christopherkarani

protocol CallBackDelegate {
    func somethingHappened()
}

class FirstClass  {
    var delegate : CallBackDelegate?
    func doSomething() {
        delegate?.somethingHappened()
    }
}

christopherkarani

//: A SpriteKit based Playground

import PlaygroundSupport
import SpriteKit

extension CGPoint {
    static func CenterOfScene(_ scene: GameScene) -> CGPoint {
        return CGPoint(x: scene.size.width / 2, y: scene.size.height / 2)
    }
}

christopherkarani

protocol SomeProtocol {
    var required: String { get }
    var optional: String? { get }
}

christopherkarani

extension SomeProtocol {
    var optional: String? { return nil }
}

christopherkarani

struct ConformsWithoutOptional {
    let required: String
}

struct ConformsWithOptional {
    let required: String
    let optional: String?
}

christopherkarani

extension Date {

    func timeAgoSinceDate(date:NSDate, numericDates:Bool) -> String {
        let calendar = NSCalendar.current
        let unitFlags: Set<Calendar.Component> = [.minute, .hour, .day, .weekOfYear, .month, .year, .second]
        let now = NSDate()
        let earliest = now.earlierDate(date as Date)
        let latest = (earliest == now as Date) ? date : now
        let components = calendar.dateComponents(unitFlags, from: earliest as Date,  to: latest as Date)
        

christopherkarani

    func estimatedFrame(forText text: String) -> CGRect {
        // width is same as cell.texView width
        //height is an arbitrary larg value
        let size = CGSize(width: 200, height: 1000)
        let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
        let attributes = [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 16)]
        return  NSString(string: text).boundingRect(with: size, options: options, attributes: attributes, context: nil)
    }

christopherkarani

extension ChatController {
    func setupKeyboardObservers() {
        NotificationCenter.default.addObserver(self, selector: #selector(handleKeyboardWillShow(withNotification:)), name: .UIKeyboardWillShow, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(handleKeyboardWillHide(withNotification:)), name: .UIKeyboardDidHide, object: nil)
    }
    @objc func handleKeyboardWillShow(withNotification notification: Notification) {
        let keyboardFrame = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as AnyObject).cgRectValue
        let keyboardDuration = (notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as AnyObject).doubleValue
        containerViewBottomAnchor?.constant = -(keyboardFrame?.height)! // bottomAnchor + constant
        UIView.animate(withDuration: keyboardDuration!) {

christopherkarani

var numbers = [Int]()

for x in 1...100 {
    numbers.append(x)
}

var num = [1,2,4,6,8,9,11,13,16,17,20]

func binarySearch(for searchValue: Int, withDatasoucre datasource: [Int]) -> Bool {
    var firstIndex = 0

christopherkarani

func isValidEmail(testStr:String) -> Bool {        
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"

    let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
    return emailTest.evaluate(with: testStr)
}