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QuartzCore Framework Reference CAConstraintLayoutManager Class Reference

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CAConstraintLayoutManager

The CAConstraintLayoutManager class provides a constraint-based layout manager. 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.

Inheritance


Conforms To


Import Statement


Swift

import QuartzCore

Objective-C

@import QuartzCore;

Availability


Available in OS X v10.5 and later.
  • Returns the shared layout manager object.

    Declaration

    Swift

    class func layoutManager() -> AnyObject!

    Objective-C

    + (id)layoutManager

    Return Value

    The shared layout manager object.

    Discussion

    You can assign the returned object to any layers that manage layout using constraints.

    Import Statement

    Objective-C

    @import QuartzCore;

    Swift

    import QuartzCore

    Availability

    Available in OS X v10.5 and later.