Mixins.swift

protocol NavigationBarTitleViewMixin {
    
    func showAppLogoInTitleView()
}

extension NavigationBarTitleViewMixin where Self:UIViewController {
    
    func showAppLogoInTitleView() {
        let logoView = UIImageView(image: UIImage(named:"navbar_brand"))
        self.navigationController!.navigationBar.setTitleVerticalPositionAdjustment(-6.0, forBarMetrics: .Default)
        self.navigationItem.titleView = logoView
    }
}