DeckTransitionViewControllerProtocol

The child view controller which contains the scroll view that should be tracked for the swipe-to-dismiss gesture.

The default heuristic for searching the UIScrollView to track traverses only the first level of subviews of the presented view controller. As a result of this, subviews of any child view controller are not inspected.

A container view controller presented using DeckTransition can implement this variable and return the child view controller which contains the scroll view to be tracked.

If this variable is not implemented or is nil, then the container view controller’s own view is searched.

If this variable is implemented and is not nil, the container view controller’s own subviews and the value returned in the scrollViewForDeck variable are both ignored, and the search continues within the child view controller returned here.

The scroll view that should be tracked for Deck’s swipe-to-dismiss gesture.

The default heuristic for searching the UIScrollView to track only traverses only the first level of subviews of the presented view controller, returning the lowermost scroll view found.

This is a similar heuristic to that used in UINavigationController (which to the best of my knowledge, is even more limited and checks only one view, the lowermost subview of the main view), however it can miss out on the intended scroll view for more complex view hierarchies. For those cases, you can implement this variable and return the UIScrollView instance which should be tracked.