[LayoutSpecExamples] Added swift counterpart. (#2576)

* [LayoutSpecExamples] Added swift counterpart.

* Fixed copyright text.

examples/LayoutSpecExamples-Swift/Sample/Utilities.swift

@@ -0,0 +1,93 @@
+//
+//  Utilities.swift
+//  Sample
+//
+//  Copyright (c) 2014-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+//  FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+//  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+//  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+
+import UIKit
+import Foundation
+
+extension UIColor {
+
+  static func darkBlueColor() -> UIColor {
+    return UIColor(red: 18.0/255.0, green: 86.0/255.0, blue: 136.0/255.0, alpha: 1.0)
+  }
+
+  static func lightBlueColor() -> UIColor {
+    return UIColor(red: 0.0, green: 122.0/255.0, blue: 1.0, alpha: 1.0)
+  }
+
+  static func duskColor() -> UIColor {
+    return UIColor(red: 255/255.0, green: 181/255.0, blue: 68/255.0, alpha: 1.0)
+  }
+
+  static func customOrangeColor() -> UIColor {
+    return UIColor(red: 40/255.0, green: 43/255.0, blue: 53/255.0, alpha: 1.0)
+  }
+
+}
+
+extension UIImage {
+
+  func makeCircularImage(size: CGSize, borderWidth width: CGFloat) -> UIImage {
+    // make a CGRect with the image's size
+    let circleRect = CGRect(origin: .zero, size: size)
+
+    // begin the image context since we're not in a drawRect:
+    UIGraphicsBeginImageContextWithOptions(circleRect.size, false, 0)
+
+    // create a UIBezierPath circle
+    let circle = UIBezierPath(roundedRect: circleRect, cornerRadius: circleRect.size.width * 0.5)
+
+    // clip to the circle
+    circle.addClip()
+
+    UIColor.white.set()
+    circle.fill()
+
+    // draw the image in the circleRect *AFTER* the context is clipped
+    self.draw(in: circleRect)
+
+    // create a border (for white background pictures)
+    if width > 0 {
+      circle.lineWidth = width;
+      UIColor.white.set()
+      circle.stroke()
+    }
+
+    // get an image from the image context
+    let roundedImage = UIGraphicsGetImageFromCurrentImageContext();
+
+    // end the image context since we're not in a drawRect:
+    UIGraphicsEndImageContext();
+
+    return roundedImage ?? self
+  }
+
+}
+
+extension NSAttributedString {
+
+  static func attributedString(string: String?, fontSize size: CGFloat, color: UIColor?) -> NSAttributedString? {
+    guard let string = string else { return nil }
+
+    let attributes = [NSForegroundColorAttributeName: color ?? UIColor.black,
+                      NSFontAttributeName: UIFont.boldSystemFont(ofSize: size)]
+
+    let attributedString = NSMutableAttributedString(string: string, attributes: attributes)
+
+    return attributedString
+  }
+  
+}