import Foundation

extension UIFont {

    @nonobjc static var loadAllFontsDO: dispatch_once_t = 0

    class func initialsAvatarFont() -> UIFont {
        loadAllFonts()
        if let retval = UIFont(name: "MyFontName",size: kInitialsAvatarFontSize) {
            return retval;
        } else {
            return UIFont.systemFontOfSize(kInitialsAvatarFontSize)
        }
    }

    class func loadAllFonts() {
        dispatch_once(&loadAllFontsDO) { () -> Void in
            registerFontWithFilenameString("thefontfilename.ttf",bundleIdentifierString: "nameOfResourceBundleAlongsideTheFrameworkBundle")
            // Add more font files here as required
        }
    }

    static func registerFontWithFilenameString(filenameString: String,bundleIdentifierString: String) {
        let frameworkBundle = NSBundle(forClass: AnyClassInYourFramework.self)
        let resourceBundleURL = frameworkBundle.URLForResource(bundleIdentifierString,withExtension: "bundle")
        if let bundle = NSBundle(URL: resourceBundleURL!) {
            let pathForResourceString = bundle.pathForResource(filenameString,ofType: nil)
            let fontData = NSData(contentsOfFile: pathForResourceString!)
            let dataProvider = CGDataProviderCreateWithCFData(fontData)
            let fontRef = CGFontCreateWithDataProvider(dataProvider)
            var errorRef: Unmanaged<CFError>? = nil

            if (CTFontManagerRegisterGraphicsFont(fontRef!,&errorRef) == false) {
                NSLog("Failed to register font - register graphics font Failed - this font may have already been registered in the main bundle.")
            }
        }
        else {
            NSLog("Failed to register font - bundle identifier invalid.")
        }
    }
}