NotificationBar & NavigationBar Extension

NotificationBar + extension.swift

/**
 NotificationBar presents status of app's internal workflow visually.

 In case of server disconnection... or receiving a new message... etc
 */
class NotificationBar: UIView{
    
    private let messageLabel: UILabel = UILabel()
    
    // You can change the mark as you wish, If it can be presented by Unicode text.
    // If you want to present an image, try it your self.
    private let checkMark = "✓ "
    private let xMark = "✗ "
    
    // Set this value as positive color.
    let positiveColor = UIColor(red: 12/255, green: 206/255, blue: 55/255, alpha: 0.935)
    
    // Set this value as negative color.
    let negativeColor = UIColor(red: 206/255, green: 11/255, blue: 37/255, alpha: 0.935)
    
    // If you set this, backgroundColor will be change refers to its value.
    var isPositive: Bool = true{
        didSet{
            switch isPositive{
            case true:
                self.backgroundColor = positiveColor
            case false:
                self.backgroundColor = negativeColor
            }
        }
    }
    
    // If you set this, presenting text message will be changed.
    var message: String?{
        didSet{
            if isPositive{
                messageLabel.text = checkMark + (message ?? "")
            }else{
                messageLabel.text = xMark + (message ?? "")
            }
        }
    }
    
    override func draw(_ rect: CGRect) {
        // Customize the label here.
        messageLabel.frame = rect
        messageLabel.font = UIFont.systemFont(ofSize: 13, weight: .light)
        messageLabel.textColor = .white
        messageLabel.textAlignment = .center
        
        self.addSubview(messageLabel)
    }
    
}

// - MARK : UINavigationBar Extension
//   There are many ways of using NotificationBar, this is a sample of it. 
extension UINavigationBar{
        
    /**
     Set this value to resize NotificationBar's presenting Size. 
     '32' is the best size to shown, but make your choice!
     */
    private var defaultNotificationBarSize: CGFloat { return 32 }
    
    /**
     Presents notification bar with given message.
     */
    func showNotification(message: String?, isPositive: Bool){
        let bar = NotificationBar(frame: CGRect(x: self.frame.origin.x, y: self.frame.maxY - (defaultNotificationBarSize*1.6), width: self.frame.width, height: defaultNotificationBarSize))
        
        bar.layer.zPosition = self.layer.zPosition - 1
        
        bar.isPositive = isPositive
        bar.message = message
        
        self.addSubview(bar)
        
        UIView.animate(withDuration: 0.5, delay: 0, options: [.curveEaseInOut], animations: {
            bar.frame.origin.y += self.defaultNotificationBarSize
        }) { _ in
            UIView.animate(withDuration: 0.5, delay: 2, options: [.curveEaseInOut], animations: {
                bar.frame.origin.y -= self.defaultNotificationBarSize
            }, completion: { _ in
                bar.removeFromSuperview()
            })
        }
    }
}

Sample usage of NotificationBar