added base Motion class and MotionAnimation class

Motion.xcodeproj/project.pbxproj

@@ -10,6 +10,7 @@
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 		961409AA1E43CF1B00E7BA99 /* Motion+Obj-C.swift in Sources */ = {isa = PBXBuildFile; fileRef = 961409A91E43CF1B00E7BA99 /* Motion+Obj-C.swift */; };
 		961409B61E43D17200E7BA99 /* Motion+Obj-C.swift in Headers */ = {isa = PBXBuildFile; fileRef = 961409A91E43CF1B00E7BA99 /* Motion+Obj-C.swift */; settings = {ATTRIBUTES = (Public, ); }; };
 		961409B61E43D17200E7BA99 /* Motion+Obj-C.swift in Headers */ = {isa = PBXBuildFile; fileRef = 961409A91E43CF1B00E7BA99 /* Motion+Obj-C.swift */; settings = {ATTRIBUTES = (Public, ); }; };
 		961409B81E43D21300E7BA99 /* Motion.h in Headers */ = {isa = PBXBuildFile; fileRef = 96C98DED1E438A5700B22906 /* Motion.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		961409B81E43D21300E7BA99 /* Motion.h in Headers */ = {isa = PBXBuildFile; fileRef = 96C98DED1E438A5700B22906 /* Motion.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		964C153D1EDCF6EA00F0869D /* Motion.swift in Sources */ = {isa = PBXBuildFile; fileRef = 964C153C1EDCF6EA00F0869D /* Motion.swift */; };
 		9657A6AC1EDA1601004461DE /* MotionObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9657A6AB1EDA1601004461DE /* MotionObserver.swift */; };
 		9657A6AC1EDA1601004461DE /* MotionObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9657A6AB1EDA1601004461DE /* MotionObserver.swift */; };
 		9657A6AE1EDA19D8004461DE /* MotionAnimator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9657A6AD1EDA19D8004461DE /* MotionAnimator.swift */; };
 		9657A6AE1EDA19D8004461DE /* MotionAnimator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9657A6AD1EDA19D8004461DE /* MotionAnimator.swift */; };
 		9657A6B31EDA63FC004461DE /* MotionContext.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9657A6B21EDA63FC004461DE /* MotionContext.swift */; };
 		9657A6B31EDA63FC004461DE /* MotionContext.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9657A6B21EDA63FC004461DE /* MotionContext.swift */; };
@@ -21,6 +22,7 @@
 
 
 /* Begin PBXFileReference section */
 /* Begin PBXFileReference section */
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 		961409A91E43CF1B00E7BA99 /* Motion+Obj-C.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "Motion+Obj-C.swift"; sourceTree = "<group>"; };
+		964C153C1EDCF6EA00F0869D /* Motion.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Motion.swift; sourceTree = "<group>"; };
 		9657A6AB1EDA1601004461DE /* MotionObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MotionObserver.swift; sourceTree = "<group>"; };
 		9657A6AB1EDA1601004461DE /* MotionObserver.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MotionObserver.swift; sourceTree = "<group>"; };
 		9657A6AD1EDA19D8004461DE /* MotionAnimator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MotionAnimator.swift; sourceTree = "<group>"; };
 		9657A6AD1EDA19D8004461DE /* MotionAnimator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MotionAnimator.swift; sourceTree = "<group>"; };
 		9657A6B21EDA63FC004461DE /* MotionContext.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MotionContext.swift; sourceTree = "<group>"; };
 		9657A6B21EDA63FC004461DE /* MotionContext.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MotionContext.swift; sourceTree = "<group>"; };
@@ -65,6 +67,7 @@
 				96C98DE21E43809D00B22906 /* LICENSE */,
 				96C98DE21E43809D00B22906 /* LICENSE */,
 				96C98DDD1E424B9000B22906 /* Info.plist */,
 				96C98DDD1E424B9000B22906 /* Info.plist */,
 				96C98DED1E438A5700B22906 /* Motion.h */,
 				96C98DED1E438A5700B22906 /* Motion.h */,
+				964C153C1EDCF6EA00F0869D /* Motion.swift */,
 				96C98DE31E4382B100B22906 /* MotionController.swift */,
 				96C98DE31E4382B100B22906 /* MotionController.swift */,
 				9657A6AB1EDA1601004461DE /* MotionObserver.swift */,
 				9657A6AB1EDA1601004461DE /* MotionObserver.swift */,
 				9657A6B21EDA63FC004461DE /* MotionContext.swift */,
 				9657A6B21EDA63FC004461DE /* MotionContext.swift */,
@@ -163,6 +166,7 @@
 				9657A6AC1EDA1601004461DE /* MotionObserver.swift in Sources */,
 				9657A6AC1EDA1601004461DE /* MotionObserver.swift in Sources */,
 				9657A6B31EDA63FC004461DE /* MotionContext.swift in Sources */,
 				9657A6B31EDA63FC004461DE /* MotionContext.swift in Sources */,
 				961409AA1E43CF1B00E7BA99 /* Motion+Obj-C.swift in Sources */,
 				961409AA1E43CF1B00E7BA99 /* Motion+Obj-C.swift in Sources */,
+				964C153D1EDCF6EA00F0869D /* Motion.swift in Sources */,
 				96C98DE41E4382B100B22906 /* MotionController.swift in Sources */,
 				96C98DE41E4382B100B22906 /* MotionController.swift in Sources */,
 			);
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			runOnlyForDeploymentPostprocessing = 0;

