AceLayout

AceLayout provides a Swifty DSL for Auto Layout.

Requirements

• iOS 9.0+ / macOS 10.11+ / tvOS 9.0+
• Xcode 13+
• Swift 5.5+

Features

• Strongly typed.
  • The compiler does not accept wrong constraints such as some.top == another.leading.
• Simple, modern and unmistakable APIs.
• No need to write boilerplates.
  • view.translatesAutoresizingMaskIntoConstraints = false
  • constraint.isActive = true

Usage

Basic

Constraints Building

Call the autoLayout method of your UIView, UILayoutGuide, NSView or NSLayoutGuide with a closure that describes Auto Layout constraints.

view.autoLayout { item in
    item.top.equal(to: anotherView, plus: 16)          // to UIView
    item.bottom.equalToSuperview()                     // to superview
    item.leading.equal(to: layoutMarginsGuide)         // to UILayoutGuide
    item.trailing.equal(to: anotherView.centerXAnchor) // to NSLayoutAnchor
    item.width.equal(to: 100)                          // to constant
    item.height.equal(to: item.width)                  // to LayoutAnchor
}

In the example, the followings are done automatically:

• Set view.translatesAutoresizingMaskIntoConstraints to false.

• Activates all constraints.

Relations

view.autoLayout { item in
    item.top.greaterThanOrEqual(to: safeAreaLayoutGuide)
    item.bottom.lessThanOrEqualToSuperview()
}

Priority

UILayoutPriority and NSLayoutConstraint.Priority are available.

view.autoLayout { item in
    item.center.equalToSuperview().priority(.required)
    item.size.equal(toSquare: 100).priority(.defaultHigh)
}

Deactivated Constraints

You can specify an argument activates to determine whether to immediately activate constraints.

let constraints = view.autoLayout(activates: false) { item in
    item.edges.equal(to: anotherView)
}
// All constraints are not active.
assert(constraints.allSatisfy { !$0.isActive })

// You can activate them at any time.
NSLayoutConstraint.activate(constraints)

Convenient Anchors

Point

view.autoLayout { item in
    item.center.equal(to: anotherView)
    item.topLeading.equalToSuperview()
}

Size

view.autoLayout { item in
    item.size.equal(to: CGSize(width: 100, height: 200))
}

HorizontalEdges and VerticalEdges

view.autoLayout { item in
    item.leadingTrailing.equal(to: anotherView)
    item.topBottom.equalToSuperview(insetBy: 16)
}

Edges

view.autoLayout { item in
    item.edges.equalToSuperview(insetBy: 16)
}

Available Anchors

XAxis

• leading
• trailing
• left
• right
• centerX

YAxis

• top
• bottom
• centerY

Baseline (only UIView / NSView)

• firstBaseline
• lastBaseline

Dimension

• width
• height

Point

• center
• topLeading
• topTrailing
• topLeft
• topRight
• bottomLeading
• bottomTrailing
• bottomLeft
• bottomRight

Size

• size

HorizontalEdges

• leadingTrailing
• leftRight

VerticalEdges

• topBottom

Edges

• edges

Using AceLayout in your project

To use the AceLayout library in a SwiftPM project, add the following line to the dependencies in your Package.swift file:

.package(url: "https://github.com/jrsaruo/AceLayout", from "1.0.0"),

and add AceLayout as a dependency for your target:

.target(name: "<target>", dependencies: [
    .product(name: "AceLayout", package: "AceLayout"),
    // other dependencies
]),

FInally, add import AceLayout in your source code.