SwiftAttributedString.swift

class SwiftAttributedString: NSObject {
    
    private var attributedString = NSMutableAttributedString()
    private var attributes = [String: AnyObject]()
    private var currentString = ""
    private var currentRange = NSRange()
    private var paragraphStyle = NSMutableParagraphStyle()
    
    init(string str: String) {
        super.init()
        attributedString = NSMutableAttributedString(string: str)
        currentString = str
        currentRange = NSMakeRange(0, currentString.length)
    }
    
    func append(str: String) -> SwiftAttributedString {
        currentString = str
        currentRange = NSMakeRange(currentRange.length + currentRange.location, str.length)
        attributedString.appendAttributedString(NSAttributedString(string: str, attributes: attributes))
        return self
    }
    
    func Color(value: UIColor) -> SwiftAttributedString {
        return applyAttribute(NSForegroundColorAttributeName, value: value)
    }
    
    func BgColor(value: UIColor) -> SwiftAttributedString {
        return applyAttribute(NSBackgroundColorAttributeName, value: value)
    }
    
    func Font(value: UIFont) -> SwiftAttributedString {
        return applyAttribute(NSFontAttributeName, value: value)
    }
    
    func Shadow(value: NSShadow) -> SwiftAttributedString {
        return applyAttribute(NSShadowAttributeName, value: value)
    }
    
    func StrikeThrough(value: Int) -> SwiftAttributedString {
        return applyAttribute(NSStrikethroughStyleAttributeName, value: value)
    }
    
    func Underline(value: Int) -> SwiftAttributedString {
        return applyAttribute(NSUnderlineStyleAttributeName, value: value)
    }
    
    func Stroke(width: Int) -> SwiftAttributedString {
        return applyAttribute(NSStrokeWidthAttributeName, value: width)
    }
    
    func Kerning(value: Double) -> SwiftAttributedString {
        return applyAttribute(NSKernAttributeName, value: value)
    }
    
    func LineSpacing(value: CGFloat) -> SwiftAttributedString {
        paragraphStyle.lineSpacing = value
        return applyAttribute(NSParagraphStyleAttributeName, value: paragraphStyle)
    }
    
    func string() -> NSAttributedString {
        return attributedString
    }
    
    internal func applyAttribute(attribute: String, value: AnyObject) -> SwiftAttributedString {
        attributes[attribute] = value
        attributedString.addAttributes(attributes, range: currentRange)
        return self
    }
}