An object that implements custom behaviors when changing from one layout to another in a collection view.


Transition layout objects are commonly used to implement interactive transitions between layouts, where the transition itself is driven by a gesture recognizer.


Initializing the Transition Layout Object

init(currentLayout: NSCollectionViewLayout, nextLayout: NSCollectionViewLayout)

Initializes and returns the transition layout object.

Updating the Transition Information

var transitionProgress: CGFloat

The completion percentage of the transition.

func updateValue(CGFloat, forAnimatedKey: NSCollectionViewTransitionLayout.AnimatedKey)

Sets the value of a key whose value you use during the animation.

func value(forAnimatedKey: NSCollectionViewTransitionLayout.AnimatedKey)

Returns the most recently set value for the specified key.

Accessing the Layout Objects

var currentLayout: NSCollectionViewLayout

The collection view’s current layout object.

var nextLayout: NSCollectionViewLayout

The collection view’s new layout object.


Conforms To

See Also


class NSCollectionViewFlowLayout

A layout that organizes items into a flexible and configurable arrangement.

protocol NSCollectionViewDelegateFlowLayout

A set of methods that a delegate implements to provide layout information to a flow layout object in a collection view.

class NSCollectionViewGridLayout

A layout that displays a single section of items in a row and column grid.

class NSCollectionViewLayoutAttributes

An object that contains layout-related attributes for an element in a collection view.

class NSCollectionViewLayout

An abstract base class that you subclass and use to generate layout information for a collection view.