Fixed an issue where using child view controllers would break and transition animations.

Motion.podspec

 Pod::Spec.new do |s|
 Pod::Spec.new do |s|
   s.name = 'Motion'
   s.name = 'Motion'
-  s.version = '1.0.7'
+  s.version = '1.0.8'
   s.license = 'BSD-3-Clause'
   s.license = 'BSD-3-Clause'
   s.summary = 'Seamless animations and transitions in Swift.'
   s.summary = 'Seamless animations and transitions in Swift.'
   s.homepage = 'http://cosmicmind.com'
   s.homepage = 'http://cosmicmind.com'

Sources/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
 	<key>CFBundleShortVersionString</key>
-	<string>1.0.7</string>
+	<string>1.0.8</string>
 	<key>CFBundleVersion</key>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 	<key>NSPrincipalClass</key>
 	<key>NSPrincipalClass</key>

Sources/Motion.swift

@@ -173,7 +173,7 @@ extension UIViewController {
      - Returns: An optional UIViewControllerAnimatedTransitioning.
      - Returns: An optional UIViewControllerAnimatedTransitioning.
      */
      */
     open func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
     open func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
-        return isMotionEnabled ? Motion(isPresenting: true, isContainer: false) : nil
+        return isMotionEnabled ? PresentingMotion(isPresenting: true, isContainer: false) : nil
     }
     }
     
     
     /**
     /**
@@ -182,7 +182,7 @@ extension UIViewController {
      - Returns: An optional UIViewControllerAnimatedTransitioning.
      - Returns: An optional UIViewControllerAnimatedTransitioning.
      */
      */
     open func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
     open func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
-        return isMotionEnabled ? Motion(isPresenting: false, isContainer: false) : nil
+        return isMotionEnabled ? DismissingMotion(isPresenting: true, isContainer: false) : nil
     }
     }
     
     
     /**
     /**
@@ -330,9 +330,15 @@ public protocol MotionDelegate {
     
     
     @objc
     @objc
     optional func motionDelayTransitionByTimeInterval(motion: Motion) -> TimeInterval
     optional func motionDelayTransitionByTimeInterval(motion: Motion) -> TimeInterval
+    
+    @objc
+    optional func motionWillBeginPresentation(presentationController: UIPresentationController)
+    
+    @objc
+    optional func motionAnimateAlongsideTransition(presentationController: UIPresentationController)
 }
 }
 
 
-open class Motion: NSObject {
+open class MotionAnimator: NSObject {
     /// A boolean indicating whether Motion is presenting a view controller.
     /// A boolean indicating whether Motion is presenting a view controller.
     open fileprivate(set) var isPresenting: Bool
     open fileprivate(set) var isPresenting: Bool
     
     
@@ -396,11 +402,6 @@ open class Motion: NSObject {
         return Motion.subviews(of: fromView)
         return Motion.subviews(of: fromView)
     }
     }
     
     
-    /// A time value to delay the transition animation by.
-    fileprivate var delayTransitionByTimeInterval: TimeInterval {
-        return fromViewController.motionDelegate?.motionDelayTransitionByTimeInterval?(motion: self) ?? 0
-    }
-    
     /// The default initializer.
     /// The default initializer.
     public override init() {
     public override init() {
         isPresenting = false
         isPresenting = false
@@ -503,7 +504,7 @@ open class Motion: NSObject {
     }
     }
 }
 }
 
 
-extension Motion: UIViewControllerAnimatedTransitioning {
+extension MotionAnimator: UIViewControllerAnimatedTransitioning {
     /**
     /**
      The animation method that is used to coordinate the transition.
      The animation method that is used to coordinate the transition.
      - Parameter using transitionContext: A UIViewControllerContextTransitioning.
      - Parameter using transitionContext: A UIViewControllerContextTransitioning.
@@ -511,21 +512,6 @@ extension Motion: UIViewControllerAnimatedTransitioning {
     @objc(animateTransition:)
     @objc(animateTransition:)
     open func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
     open func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
         self.transitionContext = transitionContext
         self.transitionContext = transitionContext
-        fromViewController.motionDelegate?.motion?(motion: self, willTransition: fromView, toView: toView)
-        
-        Motion.delay(delayTransitionByTimeInterval) { [weak self] in
-            guard let s = self else {
-                return
-            }
-            
-            s.prepareContainerView()
-            s.prepareTransitionSnapshot()
-            s.prepareTransitionPairs()
-            s.prepareTransitionView()
-            s.prepareTransitionBackgroundView()
-            s.prepareToView()
-            s.prepareTransitionAnimation()
-        }
     }
     }
     
