Expand/collapse UITableViewCell to achieve Evernote-like transition
custom-transition, ios, objective-c, uiviewanimationtransition, uiviewcontroller
Solution
An approach to consider: you can use a `UICollectionView` with two different layouts. The unexpanded layout can just be a `UICollectionViewFlowLayout` and the expanded layout can be a subclass that shrinks/fades all the cells except the one you want expanded. Then you can use `setCollectionViewLayout:animated:` to switch between them.
The green border would just be the background of the parent view, since this wouldn't involve a `UINavigationController`.
And if you want the interactive swipe gesture for going back from the expanded layout, you hook up a `UIScreenEdgePanGestureRecognizer` to an interactive collection view layout animation (see `startInteractiveTransitionToCollectionViewLayout:completion:`).
Problem
I'm interested in achieving a transition between view controllers very similar to the transition in Evernote's iOS app: When "Places" is tapped, it smoothly expands into what looks like UINavigationController with a green border around it. To collapse it, I can either tap "Back" or swipe from the left side of the screen to gradually transition to the home screen. I'm not looking for exact code samples to copy-paste, bur rather for high-level guidance on which concepts and Apple APIs to leverage. More specifically, - Which transition/animation APIs does this likely use? - How can I achieve the green border around the entire view controller once "Places" is expanded?