Crew

Fantastic DSL for Auto Layout in Swift.

Installing

Carthage

github "kzms/Crew"

Usage

Square

activate(view1 ~ .Height == view1 ~ .Width)

// same as:
// NSLayoutConstraint(item: view1, attribute: .Height, relatedBy: .Equal, toItem: view1, attribute: .Width, multiplier: 1, constant: 0).active = true

Direct setting

activate(view1 ~ .Height == 30)

// same as:
// NSLayoutConstraint(item: view1, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: 30).active = true

With CGSize

activate(view1 == CGSize(width: 100, height: 200))

// same as:
// activate(view1 ~ .Width == 100)
// activate(view1 ~ .Height == 200)

Alignment

activate((view1, view2) == .Top)

// same as
// activate(view1 ~ .Top == view2 ~ .Top)

activate((view1, view2) == [.CenterX, .CenterY])

// same as
// activate(view1 ~ .CenterX == view2 ~ .CenterX)
// activate(view1 ~ .CenterY == view2 ~ .CenterY)

Relation

activate(view2 ~ .Top == view1 ~ .Bottom)
activate(view3 ~ .Top == view2 ~ .Bottom + 10)

// same as:
// NSLayoutConstraint(item: view2, attribute: .Bottom, relatedBy: .Equal, toItem: view1, attribute: .Top, multiplier: 1, constant: 0).active = true
// NSLayoutConstraint(item: view3, attribute: .Bottom, relatedBy: .Equal, toItem: view2, attribute: .Top, multiplier: 1, constant: 10).active = true
//
// or:
// NSLayoutConstraint.activateConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:[view1][view2]-(10)-[view3]", options: 0, metrics: nil, views: ["view1": view1, "view2": view2, "view3": view3]))

Inner view

activate(view == view1 + UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10))

// same as:
// NSLayoutConstraint(item: view, attribute: .Top, relatedBy: .Equal, toItem: view1, attribute: .Top, multiplier: 1, constant: -10).active = true
// NSLayoutConstraint(item: view, attribute: .Left, relatedBy: .Equal, toItem: view1, attribute: .Left, multiplier: 1, constant: -10).active = true
// NSLayoutConstraint(item: view, attribute: .Bottom, relatedBy: .Equal, toItem: view1, attribute: .Bottom, multiplier: 1, constant: 10).active = true
// NSLayoutConstraint(item: view, attribute: .Right, relatedBy: .Equal, toItem: view1, attribute: .Right, multiplier: 1, constant: 10).active = true

Inner view (only horizontal constraints)

activate(view == view1 + UIEdgeInsets(top: .NaN, left: 10, bottom: .NaN, right: 10))

// same as:
// NSLayoutConstraint(item: view, attribute: .Left, relatedBy: .Equal, toItem: view1, attribute: .Left, multiplier: 1, constant: -10).active = true
// NSLayoutConstraint(item: view, attribute: .Right, relatedBy: .Equal, toItem: view1, attribute: .Right, multiplier: 1, constant: 10).active = true

Inner view (centering)

activate((view1, view2) == [.CenterX, .CenterY])

// same as:
// NSLayoutConstraint(item: view2, attribute: .CenterX, relatedBy: .Equal, toItem: view1, attribute: .CenterX, multiplier: 1, constant: 0).active = true
// NSLayoutConstraint(item: view2, attribute: .CenterY, relatedBy: .Equal, toItem: view1, attribute: .CenterY, multiplier: 1, constant: 0).actie = true

Priority

view1 ~ .Top == view2 ~ .Top ! 500
view == CGSize(width: 100, height: 200) ! 250

Others

See test code.
https://github.com/kzms/Crew/blob/develop/CrewTests/AutoLayoutDSLTest.swift