     
     /**
     /**
@@ -539,66 +525,7 @@ extension Motion: UIViewControllerAnimatedTransitioning {
     }
     }
 }
 }
 
 
-extension Motion {
-    /// Prepares the containerView.
-    fileprivate func prepareContainerView() {
-        containerView = transitionContext.containerView
-    }
-    
-    /// Prepares the transitionSnapshot.
-    fileprivate func prepareTransitionSnapshot() {
-        transitionSnapshot = fromView.transitionSnapshot(afterUpdates: true, shouldHide: false)
-        transitionSnapshot.frame = fromView.frame
-        containerView.insertSubview(transitionSnapshot, aboveSubview: fromView)
-    }
-    
-    /// Prepares the transitionPairs.
-    fileprivate func prepareTransitionPairs() {
-        for from in fromSubviews {
-            for to in toSubviews {
-                guard to.motionIdentifier == from.motionIdentifier else {
-                    continue
-                }
-                transitionPairs.append((from, to))
-            }
-        }
-    }
-    
-    /// Prepares the transitionView.
-    fileprivate func prepareTransitionView() {
-        transitionView.frame = toView.bounds
-        transitionView.isUserInteractionEnabled = false
-        containerView.insertSubview(transitionView, belowSubview: transitionSnapshot)
-    }
-    
-    /// Prepares the transitionBackgroundView.
-    fileprivate func prepareTransitionBackgroundView() {
-        transitionBackgroundView.backgroundColor = isPresenting ? .clear : fromView.backgroundColor ?? .clear
-        transitionBackgroundView.frame = transitionView.bounds
-        transitionView.addSubview(transitionBackgroundView)
-    }
-    
-    /// Prepares the toView.
-    fileprivate func prepareToView() {
-        toView.isHidden = isPresenting
-        containerView.insertSubview(toView, belowSubview: transitionView)
-        
-        toView.frame = fromView.frame
-        toView.updateConstraints()
-        toView.setNeedsLayout()
-        toView.layoutIfNeeded()
-    }
-    
-    /// Prepares the transition animation.
-    fileprivate func prepareTransitionAnimation() {
-        addTransitionAnimations()
-        addBackgroundAnimation()
-        cleanUpAnimation()
-        removeTransitionSnapshot()
-    }
-}
-
-extension Motion {
+extension MotionAnimator {
     /// Adds the available transition animations.
     /// Adds the available transition animations.
     fileprivate func addTransitionAnimations() {
     fileprivate func addTransitionAnimations() {
         for (from, to) in transitionPairs {
         for (from, to) in transitionPairs {
@@ -674,26 +601,7 @@ extension Motion {
     }
     }
 }
 }
 
 
-extension Motion {
-    /**
-     Creates a CAAnimationGroup.
-     - Parameter animations: An Array of CAAnimation objects.
-     - Parameter timingFunction: An MotionAnimationTimingFunction value.
-     - Parameter duration: An animation duration time for the group.
-     - Returns: A CAAnimationGroup.
-     */
-    open class func animate(group animations: [CAAnimation], timingFunction: MotionAnimationTimingFunction = .easeInEaseOut, duration: CFTimeInterval = 0.5) -> CAAnimationGroup {
-        let group = CAAnimationGroup()
-        group.fillMode = MotionAnimationFillModeToValue(mode: .forwards)
-        group.isRemovedOnCompletion = false
-        group.animations = animations
-        group.duration = duration
-        group.timingFunction = MotionAnimationTimingFunctionToValue(timingFunction: timingFunction)
-        return group
-    }
-}
-
-extension Motion {
+extension MotionAnimator {
     /**
     /**
      Calculates the animation delay time based on the given Array of MotionAnimations.
      Calculates the animation delay time based on the given Array of MotionAnimations.
      - Parameter animations: An Array of MotionAnimations.
      - Parameter animations: An Array of MotionAnimations.
@@ -752,6 +660,115 @@ extension Motion {
     }
     }
 }
 }
 
