An object that provides a constraint-based layout manager.


@interface CAConstraintLayoutManager : NSObject


You use the shared instance of this object by assigning it to the layoutManager property of any layer objects to which you have added constraints. During a layout update, Core Animation uses the layout manager to update the size and position of the sublayers based on the registered set of constraints.

Constraints let you define a set of geometric relationships between a layer and its sibling layers or between a layer and its superlayer. These relationships are expressed using constraint objects, which are instances of the CAConstraint class. When creating constraints, you can reference a layer by name using that object’s name property. You can also use the special name superlayer to refer to the layer's superlayer.

This class is not meant to be subclassed.


Creating the layout manager

+ layoutManager

Returns the shared layout manager object.


Inherits From

Conforms To

See Also

Layer Basics


An object that manages image-based content and allows you to perform animations on that content.


Methods your app can implement to respond to layer-related events.


A representation of a single layout constraint between two layers.


Methods that allow an object to manage the layout of a layer and its sublayers.


An interface that allows objects to respond to actions triggered by a CALayer change.