex)
    self.init(hexString: hexString as String, alpha: alpha)
  }
}