 
+open class Motion: MotionAnimator {
+    /// A time value to delay the transition animation by.
+    fileprivate var delayTransitionByTimeInterval: TimeInterval {
+        return fromViewController.motionDelegate?.motionDelayTransitionByTimeInterval?(motion: self) ?? 0
+    }
+    
+    /**
+     The animation method that is used to coordinate the transition.
+     - Parameter using transitionContext: A UIViewControllerContextTransitioning.
+     */
+    @objc(animateTransition:)
+    open override func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
+        super.animateTransition(using: transitionContext)
+        fromViewController.motionDelegate?.motion?(motion: self, willTransition: fromView, toView: toView)
+        
+        Motion.delay(delayTransitionByTimeInterval) { [weak self] in
+            guard let s = self else {
+                return
+            }
+            
+            s.prepareContainerView()
+            s.prepareTransitionSnapshot()
+            s.prepareTransitionPairs()
+            s.prepareTransitionView()
+            s.prepareTransitionBackgroundView()
+            s.prepareToView()
+            s.prepareTransitionAnimation()
+        }
+    }
+    
+    /// Prepares the toView.
+    fileprivate func prepareToView() {
+        toView.isHidden = isPresenting
+        containerView.insertSubview(toView, belowSubview: transitionView)
+        
+        toView.frame = fromView.frame
+        toView.updateConstraints()
+        toView.setNeedsLayout()
+        toView.layoutIfNeeded()
+    }
+}
+
+extension Motion {
+    /// Prepares the containerView.
+    fileprivate func prepareContainerView() {
+        containerView = transitionContext.containerView
+    }
+    
+    /// Prepares the transitionSnapshot.
+    fileprivate func prepareTransitionSnapshot() {
+        transitionSnapshot = fromView.transitionSnapshot(afterUpdates: true, shouldHide: false)
+        transitionSnapshot.frame = fromView.frame
+        containerView.addSubview(transitionSnapshot)
+    }
+    
+    /// Prepares the transitionPairs.
+    fileprivate func prepareTransitionPairs() {
+        for from in fromSubviews {
+            for to in toSubviews {
+                guard to.motionIdentifier == from.motionIdentifier else {
+                    continue
+                }
+                transitionPairs.append((from, to))
+            }
+        }
+    }
+    
+    /// Prepares the transitionView.
+    fileprivate func prepareTransitionView() {
+        transitionView.frame = toView.bounds
+        transitionView.isUserInteractionEnabled = false
+        containerView.insertSubview(transitionView, belowSubview: transitionSnapshot)
+    }
+    
+    /// Prepares the transitionBackgroundView.
+    fileprivate func prepareTransitionBackgroundView() {
+        transitionBackgroundView.backgroundColor = isPresenting ? .clear : fromView.backgroundColor ?? .clear
+        transitionBackgroundView.frame = transitionView.bounds
+        transitionView.addSubview(transitionBackgroundView)
+    }
+    
+    /// Prepares the transition animation.
+    fileprivate func prepareTransitionAnimation() {
+        addTransitionAnimations()
+        addBackgroundAnimation()
+        cleanUpAnimation()
+        removeTransitionSnapshot()
+    }
+}
+
+extension Motion {
+    /**
+     Creates a CAAnimationGroup.
+     - Parameter animations: An Array of CAAnimation objects.
+     - Parameter timingFunction: An MotionAnimationTimingFunction value.
+     - Parameter duration: An animation duration time for the group.
+     - Returns: A CAAnimationGroup.
+     */
+    open class func animate(group animations: [CAAnimation], timingFunction: MotionAnimationTimingFunction = .easeInEaseOut, duration: CFTimeInterval = 0.5) -> CAAnimationGroup {
+        let group = CAAnimationGroup()
+        group.fillMode = MotionAnimationFillModeToValue(mode: .forwards)
+        group.isRemovedOnCompletion = false
+        group.animations = animations
+        group.duration = duration
+        group.timingFunction = MotionAnimationTimingFunctionToValue(timingFunction: timingFunction)
+        return group
+    }
+}
+
 extension Motion {
 extension Motion {
     /// Cleans up the animation transition.
     /// Cleans up the animation transition.
     fileprivate func cleanUpAnimation() {
     fileprivate func cleanUpAnimation() {
@@ -798,3 +815,17 @@ extension Motion {
         transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
         transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
     }
     }
 }
 }
+
+open class PresentingMotion: Motion {}
+
+open class DismissingMotion: Motion {
+    /// Prepares the toView.
+    fileprivate override func prepareToView() {
+        toView.isHidden = true
+        toView.frame = fromView.frame
+        toView.updateConstraints()
+        toView.setNeedsLayout()
+        toView.layoutIfNeeded()
+    }
+    
+}