Delay to create toVC.areaRectInSuperview property, handle it in animation controller.

Author: seedante

Classes/SDENavigationControllerDelegate.swift

@@ -20,10 +20,7 @@ class SDENavigationControllerDelegate: NSObject, UINavigationControllerDelegate
 
         animationController = SDEPushAndPopAnimationController(operation: operation)
         if operation == .Push{
-            if let fromCollectionVC = fromVC as? UICollectionViewController, let toCollectionVC = toVC as? UICollectionViewController{
-                let layoutAttributes = fromCollectionVC.collectionView?.layoutAttributesForItemAtIndexPath(fromCollectionVC.selectedIndexPath)
-                let areaRect = fromCollectionVC.collectionView!.convertRect(layoutAttributes!.frame, toView: fromCollectionVC.collectionView?.superview)
-                toCollectionVC.areaRectInSuperview = areaRect
+            if let toCollectionVC = toVC as? UICollectionViewController{
                 interactionController =  SDEPopPinchInteractionController(toVC: toCollectionVC, holder: self)
             }
         }

Classes/SDEPushAndPopAnimationController.swift

@@ -47,6 +47,10 @@ class SDEPushAndPopAnimationController: NSObject, UIViewControllerAnimatedTransi
             let selectedCell = fromVC?.collectionView?.cellForItemAtIndexPath(fromVC!.selectedIndexPath)
             selectedCell?.hidden = true
 
+            let layoutAttributes = fromVC!.collectionView?.layoutAttributesForItemAtIndexPath(fromVC!.selectedIndexPath)
+            let areaRect = fromVC!.collectionView?.convertRect(layoutAttributes!.frame, toView: fromVC!.collectionView?.superview)
+            toVC!.areaRectInSuperview = areaRect!
+
             //key code, the most important code here. without this line, you can't get visibleCells from UICollectionView.
             //And, there are other ways, Just make view redraw.
             toVC?.view.layoutIfNeeded()