Adds copy methods to AudioPlayer, Gradient and Vector

C4/Core/Vector.swift

@@ -95,6 +95,14 @@ public struct Vector: Equatable, CustomStringConvertible {
         z = 0
     }
 
+    ///  Initializes a Vector from another Vector
+    ///  - parameter copy: a previously initialized Vector
+    public init(copy original: Vector) {
+        x = original.x
+        y = original.y
+        z = original.z
+    }
+
     /// The polar representation magnitude of the vector.
     /// ````
     /// let v = Vector(x: 2.0, y: 1.0, z: 0.0)

C4/UI/AudioPlayer.swift

@@ -40,6 +40,8 @@ import AVFoundation
 public class AudioPlayer: NSObject, AVAudioPlayerDelegate {
     internal var player: AVAudioPlayer!
 
+    var filename: String!
+
     /// Initializes a new audio player from a given file name
     /// ````
     /// let ap = AudioPlayer("audioTrackFileName")
@@ -66,6 +68,11 @@ public class AudioPlayer: NSObject, AVAudioPlayerDelegate {
 
         self.player = player
         player.delegate = self
+        self.filename = name
+    }
+
+    public convenience init?(copy original: AudioPlayer) {
+        self.init(original.filename)
     }
 
     /// Plays a sound asynchronously.

C4/UI/Gradient.swift

@@ -36,7 +36,7 @@ public class Gradient: View {
         return gradientView.gradientLayer
     }
 
-    var gradientView: GradientView {
+    internal var gradientView: GradientView {
         return view as! GradientView // swiftlint:disable:this force_cast
     }
 
@@ -101,18 +101,38 @@ public class Gradient: View {
         }
     }
 
+    /// The current rotation value of the view. Animatable.
+    /// - returns: A Double value representing the cumulative rotation of the view, measured in Radians.
+    public override var rotation: Double {
+        get {
+            if let number = gradientLayer.valueForKeyPath(Layer.rotationKey) as? NSNumber {
+                return number.doubleValue
+            }
+            return  0.0
+        }
+        set {
+            gradientLayer.setValue(newValue, forKeyPath: Layer.rotationKey)
+        }
+    }
+
     ///  Initializes a new Gradient.
     ///
     ///  - parameter frame:     A Rect that defines the frame for the gradient's view.
     ///  - parameter colors:    An array of Color objects that define the gradient's colors. Defaults to [C4Blue, C4Purple].
     ///  - parameter locations: An array of Double values that define the location of each gradient stop. Defaults to [0,1]
-    public convenience init(frame: Rect, colors: [Color] = [C4Blue, C4Purple], locations: [Double] = [0, 1]) {
-        assert(colors.count == locations.count, "colors and locations need to have the same number of elements")
+    public convenience override init(frame: Rect) {
         self.init()
         self.view = GradientView(frame: CGRect(frame))
-        self.colors = colors
-        self.locations = locations
+        self.colors = [C4Pink, C4Purple]
+        self.locations = [0, 1]
         self.startPoint = Point()
         self.endPoint = Point(1, 0)
     }
+
+    public convenience init(copy original: Gradient) {
+        self.init(frame: original.frame)
+        self.colors = original.colors
+        self.locations = original.locations
+        copyViewStyle(original)
+    }
 }

C4/UI/GradientLayer.swift

@@ -26,6 +26,14 @@ public class GradientLayer: CAGradientLayer {
     /// This value can be set globally, after which changes to any shape's properties will be immediate.
     public static var disableActions = true
 
+    private var _rotation = 0.0
+
+    /// The value of the receiver's current rotation state.
+    /// This value is cumulative, and can represent values beyong +/- π
+    public dynamic var rotation: Double {
+        return _rotation
+    }
+
     ///  This method searches for the given action object of the layer. Actions define dynamic behaviors for a layer. For example, the animatable properties of a layer typically have corresponding action objects to initiate the actual animations. When that property changes, the layer looks for the action object associated with the property name and executes it. You can also associate custom action objects with your layer to implement app-specific actions.
     ///
     ///  - parameter key: The identifier of the action.