EZConstraints is an easier and more descriptive way to write auto layout constraints.

• Features
• Requirements
• Installation
• Basics
• Usage
• Author
• License
• Contributions

Features

• Supports Swift 5.
• Auto Layout but with a simplified meaningful syntax.
• Sets constraints attributes like relation, priority upon creation.
• Constraints are active by default.
• Stores constraints optionally.
• Allows a view to obtain another view layout attributes like size, center, anchors.
• Assigns a layout constraint for a group of views with one call.
• No need to set 'translatesAutoresizingMaskIntoConstraints'.
• Better debugging experience with a meaningful identifiers.

Requirements

• iOS 10.0+
• Xcode 11+
• Swift 5.1+

Installation

CocoaPods is a dependency manager for Cocoa projects. For usage and installation instructions, visit their website. To integrate EZConstraints into your Xcode project using CocoaPods, specify it in your Podfile:

pod 'EZConstraints'

Basics

Typealiases

EZConstraints offers more readable typealiases for describing constraints.

• EZConstraint = UILayoutConstraint
• EZConstraints = [UILayoutConstraint]
• EZInsets = UIEdgeInsets

Filling the superview

Filling the superview with NSAutoLayout:

view.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
    view.topAnchor.constraint(equalTo: superview.topAnchor, constant: 0),
    view.leadingAnchor.constraint(equalTo: superview.leadingAnchor, constant: 0),
    view.bottomAnchor.constraint(equalTo: superview.bottomAnchor, constant: 0),
    view.trailingAnchor.constraint(equalTo: superview.trailingAnchor, constant: 0)
])

With EZConstraints:

view.edgesToSuperView()

Centering in superview

Centering the view in the superview with NSAutoLayout:

view.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
    view.centerXAnchor.constraint(equalTo: superview.centerXAnchor),
    view.centerYAnchor.constraint(equalTo: superview.centerYAnchor)
])

With EZConstraints:

view.center()

or:

view.center(offset: CGPoint(x:20, y:10))

Usage

Filling the superview

Filling the superview:

view.edgesToSuperView()

You can also specify edges and insets:

view.edgesToSuperView(including: [.left, .right], insets: .left(8) + .right(8))

EZConstraints also supports safe area insets using edgesToSuperviewSafeArea(including:, insets:).

Laying out in superview

To lay view(s) on top of the superview:

view.layTopInSuperView(constant: 20)

You can also use layLeftInSuperView(constant:), layBottomInSuperView(constant:) and layRightInSuperView(constant:).

Laying out

To lay a view below another view:

view.layBelow(view2, constant: 16)

You can also use layAbove(_:), layRight(to:) and layLeft(to:).

EZConstraints also enables you to lay out views individual margins to safe area.

view.layTopToSafeArea(constant: 16)

You can also use layLeftToSafeArea(constant:), layBottomToSafeArea(constant:) and layRightToSafeArea(constant:).

Keep in mind that calling edgesToSuperView have the same effect as:

view.layTopInSuperView(constant: 0)
view.layLeftInSuperView(constant: 0)
view.layBottomInSuperView(constant: 0)
view.layRightInSuperView(constant: 0)

The same applies to edgesToSuperviewSafeArea.

Centering

EZConstraints supports centering horizontally and vertically:

view.centerHorizontally()
view.centerVertically(yOffset: 16)

You can also center the view on the superview center:

view.center()

Sizing elements

To assign a size constraints that consists of width and height constraints:

view.sizeAnchor(CGSize(width: 30, height: 30))

Assigning a fixed width:

view.widthAnchor(.equal, constant: 100)

You can also assign the size, height, width constraint(s) of another view to a a specified view:

view.heightAnchor(with: view2)

You can also use heightAnchor(with:) and widthAnchor(with:) for the same purpose. squareSizeWith(sideLengthOf:) gives the view a square shape with a specified side length that is equal for all sides.

Assigning aspect ratio constraint:

view.aspectRatio(multiplier: 1.5) // width = height * 1.5

Assigning aspect ratio constraint between two views:

view.aspectRatio(by: view2, multiplier: 0.5) // view.width = view2.height * 0.5

Debug Identifier

The debug identifier is an id that is assigned automatically to every constraint upon creation. This identifier allows you to debug conflicting constraints by clearing the ambiguity and make it easier to know the reason of the problem. The identifier has a specified pattern: id : <View1 Address>.Function_Name relation <View2 Address> * multiplier + constant(pt)

Attributes that will not appear in the identifier:

• <View2 Address>, If it is nil which is the case in 'widthAnchor(_:, constant:)' for example.
• multiplier, If multiplier == 1.0.
• constant, If constant == 0.
• Other attributes like priority.

Examples:

• id : 0x000000000000.layoutLeftInSuperView = 0x111111111111 + 24.0pt
• id : 0x000000000000.widthAnchor = 100.0pt'

License

EZConstraints is released under the MIT license. See LICENSE for details.

Author

Mohamed Shiha

Contributions

If you have feature requests or bug reports, feel free to help out by sending pull requests or by creating new issues.