issue-2: added completion block to motion animations

Sources/Motion.swift

@@ -235,7 +235,7 @@ extension UIView {
     /**
      Snapshots the view instance for animations during transitions.
      - Parameter afterUpdates: A boolean indicating whether to snapshot the view
-     after a render update, or as is. 
+     after a render update, or as is.
      - Parameter shouldHide: A boolean indicating whether the view should be hidden
      after the snapshot is taken.
      - Returns: A UIView instance that is a snapshot of the given UIView.
@@ -243,6 +243,9 @@ extension UIView {
     open func transitionSnapshot(afterUpdates: Bool, shouldHide: Bool = true) -> UIView {
         isHidden = false
         
+        // Material specific.
+        (self as? PulseableLayer)?.pulseLayer?.isHidden = true
+        
         let oldCornerRadius = layer.cornerRadius
         layer.cornerRadius = 0
         
@@ -288,6 +291,9 @@ extension UIView {
         v.motionTransform = motionTransform
         v.backgroundColor = backgroundColor
         
+        // Material specific.
+        (self as? PulseableLayer)?.pulseLayer?.isHidden = false
+        
         isHidden = shouldHide
         
         return v
@@ -422,9 +428,9 @@ open class Motion: NSObject {
     
     /**
      An initializer to modify the presenting and container state.
-     - Parameter isPresenting: A boolean value indicating if the 
+     - Parameter isPresenting: A boolean value indicating if the
      Motion instance is presenting the view controller.
-     - Parameter isContainer: A boolean value indicating if the 
+     - Parameter isContainer: A boolean value indicating if the
      Motion instance is a container view controller.
      */
     public init(isPresenting: Bool, isContainer: Bool) {
@@ -469,7 +475,6 @@ open class Motion: NSObject {
             if !$0 {
                 DispatchQueue.main.async(execute: block)
             }
-            
             cancelable = nil
         }
         
@@ -524,7 +529,6 @@ extension Motion: UIViewControllerAnimatedTransitioning {
     @objc(animateTransition:)
     open func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
         self.transitionContext = transitionContext
-        
         fromViewController.motionDelegate?.motion?(motion: self, willTransition: fromView, toView: toView)
         
         Motion.delay(delayTransitionByTimeInterval) { [weak self] in
@@ -658,7 +662,7 @@ extension Motion {
                 snapshotChildGroup.timingFunction = MotionAnimationTimingFunctionToValue(timingFunction: tf)
                 
                 snapshot.animate(snapshotGroup)
-                snapshot.subviews.first!.animate(snapshotChildGroup)
+                snapshot.subviews.first?.animate(snapshotChildGroup)
             }
         }
     }

Sources/MotionAnimation.swift

@@ -93,6 +93,9 @@ public enum MotionAnimation {
     case size(width: CGFloat, height: CGFloat)
 }
 
+@available(iOS 10, *)
+extension CALayer: CAAnimationDelegate {}
+
 extension CALayer {
     
     /**
@@ -111,7 +114,10 @@ extension CALayer {
      */
     open func animate(_ animations: [CAAnimation]) {
         for animation in animations {
-            animation.delegate = self
+            if nil == animation.delegate {
+                animation.delegate = self
+            }
+            
             if let a = animation as? CABasicAnimation {
                 a.fromValue = (presentation() ?? self).value(forKeyPath: a.keyPath!)
             }
@@ -126,6 +132,8 @@ extension CALayer {
         }
     }
     
+    open func animationDidStart(_ anim: CAAnimation) {}
+    
     /**
      A delegation function that is executed when the backing layer stops
      running an animation.
@@ -134,9 +142,9 @@ extension CALayer {
      because it was completed or interrupted. True if completed, false
      if interrupted.
      */
-    open func animationDidStop(_ animation: CAAnimation, finished flag: Bool) {
-        guard let a = animation as? CAPropertyAnimation else {
-            if let a = (animation as? CAAnimationGroup)?.animations {
+    open func animationDidStop(_ anim: CAAnimation, finished flag: Bool) {
+        guard let a = anim as? CAPropertyAnimation else {
+            if let a = (anim as? CAAnimationGroup)?.animations {
                 for x in a {
                     animationDidStop(x, finished: true)
                 }
@@ -171,9 +179,10 @@ extension CALayer {
     /**
      A function that accepts an Array of MotionAnimation values and executes them.
      - Parameter animations: An Array of MotionAnimation values.
+     - Parameter completion: An optional completion block.
      */
-    open func motion(_ animations: [MotionAnimation]) {
-        motion(delay: 0, duration: 0.35, timingFunction: .easeInEaseOut, animations: animations)
+    open func motion(_ animations: [MotionAnimation], completion: (() -> Void)? = nil) {
+        motion(delay: 0, duration: 0.35, timingFunction: .easeInEaseOut, animations: animations, completion: completion)
     }
     
     /**
@@ -182,8 +191,9 @@ extension CALayer {
      - Parameter duration: The animation duration TimeInterval.
      - Parameter timingFunction: The animation MotionAnimationTimingFunction.
      - Parameter animations: An Array of MotionAnimations.
+     - Parameter completion: An optional completion block.
      */
-    fileprivate func motion(delay: TimeInterval, duration: TimeInterval, timingFunction: MotionAnimationTimingFunction, animations: [MotionAnimation]) {
+    fileprivate func motion(delay: TimeInterval, duration: TimeInterval, timingFunction: MotionAnimationTimingFunction, animations: [MotionAnimation], completion: (() -> Void)? = nil) {
         var t = delay
         
         for v in animations {
@@ -311,13 +321,16 @@ extension CALayer {
             g.timingFunction = MotionAnimationTimingFunctionToValue(timingFunction: tf)
             
             s.animate(g)
+            
+            guard let execute = completion else {
+                return
+            }
+            
+            Motion.delay(d, execute: execute)
         }
     }
 }
 
-@available(iOS 10, *)
-extension CALayer: CAAnimationDelegate {}
-
 extension UIView {
     /// Computes the rotation of the view.
     open var motionRotationAngle: CGFloat {
@@ -385,9 +398,10 @@ extension UIView {
      A function that accepts an Array of MotionAnimation values and executes
      them on the view's backing layer.
      - Parameter animations: An Array of MotionAnimation values.
+     - Parameter completion: An optional completion block.
      */
-    open func motion(_ animations: [MotionAnimation]) {
-        layer.motion(animations)
+    open func motion(_ animations: [MotionAnimation], completion: (() -> Void)? = nil) {
+        layer.motion(animations, completion: completion)
     }
 }