Implementation for some kind of "folder to content" animation for UICollectionView. MasterViewController is list of some folder or whatever. On clicking on this cell we have "open animation", and push DetailViewController with content.
There not used useLayoutToLayoutNavigationTransitions cause in this case you just change layout for UICollectionViewController. And you need some kind of dirty hack for changing content for this cells. And you still can't use different kind of UICollectionCell for master and detail view controllers.
So I make this behaviour by implementing usual UIViewControllerAnimatedTransitioning object and different start UICollectionViewFlowLayout for DetailViewController. On the first call of layoutAttributesForElementsInRect we just return attributes, that make our detail cells same as components of master cell content. And in some point in animateTransition(transitionContext: _) make this layout invalidate or replace with another.
- Look up for rewrite behaviour from invalidation to two different layouts. And just do animate change between layouts.
- Swift 2.2
CollectionTransition is available under the MIT license. See the LICENSE file for more info.