BBLayoutKit

A simple and lightweight Auto-Layout Kit that makes you feels laying out views as a fun game. BBLayaoutKit supports UIKit on iOS & tvOS and AppKit on MacOS so you wouldn't have to worry about using different solutions on different platforms. BBLayoutKit is compiled on Xcode 12.0 using Swift 5.3 and will be updated for all future releases.

Why use BBLayoutKit?

Have you ever had to write lines and lines of code to add subviews and anchor them like the following:

view.addSubview(subview)
subview.translatesAutoresizingMaskIntoConstraints = false

subview.topAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
...
subview.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true

Worry no more BBLayoutKit helps you with this situation as follows:

view.addSubview(subview) {
    subview.top      == view.bottom
    ...
    subview.trailing == view.trailing
}
// Or in short 🙂
view.addSubview(subview) { $0.sides == $1.sides }

// Or even shorter 😎
view.addSubview(subview) { $0 === $1 }

You see thats all thats required. Now, you might be wondering what would you do if you had to make a constraint with a relation that's not equal but, less than or greater than, like the following:

subview.leadingAnchor.constraint(lessThanOrEqualTo: view.leadingAnchor, constant: -8).isActive = true
subview.trailingAnchor.constraint(greaterThanOrEqualTo: view.trailingAnchor: constant: 16).isActive = true

BBLayoutKit let's you do this:

subview.leading  <= view.leading
subview.trailing >= view.trailing

In the case of constants you can add or substract them in the same expresion, so instead of this:

subview.topAnchor.constraint(equalTo: view.bottomAnchor, constant: 16).isActive = true
subview.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: -32).isActive = true

You only need this: subview.top == view.bottom + 16 subview.leading == view.trailing - 32 If you would like to get the constraint for animations or reference in future, just do:

let subviewTopConstraint      = subview.top == view.bottom + 16
subviewTopConstraint.constant = 32

If you don't want the constraints to not be active on the first go just do, '!=' or even '!<=' and '!>=', like the following:

subview.top      != view.bottom
subview.leading  !<= view.leading
subview.trailing !>= view.trailing

In case of dimensions like height or width:

subview.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 2, constant: 8).isActive = true
subview.heightAnchor.constraint(equalToConstant: 64).isActive = true

You only need this:

subview.width  == view.width * 2 + 8
subview.height == 64

For addSubview and translatesAutoresizingMaskIntoConstraints = false you could just write a closure as follows:

view.addSubview(subview) {
  subview.sides <= view.sides
}

You also have other helpers like sides that include all sides, and size which takes a CGSize and also both horizontal and vertical constraints and centers.

// Constraint all sides with a padding of 2
subview.sides == view.sides + 2

// Constraint all sides with different padding on each side.
subview.sides == view.sides + UIEdgeInsets(t: 1, l: 2, b: 4, r: 8)

// Align both centers of view and subview
subview.centers == view.centers

// Constraint both centers with offsets 4 and 8.
subview.centers == view.centers + UIOffset(x: 4, y: 8)

// Constraint vertical(top and bottom) or horizontal(leading and trailing)
subview.vertical   == view.vertical
subview.horizontal == view.horizontal

// Constraint size either with CGSize or both sides 64
subview.size == CGSize(w: 8, h: 16)
subview.size == 64

Installation

Swift Package Manager

The Swift Package Manager is a tool for automating the distribution of Swift code and is integrated into the swift compiler. It is in early development, but BBLoader does support its use on supported platforms.

Once you have your Swift package set up, adding BBLoader as a dependency is as easy as adding it to the dependencies value of your Package.swift.

dependencies: [
    .package(url: "https://github.com/bibinjacobpulickal/BBLayoutKit.git", .upToNextMajor(from: "1.0.0"))
]

From Xcode 11.0+ you only need to provide the above mentioned URL.

Features

Remove repetitive code while creating new view.
Fill super view or any other view with/without padding.
Align center with super view or any other view.

Requirements

iOS 9.0+
Xcode 8.3+
Swift 3.0+

License

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