How to Access a Shadowed Top Level Function in Swift

Is it possible to access a shadowed top level function in Swift?

You can prepend the module name, in this case Swift:

extension Int {
    func clamp(left: Int, right: Int) -> Int {
        return Swift.min(Swift.max(self, left), right)
    }
}

And just for fun: You get the same result with

extension Int {
    func clamp(left: Int, right: Int) -> Int {
        return (left ... right).clamp(self ... self).start
    }
}

using the clamp() method from ClosedInterval.

add Shadow on UIView using swift 3

CODE SNIPPET:

extension UIView {

  // OUTPUT 1
  func dropShadow(scale: Bool = true) {
    layer.masksToBounds = false
    layer.shadowColor = UIColor.black.cgColor
    layer.shadowOpacity = 0.5
    layer.shadowOffset = CGSize(width: -1, height: 1)
    layer.shadowRadius = 1

    layer.shadowPath = UIBezierPath(rect: bounds).cgPath
    layer.shouldRasterize = true
    layer.rasterizationScale = scale ? UIScreen.main.scale : 1
  }

  // OUTPUT 2
  func dropShadow(color: UIColor, opacity: Float = 0.5, offSet: CGSize, radius: CGFloat = 1, scale: Bool = true) {
    layer.masksToBounds = false
    layer.shadowColor = color.cgColor
    layer.shadowOpacity = opacity
    layer.shadowOffset = offSet
    layer.shadowRadius = radius

    layer.shadowPath = UIBezierPath(rect: self.bounds).cgPath
    layer.shouldRasterize = true
    layer.rasterizationScale = scale ? UIScreen.main.scale : 1
  }
}

NOTE: If you don't pass any parameter to that function, then the scale argument will be true by default. You can define a default value for any parameter in a function by assigning a value to the parameter after that parameter’s type. If a default value is defined, you can omit that parameter when calling the function.

OUTPUT 1:

shadowView.dropShadow()

OUTPUT 2:

shadowView.dropShadow(color: .red, opacity: 1, offSet: CGSize(width: -1, height: 1), radius: 3, scale: true)

layer.shouldRasterize = true will make the shadow static and cause a shadow for the initial state of the UIView. So I would recommend not to use layer.shouldRasterize = true in dynamic layouts like view inside a UITableViewCell.

Swift How to DRY code in variable closures?

You can create a function and reuse it

func descriptionTextView(with text: String) -> UITextView {
    let textView = UITextView()
    let shadow = NSShadow()
    shadow.shadowColor = UIColor.white
    shadow.shadowOffset = CGSize(width: 1, height: 1)
    let attributes: [NSAttributedString.Key: Any] = [
        .font: UIFont.init(name: "Marker felt", size: 25)!,
        .foregroundColor: UIColor.init(red: 91.0/255.0, green: 91.0/255.0, blue: 91.0/255.0, alpha: 1.0),
        .shadow: shadow
    ]
    let attributedText = NSAttributedString(string: text, attributes: attributes)
    textView.attributedText = attributedText
    textView.textAlignment = .center
    textView.isEditable = false
    textView.isScrollEnabled = false
    textView.isSelectable = false
    textView.translatesAutoresizingMaskIntoConstraints = false
    textView.backgroundColor = .clear
    return textView
}

lazy var descriptionTextViewOne: UITextView = descriptionTextView(with: "Tap anywhere to start\nyour day right!")

lazy var descriptionTextViewTwo: UITextView = descriptionTextView(with: "A happy video a day\nmakes the heartache\ngo away.")

How do I get and store an initial value of a property of a UIView?

You cannot declare it as a class level property because it won't be created until the ViewController is instantiated. I think what you want to do is as follows.

//instantiate with an initial value of 0.0 
public var inputRest : CGFloat = 0.0 

override func viewDidLoad() {
    super.viewDidLoad()

    //you can do this here, because the userInputView will have been created
    self.inputRest = self.userInputView.frame.origin.y
}

This is an inherent limitation of ViewControllers which are instantiated from a storyboard not being able to have let properties which can only be defined once. There are ways around this by overwriting the constructor used to create the view controller from the coder, but it's a lot of work, not easy to read, and very much a lot of work for nothing.

Fix error in Swift simd library (and missing documentation?)

float2 already has a min method that takes no arguments. (There is an explanation for the methods when you choose to go to their definition in Xcode)

Try using Swift.min to explicitly call swift's implementation

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