updated to Motion.async and partial update on TabsController lifecycle

Sources/iOS/Layout.swift

@@ -635,7 +635,7 @@ fileprivate extension Layout {
      - Parameter for view: A UIView.
      */
     class func updateConstraints(for view: UIView) {
-        DispatchQueue.main.async {
+        Motion.async {
             view.setNeedsLayout()
             view.layoutIfNeeded()
             view.updateConstraintsIfNeeded()

Sources/iOS/Material+UIImage.swift

@@ -30,6 +30,7 @@
 
 import UIKit
 import Accelerate
+import Motion
 
 @objc(ImageFormat)
 public enum ImageFormat: Int {
@@ -198,7 +199,7 @@ extension UIImage {
      */
     open class func contentsOfURL(url: URL, completion: @escaping ((UIImage?, Error?) -> Void)) {
         URLSession.shared.dataTask(with: URLRequest(url: url)) { [completion = completion] (data: Data?, response: URLResponse?, error: Error?) in
-            DispatchQueue.main.async {
+            Motion.async {
                 if let v = error {
                     completion(nil, v)
                 } else if let v = data {

Sources/iOS/NavigationDrawerController.swift

@@ -29,6 +29,7 @@
  */
 
 import UIKit
+import Motion
 
 @objc(NavigationDrawerPosition)
 public enum NavigationDrawerPosition: Int {
@@ -863,7 +864,7 @@ open class NavigationDrawerController: TransitionController {
 	
 	/// Shows the statusBar.
 	fileprivate func showStatusBar() {
-        DispatchQueue.main.async { [weak self] in
+        Motion.async { [weak self] in
             guard let s = self else {
                 return
             }
@@ -884,7 +885,7 @@ open class NavigationDrawerController: TransitionController {
             return
         }
         
-        DispatchQueue.main.async { [weak self] in
+        Motion.async { [weak self] in
             guard let s = self else {
                 return
             }

Sources/iOS/TabsController.swift

@@ -197,48 +197,48 @@ fileprivate extension TabsController {
             return
         }
         
-        fvc.beginAppearanceTransition(false, animated: true)
+        guard let fvcIndex = viewControllers.index(of: fvc) else {
+            return
+        }
         
-        let fvcIndex = viewControllers.index(of: fvc)
-        let tvcIndex = viewControllers.index(of: viewController)
+        guard let tvcIndex = viewControllers.index(of: viewController) else {
+            return
+        }
         
-        let tvc = viewController
-        tvc.view.isHidden = false
-        tvc.view.frame = container.bounds
-                
-        var isAuto = false
+        viewController.view.isHidden = false
+        viewController.view.frame = container.bounds
         
-        switch tvc.motionModalTransitionType {
+        var isAuto = false
+        switch viewController.motionModalTransitionType {
         case .auto:
             isAuto = true
-            tvc.motionModalTransitionType = fvcIndex! < tvcIndex! ? .slide(direction: .left) : .slide(direction: .right)
+            viewController.motionModalTransitionType = fvcIndex < tvcIndex ? .slide(direction: .left) : .slide(direction: .right)
         default:break
         }
         
         if isTriggeredByUserInteraction {
-            delegate?.tabsController?(tabsController: self, willSelect: tvc)
+            delegate?.tabsController?(tabsController: self, willSelect: viewController)
         }
         
         view.isUserInteractionEnabled = false
-        Motion.shared.transition(from: fvc, to: tvc, in: container) { [weak self, tvc = tvc, isAuto = isAuto, completion = completion] (isFinished) in
+        
+        Motion.shared.transition(from: fvc, to: viewController, in: container) { [weak self, viewController = viewController, isAuto = isAuto, completion = completion] (isFinished) in
             guard let s = self else {
                 return
             }
             
             if isAuto {
-                tvc.motionModalTransitionType = .auto
+                viewController.motionModalTransitionType = .auto
             }
             
-            s.rootViewController = tvc
+            s.rootViewController = viewController
             s.view.isUserInteractionEnabled = true
             s.removeViewController(viewController: fvc)
             
-            fvc.endAppearanceTransition()
-            
             completion?(isFinished)
             
             if isTriggeredByUserInteraction {
-                s.delegate?.tabsController?(tabsController: s, didSelect: tvc)
+                s.delegate?.tabsController?(tabsController: s, didSelect: viewController)
             }
         }
     }
@@ -254,15 +254,6 @@ internal extension TabsController {
 fileprivate extension TabsController {
     /// Prepares all the view controllers.
     func prepareViewControllers() {
-        for i in 0..<viewControllers.count {
-            guard i != selectedIndex else {
-                continue
-            }
-            
-            viewControllers[i].view.isHidden = true
-            prepareViewController(at: i)
-        }
-        
         prepareViewController(at: selectedIndex)
         prepareRootViewController()
     }