Tree structure with swift 3

https://www.codeproject.com/Tips/1101832/Tree-View-in-Swift-For-iOS

Longpress event in swift 3

override func viewDidLoad() {

        super.viewDidLoad() 

var longPressGesture : UILongPressGestureRecognizer!

 longPressGesture = UILongPressGestureRecognizer(target: self, action: #selector(MainView.handleLongGesture))

        self.view?.addGestureRecognizer(longPressGesture)

  }

    func handleLongGesture() {

        

        print("long press")

       // do Actions 

        }

    }

Solve Gradient covers the background view in swift 3

Apply Gradient to View

class Testing: UIViewController {

    

   

    override func viewDidLoad() {

        super.viewDidLoad()

       setGradientBackground()

    }

    

    func setGradientBackground() {

        let colorTop =  UIColor(red: 255.0/255.0, green: 149.0/255.0, blue: 0.0/255.0, alpha: 1.0).cgColor

        let colorBottom = UIColor(red: 255.0/255.0, green: 94.0/255.0, blue: 58.0/255.0, alpha: 1.0).cgColor

        

        let gradientLayer = CAGradientLayer()

        gradientLayer.colors = [ colorTop, colorBottom]

        gradientLayer.locations = [ 0.0, 1.0]

        gradientLayer.frame = self.view.bounds

        

        self.view.layer.addSublayer(gradientLayer) // --> This will hides the background view

    }

-->Some times it will apply full view,  better to apply gradient in viewDidLoad()

replace self.view.layer.addSublayer(gradientLayer) with 

self.view.layer.insertSublayer(gradientLayer, at: 0), this will put the layer "below" all others 

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background gradient to fill Landscape mode

-> some times gradient view will not cover total view when rotate screen .

we can solve this one to add below code

override func willAnimateRotation(to toInterfaceOrientation: UIInterfaceOrientation, duration: TimeInterval) {

        self.view.layer.sublayers?.first?.frame = self.view.bounds

}