Sources/MotionContext.swift

@@ -31,5 +31,64 @@
 import UIKit
 import UIKit
 
 
 open class MotionContext {
 open class MotionContext {
+    /// A reference to the transition container.
+    fileprivate var transitionContainer: UIView
     
     
+    /// An index source of identifiers to their corresponding view.
+    fileprivate var transitionSourceIdentifierToView = [String: UIView]()
+    
+    /// An index of destination identifiers to their corresponding view.
+    fileprivate var transitionDestinationIdentifierToView = [String: UIView]()
+    
+    /// An index of views to their corresponding snapshot view.
+    fileprivate var transitionSnapshotToView = [UIView: UIView]()
+    
+    /// A reference to the transition from views.
+    fileprivate var fromViews: [UIView]!
+    
+    /// A reference to the transition to views.
+    fileprivate var toViews: [UIView]!
+    
+    /**
+     An initializer that accepts a given transition container view.
+     - Parameter transitionContainer: A UIView.
+     */
+    init(transitionContainer: UIView) {
+        self.transitionContainer = transitionContainer
+    }
+}
+
+extension MotionContext {
+    /**
+     Prepares the source views to their identifiers.
+     - Parameter views: An Array of UIViews.
+     - Parameter identifierIndex: An Dictionary of identifiers to UIViews.
+     */
+    fileprivate func prepare(views: [UIView], identifierIndex: inout [String: UIView]) {
+        for v in views {
+            v.layer.removeAllAnimations()
+            
+            guard transitionContainer.convert(v.bounds, from: v).intersects(transitionContainer.bounds) else {
+                return
+            }
+            
+            if let i = v.motionIdentifier {
+                identifierIndex[i] = v
+            }
+        }
+    }
+}
+
+extension MotionContext {
+    /**
+     Sets the views that will transition from one state to another.
+     - Parameter fromViews: An Array of UIViews.
+     - Parameter toViews: An Array of UIViews.
+     */
+    fileprivate func set(fromViews: [UIView], toViews: [UIView]) {
+        self.fromViews = fromViews
+        self.toViews = toViews
+        prepare(views: fromViews, identifierIndex: &transitionSourceIdentifierToView)
+        prepare(views: toViews, identifierIndex: &transitionDestinationIdentifierToView)
+    }
 }
 }

Sources/MotionController.swift

@@ -116,6 +116,33 @@ open class MotionController: NSObject, MotionSubscriber {
 
 
 extension MotionController {
 extension MotionController {
     /**
     /**
+     Retrieves all the subviews of a given view.
+     - Parameter of view: A UIView.
+     - Returns: An Array of UIViews.
+     */
+    fileprivate func subviews(of view: UIView) -> [UIView] {
+        var views: [UIView] = []
+        subviews(of: view, views: &views)
+        return views
+    }
+    
+    /**
+     Populates an Array of UIViews with the subviews of a given view.
+     - Parameter of view: A UIView.
+     - Returns: An Array of UIViews.
+     */
+    fileprivate func subviews(of view: UIView, views: inout [UIView]) {
+        for v in view.subviews {
+            if nil != v.motionIdentifier {
+                views.append(v)
+            }
+            subviews(of: v, views: &views)
+        }
+    }
+}
+
+extension MotionController {
+    /**
      Handles the animation update for the display link.
      Handles the animation update for the display link.
      - Parameter displayLink: A CADisplayLink.animation
      - Parameter displayLink: A CADisplayLink.animation
      */
      */